Background: Borrelia infections, especially chronic neuroborreliosis ( NB), may cause considerable diagnostic problems. This diagnosis is based on symptoms and findings in the cerebrospinal fluid but is not always conclusive. Purpose: To evaluate brain magnetic resonance imaging ( MRI) in chronic NB, to compare the findings with healthy controls, and to correlate MRI findings with disease duration. Material and Methods: Sixteen well- characterized patients with chronic NB and 16 matched controls were examined in a 1.5T scanner with a standard head coil. T1- ( with and without gadolinium), T2-, and diffusion- weighted imaging plus fluid- attenuated inversion recovery ( FLAIR) imaging were used. Results: White matter lesions and lesions in the basal ganglia were seen in 12 patients and 10 controls ( no significant difference). Subependymal lesions were detected in patients down to the age of 25 and in the controls down to the age of 43. The number of lesions was correlated to age both in patients ( rho=0.83, P < 0.01) and in controls ( rho=0.61, P < 0.05), but not to the duration of disease. Most lesions were detected with FLAIR, but many also with T2- weighted imaging. Conclusion: A number of MRI findings were detected in patients with chronic NB, although the findings were unspecific when compared with matched controls and did not correlate with disease duration. However, subependymal lesions may constitute a potential finding in chronic NB.

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Exposure to a strong T-helper 2 (Th2)-like environment during fetal development may promote allergy development. Increased cord blood (CB) levels of the Th2-associated chemokine CCL22 were associated with allergy development during the first 2 y of life. The aim of the present study was to determine whether CB Th1- and Th2-associated chemokine levels are associated with allergy development during the first 6 y of life, allowing assessment of respiratory allergic symptoms usually developing in this period. The CB levels of cytokines, chemokines, and total IgE were determined in 56 children of 20 women with allergic symptoms and 36 women without allergic symptoms. Total IgE and allergen-specific IgE antibody levels were quantified at 6, 12, 24 mo, and 6 y of age. Increased CB CCL22 levels were associated with development of allergic sensitization and asthma and increased CCL17 levels with development of allergic symptoms, including asthma. Sensitized children with allergic symptoms showed higher CB CCL17 and CCL22 levels and higher ratios between these Th2-associated chemokines and the Th1-associated chemokine CXCL10 than nonsensitized children without allergic symptoms. A pronounced Th2 deviation at birth, reflected by increased CB CCL17 and CCL22 levels, and increased CCL22/CXCL10 and CCL17/CXCL10 ratios might promote allergy development later in life.

The patient, a 31-year-old male, sustained an electric burn injury (16 kV, AC/DC) while working with electric power lines. He was acutely admitted to a national burn center in Southeast Sweden, where burns equalling 29% of the total body surface area were noted. The burns were located at the front of the abdomen, upper arms bilaterally, and the left hip region, and the lesions were estimated to be mainly of the dermal type, what was believed initially to be caused mainly by an electric flash. There were no obvious entry or exit sites of the electric current. However, myoglobin in plasma was elevated as a sign of muscular degradation, suggesting that at least some current had passed through the tissues. According to the paramedic report there was an episode of a few minutes of unconsciousness immediately after the injury, but the patient was fully awake and alert on admission. There was no concomitant trauma.

