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  • 1.
    Alehagen, Urban
    et al.
    Linköpings universitet, Institutionen för medicin och hälsa, Kardiologi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Hjärtcentrum, Kardiologiska kliniken.
    Dahlström, Ulf
    Linköpings universitet, Institutionen för medicin och hälsa, Kardiologi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Hjärtcentrum, Kardiologiska kliniken.
    Lindahl, Tomas
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Klinisk kemi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Laboratoriemedicinskt centrum, Klinisk kemi.
    Cystatin C and NT-proBNP, a powerful combination of biomarkers for predicting cardiovascular mortality in elderly patients with heart failure: results from a 10-year study in primary care2009Ingår i: EUROPEAN JOURNAL OF HEART FAILURE, ISSN 1388-9842, Vol. 11, nr 4, s. 354-360Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Heart failure (HF) is common among the elderly patients. It is essential to identify those at high risk in order to optimize the use of resources. We aimed to evaluate whether a combination of two biomarkers might give better prognostic information about the risk of cardiovascular (CV) mortality in patients with symptoms associated with HF, compared with only one biomarker. Four hundred and sixty-four primary health-care patients (mean age 73 years, range 65-87) with symptoms of HF were examined. All patients were evaluated using Doppler echocardiography and blood samples, including measurement of cystatin C and NT-proBNP. The patients were followed over a 10-year period. Patients with serum cystatin C levels within the highest quartile had almost three times the risk (HR: 2.92; 95% CI: 1.23-4.90) of CV mortality compared with those patients who had levels within the first, second, or third quartiles. If, at the same time, the patient had a plasma concentration of NT-proBNP within the highest quartile, the risk increased to andgt; 13 times (HR: 13.61; 95% CI: 2.56-72.24) during 10 years of follow-up or andgt; 17 times (HR: 17.04; 95% CI: 1.80-163.39) after 5 years of follow-up. Combined analysis of cystatin C and NT-proBNP could provide important prognostic information among elderly patients in the community with symptoms of HF.

  • 2.
    Alehagen, Urban
    et al.
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för medicin och vård, Kardiologi. Östergötlands Läns Landsting, Hjärtcentrum, Kardiologiska kliniken.
    Dahlström, Ulf
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för medicin och vård, Kardiologi. Östergötlands Läns Landsting, Hjärtcentrum, Kardiologiska kliniken.
    Lindahl, Tomas
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för biomedicin och kirurgi, Avdelningen för klinisk kemi. Östergötlands Läns Landsting, Laboratoriemedicinskt centrum, Klinisk kemi.
    Elevated D-dimer level is an independent risk factor for cardiovascular death in out-patients with symptoms compatible with heart failure2004Ingår i: Thrombosis and Haemostasis, ISSN 0340-6245, Vol. 92, nr 6, s. 1250-1258Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    D-dimer, a marker of fibrin turnover, exhibits many interesting properties as a biological marker of thrombosis. Some of the properties of D-dimer might also be used to provide additional information about patients with heart failure. In this study, we evaluate the prognostic information acquired from D-dimer concerning increased risk of cardiovascular mortality in an elderly population with symptoms associated with heart failure. A cardiologist examined 458 elderly patients, out of 548 invited, attending primary care for symptoms of dyspnoea, fatigue and/or peripheral oedema and assessed NYHA functional class and cardiac function. Abnormal systolic function was defined as EF <40% on Doppler echocardiography. Abnormal diastolic function was defined as reduced E/A ratio and/or an abnormal pattern of pulmonary venous flow. Blood samples were drawn, and BNP and D-dimer were analysed. D-dimer was analysed using an automated micro-latex assay. A statistical analysis was performed to identify the prognostic value of increased plasma concentration of D-dimer. Results showed that during a median follow-up period of 5.5 years, 68 (14%) patients died of cardiovascular disease. No gender difference was noted. A plasma concentration of D-dimer >0.25mg/L increased the risk almost 4-fold. In conclusion, D-dimer is an independent risk factor for cardiovascular mortality that may be used to risk-stratify patients with heart failure. © 2004 Schattauer GmbH, Stuttgart.

  • 3.
    Alehagen, Urban
    et al.
    Linköpings universitet, Institutionen för medicin och hälsa, Kardiologi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Hjärtcentrum, Kardiologiska kliniken.
    Dahlström, Ulf
    Linköpings universitet, Institutionen för medicin och hälsa, Kardiologi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Hjärtcentrum, Kardiologiska kliniken.
    Lindahl, Tomas L
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Klinisk kemi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Laboratoriemedicinskt centrum, Klinisk kemi.
    Low plasma concentrations of coagulation factors II, VII and XI indicate increased risk among elderly with symptoms of heart failure.2010Ingår i: Blood coagulation & fibrinolysis : an international journal in haemostasis and thrombosis, ISSN 1473-5733, Vol. 21, nr 1, s. 62-9Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Heart failure is a serious condition, and it is, therefore, important to identify patients at high risk as early as possible in order to initiate appropriate treatment. The condition results in complicated disease mechanisms including disturbances in blood coagulation. The aim of the present study was to evaluate whether low plasma concentrations of coagulation factors (F) II, VII and XI influence cardiovascular mortality in an elderly population with possible heart failure. A cardiologist evaluated 450 elderly patients who attended primary healthcare because of symptoms associated with heart failure. He recorded new patient history, conducted a clinical examination, took blood samples, determined concentrations of B-type natriuretic peptide and FII, FVII, FXI and performed Doppler echocardiography. The patients were followed over almost a 10-year period during which all mortality was registered. In patients with suspected heart failure, those with low plasma concentrations of FII, FVII, FXI or all had a significantly higher mortality rate during the follow-up period of 10 years as compared with those with higher plasma concentrations, in contrast with findings in previous reports on patients with acute coronary syndromes. In the group with a plasma concentration of the first versus the ninth decile of FII, FVII, FXI or all, the risk of cardiovascular mortality increased two to three times.

  • 4.
    Alehagen, Urban
    et al.
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för kardiovaskulär medicin. Linköpings universitet, Medicinska fakulteten. Region Östergötland, Hjärt- och Medicincentrum, Kardiologiska kliniken US.
    Lindahl, Tomas
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Medicinska fakulteten. Region Östergötland, Diagnostikcentrum, Klinisk kemi.
    Aaseth, Jan
    Innlandet Hospital Trust, Norway; Hedmark University of Coll, Norway.
    Svensson, Erland
    Swedish Def Research Agency, Sweden.
    Johansson, Peter
    Region Östergötland, Hjärt- och Medicincentrum, Kardiologiska kliniken US. Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för kardiovaskulär medicin. Linköpings universitet, Medicinska fakulteten.
    Levels of sP-selectin and hs-CRP Decrease with Dietary Intervention with Selenium and Coenzyme Q10 Combined: A Secondary Analysis of a Randomized Clinical Trial2015Ingår i: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 10, nr 9, s. e0137680-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Background/Objectives Inflammation and oxidative stress are central in many disease states. The major anti-oxidative enzymes contain selenium. The selenium intake in Europe is low, and supplementation with selenium and coenzyme Q(10) , important anti-oxidants, was evaluated in a previous study. The aim of this study was to evaluate response on the inflammatory biomarkers C-reactive protein, and sP-selectin, and their possible impact on cardiovascular mortality. Subjects/Methods 437 elderly individuals were included in the study. Clinical examination, echocardiography, electrocardiography and blood samples were drawn. The intervention time was 48 months, and median follow-up was 5.2 years. The effects on inflammation/atherosclerosis were evaluated through analyses of CRP and sP-selectin. Evaluations of the effect of the intervention was performed using repeated measures of variance. All mortality was registered, and endpoints of mortality were assessed by Kaplan-Meier plots. Results The placebo group showed a CRP level of 4.8 ng/mL at the start, and 5.1 ng/mL at the study end. The active supplementation group showed a CRP level of 4.1 ng/mL at the start, and 2.1 ng/mL at the study end. SP-selectin exhibited a level of 56.6mg/mL at the start in the placebo group and 72.3 mg/mL at the study end, and in the active group the corresponding figures were 55.9 mg/mL and 58.0 mg/mL. A significantly smaller increase was demonstrated through repeated measurements of the two biomarkers in those on active supplementation. Active supplementation showed an effect on the CRP and sP-selectin levels, irrespective of the biomarker levels. Reduced cardiovascular mortality was demonstrated in both those with high and low levels of CRP and sP-selectin in the active supplementation group. Conclusion CRP and sP-selectin showed significant changes reflecting effects on inflammation and atherosclerosis in those given selenium and coenzyme Q(10) combined. A reduced cardiovascular mortality could be demonstrated in the active group, irrespective of biomarker level. This result should be regarded as hypothesis-generating, and it is hoped it will stimulate more research in the area.

  • 5.
    Alfredsson, Joakim
    et al.
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för kardiovaskulär medicin. Linköpings universitet, Medicinska fakulteten. Region Östergötland, Hjärt- och Medicincentrum, Kardiologiska kliniken US.
    Lindahl, Tomas L
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Medicinska fakulteten. Östergötlands Läns Landsting, Diagnostikcentrum, Klinisk kemi.
    Gustafsson, Kerstin M
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Medicinska fakulteten.
    Janzon, Magnus
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för kardiovaskulär medicin. Linköpings universitet, Medicinska fakulteten. Region Östergötland, Hjärt- och Medicincentrum, Kardiologiska kliniken US.
    Jonasson, Lena
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för kardiovaskulär medicin. Linköpings universitet, Hälsouniversitetet. Region Östergötland, Hjärt- och Medicincentrum, Kardiologiska kliniken US.
    Logander, Elisabeth
    Region Östergötland, Hjärt- och Medicincentrum, Kardiologiska kliniken US. Linköpings universitet, Institutionen för medicin och hälsa. Linköpings universitet, Medicinska fakulteten.
    Nilsson, Lennart
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för kardiovaskulär medicin. Linköpings universitet, Hälsouniversitetet. Region Östergötland, Hjärt- och Medicincentrum, Kardiologiska kliniken US.
    Swahn, Eva
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för kardiovaskulär medicin. Linköpings universitet, Hälsouniversitetet. Region Östergötland, Hjärt- och Medicincentrum, Kardiologiska kliniken US.
    Large early variation of residual platelet reactivity in Acute Coronary Syndrome patients treated with clopidogrel: Results from Assessing Platelet Activity in Coronary Heart Disease (APACHE).2015Ingår i: Thrombosis Research, ISSN 0049-3848, E-ISSN 1879-2472, Vol. 136, nr 2, s. 335-340Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    INTRODUCTION: There is a large inter-individual variation in response to clopidogrel treatment and previous studies have indicated higher risk of thrombotic events in patients with high residual platelet reactivity (HRPR), but the optimal time-point for testing is not established. The aim of this study was to investigate the optimal time-point for aggregometry testing and the risk of major adverse cardiac events associated with HRPR.

    METHOD AND RESULTS: We included 125 patients with ACS (73 with STEMI, and 71 received abciximab). The prevalence of HRPR varied substantially over time. The rate of HRPR in patients treated and not treated with abciximab were 43% vs 67% (p=0.01) before, 2% vs 23% (p=0.001) 6-8h after, 8% vs 9% (p=0.749) 3days after, and 23% vs 12% (p=0.138) 7-9 days after loading dose of clopidogrel. We found HRPR in 18% of the patients but only four ischemic events during 6months follow-up, with no significant difference between HRPR patients compared to the rest of the population. There were 3 TIMI major bleedings, all of which occurred in the low residual platelet reactivity (LRPR) group.

    CONCLUSION: There is a large variation in platelet reactivity over time, also depending on adjunctive therapy, which has a large impact on optimal time-point for assessment. We found HRPR in almost 1 in 5 patients, but very few MACE, and not significantly higher in HRPR patients. In a contemporary ACS population, with low risk for stent thrombosis, the predictive value of HRPR for ischemic events will probably be low.