Objective: Atherosclerosis is characterized by a chronic inflammatory response involving activated T cells and impairment of natural killer (NK) cells. An increased T cell activity has been associated with plaque instability and risk of acute cardiac events. Lymphocyte analyses in blood are widely used to evaluate the immune status. However, peripheral blood contains only a minor proportion of lymphocytes. In this study, we hypothesized that thoracic lymph nodes from patients with stable angina (SA) and acute coronary syndrome (ACS) might add information to peripheral blood analyses. less thanbrgreater than less thanbrgreater thanMethods: Peripheral blood and lymph nodes were collected during coronary by-pass surgery in 13 patients with SA and 13 patients with ACS. Lymphocyte subpopulations were assessed by flow cytometry using antibodies against CD3, CD4, CD8, CD19, CD16/56, CD25, Foxp3, CD69, HLA-DR, IL-18 receptor (R) and CCR4. less thanbrgreater than less thanbrgreater thanResults: Lymph nodes revealed a lymphocyte subpopulation profile substantially differing from that in blood including a higher proportion of B cells, lower proportions of CD8(+) T cells and NK cells and a 2-fold higher CD4/CD8 ratio. CD4(+)CD69(+) cells as well as Foxp3(+) regulatory T cells were markedly enriched in lymph nodes (p andlt; 0.001) while T helper 1-like (CD4(+)IL-18R(+)) cells were more frequent in blood (p andlt; 0.001). The only significant differences between ACS and SA patients involved NK cells that were reduced in the ACS group. However, despite being reduced, the NK cell fraction in ACS patients contained a significantly higher proportion of IL-18R(+) cells compared with SA patients (p andlt; 0.05). less thanbrgreater than less thanbrgreater thanConclusion: There were several differences in lymphocyte subpopulations between blood and lymph nodes. However, the lymphocyte perturbations in peripheral blood of ACS patients compared with SA patients were not mirrored in lymph nodes. The findings indicate that lymph node analyses in multivessel coronary artery disease may not reveal any major changes in the immune response that are not detectable in blood.

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Background

Evaluation of intraepithelial duodenal lymphocytosis (IDL) is important in celiac disease (CD). There is no established cut-off value for increased number of IELs in the bulb.

We therefore investigated the relation between IEL counts in the bulb and duodenal specimens in non-celiac subjects.

Methods

The number of CD3+ IELs was determined in specimens from the second part of the duodenum and from the bulb in 34 non-celiac subjects. The numbers of IELs in the villus tip and sides were counted and the quotient tip/side was calculated. HLA DQ2/DQ8 and serum antibodies against transglutaminase were analysed.

Results

The mean number of IELs per 100 enterocytes (95% CI) in specimens was 14.7 (11.8-17.6) in the bulb, and 21.2 (17.0-25.5) in the second part of the duodenum (p<0.01). There was no difference in IEL count or distribution comparing patients carrying or lacking HLA DQ2/DQ8.

Conclusions

IEL count in non-celiac, HLA DQ2/DQ8 positive or negative patients is significantly lower in the bulb than in the second part of the duodenum. These findings implicate that the site of biopsy should be taken into account when considering duodenal lymphocytosis.

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Objective: There is emerging evidence for CD8(+) T cell alterations in blood from patients with coronary artery disease (CAD). We examined whether the distribution and phenotype of CD8(+)CD56(+) T cells differed according to the clinical manifestation of CAD. less thanbrgreater than less thanbrgreater thanMethods: Patients with acute coronary syndrome (ACS, n = 30), stable angina (SA, n = 34) and controls (n = 36) were included. Blood was collected before and up to 12 months after referral for coronary investigation. CD8(+)CD56(+) T cells were assessed by flow cytometry for expression of surface markers, apoptosis, and intracellular expression of cytokines. less thanbrgreater than less thanbrgreater thanResults: The proportions of CD8(+)CD56(+) T cells were significantly higher in both ACS and SA patients compared with controls, and remained so after 3 and 12 months. This was independent of age, sex, systemic inflammation and cytomegalovirus seropositivity. CD8(+)CD56(+) T cells differed from CD8(+)CD56(-) T cells in terms of lower CD28 expression and fewer apoptotic cells. Both CD8(+) T cell subsets were positive for interferon (IFN)-gamma and tumor necrosis factor, although IFN-gamma was significantly more confined to the CD8(+)CD56(+) T cells. less thanbrgreater than less thanbrgreater thanConclusion: The persistent accumulation of CD8(+)CD56(+) T cells in ACS and SA patients share several features with immunological aging. It also contributes to a larger IFN-gamma(+) pool in blood, and may thereby hypothetically drive the atherosclerotic process in a less favorable direction.

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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.

[No abstract available]

Background This study was done to evaluate the diagnostic utility of antibodies against deamidated gliadin peptides compared to traditional markers for coeliac disease. Aim To evaluate diagnostic utility of antibodies against deamidated gliadin peptide (DGP). Methods Sera from 176 adults, referred for endoscopy without previous analysis of antibodies against tissue transglutaminase (tTG) or endomysium (EmA), were retrospectively analysed by ELISAs detecting IgA/IgG antibodies against DGP or a mixture of DGP and tTG, and compared with IgA-tTG and EmA. Seventy-nine individuals were diagnosed with coeliac disease. Results Receiver operating characteristic analyses verified the manufacturers cut-off limits except for IgA/IgG-DGP/ tTG. In sera without IgA deficiency, the sensitivity was higher for IgA/IgG-DGP (0.85-0.87) compared with IgA-tTg (0.76) and EmA (0.61). All tests showed high specificity (0.95-1.00). Eighteen coeliac disease-sera were negative regarding IgA-tTG, nine of which were positive for IgA/IgG-DGP. Sera from coeliac disease-patients greater than70 years were more often negative for IgA-tTG (50%) and IgA/IgG-DGP (36%) than younger patients (15% and 8% respectively) (P less than 0.01). Three of the four IgA-deficient patients were positive in the IgA/IgG-DGP assay. Conclusions In this study of patients unselected regarding IgA-tTg/EmA, thus unbiased in this respect, IgA/IgG-DGP identified adult coeliac disease patients negative for antibodies against endomysium and tissue transglutaminase. Serology is often negative in elderly patients with coeliac disease; a small bowel biopsy should therefore be performed generously before coeliac disease is excluded.

We used ELISPOT and cell ELISA to study secretion of IL-4, IFN-γ, TGF-β, IL-6, and TNF-α by circulating mononuclear cells during the course of Guillain-Barré syndrome (GBS). Compared to healthy controls, patients with GBS had higher numbers of TGF-β-secreting cells and the number of individuals with myelin-peptide-induced IL-4 and TGF-β secretion was higher in the GBS group. No significant differences were seen concerning the predominantly pro-inflammatory cytokines IFN-γ, IL-6 or TNF-α. Our findings indicate a down-regulatory role for TGF-β and IL-4 in GBS.

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Objective. Insights into the pathogenesis of inflammatory myopathies have led to new diagnostic methods. The aims of our study were (1) to evaluate the consequences of using the classification of Amato/European Neuromuscular Centre Workshop (ENMC), compared to that of Bohan and Peter; and (2) to evaluate any diagnostic benefit in using an extended pathological investigation. less thanbrgreater than less thanbrgreater thanMethods. From a consecutive retrospective database, we evaluated 99 patients for classification. Patients with inclusion body myositis (IBM) were classified according to Griggs, et al. In addition to routine stainings and immunohistochemistry, a multilevel serial sectioning procedure was performed on paraffin-embedded material, to identify scarce pathological findings. less thanbrgreater than less thanbrgreater thanResults. Classification according to Bohan and Peter could be performed for 83 of the 99 patients, whereas only 60 patients met the Amato/ENMC criteria, the latter resulting in the following diagnostic groups: IBM (n = 18), nonspecific myositis (n = 14), polymyositis (n = 12), dermatomyositis (n = 10), dermatomyositis sine dermatitis (n = 5), and immune-mediated necrotizing myopathy (n = 1). Most of the Amato/ENMC diagnostic groups harbored patients from several of the Bohan and Peter groups, which included a substantial group lacking proximal muscle weakness. The serial sectioning procedure was essential for classification of 9 patients (15%), and led to a more specific diagnosis for 13 patients (22%) according to Amato/ENMC. less thanbrgreater than less thanbrgreater thanConclusion. The classification of Amato/ENMC was more restrictive, forming groups based on clinical criteria and specified myopathological findings, which clearly differed from the groups of the Bohan and Peter classification. An extended pathological investigation increased the diagnostic yield of a muscle biopsy and highlights the quantity and specificity of certain pathological findings.