  • 6.
    Alfredsson, Joakim
    et al.
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för kardiovaskulär medicin. Linköpings universitet, Medicinska fakulteten. Region Östergötland, Hjärt- och Medicincentrum, Kardiologiska kliniken US.
    Swahn, Eva
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för kardiovaskulär medicin. Linköpings universitet, Medicinska fakulteten. Region Östergötland, Hjärt- och Medicincentrum, Kardiologiska kliniken US.
    Gustafsson, Kerstin
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Medicinska fakulteten. Region Östergötland, Diagnostikcentrum, Klinisk kemi.
    Janzon, Magnus
    Linköpings universitet, Medicinska fakulteten. Region Östergötland, Hjärt- och Medicincentrum, Kardiologiska kliniken US. Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för kardiovaskulär medicin.
    Jonasson, Lena
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för kardiovaskulär medicin. Linköpings universitet, Hälsouniversitetet. Region Östergötland, Hjärt- och Medicincentrum, Kardiologiska kliniken US.
    Logander, Elisabeth
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för kardiovaskulär medicin. Linköpings universitet, Medicinska fakulteten. Region Östergötland, Hjärt- och Medicincentrum, Kardiologiska kliniken US.
    Nilsson, Lennart
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för kardiovaskulär medicin. Linköpings universitet, Medicinska fakulteten. Region Östergötland, Hjärt- och Medicincentrum, Kardiologiska kliniken US.
    Lindahl, Tomas
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Medicinska fakulteten. Region Östergötland, Diagnostikcentrum, Klinisk kemi.
    Individual long-term variation of platelet reactivity in patients with dual antiplatelet therapy after myocardial infarction.2019Ingår i: Platelets, ISSN 0953-7104, E-ISSN 1369-1635, Vol. 30, nr 5, s. 572-578Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    There is a large inter-individual variation in response to clopidogrel treatment, and previous studies have indicated higher risk of thrombotic events in those with high residual platelet reactivity (HPR). Less is known about individual variation over time. The aim of this prospective cohort study was to investigate intra-individual variation in platelet reactivity. Platelet aggregation in whole blood was assessed in 77 patients, at 3 days, 8 days and 6 months after admission for acute myocardial infarction and loading dose of clopidogrel. All patients were treated with aspirin and clopidogrel through 6-month follow-up. We found a significant increase in median ADP-stimulated aggregation from third to eighth day (195 vs. 250 AU*min, p-value = 0.001) but not from day 8 to 6 months (250 vs. 223 AU*min, p-value = 0.666). There was no significant change in the overall rate of HPR (15.6% vs 20.8%, p-value 0.503) or low platelet reactivity (LPR) (37.7% vs 33.8%, p-value = 0.609) from day 8 to 6-month follow-up. In contrast, more than one in four changed HPR status, 15.6% from non-HPR to HPR and 10.4% HPR to non-HPR. A shift in LPR status appeared even more frequent, occurring in about one of three patients. In spite of similar median aggregation and rate of HPR during 6-month follow-up, about one in four of the patients changed HPR status and one in three changed LPR status. This may be important information for a concept of risk stratification based on a single aggregation value early after an acute coronary syndromes.

  • 7.
    Arbring, Kerstin
    et al.
    Linköpings universitet, Institutionen för medicin och hälsa, Internmedicin. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Närsjukvården i centrala Östergötland, Medicinska akutkliniken.
    Chaireti, Roza
    Linköpings universitet, Institutionen för klinisk och experimentell medicin. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Närsjukvården i centrala Östergötland, Medicinska akutkliniken.
    Janzon, Magnus
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för kardiovaskulär medicin. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Hjärt- och Medicincentrum, Kardiologiska kliniken US.
    Uppugunduri, Srinivas
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Klinisk kemi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Diagnostikcentrum, Klinisk kemi.
    Jansson, Kjell
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för kardiovaskulär medicin. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Hjärt- och Medicincentrum, Fysiologiska kliniken US.
    Lindahl, Tomas
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Diagnostikcentrum, Klinisk kemi.
    First experience of structured introduction of new oral anticoagulants in a Swedish health care district: dabigatran as an alternative to warfarin in atrial fibrillation2013Konferensbidrag (Refereegranskat)
  • 8.
    Arbring, Kerstin
    et al.
    Linköpings universitet, Institutionen för medicin och hälsa, Internmedicin. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Närsjukvården i centrala Östergötland, Medicinska akutkliniken.
    Uppugunduri, Srinivas
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Klinisk kemi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Diagnostikcentrum, Klinisk kemi.
    Lindahl, Tomas
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Klinisk kemi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Diagnostikcentrum, Klinisk kemi.
    Comparison of prothrombin time (INR) results and main characteristics of patients on warfarin treatment in primary health care centers and anticoagulation clinics2013Ingår i: BMC Health Services Research, ISSN 1472-6963, E-ISSN 1472-6963, Vol. 13Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Background

    Oral anticoagulant therapy is used to prevent thrombosis in patients with atrial fibrillation (AF), venous thrombosis and prosthetic heart valves. The introduction of new therapies emphasizes the need to discern the best practice for the patients remaining on warfarin treatment. This study compares patient characteristics and therapeutic control in two settings managing warfarin treatment: Swedish primary health care centers (PHCC) and specialized anticoagulation clinics (ACC).

    Methods

    Prothrombin time (PT) test results reported as International Normalized Ratio (INR) were collected for five consecutive days from patients on warfarin treatment; 564 PHCC and 927 ACC patients. Therapeutic control was calculated as PT test results in relation to intended therapeutic range (TR). Mann–Whitney Rank Sum Test and Chi2 test were used for statistical comparisons.

    Results

    The PHCC patients were older than the ACC patients, 76 v. 70 years (p<0.01) with a predominance of men in both groups. The reasons for treating differed between the groups. Seventy-two percent of PHCC patients and 66% of ACC patients had a PT-INR within the intended TR (p<0.05). Men generally had better results than women (72% v. 63%, p<0.001) and particularly in the PHCC group v. the ACC group (78% v. 69%, p<0.01).

    PT-INR above intended TR was significantly more common in the ACC setting, (p<0.05), for women overall (p<0.01), for women in the PHCC setting, and for ACC men (p<0.05).

    Conclusions

    In this study both settings achieved good therapeutic control of warfarin treatment with a minor advantage for PHCC over ACC, and better results for men, especially in the PHCC setting. As patient characteristics differ between the PHCC and ACC, it is important to conduct further randomized studies to discern the best practice locally for warfarin management also after the introduction of new drugs.

  • 9.
    Arvidsson, Sara
    et al.
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad Fysik.
    Askendal, Agneta
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad Fysik.
    Lindahl, Tomas
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för klinisk och experimentell medicin, Klinisk kemi. Östergötlands Läns Landsting, Laboratoriemedicinskt centrum, Klinisk kemi.
    Tengvall, Pentti
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad Fysik.
    Detection of surface bound complement at increasing serum anticoagulant concentrations2008Ingår i: Colloids and Surfaces B: Biointerfaces, ISSN 0927-7765, E-ISSN 1873-4367, Vol. 62, s. 214-219Artikel i tidskrift (Refereegranskat)
    Abstract [en]

      

  • 10. Axelsson Rosén, Stina
    et al.
    Hägg, Staffan
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för medicin och vård, Klinisk farmakologi. Östergötlands Läns Landsting, Laboratoriemedicinskt centrum, Klinisk farmakologi.
    Eriksson, Andreas
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för medicin och vård, Farmakologi.
    Lindahl, Tomas
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för biomedicin och kirurgi, Avdelningen för klinisk kemi. Östergötlands Läns Landsting, Laboratoriemedicinskt centrum, Klinisk kemi.
    Whiss, Per A
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för medicin och vård, Farmakologi.
    In vitro effects of antipsychotics on human platelet adhesion and aggregation and plasma coagulation2007Ingår i: Clinical and experimental pharmacology & physiology, ISSN 0305-1870, E-ISSN 1440-1681, Vol. 34, nr 8, s. 775-780Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    1. Several studies suggest an association between venous thromboembolism and the use of antipsychotic drugs, especially clozapine, but the biological mechanisms are unknown. It has been suggested that antipsychotic drugs enhance aggregation of platelets and thereby increase the risk of venous thrombosis. The purpose of the present study was to examine the effects of clozapine and its main metabolite, N-desmethyl clozapine, as well as olanzapine, risperidone and haloperidol, on platelet adhesion and aggregation and on plasma coagulation in vitro. 2. Blood was collected from healthy subjects free of medication. Platelet adhesion to different protein surfaces and aggregation were measured in microplates. The coagulation methods of activated partial thromboplastin time (APTT) and prothrombin time were performed in platelet-poor plasma. 3. Clozapine was the only compound that increased platelet adhesion and aggregation and shortened APTT. The effect appeared at therapeutic concentrations and was significant but weak. 4. This weak effect of clozapine on haemostasis may explain, in part, the association of this compound and venous thromboembolism. © 2007 The Authors.

  • 11. Besselaar van den, AMHP
    et al.
    Houbouyan-Refeillard, LL
    Aillaud, MF
    Denson, KWE
    Johnston, M
    Kitchen, S
    Lindahl, Tomas
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för biomedicin och kirurgi, Klinisk kemi. Östergötlands Läns Landsting, Laboratoriemedicinskt centrum, Klinisk kemi.
    Multicenter evaluation of lyophilized and deep-frozen plasmas for assignment of the international normalized ratio.1999Ingår i: Thrombosis and Haemostasis, ISSN 0340-6245, Vol. 82, s. 1451-1455Artikel i tidskrift (Refereegranskat)
  • 12.
    Bjorses, Katarina
    et al.
    Lund University.
    Faxälv, Lars
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Klinisk kemi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Diagnostikcentrum, Klinisk kemi.
    Montan, Carl
    Lund University.
    Wildt-Persson, Katarina
    Magle Life Science.
    Fyhr, Peter
    Magle Life Science.
    Holst, Jan
    Lund University.
    Lindahl, Tomas
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Klinisk kemi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Diagnostikcentrum, Klinisk kemi.
    In vitro and in vivo evaluation of chemically modified degradable starch microspheres for topical haemostasis2011Ingår i: ACTA BIOMATERIALIA, ISSN 1742-7061, Vol. 7, nr 6, s. 2558-2565Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Degradable starch microspheres (DSMs) are starch chains cross-linked with epichlorhydrin, forming glycerol-ether links. DSMs have been used for many years for temporary vascular occlusion and drug delivery in treatment of malignancies. They are also approved and used for topical haemostasis by absorbing excess fluid from the blood and concentrating endogenous coagulation factors, thereby facilitating haemostasis. This mechanism of action is not sufficient for larger bleedings in current chemical formulations of DSMs, and modification of DSMs to trigger activation of platelets or coagulation would be required for use in such applications. Chemical modifications of DSMs with N-octenyl succinic anhydride, chloroacetic acid, acetic anhydride, diethylaminoethyl chloride and ellagic acid were performed and evaluated in vitro with thrombin generation and platelet adhesion tests, and in vivo using an experimental renal bleeding model in rat. DSMs modified to activate platelets in vitro were superior in haemostatic capacity in vivo. Further studies with non-toxic substances are warranted to confirm these results and develop the DSM as a more effective topical haemostatic agent.

  • 13.
    Boij, R
    et al.
    Linköpings universitet, Institutionen för klinisk och experimentell medicin. Linköpings universitet, Hälsouniversitetet.
    Berg, Göran
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Obstetrik och gynekologi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Barn- och kvinnocentrum, Kvinnokliniken i Linköping.
    Nilsson-Ekdahl, K
    Uppsala University.
    Svensson, J
    Linköpings universitet, Institutionen för klinisk och experimentell medicin. Linköpings universitet, Hälsouniversitetet.
    Sandholm, K
    Linneus University.
    Lindahl, Tomas
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Klinisk kemi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Diagnostikcentrum, Klinisk kemi.
    Matthiesen, Leif
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Obstetrik och gynekologi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Barn- och kvinnocentrum, Kvinnokliniken i Linköping.
    Jenmalm, Maria
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Pediatrik. Linköpings universitet, Hälsouniversitetet.
    Palonek, E
    Karolinska University.
    Jarle, M
    Karolinska University.
    Biomarkers of coagulation, inflammation and angiogenesis are independently associated with preeclampsia in JOURNAL OF REPRODUCTIVE IMMUNOLOGY, vol 94, issue 1, pp 109-1092012Ingår i: JOURNAL OF REPRODUCTIVE IMMUNOLOGY, Elsevier , 2012, Vol. 94, nr 1, s. 109-109Konferensbidrag (Refereegranskat)
    Abstract [en]

    n/a

  • 14.
    Boij, Roland
    et al.
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Obstetrik och gynekologi. Linköpings universitet, Hälsouniversitetet.
    Svensson, Judit
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Klinisk immunologi. Linköpings universitet, Hälsouniversitetet.
    Nilsson-Ekdahl, Kristina
    Uppsala University, Sweden Linneaus University, Sweden .
    Sandholm, Kerstin
    Linneaus University, Sweden .
    Lindahl, Tomas
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Klinisk kemi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Diagnostikcentrum, Klinisk kemi.
    Palonek, Elzbieta
    Karolinska University Hospital, Sweden Doping Control Lab, Sweden .
    Garle, Mats
    Karolinska University Hospital, Sweden Doping Control Lab, Sweden .
    Berg, Göran
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Obstetrik och gynekologi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Barn- och kvinnocentrum, Kvinnokliniken i Linköping.
    Ernerudh, Jan
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Klinisk immunologi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Diagnostikcentrum, Klinisk immunologi och transfusionsmedicin.
    Jenmalm, Maria
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Pediatrik. Linköpings universitet, Hälsouniversitetet.
    Matthiesen, Leif
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Obstetrik och gynekologi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Barn- och kvinnocentrum, Kvinnokliniken i Linköping.
    Biomarkers of Coagulation, Inflammation, and Angiogenesis are Independently Associated with Preeclampsia2012Ingår i: AMERICAN JOURNAL OF REPRODUCTIVE IMMUNOLOGY, ISSN 1046-7408, Vol. 68, nr 3, s. 258-270Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Problem Although preeclampsia has been associated with inflammation, coagulation, and angiogenesis, their correlation and relative contribution are unknown. Method of Study About 114 women with preeclampsia, 31 with early onset (EOP) and 83 with late onset preeclampsia (LOP), and 100 normal pregnant controls were included. A broad panel of 32 biomarkers reflecting coagulation, inflammation, and angiogenesis was analyzed. Results Preeclampsia was associated with decreased antithrombin, IL-4 and placental growth factor levels and with increased C3a, pentraxin-3, and sFlt-1 levels, with more marked differences in the EOP group. The Th1-associated chemokines CXCL10 and CXCL11 were significantly higher in the preeclampsia and EOP group than in controls, respectively. No correlations between the biomarkers were found in preeclampsia. Multivariate logistic regression tests confirmed the results. Conclusions Cytokines, chemokines and complement activation seem to be part of a Th1-like inflammatory reaction in preeclampsia, most pronounced in EOP, where chemokines may be more useful than cytokines as biomarkers. Biomarkers were not correlated suggesting partly independent or in time separated mechanisms.

  • 15.
    Boknäs, Niklas
    et al.
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Hälsouniversitetet.
    Faxälv, Lars
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Diagnostikcentrum, Klinisk kemi.
    Lindahl, Tomas L
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Diagnostikcentrum, Klinisk kemi.
    Ramström, Sofia
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Hälsouniversitetet.
    Contact activation: important to consider when measuring the contribution of tissue factor-bearing microparticles to thrombin generation using phospholipid-containing reagents2014Ingår i: Journal of Thrombosis and Haemostasis, ISSN 1538-7933, E-ISSN 1538-7836, Vol. 12, nr 4, s. 515-518Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Background A commercial MP reagent containing phospholipids is used for thrombin generation (TG) measurements to estimate the procoagulant activity of microparticles (MPs). Previous reports have shown that contact activation affects TG when TF levels are low, and that addition of phospholipids might augment this effect. Objectives To quantify the impact of contact activation on TG in the presence of phospholipids and low/no TF, as is the case using a commercially available MP-reagent. Methods Thrombin generation was analyzed using MP- or platelet-rich plasma (PRP)-reagent in the presence and absence of corn trypsin inhibitor and anti-TF antibodies, respectively. To quantify the impact of different experimental parameters on contact activation, microparticle-depleted plasma was analyzed in the presence of different concentrations of phospholipids, TF and/or contact activating agents (kaolin). Results Even with low contact activating blood collection tubes, substantial thrombin generation was observed with the MP-reagent, but this was completely inhibited by addition of corn trypsin inhibitor. Control experiments illustrate that the phospholipids in the reagent play a major role in enhancing TG initiated by FXIIa. Even with the PRP-reagent, which is recommended for determining the content of phospholipids from MPs, TG was partly dependent on contact activation. Conclusions Contact activation plays a major role in TG when using reagents/samples containing phospholipids but little or no tissue factor. This needs to be considered and accounted for in future clinical studies using TG to assess the procoagulant activity of MPs.

  • 16.
    Boknäs, Niklas
    et al.
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Hälsouniversitetet.
    Faxälv, Lars
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Diagnostikcentrum, Klinisk kemi.
    Sanchez Centellas, Daniel
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Hälsouniversitetet.
    Wallstedt, Maria
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Hälsouniversitetet.
    Ramström, Sofia
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Hälsouniversitetet.
    Grenegård, Magnus
    University of Örebro, Sweden.
    Lindahl, Tomas
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Diagnostikcentrum, Klinisk kemi.
    Thrombin-induced platelet activation via PAR4: pivotal role for exosite II2014Ingår i: Thrombosis and Haemostasis, ISSN 0340-6245, Vol. 112, nr 3, s. 558-565Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Thrombin-induced platelet activation via PAR1 and PAR4 is an important event in haemostasis. Although the underlying mechanisms responsible for ensuring efficient PAR1 activation by thrombin have been extensively studied, the potential involvement of recognitions sites outside the active site of the protease in thrombin-induced PAR4 activation is largely unknown. In this study, we developed a new assay to assess the importance of exosite I and II for PAR4 activation with alpha- and gamma-thrombin. Surprisingly, we found that exosite II is critical for activation of PAR4. We also show that this dependency on exosite II likely represents a new mechanism, as it is unaffected by blockage of the previously known interaction between thrombin and glycoprotein Ib alpha.

  • 17.
    Boknäs, Niklas
    et al.
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Hälsouniversitetet.
    Faxälv, Lars
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Diagnostikcentrum, Klinisk kemi.
    Ström, Jakob O
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Hälsouniversitetet.
    Tengvall, Pentti
    Sahlgrenska Academy, University of Gothenburg, Sweden.
    Theodorsson, Elvar
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Diagnostikcentrum, Klinisk kemi.
    Ramström, Sofia
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Hälsouniversitetet.
    Lindahl, Tomas L
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Diagnostikcentrum, Klinisk kemi.
    Response: platelets do not generate activated factor XII--how inappropriate experimental models have led to misleading conclusions2014Ingår i: Blood, ISSN 0006-4971, E-ISSN 1528-0020, Vol. 124, nr 10, s. 1692-1694Artikel i tidskrift (Övrigt vetenskapligt)
  • 18.
    Chaireti, Roza
    et al.
    Linköpings universitet, Institutionen för klinisk och experimentell medicin. Linköpings universitet, Hälsouniversitetet.
    Arbring, Kerstin
    Linköpings universitet, Institutionen för medicin och hälsa. Linköpings universitet, Hälsouniversitetet.
    Olsen, Ole H.
    Novo Nordisk A/S, Novo Nordisk Park, Måløv, Danmark.
    Persson, Egon
    Novo Nordisk A/S, Novo Nordisk Park, Måløv, Danmark.
    Lindahl, Tomas L.
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för biomedicin och kirurgi, Avdelningen för klinisk kemi.
    Thrombin generation and levels of factor VII activity measured in the presence of rabbit and human thromboplastins in patients with mild factor VII deficiency – effects of mutations in factor VIIManuskript (preprint) (Övrigt vetenskapligt)
    Abstract [en]

    Background/Aim: It is known that spontaneous prolonged prothrombin time-international normalized ratio may be caused by deficiency of factor VII (FVII). The activity of FVII in the presence of thromboplastins of different origin is affected by the presence of specific mutations in the F7 gene. The present study aims to evaluate patients with mild FVII deficiency and somewhat discrepant FVII activity depending on the use of human or rabbit thromboplastin in relation to mutations in the FVII gene and markers of thrombin generation.

    Patients and methods: A cohort of 10 patients with mild deficiency of FVII and discrepant FVII activity was investigated. The median ratio of the FVII activity in the presence of human/rabbit thromboplastin was 1.4. All but 1 patient had mild to no bleeding symptoms. A genetic analysis of the F7 gene was performed. Thrombin generation was measured by the calibrated automated thrombogram in platelet poor plasma in the presence of human recombinant and different dilutions of rabbit thromboplastin and compared with thrombin generation in healthy controls (n=12). Thrombin generation was measured in 9 patients as 1 was treated with warfarin at the time of the blood sampling.

    Results: Six previously described mutations were found. Two of those (FVII Padua and FVII Shinjo) are known to affect the results for FVII activity dependent on the species origin of the thromboplastin. Nine out of 10 patients had one mutation in common (Arg353Gln), which however does not affect the binding site of FVII to tissue factor. Lagtime and ttpeak increased with decreasing concentrations of thromboplastin and total and maximum thrombin concentrations increased with increasing thromboplastin concentrations in the patients with FVII deficiency. ETP in patients with FVII deficiency was 86% of ETP in controls.

    Discussion: The Arg353Gln mutation was very common, however it does not appear to affect the reactivity towards thromboplastins of different origins. Although ETP was higher in the healthy controls, thrombin generation in FVII deficient patients was enough to sustain normal haemostasis. The expected thrombin generation patterns with increasing thromboplastin concentrations were confirmed for the patients in this study.

  • 19.
    Chaireti, Roza
    et al.
    Linköpings universitet, Institutionen för klinisk och experimentell medicin. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Närsjukvården i centrala Östergötland, Medicinska akutkliniken.
    Gustafsson, K M.
    Linköpings universitet, Institutionen för klinisk och experimentell medicin. Linköpings universitet, Hälsouniversitetet.
    Bystrom, B
    Karolinska Institute, Sweden .
    Bremme, K
    Karolinska Institute, Sweden .
    Lindahl, Tomas
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Diagnostikcentrum, Klinisk kemi.
    Endogenous thrombin potential is higher during the luteal phase than during the follicular phase of a normal menstrual cycle2013Ingår i: Human Reproduction, ISSN 0268-1161, E-ISSN 1460-2350, Vol. 28, nr 7, s. 1846-1852Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Do thrombin generation and haemostatic parameters differ during the two phases of the menstrual cycle? less thanbrgreater than less thanbrgreater thanTotal thrombin concentration is higher during the luteal phase compared with the follicular phase of the menstrual cycle. less thanbrgreater than less thanbrgreater thanThe coagulation cascade is affected by many variables, such as fluctuations in the levels of sex hormones. The studies on the variations in haemostatic parameters during the menstrual cycle have produced diverse results. less thanbrgreater than less thanbrgreater thanThrombin generation and selected haemostatic parameters (fibrinogen, factor II, factor VII, factor VIII, factor X, von Willebrand factor, antithrombin and D-dimer) were measured during the two phases of a normal menstrual cycle in 102 healthy women not taking any form of hormone medication. less thanbrgreater than less thanbrgreater thanThe study cohort consisted of 102 healthy women with regular menstrual cycles. Thrombin generation was measured by the calibrated automated thrombogram method. Progesterone and sex hormone-binding globulin were measured by chemiluminescence enzyme immunoassays. Estradiol was measured by a sensitive radioimmunoassay. Fibrinogen was measured by a clotting method, antithrombin was measured by a chromogenic method and factor II, factor VII, factor VIII, factor X, von Willebrand factor and D-dimer were measured by photometric methods. less thanbrgreater than less thanbrgreater thanIt was shown that the total amount of generated thrombin (Endogenous Thrombin Potential) was significantly higher during the luteal compared with the follicular phase (P 0.027). Factor X was significantly higher during the follicular phase (P 0.028). Progesterone exhibited significant associations (measured by the least squares regression analysis) with fibrinogen and factor X during the follicular phase (P 0.043 and P 0.033, respectively) and with factors II and VII during the luteal phase (P 0.034 and P 0.024, respectively). The validity of the results from the regression analysis was further confirmed by performing correlation analyses (Pearson correlation matrix) for haemostatic markers for the luteal and follicular phases (accepted correlation level 0.8). less thanbrgreater than less thanbrgreater thanThe wide confidence interval for the differences in endogenous thrombin potential during the two phases could imply that the size of the cohort may not be sufficient to fully evaluate the biological variations. Additionally, the haemostatic markers were not shown to have significant associations with thrombin generation, suggesting that the increased thrombin concentration during the luteal phase would be mediated by another mechanism, as yet unidentified. less thanbrgreater than less thanbrgreater thanThe associations between progesterone and the haemostatic markers, as shown for both phases of the menstrual cycle, suggest a previously unknown or undefined yet potentially significant role for progesterone in the coagulation system. However, it has been shown that the use of progestogen-only preparations does not affect the coagulation system, which is partly the reason why they are considered safe for women with thrombophilia or previous thrombotic event. Further studies are required in order to demonstrate whether our results can be extrapolated for synthetic progestins, which might have significant implication on the indications for their use. less thanbrgreater than less thanbrgreater thanThis study was supported by the Karolinska Institutet, Linkping University and the County Council of stergtland. The authors report no conflicts of interest.