The unique absence of major histocompatibility complex class I antigen (MHC-I) expression in normal muscle is one possible mechanism protecting striated muscle. In order to define their possible involvement in protection of normal muscle. we investigated the expression of molecules involved in muscle fibre death and survival mechanisms (Bcl-2, Fas, Fas-ligand and TRAIL), focusing on disorders with possible involvement of cytotoxic T cells. We studied muscle biopsies from 20 healthy volunteers, from 10 patients affected by polymyositis and 10 by Duchenne muscular dystrophy. By using immunohistochemistry, Western blot and real-time PCR we detected a constitutional expression of Bcl-2 in healthy muscle, whereas the expression was weaker in disease processes. Fas-L and TRAIL were not detected in muscle fibres, and Fas only in muscle affected by disease. Our findings indicate that the major apoptotic protein Bcl-2 might have a hitherto unrecognized role in the protection of normal muscle.

Background:Multiple sclerosis (MS) is hypothetically caused by autoreactive Th1 and Th17 cells, whereas Th2 and regulatory T cells may confer protection. The development of Th subpopulations is dependant on the expression of lineage-specific transcription factors.

Objective:The aim of this study was to assess the balance of CD4⁺T cell populations in relapsing-remitting MS.

Methods:Blood mRNA expression of TBX21, GATA3, RORC, FOXP3 and EBI3 was assessed in 33 patients with relapsing-remitting MS and 20 healthy controls. In addition, flow cytometry was performed to assess T lymphocyte numbers.

Results:In relapsing-remitting MS, diminished expression of FOXP3 (Treg) was found (p < 0.05), despite normal numbers of CD4⁺CD25^hiTreg. Immunoregulatory EBI3 and Th2-associated GATA3 ([a-z]+) was also decreased in MS (p < 0.005 and p < 0.05, respectively). Expression of TBX21 (Th1) and RORC (Th17) did not differ between patients and controls. Similar changes were observed when analysing beta-interferon treated (n = 12) or untreated (n = 21) patients. Analysis of transcription factor ratios, comparing TBX21/GATA3 and RORC/FOXP3, revealed an increase in the RORC/FOXP3 ratio in patients with relapsing-remitting MS (p < 0.005).

Conclusion:Our findings indicate systemic defects at the mRNA level, involving downregulation of beneficial CD4⁺phenotypes. This might play a role in disease development by permitting activation of harmful T cell populations.

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PROBLEM: A T-helper cell type 2 (Th2) cytokine dominated microenvironment has been predicted to be crucial for successful pregnancy. However, little information is available about local cytokine secretion in the human decidua. We determined the spontaneous secretion of interleukin-4 (IL-4), interferon-γ (IFN-γ) and IL-10 by decidual mononuclear cells at the single cell level and compared it with their secretion by peripheral blood mononuclear cells (PBMC) in the first trimester of pregnancy.

METHODS OF STUDY: The cytokine secretion from decidual and blood cells was detected by a sensitive enzyme-linked immunosorbent spot-forming cell (ELISPOT)-assay.

RESULTS: Cells secreting IL-4 (median 153, range 8–530), IL-10 (median 188, range 32–1600) and IFN-γ (median 123, range 15–1140) were detected in all decidual and blood samples. The cytokine secretion showed a co-linear pattern in both the blood and decidua, i.e. when one cytokine was secreted at high levels, the others followed the trend. No correlation was found between the number of cytokine secreting cells in blood and decidua for any of the cytokines.

CONCLUSIONS: Interleukin-4 and IL-10 are locally secreted in the decidua early during normal pregnancy, probably counteracting the fetal rejecting effects of co-expressed IFN-γ. The cytokine secretion by blood cells does not generally reflect the local secretion pattern during first trimester pregnancy.

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Objective. The use of rituximab in vasculitis has increased interest in B cell biology. A subpopulalion of B cells expressing CD25 shows antigen-presenting properties and may have regulatory functions. We assessed subpopulations of B cell maturation (Bm) and markers related to activity and antigen presentation, and related the findings to disease activity. Methods. Multiparameter flow cytometry was used to assess numbers and proportions of circulating lymphocytes from 34 patients with vasculitis (16 remission, 18 active) and 20 controls. Results. Active vasculitis samples showed decreased proportions of Bm1 (7.8% vs 11%; p = 0.041), Bm2 (0.2% vs 0.7%; p = 0.002), and Bm3/Bm4 (0.1% vs 0.3%; p = 0.006), compared with controls; Bm2 cells were the most frequently occurring B cells but they were not significantly different in active vasculitis (74% vs 62%; p = 0.083). In patients with remission the proportion of CD25+ B cells was increased compared to controls (48% vs 29%, respectively; p = 0.006) and also compared to active vasculitis (23%; p = 0.006). The proportion of CD86+ B cells was also increased (31%) compared to active vasculitis (8%; p = 0.001), and to controls (6%; p = 0.0003). In multivariate analysis. Bm2 cells and CD25+27- B cells were independently influencing the patient group. Conclusion. In active vasculitis, a lower proportion of Bm I cells may indicate activated B cells. Patients in remission had higher proportions of CD25+ (a-chain of interleukin 2 receptor) and CD86+ (costimulatory molecule) B cells. We suggest that these B cells may have a regulatory role, or alternatively may result from previous treatment.

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Objective. T helper cells lacking CD28 (CD4+CD28-) have been implicated in the pathogenesis of granulomatosis with polyangiitis (Wegener; GPA) and microscopic polyangiitis (MPA). Expansions of CD4+CD28- and CD8+CD28- T cells have also been associated with latent cytomegalovirus (CMV) infection. We assessed these T cells with and without coexpression of CD56 and CD57 in relation to vasculitis as well as CMV status. less thanbrgreater than less thanbrgreater thanMethods. Blood from 16 patients in remission (12 GPA, 4 MPA), 18 patients with active vasculitis (12 GPA, 6 MPA), and 20 healthy controls was examined by flow cytometry for expression of CD4, CD8, CD56, CD57, and CD28 on T cells. The influence of age, CMV status, presence of disease, and disease activity on T cell subpopulations was tested with multiple regression analyses. less thanbrgreater than less thanbrgreater thanResults. In active vasculitis, the total numbers and proportion of lymphocytes were decreased. Total numbers of CD4+, CD8+, CD4+CD28-, CD8+CD28-, CD4+CD57+, and CD8+CD57+ T subpopulations were decreased to the same extent, implying unchanged proportions. Multivariate analyses showed no associations between vasculitis and CD28- or CD57+ T subpopulations, whereas immunoglobulin G antibodies to CMV were associated with expanded proportions of CD28 and CD57+ T cells, in both the CD4+ and the CD8+ compartments. less thanbrgreater than less thanbrgreater thanConclusion. CD28- and CD57+ T cells were associated with latent CMV infection and not with a diagnosis of GPA or MPA. Vasculitis assessment should include CMV status.

Problem During pregnancy, the maternal immune system needs to adapt in order not to reject the semi-allogenic fetus. Method In this review, we describe and discuss the role of regulatory T (Treg) cells in fetal tolerance. Results Treg cells constitute a T helper lineage that is derived from thymus (natural Treg cells) or is induced in the periphery (induced Treg cells). Treg cells are enriched at the fetal-maternal interface, showing a suppressive phenotype. In contrast, Treg cells are not increased in the circulation of pregnant women, and the suppressive capacity is similar to that in nonpregnant women. However, aberrations in Treg frequencies and functions, both systemically and in the uterus, may be involved in the complications of pregnancy. Conclusion Treg cells seem to have distinguished roles locally versus systemically, based on their distribution and phenotype.

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Background. Despite advances in medical practices, in recent decades permanent reductions in joint function have not been achieved, and the high mortality rate of patients with staphylococcal septic arthritis has not substantially improved. Methods. We evaluated the effects of a combined tumor necrosis factor (TNF) inhibitor and antibiotic therapy on the course of Staphylococcus aureus arthritis and sepsis in mice. Results. Treatment with the combination of a TNF inhibitor and an antibiotic resulted in a quicker relief of clinical arthritis in mice with septic arthritis, compared with an antibiotic monotherapy. Both histopathologically verified synovitis and the extent of joint destruction were reduced by this combined treatment. Importantly, anti-TNF treatment significantly improved the survival rate of mice with S. aureus sepsis and staphylococcal enterotoxin shock syndrome; this effect might be the result of a partial restoration of the hemostatic balance between coagulation and fibrinolysis. Finally, we demonstrated that anti-TNF treatment downregulates high-mobility group protein B1 in staphylococcal enterotoxin shock syndrome. Conclusions. Thus, simultaneous systemic TNF inhibition and antibiotic therapy has beneficial effects on the outcome of S. aureus arthritis and sepsis in a mouse model, suggesting that the combination of a TNF inhibitor and antibiotics represents a novel therapeutic strategy for the treatment of staphylococcal infections.