  • 20.
    Chaireti, Roza
    et al.
    Linköpings universitet, Institutionen för klinisk och experimentell medicin. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Närsjukvården i centrala Östergötland, Medicinska akutkliniken.
    Jennersjö, Cecilia
    Linköpings universitet, Institutionen för medicin och hälsa, Internmedicin. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Närsjukvården i centrala Östergötland, Medicinska akutkliniken.
    Lindahl, Tomas
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Klinisk kemi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Diagnostikcentrum, Klinisk kemi.
    Is thrombin generation at the time of an acute thromboembolic episode a predictor of recurrence? The LInkoping Study on Thrombosis (LIST) - A 7-year follow-up2013Ingår i: Thrombosis Research, ISSN 0049-3848, E-ISSN 1879-2472, Vol. 131, nr 2, s. 135-139Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Introduction: Venous thromboembolism(VTE) is considered a chronic disease, since a high percentage of patients experience recurrences. Oral anticoagulants are effective in preventing recurrences at a price of potential bleeding complications, which underlines the importance of finding reliable markers for estimating the individual recurrence risk. In this report we evaluate thrombin generation markers at the time of an acute VTE as predictive markers for recurrence risk. Gender, presence of factor V Leiden and acquired provocative factors were taken into consideration. Additionally, we study the correlation between thrombin generation at the time of an acute VTE and thrombin generation measured four to eight weeks after discontinuation of anticoagulants. less thanbrgreater than less thanbrgreater thanMaterials and Methods: Themain cohort consisted of 115 patients with a confirmed thromboembolic event at inclusion. The follow-up period was seven years. less thanbrgreater than less thanbrgreater thanResults: Patients with an initial unprovoked VTE and at least one recurrence had significantly prolonged thrombin generation, whereas those without recurrences had higher maximum and total thrombin concentration. In contrast, when thrombin generation was measured one to two months after discontinuation of anticoagulant treatment, it was shown that the patients who experienced recurrences had higher maximum thrombin concentration. less thanbrgreater than less thanbrgreater thanConclusions: Our study shows that thrombin generation profiles at the time of a VTE correlate to the clinical course after the acute episode. The great over-lap in thrombin generation between patients with and without recurrences though, makes the use of thrombin generation profiles for advice on length of oral anticoagulation for an individual patient doubtful at the present stage of knowledge.

  • 21. Chaireti, Roza
    et al.
    Jennersjö, Cecilia
    Linköpings universitet, Institutionen för medicin och hälsa, Internmedicin. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Närsjukvården i centrala Östergötland, Akutkliniken.
    Lindahl, Tomas L
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Klinisk kemi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Laboratoriemedicinskt centrum, Klinisk kemi.
    Thrombin generation and D-dimer concentrations in a patient cohort investigated for venous thromboembolism. Relations to venous thrombosis, factor V Leiden and prothrombin G20210A. The LIST study.2009Ingår i: Thrombosis Research, ISSN 0049-3848, E-ISSN 1879-2472, Vol. 124, nr 2, s. 178-84Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    INTRODUCTION: The present study evaluated possible relations between various markers of thrombin generation, D-dimer and venous thromboembolism in outpatients with and without the FV Leiden and the protrombin mutations. PATIENTS AND METHODS: Our cohort consisted of 98 patients with the FV Leiden and 15 with the prothrombin mutation and an equal number of age- and gender-matched controls. All subjects were investigated due to suspicion of venous thromboembolism and the diagnosis was objectively confirmed or refuted. RESULTS: We compared the D-dimer values and the thrombin generation markers among different patient groups (with/without thromboembolism, with/without genetic factors, gender-linked). The only statistically significant difference noted was prolonged time both for the initiation and termination of thrombin generation in patients with thrombosis. This applied to controls and to patients heterozygous for the FV Leiden. Additionally, the D-dimer values were elevated in patients with the FV Leiden. No difference was found among the patients with prothrombin mutation and their controls. DISCUSSION: Multi-variant analysis indicated that the difference in D-dimer between FV Leiden patients and controls was due to the greater number of patients with confirmed thrombosis in the former group, a finding supported by an independent prospective study on postoperative thrombosis. Neither D-dimer concentration nor thrombin generation depend on FV Leiden. The total amount of thrombin generated was not related to diagnosis. The prolonged thrombin generation noted in controls and FV Leiden heterozygotes with thrombosis may point out different thrombin generation profiles in different patient populations and requires further studies.

  • 22.
    Chaireti, Roza
    et al.
    Karolinska Institute, Sweden.
    Lindahl, Tomas
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Medicinska fakulteten. Region Östergötland, Diagnostikcentrum, Klinisk kemi.
    Bystrom, Birgitta
    Karolinska Institute, Sweden.
    Bremme, Katarina
    Karolinska Institute, Sweden.
    Larsson, Anders
    Uppsala University, Sweden.
    Inflammatory and endothelial markers during the menstrual cycle2016Ingår i: Scandinavian Journal of Clinical and Laboratory Investigation, ISSN 0036-5513, E-ISSN 1502-7686, Vol. 76, nr 3, s. 190-194Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Background The menstrual cycle exhibits a pattern of repeated inflammatory activity. The present study aims to evaluate inflammatory and endothelial markers during the two phases of a menstrual cycle. Methods The study cohort consisted of 102 women with regular menstrual cycles. Inflammatory and endothelial markers (interleukin-6 [IL-6], pentraxin-3 [PTX-3], hs-C reactive protein [hs-CRP], sE-selectin, sP-selectin, intracellular and vascular cell adhesion molecules [ICAM-1 and VCAM-1] and cathepsins L, B and S) were measured during the early follicular and the late luteal phase of a normal menstrual cycle. Results Pentraxin-3 (PTX-3) and hs-CRP were significantly higher during the follicular phase compared to the luteal phase (p &lt; 0.001 respectively p = 0.025). The other inflammatory and endothelial markers, with the exception of cathepsin B, were higher, albeit not significantly, during the follicular phase. Conclusions Inflammatory activity, expressed mainly by members of the pentraxin family, is higher during the early follicular compared to the luteal phase. This could be associated to menstruation but the exact mechanisms behind this pattern are unclear and might involve the ovarian hormones or an effect on hepatocytes.

  • 23.
    Chaireti, Roza
    et al.
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Närsjukvården i centrala Östergötland, Medicinska akutkliniken. Karolinska Univ Hosp, Coagulat Unit, Div Haematol, Dept Med, Stockholm, Sweden.
    Rajani, Rupesh
    Division of Gastroenterology & Hepatology, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden.
    Bergquist, Annika
    Division of Gastroenterology & Hepatology, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden.
    Melin, Tor
    Division of Gastroenterology & Hepatology, University Hospital, Lund, Sweden.
    Friis-Liby, Inga-Lill
    Department of Medicine, Sahlgrenska University Hospital, Gothenburg, Sweden.
    Kapraali, Marjo
    Karolinska Institutet, Department of Clinical Sciences Danderyd Hospital, Division of Medicine, Stockholm, Sweden.
    Kechagias, Stergios
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för kardiovaskulär medicin. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Hjärt- och Medicincentrum, Magtarmmedicinska kliniken.
    Lindahl, Tomas L.
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Diagnostikcentrum, Klinisk kemi.
    Almer, Sven
    Division of Gastroenterology & Hepatology, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden; Karolinska Inst, Dept Med, Solna, Sweden.
    Increased thrombin generation in splanchnic vein thrombosis is related to the presence of liver cirrhosis and not to the thrombotic event2014Ingår i: Thrombosis Research, ISSN 0049-3848, E-ISSN 1879-2472, Vol. 134, nr 2, s. 455-461Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Background: In recent years there have been increasing evidence associating liver disease with hypercoagulability, rather than bleeding.

    Aims: To evaluate the haemostatic potential in patients with liver disease.

    Methods: We measured thrombin generation in the presence and absence of thrombomodulin in patients with portal vein thrombosis (PVT, n=47), Budd-Chiari syndrome (BCS, n=15) and cirrhosis (n=24) and compared the results to those obtained from healthy controls (n=21). Fifteen patients with PVT and 10 patients with BCS were treated with warfarin and were compared with an equal number of patients with atrial fibrillation matched for prothrombin time-international normalized ratio. We assessed resistance to thrombomodulin by using ratios [marker measured in the presence]/[marker measured in the absence of thrombomodulin].

    Results: There were no differences between patients with BCS, patients on warfarin treatment and controls. Cirrhotic patients generated more thrombin in the presence of thrombomodulin and exhibited thrombomodulin resistance compared with controls [p=0.006 for endogenous thrombin potential (ETP) and p<0.001 for peak thrombin. P<0.001 for both ratios ETP and peak] and patients with non-cirrhotic PVT (p=0.001, p=0.006, p<0.001, p<0.001 for ETP, peak, ratio ETP, ratio peak). The patients with cirrhotic PVT exhibited higher ETP (p=0.044) and peak (p=0.02) in the presence of thrombomodulin than controls, as well as thrombomodulin resistance (ETP ratio: p=0.001, peak ratio: p=0.001).

    Conclusions: Hypercoagulability and thrombomodulin resistance in patients with cirrhosis were independent of the presence of splanchnic vein thrombosis. The hypercoagulability in patients with cirrhotic PVT could have implications for considering longer treatment with anticoagulants in this group.

  • 24.
    Claesson, Kjersti
    et al.
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Medicinska fakulteten.
    Lindahl, Tomas
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Medicinska fakulteten. Region Östergötland, Diagnostikcentrum, Klinisk kemi.
    Faxälv, Lars
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Medicinska fakulteten. Region Östergötland, Diagnostikcentrum, Klinisk kemi.
    Counting the platelets: a robust and sensitive quantification method for thrombus formation2016Ingår i: Thrombosis and Haemostasis, ISSN 0340-6245, Vol. 115, nr 6, s. 1178-1190Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Flow chambers are common tools used for studying thrombus formation in vitro. However, the use of such devices is not standardised and there is a large diversity among the flow chamber systems currently used, and also in the methods used for quantifying the thrombus development. It was the study objective to evaluate a new method for analysis and quantification of platelet thrombus formation that can facilitate comparison of results between research groups. Whole blood was drawn over a collagen patch in commercial Ibid or in-house constructed PDMS flow chambers. Five percent of the platelets were fluorescently labelled and z-stack time-lapse images were captured during thrombus formation. Images were processed in a Python script in which the number of platelets and their respective x-, y- and z-positions were obtained. For comparison with existing methods the platelets were also labelled and quantified using fluorescence intensity and thrombus volume estimations by confocal microscopy. The presented method was found less sensitive to microscope and image adjustments and provides more details on thrombus development dynamics than the methods for measuring fluorescence intensity and thrombus volume estimation. The platelet count method produced comparable results with commercial and PDMS flow chambers, and could also obtain information regarding the stability of each detected platelet in the thrombus. In conclusion, quantification of thrombus formation by platelet count is a sensitive and robust method that enables measurement of platelet accumulation and platelet stability in an absolute scale that could be used for comparisons between research groups.

  • 25.
    Connolly-Andersen, Anne-Marie
    et al.
    Umeå University, Sweden.
    Sundberg, Erik
    Umeå University, Sweden.
    Ahlm, Clas
    Umeå University, Sweden.
    Hultdin, Johan
    Umeå University, Sweden.
    Baudin, Maria
    Umeå University, Sweden.
    Larsson, Johanna
    Umeå University, Sweden.
    Dunne, Eimear
    Royal Coll Surgeons Ireland, Ireland.
    Kenny, Dermot
    Royal Coll Surgeons Ireland, Ireland.
    Lindahl, Tomas
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Medicinska fakulteten. Region Östergötland, Diagnostikcentrum, Klinisk kemi.
    Ramström, Sofia
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Medicinska fakulteten.
    Nilsson, Sofie
    Umeå University, Sweden.
    Increased Thrombopoiesis and Platelet Activation in Hantavirus-Infected Patients2015Ingår i: Journal of Infectious Diseases, ISSN 0022-1899, E-ISSN 1537-6613, Vol. 212, nr 7, s. 1061-1069Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Background. Thrombocytopenia is a common finding during viral hemorrhagic fever, which includes hemorrhagic fever with renal syndrome (HFRS). The 2 main causes for thrombocytopenia are impaired thrombopoiesis and/or increased peripheral destruction of platelets. In addition, there is an increased intravascular coagulation risk during HFRS, which could be due to platelet activation. Methods. Thrombopoiesis was determined by quantification of platelet counts, thrombopoietin, immature platelet fraction, and mean platelet volume during HFRS. The in vivo platelet activation was determined by quantification of soluble P-selectin (sP-selectin) and glycoprotein VI (sGPVI). The function of circulating platelets was determined by ex vivo stimulation followed by flow cytometry analysis of platelet surface-bound fibrinogen and P-selectin exposure. Intravascular coagulation during disease was determined by scoring for disseminated intravascular coagulation (DIC) and recording thromboembolic complications. Results. The levels of thrombopoietin, immature platelet fraction, and mean platelet volume all indicate increased thrombopoiesis during HFRS. Circulating platelets had reduced ex vivo function during disease compared to follow-up. Most interestingly, we observed significantly increased in vivo platelet activation in HFRS patients with intravascular coagulation (DIC and thromboembolic complications) as shown by sP-selectin and sGPVI levels. Conclusions. HFRS patients have increased thrombopoiesis and platelet activation, which contributes to intravascular coagulation.

  • 26.
    Davidson, Thomas
    et al.
    Linköpings universitet, Institutionen för medicin och hälsa, Avdelningen för hälso- och sjukvårdsanalys. Linköpings universitet, Medicinska fakulteten.
    Lindelof, Ann
    Region Östergötland, Närsjukvården i östra Östergötland.
    Wallen, Torbjorn
    Östergötlands Läns Landsting, Närsjukvården i östra Östergötland, Medicinkliniken ViN. Vastervik Hospital, Sweden.
    Lindahl, Tomas
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Medicinska fakulteten. Region Östergötland, Diagnostikcentrum, Klinisk kemi.
    Hallert, Claes
    Linköpings universitet, Institutionen för samhälls- och välfärdsstudier, Hälsa, Aktivitet, Vård (HAV). Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Närsjukvården i östra Östergötland, Medicinkliniken ViN. Östergötlands Läns Landsting, Närsjukvården i centrala Östergötland.
    Point-of-care monitoring of warfarin treatment in community dwelling elderly - A randomised controlled study2015Ingår i: Journal of Telemedicine and Telecare, ISSN 1357-633X, E-ISSN 1758-1109, Vol. 21, nr 5, s. 298-301Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The objective of this study was to assess clinical effectiveness and costs of launching point-of-care monitoring of warfarin treatment in community dwelling frail elderly patients. A prospective multicentre controlled randomised study over 12 months comparing a point-of-care strategy with usual monitoring routines was carried out in primary healthcare centres and anticoagulation clinics in southeast Sweden. The subjects were community dwelling elderly across rural southeast Sweden on chronic warfarin treatment. Main outcome measures were time in therapeutic range (TTR), rate of treatment-related adverse events and costs. The study comprised 103 elderly people (61% women) mean age 86 yrs (range 75-98) treated with warfarin for median 9 yrs (range 1-18). Patients randomised to start point-of-care monitoring (n = 55) showed 75.9% in TTR before trial vs. 72.6% during trial (ns). The patients randomised to continue on usual monitoring routines (n = 48) showed 75.2% in TTR prior to trial vs. 72.9% during trial (ns). The point-of-care monitoring showed potential savings of SEK 624 per patient annually (based partly on effects that were not statistically significant). The study shows that point-of-care monitoring of warfarin treatment in community dwelling elderly in rural areas is as effective as usual monitoring routines and that it may offer savings to society.

  • 27.
    Dudek, Magdalena M
    et al.
    Dublin City University.
    Kent, Nigel
    Dublin Institute Technology.
    Gustafsson, Kerstin
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för klinisk och experimentell medicin, Klinisk kemi.
    Lindahl, Tomas
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Klinisk kemi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Laboratoriemedicinskt centrum, Klinisk kemi.
    Killard, Anthony J
    Dublin City University.
    Fluorescence-Based Blood Coagulation Assay Device for Measuring Activated Partial Thromboplastin Time2011Ingår i: ANALYTICAL CHEMISTRY, ISSN 0003-2700, Vol. 83, nr 1, s. 319-328Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The measurement of blood clotting time is important in a range of clinical applications such as assessing coagulation disorders and controlling the effect of various anticoagulant drug therapies. Clotting time tests essentially measure the onset of clot formation which results from the formation of fibrin fibers in the blood sample. However, such assays are inherently imprecise due to the highly variable nature of the clot formation process and the sample matrix. This work describes a clotting time measurement assay which uses a fluorescent probe to very precisely detect the onset of fibrin clot formation. It uses a microstructured surface which enhances the formation of multiple localized clot loci and which results in the abrupt redistribution of the fluorescent label at the onset of clot formation in both whole blood and plasma. This methodology was applied to the development of an activated partial thromboplastin time (aPTT) test in a lateral flow microfluidic platform and used to monitor the effect of heparin dosage where it showed linearity from 0 to 2 U/mL in spiked plasma samples (R-2=0.996, n = 3), correlation against gold standard coagulometry of 0.9986, and correlation against standard hospital aPTT in 32 patient samples of 0.78.

  • 28.
    Egberg, N.
    et al.
    Departments of Clinical Chemistry, Karolinska Hospital, Stockholm.
    Fagerberg, I
    Sahlgrenska University Hospital, Gothenburg.
    Hillarp, A
    Malmö University Hospital, Malmö.
    Lindahl, Tomas
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för biomedicin och kirurgi, Avdelningen för klinisk kemi. Östergötlands Läns Landsting, Laboratoriemedicinskt centrum, Klinisk kemi.
    Stigendal, L
    Department of Medicine, Sahlgrenska University Hospital, Gothenburg, Sweeden.
    Letter: Guidelines on preparation, certification, and use of certified plasmas for ISI calibration and INR determination - A rebuttal2005Ingår i: Journal of Thrombosis and Haemostasis, ISSN 1538-7933, E-ISSN 1538-7836, Vol. 3, nr 10, s. 2370-2372Artikel i tidskrift (Övrigt vetenskapligt)
    Abstract [en]

    [No abstract available]

  • 29. Egberg, N
    et al.
    Hillarp, A
    Johnsson, H
    Lindahl, Tomas
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för biomedicin och kirurgi, Klinisk kemi. Östergötlands Läns Landsting, Laboratoriemedicinskt centrum, Klinisk kemi.
    Stigendal, L
    Protrombinkomplexmätning bör anges som en kvot, inte i procent.1999Ingår i: Läkartidningen, ISSN 0023-7205, E-ISSN 1652-7518, Vol. 96, s. 2489-2491Artikel i tidskrift (Övrig (populärvetenskap, debatt, mm))
  • 30. Egberg, N
    et al.
    Hillarp, A
    Johnsson, H
    Lindahl, Tomas
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för biomedicin och kirurgi, Klinisk kemi. Östergötlands Läns Landsting, Laboratoriemedicinskt centrum, Klinisk kemi.
    Stigendal, S
    Nya svarsrutiner för protrombinkomplex.1999Ingår i: Vårdfacket, ISSN 0347-0911, Vol. 5, s. 44-46Artikel i tidskrift (Övrig (populärvetenskap, debatt, mm))
  • 31. Egberg, N
    et al.
    Hillarp, A
    Johnsson, H
    Lindahl, Tomas
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för biomedicin och kirurgi, Klinisk kemi. Östergötlands Läns Landsting, Laboratoriemedicinskt centrum, Klinisk kemi.
    Stigendal, S
    Protrombinkomplexmetoden förändras. Svar i % ersätts med INR.1999Ingår i: Laboratoriet, ISSN 0345-696X, Vol. 3Artikel i tidskrift (Övrig (populärvetenskap, debatt, mm))
  • 32.
    Ekblad, Tobias
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Sensorvetenskap och Molekylfysik. Linköpings universitet, Tekniska högskolan.
    Faxälv, Lars
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Klinisk kemi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Laboratoriemedicinskt centrum, Klinisk kemi.
    Andersson, Olof
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Sensorvetenskap och Molekylfysik. Linköpings universitet, Tekniska högskolan.
    Wallmark, Nanny
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Molekylär fysik. Linköpings universitet, Tekniska fakulteten.
    Larsson (Kaiser), Andréas
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Sensorvetenskap och Molekylfysik. Linköpings universitet, Tekniska högskolan.
    Lindahl, Tomas L.
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Klinisk kemi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Laboratoriemedicinskt centrum, Klinisk kemi.
    Liedberg, Bo
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Sensorvetenskap och Molekylfysik. Linköpings universitet, Tekniska högskolan.
    Patterned Hydrogels for Controlled Platelet Adhesion from Whole Blood and Plasma2010Ingår i: Advanced Functional Materials, ISSN 1616-301X, E-ISSN 1616-3028, Vol. 20, nr 15, s. 2396-2403Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This work describes the preparation and properties of hydrogel surface chemistries enabling controlled and well-defined cell adhesion. The hydrogels may be prepared directly on plastic substrates, such as polystyrene slides or dishes, using a quick and experimentally simple photopolymerization process, compatible with photolithographic and microfluidic patterning methods. The intended application for these materials is as substrates for diagnostic cell adhesion assays, particularly for the analysis of human platelet function. The adsorption of fibrinogen and other platelet promoting molecules is shown to be completely inhibited by the hydrogel, provided that the film thickness is sufficient (>5 nm). This allows the hydrogel to be used as a matrix for presenting selected bioactive ligands without risking interference from nonspecifically adsorbed platelet adhesion factors, even in undiluted whole blood and blood plasma. This concept is demonstrated by preparing patterns of proteins on hydrogel surfaces, resulting in highly controlled platelet adhesion. Further insights into the protein immobilization and platelet adhesion processes are provided by studies using imaging surface plasmon resonance. The hydrogel surfaces used in this work appear to provide an ideal platform for cell adhesion studies of platelets, and potentially also for other cell types.

  • 33.
    Elvers, Margitta
    et al.
    University of Tubingen, Germany .
    Grenegård, Magnus
    Linköpings universitet, Institutionen för medicin och hälsa, Farmakologi. Linköpings universitet, Hälsouniversitetet.
    Khoshjabinzadeh, Hanieh
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Klinisk kemi. Linköpings universitet, Hälsouniversitetet.
    Muenzer, Patrick
    University of Tubingen, Germany .
    Borst, Oliver
    University of Tubingen, Germany University of Tubingen, Germany .
    Tian, Huasong
    Columbia University, NY 10032 USA .
    Di Paolo, Gilbert
    Columbia University, NY 10032 USA .
    Lang, Florian
    University of Tubingen, Germany .
    Gawaz, Meinrad
    University of Tubingen, Germany .
    Lindahl, Tomas
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Klinisk kemi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Diagnostikcentrum, Klinisk kemi.
    Fälker, Knut
    Linköpings universitet, Institutionen för klinisk och experimentell medicin. Linköpings universitet, Hälsouniversitetet.
    A novel role for phospholipase D as an endogenous negative regulator of platelet sensitivity2012Ingår i: Cellular Signalling, ISSN 0898-6568, E-ISSN 1873-3913, Vol. 24, nr 9, s. 1743-1752Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Platelet aggregation, secretion and thrombus formation play a critical role in primary hemostasis to prevent excessive blood loss. On the other hand, uncontrolled platelet activation leads to pathological thrombus formation resulting in myocardial infarction or stroke. Stimulation of heterotrimeric G-proteins by soluble agonists or immunoreceptor tyrosine based activation motif-coupled receptors that interact with immobilized ligands such as the collagen receptor glycoprotein (GP) VI lead to the activation of phospholipases that cleave membrane phospholipids to generate soluble second messengers. Platelets contain the phospholipases (PL) D1 and D2 which catalyze the hydrolysis of phosphatidylcholine to generate the second messenger phosphatidic acid (PA). The production of PA is abrogated by primary alcohols that have been widely used for the analysis of PLD-mediated processes. However, it is not clear if primary alcohols effectively reduce PA generation or if they induce PLD-independent cellular effects. In the present study we made use of the specific PLD inhibitor 5-fluoro-2-indolyl des-chlorohalopemide (FIPI) and show for the first time, that FIPI enhances platelet dense granule secretion and aggregation of human platelets. Further. FIPI has no effect on cytosolic Ca2+ activity but needs proper Rho kinase signaling to mediate FIPI-induced effects on platelet activation. Upon FIPI treatment the phosphorylation of the PKC substrate pleckstrin was prominently enhanced suggesting that FIPI affects PKC-mediated secretion and aggregation in platelets. Similar effects of FIPI were observed in platelets from mouse wild-type and Pld1(-/-) mice pointing to a new role for PLD2 as a negative regulator of platelet sensitivity.