Introduction:Pregnancy challenges the immune system. Thus, tolerance to the semi-allogenic fetus must be supported while the mother and fetus still must be protected against infectious agents. Pregnancy is associated with a Th2 deviated immune system, away from a harmful Th1 associated immunity, although this may be a simplified view. Regulatory T cells (Tregs) are enriched in the uterus, but occur at normal frequency in the circulation. It has become increasingly evident that Tregs and T helper cells are not stably committed lineages but are plastic, showing close relationships between subsets. We hypothesize that an increased T cell flexibility in pregnancy can help to explain the paradox of simultaneous tolerance and strong antimicrobial responses. Our aim was to investigate whether the plasticity concept is applicable for the Treg subset, and if it involves the entire T helper population.

Material and methods: Isolated Tregs (CD4dimCD25high) and control cells (CD4+CD25−) from second trimester pregnant (n = 14) and non-pregnant women (n = 14) were stimulated for 24 h with plate-bound anti-CD3/anti-CD28. Signature gene and protein expression of each T cell subset was measured using transcription factor expression by real time-PCR and multiplex bead array of cell culture supernatants, respectively. The whole PBMC fraction is also used in ongoing experiments and either stimulated with plate-bound anti-CD3/anti-CD28 or with the Th1, Th2 and Th17 deviating microbial agents PPD (Th1), TT (Th2) and C. albicans hyphae (Th17). After culturing, the cells are stained for intracellular transcription factors associated with Th1, Th2, Th17 and Treg immunity.

Results: Stimulated Tregs from pregnant compared to non-pregnant women showed significantly higher levels of markers for Treg cells (Foxp3 mRNA), Th2 cells (GATA-3 mRNA and IL4 protein) and a tendency to increase in markers of Th17 (RORC mRNA and IL-17 protein), whereas Th1 markers (Tbet mRNA and IFN-γ) showed no difference between pregnant and non-pregnant women. Further, ongoing studies may reveal if the entire T helper population shows a higher degree of responsiveness during pregnancy.

Conclusions: Our results imply an increased plasticity of the Treg population during pregnancy, suggesting that Treg cells are able to switch to a Th2/Th17-like phenotype, depending on current demands of tolerance or infectious threats.

It is known that as we age, immune dysregulation often occurs, leading to failing health, and increased susceptibility to a number of different diseases. In this study we have investigated plasma cytokine profiles in order to identify immune markers of ageing. Plasma samples were obtained from 138 participants of the Swedish longitudinal NONA study (aged 86, 90 and 94 years) and 18 healthy Swedish volunteers (aged between 32 and 59 years). Our results show significantly increased levels of the pro-inflammatory cytokine interleukin-6 (P<0.0001) and soluble intercellular adhesion molecule-1 (P<0.0001) in the elderly group. The anti-inflammatory cytokine interleukin-10 did not alter with age whereas active (naturally processed) transforming growth factor-ß levels were significantly (P<0.0001) increased in the elderly group. No difference was observed between males and females. These data suggest that there are measurable changes in cytokine profiles with ageing with increased levels of potentially harmful molecules, which may contribute to immune alterations and declining health in the elderly population. © 2003 Elsevier Science Ireland Ltd. All rights reserved.