  • 34. Enström, Camilla
    et al.
    Osman, Abdimajid
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för klinisk och experimentell medicin, Klinisk kemi. Östergötlands Läns Landsting, Laboratoriemedicinskt centrum, Klinisk kemi.
    Lindahl, Tomas
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för klinisk och experimentell medicin, Klinisk kemi. Östergötlands Läns Landsting, Laboratoriemedicinskt centrum, Klinisk kemi.
    A genotyping method for VKORC1 1173C>T by Pyrosequencing® technology2008Ingår i: Scandinavian Journal of Clinical and Laboratory Investigation, ISSN 0036-5513, E-ISSN 1502-7686, Vol. 68, nr 5, s. 427-430Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Vitamin K epoxide reductase complex subunit 1 (VKORC1) is the site of inhibition by warfarin and other anti-vitamin K drugs during oral anticoagulant therapy. The SNP rs9934438 in intron 1 of VKORC1 (c.173+1000C>T or 1173C>T) discriminating the VKORC1*2 haplotype is associated with low warfarin dose requirement and unstable prothrombin time - international normalized ratio. To genotype this SNP, we have developed a rapid method using Pyrosequencing® technology. The proposed method takes a post-PCR sample preparation of less than 1 h and a DNA sequencing time of less than 15 min to genotype 96 samples. The current method was compared with a dHPLC method that we reported previously. Genotype frequencies at VKORC1 1173C>T for our Swedish population were 38 % wild-type, 40 % heterozygote and 22 % homozygote. The frequency of the T-allele was 0.42, which exactly matches the frequency previously reported for Germans. The current method can be used to determine whether patients initiating warfarin therapy are carriers of SNP 1173 C>T that is strongly associated with low warfarin dose requirement. © 2008 Informa UK Ltd (Informa Healthcare, Taylor & Francis AS).

  • 35.
    Ericsson, Emma
    et al.
    Linköpings universitet, Institutionen för fysik, kemi och biologi. Linköpings universitet, Tekniska högskolan.
    Faxälv, Lars
    Linköpings universitet, Institutionen för klinisk och experimentell medicin. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Laboratoriemedicinskt centrum, Klinisk kemi.
    Weissenrieder, Anna
    St Paul, USA.
    Askendal, Agneta
    Linköpings universitet, Institutionen för fysik, kemi och biologi. Linköpings universitet, Tekniska högskolan.
    Lindahl, Tomas
    Linköpings universitet, Institutionen för klinisk och experimentell medicin. Linköpings universitet, Hälsouniversitetet.
    Tengvall, Pentti
    Linköpings universitet, Institutionen för fysik, kemi och biologi. Linköpings universitet, Tekniska högskolan.
    Glycerol monooleate-blood interactions2009Ingår i: Colloids and Surfaces B: Biointerfaces, ISSN 0927-7765, E-ISSN 1873-4367, Vol. 68, nr 1, s. 20-26Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In the present study the initial blood compatibility of glycerol monooleate (GMO)-coated surfaces was evaluated after deposition to surfaces and in bulk. The model surface was silica onto which multiple layers of fibrinogen or human serum albumin (HSA) was immobilized. The protein-coated surfaces were subsequently dip-coated in GMO in ethanol and used for blood plasma and whole blood experiments. The characterization methods included null ellipsometry, scanning electron microscopy, imaging of coagulation, hemolysis test and whole blood coagulation time by free oscillation rheometry.

    The results showed a GMO film thickness of approximately 350 angstrom (similar to 4 mu g/cm(2)) upon dip-coating in ethanolic solution. A major part of the deposited layer detached in aqueous solutions, especially during shear conditions. The coagulation time on GMO was significantly prolonged compared to that on HSA coated silica. Whole blood tests showed that GMO is a very weak hemolytic agent. Deposited GMO detached easily from surfaces upon rinsing or shearing, although a stable layer with undefined phase structure and a thickness of 50-70 angstrom remained on HSA and fibrinogen precoated surfaces. This indicates that GMO has stronger adhesive forces to its substrate compared to the cohesive forces acting within the bulk GMO. The ability of GMO to detach from itself and tentatively form micelles or lipid bilayers when subjected to flowing blood may be of use in extravascular applications. It is concluded that GMO results in weak blood activation, and the material may in spite of this be suitable in selected biomaterial applications, especially as a biosealant and in colloidal dispersions.

  • 36.
    Eriksson, Andreas
    et al.
    Linköpings universitet, Institutionen för medicin och hälsa, Farmakologi. Linköpings universitet, Hälsouniversitetet.
    Jonasson, Lena
    Linköpings universitet, Institutionen för medicin och hälsa, Kardiologi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Hjärtcentrum, Kardiologiska kliniken.
    Lindahl, Tomas
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Klinisk kemi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Laboratoriemedicinskt centrum, Klinisk kemi.
    Hedbäck, Bo
    Linköpings universitet, Institutionen för medicin och hälsa, Kardiologi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Hjärtcentrum, Kardiologiska kliniken.
    Whiss, Per
    Linköpings universitet, Institutionen för medicin och hälsa, Farmakologi. Linköpings universitet, Hälsouniversitetet.
    Static platelet adhesion, flow cytometry and serum TXB2 levels for monitoring platelet inhibiting treatment with ASA and clopidogrel in coronary artery disease: a randomised cross-over study2009Ingår i: Journal of Translational Medicine, ISSN 1479-5876, E-ISSN 1479-5876, Vol. 7, nr 42Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Background: Despite the use of anti-platelet agents such as acetylsalicylic acid (ASA) and clopidogrel in coronary heart disease, some patients continue to suffer from atherothrombosis. This has stimulated development of platelet function assays to monitor treatment effects. However, it is still not recommended to change treatment based on results from platelet function assays. This study aimed to evaluate the capacity of a static platelet adhesion assay to detect platelet inhibiting effects of ASA and clopidogrel. The adhesion assay measures several aspects of platelet adhesion simultaneously, which increases the probability of finding conditions sensitive for anti-platelet treatment. Methods: With a randomised cross-over design we evaluated the anti-platelet effects of ASA combined with clopidogrel as well as monotherapy with either drug alone in 29 patients with a recent acute coronary syndrome. Also, 29 matched healthy controls were included to evaluate intra-individual variability over time. Platelet function was measured by flow cytometry, serum thromboxane B-2 (TXB2)-levels and by static platelet adhesion to different protein surfaces. The results were subjected to Principal Component Analysis followed by ANOVA, t-tests and linear regression analysis. Results: The majority of platelet adhesion measures were reproducible in controls over time denoting that the assay can monitor platelet activity. Adenosine 5-diphosphate (ADP)-induced platelet adhesion decreased significantly upon treatment with clopidogrel compared to ASA. Flow cytometric measurements showed the same pattern (r(2) = 0.49). In opposite, TXB2-levels decreased with ASA compared to clopidogrel. Serum TXB2 and ADP-induced platelet activation could both be regarded as direct measures of the pharmacodynamic effects of ASA and clopidogrel respectively. Indirect pharmacodynamic measures such as adhesion to albumin induced by various soluble activators as well as SFLLRN-induced activation measured by flow cytometry were lower for clopidogrel compared to ASA. Furthermore, adhesion to collagen was lower for ASA and clopidogrel combined compared with either drug alone. Conclusion: The indirect pharmacodynamic measures of the effects of ASA and clopidogrel might be used together with ADP-induced activation and serum TXB2 for evaluation of anti-platelet treatment. This should be further evaluated in future clinical studies where screening opportunities with the adhesion assay will be optimised towards increased sensitivity to anti-platelet treatment.

  • 37. Eriksson, Mats
    et al.
    Christensen, Kjeld
    Lindahl, Tomas
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för biomedicin och kirurgi, Klinisk kemi. Östergötlands Läns Landsting, Laboratoriemedicinskt centrum, Klinisk kemi.
    Larsson, Anders
    Pharmaceutical thrombosis prevention in cardiovascular disease2002Ingår i: Expert Opinion on Investigational Drugs, ISSN 1354-3784, E-ISSN 1744-7658, Vol. 11, s. 553-563Artikel i tidskrift (Refereegranskat)
  • 38.
    Erlinge, David
    et al.
    Lund University, Sweden .
    Gurbel, Paul A.
    Sinai Centre Thrombosis Research, MD USA .
    James, Stefan
    Uppsala University, Sweden .
    Lindahl, Tomas
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Diagnostikcentrum, Klinisk kemi.
    Svensson, Peter
    Lund University, Sweden .
    Ten Berg, Jurrien M.
    St Antonius Hospital, Netherlands .
    Foley, David P.
    Beaumont Hospital, Ireland .
    Wagner, Henrik
    Lund University, Sweden .
    Brown, Patricia B.
    Eli Lilly and Co, IN USA .
    Luo, Junxiang
    Eli Lilly and Co, IN USA .
    Zhou, Chunmei
    Eli Lilly and Co, IN USA .
    Moser, Brian A.
    Eli Lilly and Co, IN USA .
    Jakubowski, Joseph A.
    Eli Lilly and Co, IN USA .
    Small, David S.
    Eli Lilly and Co, IN USA .
    Winters, Kenneth J.
    Eli Lilly and Co, IN USA .
    Angiolillo, Dominick J.
    University of Florida, FL USA .
    Prasugrel 5 mg in the Very Elderly Attenuates Platelet Inhibition But Maintains Noninferiority to Prasugrel 10 mg in Nonelderly Patients2013Ingår i: Journal of the American College of Cardiology, ISSN 0735-1097, E-ISSN 1558-3597, Vol. 62, nr 7, s. 577-583Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Objectives This study assessed pharmacodynamic (PD) response to the reduced prasugrel maintenance dose of 5 mg in very elderly (VE) patients (andgt;= 75 years of age). less thanbrgreater than less thanbrgreater thanBackground In the TRITON-TIMI 38 (TRial to Assess Improvement in Therapeutic Outcomes by Optimizing Platelet InhibitioN with Prasugrel-Thrombolysis In Myocardial Infarction 38) study prasugrel 10 mg reduced ischemic events versus clopidogrel 75 mg, but increased bleeding in VE patients. less thanbrgreater than less thanbrgreater thanMethods We examined PD and active metabolite pharmacokinetics (PKs) with prasugrel 5 and 10 mg and clopidogrel 75 mg in a 3-period (12 days each) blinded, crossover study in VE (n = 73; mean: 79 +/- 3 years of age) or (n 82) nonelderly (NE) (andgt;= 45 to andlt;65 years of age; mean: 56 +/- 5 years of age) stable coronary artery disease (CAD) patients receiving background aspirin. Assays included light transmission aggregometry (LTA), VerifyNow P2Y12 (VN-P2Y12), and vasodilator-associated stimulated phosphoprotein (VASP). The primary comparison was noninferiority of maximum platelet aggregation (MPA) comparing the median for prasugrel 5 mg in VE versus the 75th percentile for prasugrel 10 mg in NE, using a pre-specified 1-sided 97.5% confidence interval for the difference andlt;15%. less thanbrgreater than less thanbrgreater thanResults Prasugrel 5 mg in VE met the primary PD noninferiority criterion versus prasugrel 10 mg in NE. For prasugrel 5 mg, MPA was significantly lower (57 +/- 14%) than clopidogrel (63 +/- 14%; p andlt; 0.001) in VE but higher than prasugrel 10 mg in NE (46 +/- 12%; p andlt; 0.001). PD response by LTA, VN-P2Y12, and VASP during all treatments appeared similar between age cohorts. Prasugrel 5 mg resulted in fewer VE poor responders than clopidogrel. Rates of mild bleeding were higher with prasugrel 10 mg but similar for prasugrel 5 mg versus clopidogrel 75 mg. less thanbrgreater than less thanbrgreater thanConclusions In aspirin-treated stable CAD patients, prasugrel 5 mg in VE attenuated platelet inhibition while meeting pre-specified noninferiority criterion versus prasugrel 10 mg in NE, with significantly better PD response and fewer poor responders compared to clopidogrel 75 mg in VE. (Comparison of Prasugrel and Clopidogrel in Very Elderly and Non-Elderly Patients With Stable Coronary Artery Disease [GENERATIONS]; NCT01107912)

  • 39.
    Faxälv, Lars
    et al.
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Klinisk kemi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Diagnostikcentrum, Klinisk kemi.
    Boknäs, Niklas
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Hälsouniversitetet.
    Lindahl, Tomas
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Klinisk kemi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Diagnostikcentrum, Klinisk kemi.
    PAR1, PAR4 and GPIB form functional interdependent units in a receptor complex mediating platelet activation by thrombin in JOURNAL OF THROMBOSIS AND HAEMOSTASIS, vol 9, issue SI, pp 11-112011Ingår i: JOURNAL OF THROMBOSIS AND HAEMOSTASIS, Wiley-Blackwell , 2011, Vol. 9, nr SI, s. 11-11Konferensbidrag (Refereegranskat)
    Abstract [en]

    n/a

  • 40.
    Faxälv, Lars
    et al.
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Diagnostikcentrum, Klinisk kemi.
    Boknäs, Niklas
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Hälsouniversitetet.
    Ström, Jakob
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Klinisk kemi. Linköpings universitet, Hälsouniversitetet.
    Tengvall, Pentti
    University of Gothenburg, Gothenburg, Sweden .
    Theodorsson, Elvar
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Hälsouniversitetet. Region Östergötland, Diagnostikcentrum, Klinisk kemi.
    Ramström, Sofia
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Hälsouniversitetet.
    Lindahl, Tomas
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Diagnostikcentrum, Klinisk kemi.
    Putting polyphosphates to the test: evidence against platelet-induced activation of factor XII2013Ingår i: Blood, ISSN 0006-4971, E-ISSN 1528-0020, Vol. 122, nr 23, s. 3818-3824Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The recent claim that stimulated platelets activate the intrinsic pathway of coagulation by the release of polyphosphates has been considered a breakthrough in hemostasis research. In little more than 3 years, the original publication by Muller et al has been cited greater than100 times. However, none of the citing articles has sought to independently validate this potentially paradigm-shifting concept. To this end, we performed extensive experimentation in vitro and in vivo in an attempt to verify the claim that factor XII (FXII) is primarily activated by stimulated platelets. In contrast to the original assertion, platelet-derived polyphosphates were found to be weak activators of FXII, with a FXIIa-generating activity of less than10% compared with equivalent concentrations of kaolin. Using different coagulation assays, it was shown that platelet contribution to whole blood coagulation was unrelated to the generation of activated FXII in vitro. Additionally, key results used to verify the hypothesis in the original study in vivo were found to be irreproducible. We conclude that platelet-derived polyphosphates are not physiologically relevant activators of FXII.

  • 41.
    Faxälv, Lars
    et al.
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Diagnostikcentrum, Klinisk kemi.
    Bolin, Maria
    Linköpings universitet, Institutionen för teknik och naturvetenskap. Linköpings universitet, Tekniska högskolan.
    Jager, Edwin
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Biosensorer och bioelektronik. Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska fakulteten.
    Lindahl, Tomas
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Diagnostikcentrum, Klinisk kemi.
    Berggren, Magnus
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Fysik och elektroteknik. Linköpings universitet, Tekniska högskolan.
    Electronic control of platelet adhesion using conducting polymer microarrays2014Ingår i: Lab on a Chip, ISSN 1473-0197, E-ISSN 1473-0189, Vol. 14, nr 16, s. 3043-3049Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We hereby report a method to fabricate addressable micropatterns of e-surfaces based on the conducting polymer poly(3,4-ethylenedioxythiophene) doped with the anion tosylate (PEDOT:Tos) to gain dynamic control over the spatial distribution of platelets in vitro. With thin film processing and microfabrication techniques, patterns down to 10 mu m were produced to enable active regulation of platelet adhesion at high spatial resolution. Upon electronic addressing, both reduced and oxidized surfaces were created within the same device. This surface modulation dictates the conformation and/or orientation, rather than the concentration, of surface proteins, thus indirectly regulating the adhesion of platelets. The reduced electrode supported platelet adhesion, whereas the oxidized counterpart inhibited adhesion. PEDOT:Tos electrode fabrication is compatible with most of the classical patterning techniques used in printing as well as in the electronics industry. The first types of tools promise ultra-low-cost production of low-resolution (greater than30 mu m) electrode patterns that may combine with traditional substrates and dishes used in a classical analysis setup. Platelets play a pronounced role in cardiovascular diseases and have become an important drug target in order to prevent thrombosis. This clinical path has in turn generated a need for platelet function tests to monitor and assess platelet drug efficacy. The spatial control of platelet adherence presented here could prove valuable for blood cell separation or biosensor microarrays, e.g. in diagnostic applications where platelet function is evaluated.

  • 42.
    Faxälv, Lars
    et al.
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Klinisk kemi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Laboratoriemedicinskt centrum, Klinisk kemi.
    Ekblad, Tobias
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Sensorvetenskap och Molekylfysik. Linköpings universitet, Tekniska högskolan.
    Liedberg, Bo
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Sensorvetenskap och Molekylfysik. Linköpings universitet, Tekniska högskolan.
    Lindahl, Tomas L.
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Klinisk kemi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Laboratoriemedicinskt centrum, Klinisk kemi.
    Blood compatibility of photografted hydrogel coatings2010Ingår i: ACTA BIOMATERIALIA, ISSN 1742-7061, Vol. 6, nr 7, s. 2599-2608Artikel i tidskrift (Övrigt vetenskapligt)
    Abstract [en]

    In this work we have evaluated the haemocompatibility of different surface modifications, intended for biomaterials and biosensor applications. Polystyrene slides were coated with thin hydrogel films by self-initiated photografting of four different monomers. The hydrogel surface modifications were thoroughly characterized and tested for their protein resistance and ability to facilitate platelet adhesion and activation of the coagulation system. There was very little protein adsorption from human plasma on the hydrogels formed from poly(ethylene glycol) methacrylate (PEGMA) and 2-hydroxyethyl methacrylate (HEMA). Platelet adhesion tests performed under both static and flow conditions showed that these coatings also demonstrated very high resistance towards platelet adhesion. A small amount of platelets were found to adhere to hydrogels formed from ethylene glycol methyl ether methacrylate (EGMEMA) and 2-carboxyethyl methacrylate (CEA). The polystyrene substrates themselves facilitated large amounts of platelet adhesion under both static and flow conditions. Utilizing a novel setup for imaging of coagulation, it was shown that none of the hydrogel surfaces activated the coagulation system to any great extent. We suggest that this simple fabrication method can be used to produce hydrogel coatings with unusually high blood compatibility, suitable for demanding biomaterials applications.

  • 43.
    Faxälv, Lars
    et al.
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Klinisk kemi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Laboratoriemedicinskt centrum, Klinisk kemi.
    Hume, Jasmin
    Deptartment of Applied Physics, Chalmers University of Technology,.
    Lindahl, Tomas L.
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Klinisk kemi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Laboratoriemedicinskt centrum, Klinisk kemi.
    Kasemo, Bengt
    Department of Applied Physics, Chalmers University of Technology, SE-412 96 Göteborg, Sweden.
    Svedhem, Sofia
    Department of Applied Physics, Chalmers University of Technology, SE-412 96 Göteborg, Sweden.
    Activation of blood coagulation at charged supported lipid membranesManuskript (preprint) (Övrigt vetenskapligt)
    Abstract [en]

    The purpose of this work was to investigate the relationship between surface charge of phospholipid membranes and coagulation. Also, we wanted to demonstrate that coagulation at phospholipid membranes could successfully be studied in the method for imaging of coagulation.

    Analytical procedure: Supported phospholipid membranes were formed from palmitoyl-oleoyl-glycero-3-ethylphosphocholine (POEPC), 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC), and 1- palmitoyl-2-oleoyl-sn-glycero-3-[phospho-L-serine] (POPS) on silicon substrates. The surface charge of the phospholipid membranes was controlled by using different compositions of POPS (negative net charge), POPC (weak negative net charge) and POEPC (positive net charge). Imaging of coagulation experiments were performed on all phospholipid membrane coated surfaces as well as the clean silicon substrate. The experiments were performed in platelet-free plasma (PFP) diluted 50:50 with phosphate-buffered saline (PBS).

    Results: Comparing the negatively charged SiO2 surface with the negatively charged POPS (30%)/POPC(70%) we found an interesting difference. Although both surfaces activated coagulation rapidly, the POPS surface facilitated a faster propagation of coagulation from the surface than the SiO2 surface. It was also found that in order for the phospholipid membranes to exert procoagulant properties, the POPS content in the membrane had to exceed ~6 %. It was also found that positively charged phospholipid membranes did not induce activation of coagulation.

    Conclusions: The work in this paper demonstrated that the coagulation process at phospholipid membranes can be studied in a straightforward manner using the imaging of coagulation setup. Furthermore, we speculate that the negatively charged phospholipid membranes but not the SiO2 surface can support the binding of coagulation factor complexes, thus facilitating a faster propagation of coagulation. The fact that the POPS content must exceed ~ 6% to fully exert procoagulant properties was also a very interesting result, especially since platelets, when activated, become procoagulant by increasing their negatively charged phosphatidylserine exposure from ~0 % to maximally ~10 %.

  • 44.
    Faxälv, Lars
    et al.
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Klinisk kemi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Laboratoriemedicinskt centrum, Klinisk kemi.
    Ramström, Sofia
    Molecular and Cellular Therapeutics, Royal College of Surgeons in Ireland, Dublin, Ireland.
    Soutukorva, Kristina
    Linköpings universitet, Institutionen för klinisk och experimentell medicin. Linköpings universitet, Hälsouniversitetet.
    Tengvall, Pentti
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad Fysik. Linköpings universitet, Tekniska högskolan.
    Lindahl, Tomas L.
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Klinisk kemi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Laboratoriemedicinskt centrum, Klinisk kemi.
    The role of coagulation factor XII in propagation of coagulationManuskript (preprint) (Övrigt vetenskapligt)
    Abstract [en]

    The physiological relevance and function of coagulation factor XII (FXII), the first zymogen in the intrinsic pathway, has for a long time been a matter of debate. The aim of this study was to shed some light on the role of factor XII in thrombus formation with a focus on its effect during the propagation phase of coagulation. In order to study propagation of coagulation we utilized a new imaging method to measure propagation rates from an activating surface in both platelet-free plasma and platelet-rich plasma. The most essential results revealed that both FXII and its substrate FXI are located on the surface of activated platelets. The surface of preexisting clots does not support coagulation in a FXII dependent manner. However, we found strong evidence for an accelerated propagation of tissue factor initiated coagulation when contact activation of FXII simultaneously occurred in the proximity. In vivo sources for contact activation may be exposed subendothelial collagen as well as soluble and cell derived poly-anions. If such in vivo contact activation of FXII occurs, even though moderate, it could contribute to in vivo thrombus growth rate and thus be of pathophysiological importance.

  • 45.
    Faxälv, Lars
    et al.
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Klinisk kemi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Laboratoriemedicinskt centrum, Klinisk kemi.
    Tengvall, Pentti
    Linköpings universitet, Institutionen för fysik, kemi och biologi, Tillämpad Fysik. Linköpings universitet, Tekniska högskolan.
    Lindahl, Tomas L
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Klinisk kemi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Laboratoriemedicinskt centrum, Klinisk kemi.
    Imaging of blood plasma coagulation and its propagation at surfaces2008Ingår i: Journal of biomedical materials research. Part A, ISSN 1552-4965, Vol. 85, nr 4, s. 1129-1134Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A new method utilizing image capture and processing was developed for the analysis of blood plasma coagulation at surfaces. The coagulation was detected in a cuvette by time-lapse image capture of light scattering from the developing fibrin network. By image processing and computer analysis of the captured image data, both early detection of coagulation at the surface and the propagation phase of coagulation could be measured in the same experiment. It is possible to use both platelet-rich plasma (PRP) and platelet-free plasma (PFP) with the method, and thereby study the platelet contribution to both surface coagulation and propagation of coagulation. Two well-known model surfaces, hydrophilic and hydrophobic glass, were used in combination with PRP and PFP to illustrate the method. Hydrophilic glass activated coagulation significantly faster (PRP: 7.0 +/- 1.7 min, PFP: 5.9 +/- 1.2 min, n= 16) than hydrophobic glass (PRP: 50 +/- 14 min, PFP: 65 +/- 32 min, n = 16) in both PRP and PFP. Hydrophilic surfaces showed a faster initial propagation of coagulation adjacent to the surface (mean velocity: 0.14 +/- 0.05 mm/ minute) compared with the propagation observed further out from the surface (mean velocity: 0.05 +/- 0.01 mm/min). The method is very flexible and can be suitable for screening hemocompatibility of biomaterials.

  • 46.
    Ferrandis, Maria-José
    et al.
    Department of Clinical Chemistry, Blekinge County Hospital, Sweden.
    Ryden, Ingvar
    Department of Clinical Chemistry, Blekinge County Hospital, Sweden.
    Lindahl, Tomas L.
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Klinisk kemi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Diagnostikcentrum, Klinisk kemi.
    Larsson, Anders
    Department of Medical Sciences, Section of Clinical Chemistry, Uppsala University, Uppsala, Sweden.
    Ruling out cardiac failure: Cost-benefit analysis of a sequential testing strategy with NT-proBNP before echocardiography2013Ingår i: Upsala Journal of Medical Sciences, ISSN 0300-9734, E-ISSN 2000-1967, Vol. 118, nr 2, s. 75-79Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Objectives. To estimate the possible economic benefit of a sequential testing strategy with NT-proBNP to reduce the number of echocardiographies.

    Methods. Retrospective study in a third-party payer perspective. The costs were calculated from three Swedish counties: Blekinge, Östergötland, and Uppland. Two cut-off levels of NT-proBNP were used: 400 and 300 pg/mL. The cost-effectiveness of the testing strategy was estimated through the short-term cost avoidance and reduction in demand for echocardiographies.

    Results. The estimated costs for NT-proBNP tests and echocardiographies per county were reduced by 33%–36% with the 400 pg/mL cut-off and by 28%–29% with the 300 pg/mL cut-off. This corresponded to a yearly cost reduction of approximately €2–5 million per million inhabitants in these counties.

    Conclusion. The use of NT-proBNP as a screening test could substantially reduce the number of echocardiographies in the diagnostic work-up of patients with suspected cardiac failure, as well as the associated costs.

  • 47.
    Fink, Helen
    et al.
    University of Gothenburg.
    Faxälv, Lars
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Klinisk kemi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Laboratoriemedicinskt centrum, Klinisk kemi.
    Molnar, Gabor F
    Semmelweis University of Medicine.
    Drotz, Kristoffer
    Chalmers.
    Risberg, Bo
    University of Gothenburg.
    Lindahl, Tomas
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Klinisk kemi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Laboratoriemedicinskt centrum, Klinisk kemi.
    Sellborn, Anders
    University of Gothenburg.
    Real-time measurements of coagulation on bacterial cellulose and conventional vascular graft materials2010Ingår i: ACTA BIOMATERIALIA, ISSN 1742-7061, Vol. 6, nr 3, s. 1125-1130Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The search for a functional, small diameter (andlt;5 mm) vascular graft has been ongoing for over 30 years, but yet there is no consistently reliable synthetic graft The primary mechanisms of graft failure are intimal hyperplasia. poor blood flow and surface thrombogenicity Bacterial cellulose (BC) became therefore a proposed new biosynthetic vascular graft material Since conventional methods are not suited for coagulation measurements on BC, we have adapted the automated calibrated thrombin generation method for measurements of biomaterial-induced coagulation of BC as compared with clinically used graft materials ie, expanded poly(tetrafluoroethylene) (ePTFE) and poly(ethyleneterephtalat) (PET) We have also visualized the coagulation propagation at the material surfaces Thrombin generation experiments revealed dramatic differences between the materials tested. Both ePTFE and BC were found to generate longer lag times and ttpeak values than PET Most importantly. BC was found to generate the lowest.. peak", indicating a slower coagulation process at the surface These results are also Supported by the measurements of factor XIIa generation and analysis of surface coagulation times, which were detected in the following increasing order (mean +/- SD) PET (27 +/- 8 min) andlt; BC (46 +/- 9 min) andlt; ePTFE (61 +/- 21 min) Real-time measurement of coagulation seems to have the potential for becoming a powerful too] for evaluation of biomaterials for blood-contacting devices

  • 48.
    Fälker, Knut
    et al.
    Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för klinisk och experimentell medicin, Klinisk kemi.
    Haglund, Linda
    Linköpings universitet, Institutionen för medicin och hälsa, Farmakologi. Linköpings universitet, Hälsouniversitetet.
    Gunnarsson, Peter
    Linköpings universitet, Institutionen för medicin och hälsa, Farmakologi. Linköpings universitet, Hälsouniversitetet.
    Nylander, Martina
    Linköpings universitet, Institutionen för medicin och hälsa, Farmakologi. Linköpings universitet, Hälsouniversitetet.
    Lindahl, Tomas
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Klinisk kemi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Diagnostikcentrum, Klinisk kemi.
    Grenegård, Magnus
    Linköpings universitet, Institutionen för medicin och hälsa, Farmakologi. Linköpings universitet, Hälsouniversitetet.
    Protease-activated receptor 1 (PAR1) signalling desensitization is counteracted via PAR4 signalling in human platelets2011Ingår i: Biochemical Journal, ISSN 0264-6021, E-ISSN 1470-8728, Vol. 436, s. 469-480Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    FARs (protease-activated receptors) 1 and 4 belong to the family of G-protein-coupled receptors which induce both G(alpha 12/13) and G(alpha q) signalling. By applying the specific PAR1- and PAR4-activating hexapeptides, SFLLRN and AYPGKF respectively, we found that aggregation of isolated human platelets mediated via PAR1, but not via PAR4, is abolished upon homologous receptor activation in a concentration- and time-dependent fashion. This effect was not due to receptor internalization, but to a decrease in Ca(2+) mobilization, PKC (protein kinase C) signalling and alpha-granule secretion, as well as to a complete lack of dense granule secretion. Interestingly, subthreshold PAR4 activation rapidly abrogated PAR1 signalling desensitization by differentially reconstituting these affected signalling events and functional responses, which was sufficient to re-establish aggregation. The lack of ADP release and P2Y(12) receptor-induced G(alpha i) signalling accounted for the loss of the aggregation response, as mimicking G(alpha i/z) signalling with 2-MeS-ADP (2-methylthioadenosine-5-O-diphosphate) or epinephrine (adrenaline) could substitute for intermediate PAR4 activation. Finally, we found that the re-sensitization of PAR1 signalling-induced aggregation via PAR4 relied on PKC-mediated release of both ADP from dense granules and fibrinogen from alpha-granules. The present study elucidates further differences in human platelet PAR signalling regulation and provides evidence for a cross-talk in which PAR4 signalling counteracts mechanisms involved in PAR1 signalling down-regulation.

  • 49.
    Fälker, Knut
    et al.
    Linköpings universitet, Institutionen för klinisk och experimentell medicin. Linköpings universitet, Hälsouniversitetet.
    Klarstrom-Engstrom, Kristin
    University of Örebro, Sweden .
    Bengtsson, Torbjorn
    University of Örebro, Sweden .
    Lindahl, Tomas
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Avdelningen för mikrobiologi och molekylär medicin. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Diagnostikcentrum, Klinisk kemi.
    Grenegard, Magnus
    University of Örebro, Sweden .
    The Toll-like receptor 2/1 (TLR2/1) complex initiates human platelet activation via the src/Syk/LAT/PLC gamma 2 signalling cascade2014Ingår i: Cellular Signalling, ISSN 0898-6568, E-ISSN 1873-3913, Vol. 26, nr 2, s. 279-286Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The specific TLR2/1 complex activator Pam3CSK4 has been shown to provoke prominent activation and aggregation of human non-nucleated platelets. As Pam3CSK4-evoked platelet activation does not employ the major signalling pathway established in nucleated immune cells, we investigated if the TLR2/1 complex on platelets may initiate signalling pathways known to be induced by physiological agonists such as collagen via GPVI or thrombin via PARs. We found that triggering TLR2/1 complex-signalling with Pam3CSK4, in common with that induced via GPVI, and in contrast to that provoked by PARS, involves tyrosine phosphorylation of the adaptor protein LAT as well as of PLC gamma 2 in a src- and Syk-dependent manner. In this respect, we provide evidence that Pam3CSK4 does not cross-activate GPVI. Further, by the use of platelets from a Glanzmanns thrombasthenia patient lacking beta(3), in contrast to findings in nucleated immune cells, we show that the initiation of platelet activation by Pam3CSK4 does not involve integrin beta(3) signalling; whereas the latter, subsequent to intermediate TXA2 synthesis and signalling, was found to be indispensable for proper dense granule secretion and full platelet aggregation. Together, our findings reveal that triggering the TLR2/1 complex with Pam3CSK4 initiates human platelet activation by engaging tyrosine kinases of the src family and Syk, the adaptor protein LAT, as well as the key mediator PLC gamma 2.

  • 50.
    Grenegård, Magnus
    et al.
    Linköpings universitet, Institutionen för medicin och hälsa, Farmakologi. Linköpings universitet, Hälsouniversitetet.
    Vretenbrant-Öberg, Karin
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Klinisk kemi. Linköpings universitet, Hälsouniversitetet.
    Nylander, Martina
    Linköpings universitet, Institutionen för medicin och hälsa, Farmakologi. Linköpings universitet, Hälsouniversitetet.
    Désilets, Stéphanie
    Linköpings universitet, Institutionen för medicin och hälsa, Farmakologi. Linköpings universitet, Hälsouniversitetet.
    Lindström, Eva G
    Linköpings universitet, Institutionen för medicin och hälsa, Farmakologi. Linköpings universitet, Hälsouniversitetet.
    Larsson, Anders
    Department of Medical Sciences, University Hospital, Uppsala SE-75105, Sweden.
    Ramström, Ida
    Linköpings universitet, Institutionen för medicin och hälsa, Farmakologi. Linköpings universitet, Hälsouniversitetet.
    Ramström, Sofia
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Klinisk kemi. Linköpings universitet, Hälsouniversitetet.
    Lindahl, Tomas L
    Linköpings universitet, Institutionen för klinisk och experimentell medicin, Klinisk kemi. Linköpings universitet, Hälsouniversitetet. Östergötlands Läns Landsting, Laboratoriemedicinskt centrum, Klinisk kemi.
    The ATP-gated P2X1 receptor plays a pivotal role in activation of aspirin-treated platelets by thrombin and epinephrine2008Ingår i: Journal of Biological Chemistry, ISSN 0021-9258, E-ISSN 1083-351X, Vol. 283, nr 27, s. 18493-18504Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Human platelets express protease-activated receptor 1 (PAR1) and PAR4 but limited data indicate for differences in signal transduction. We studied the involvement of PAR1 and PAR4 in the cross-talk between thrombin and epinephrine. The results show that epinephrine acted via alpha(2A)-adrenergic receptors to provoke aggregation, secretion, and Ca(2+) mobilization in aspirin-treated platelets pre-stimulated with subthreshold concentrations of thrombin. Incubating platelets with antibodies against PAR4 or the PAR4-specific inhibitor pepducin P4pal-i1 abolished the aggregation. Furthermore, platelets pre-exposed to the PAR4-activating peptide AYPGKF, but not to the PAR1-activating peptide SFLLRN, were aggregated by epinephrine, whereas both AYPGKF and SFLLRN synergized with epinephrine in the absence of aspirin. The roles of released ATP and ADP were elucidated by using antagonists of the purinergic receptors P2X(1), P2Y(1), and P2Y(12) (i.e. NF449, MRS2159, MRS2179, and cangrelor). Intriguingly, ATP, but not ADP, was required for the epinephrine/thrombin-induced aggregation. In Western blot analysis, a low concentration of AYPGKF, but not SFLLRN, stimulated phosphorylation of Akt on serine 473. Moreover, the phosphatidyl inositide 3-kinase inhibitor LY294002 antagonized the effect of epinephrine combined with thrombin or AYPGKF. Thus, in aspirin-treated platelets, PAR4, but not PAR1, interacts synergistically with alpha(2A)-adrenergic receptors, and the PI3-kinase/Akt pathway is involved in this cross-talk. Furthermore, in PAR4-pretreated platelets, epinephrine caused dense granule secretion, and subsequent signaling from the ATP-gated P2X(1)-receptor and the alpha(2A)-adrenergic receptor induced aggregation. These results suggest a new mechanism that has ATP as a key element and circumvents the action of aspirin on epinephrine-facilitated PAR4-mediated platelet activation.

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