Lyme borreliosis (LB) is the most common tick-borne disease in the northern hemisphere. The infection is caused by spirochaetes from the Borrelia (B.) burgdorferi sensu lato (s.l.) group. The clinical outcome after B. burgdorferi s.l. infection differs between individuals from asymptomatic infection without history of LB to individuals who experience persistent symptoms post-treatment for more than six months after treatment. The difference in clinical outcome is not thought to be associated with persistent infection, but could instead be affected by the host’s ability to mount an optimal immune response to the spirochaete.

The hypothesis of this thesis was that a strong inflammatory Th1-like immune response is required in the early stage of infection in order to achieve both an optimal eradication of the B. burgdorferi s.l. bacteria and a good clinical outcome. The inflammatory response must be down-regulated by an anti-inflammatory response in order to avoid excessive immune responses that will end in tissue injury. The proper down-regulation will also protect against development of a chronic Th1-like inflammatory response, with activated cytotoxic cells, which may lead to LB with persistent symptoms post-treatment.

The thesis aimed to investigate the immunological mechanisms behind the optimal resolution of human B. burgdorferi s.l. infection and to define the aberrant mechanisms leading to development of persisting symptoms.

prospective study on newly tick-bitten individuals showed that although 25% of the collected ticks were infected with B. burgdorferi s.l. very few individuals bitten by infected ticks developed LB (3.7%). In addition, 4.9% of the individuals bitten by infected ticks developed asymptomatic infection, i.e. B. burgdorferi s.l.-specific antibody seroconversion without LB. Approximately one third of all tick-bitten study subjects reported self-experienced symptoms possibly associated with LB. Individuals bitten by infected ticks were more likely to report experience of symptoms than those bitten by uninfected ticks. Thus, only 8.6% of the individuals bitten by B. burgdorferi s.l.-infected ticks were infected, verified by seroconversion, and out of them 57% were asymptomatic.

A prospective study on EM patients showed that a good clinical outcome was associated with a strong early Th1 immune response since EM patients with persistent symptoms six months after treatment had reduced expression of Th1 cytokines in their EM lesions compared with EM patients without symptoms.

The investigation of blood samples from newly tick-bitten individuals, for detection of possible early immune biomarkers indicating good clinical outcome of LB, showed that none of the investigated markers clearly discriminated between the individuals who developed LB, asymptomatic individuals, or non-infected individuals. However, tick-bitten individuals who developed asymptomatic infection showed an increase of early Th1-associated biomarkers in blood compared to individuals who developed clinical LB.

In an experimental study, Th2-immune-deviated mice had more pronounced clinical signs of infection and could not eradicate the spirochaete as efficiently as non-deviated B. burgdorferi sensu stricto (s.s.)-infected mice. Non-deviated B. burgdorferi s.s.-infected mice showed a decrease of mRNA expression associated with Th2, anti-inflammatory and Treg/Th1 responses during the course of infection, which suggested a termination of the inflammatory response – something that was not seen in the immune-deviated mice. Trends for increased expression of pro-inflammatory GM-CSF and Treg marker Foxp3 in immune-deviated mice suggested on-going inflammation. Non-deviated B. burgdorferi s.s.-infected mice showed increased systemic expression of the Th1-associated CXCL9 and CXCL10 during the course of infection, while immune-deviated mice showed an initial decrease in both chemokines at day 15 p.i. compared with day 0 p.i.

In conclusion, the risk of developing LB after a tick bite is low, and no infection or asymptomatic infection are the most common outcomes after a tick bite. The early immune response in humans and the immune response towards B. burgdorferi s.s. infection in mice support the hypothesis that a strong pro-inflammatory Th1 response is needed for an optimal clinical outcome and eradication of bacteria.

The clinical outcome following infection with Borrelia (B.) burgdorferi sensu lato (s.l.) differs between individuals, ranging from asymptomatic infection to Lyme borreliosis (LB) with persistent symptoms post-treatment. Previous studies in mice and humans have generated the hypothesis that a successful outcome of B. burgdorferi s.l. infection is associated with an early strong pro-inflammatory T helper (Th)1-like immune response. The aim of this study was to assess the early course of events in B. burgdorferi s.l.-associated inflammation by screening for possible early immune biomarkers in peripheral blood from newly tick-bitten persons. The study subjects bitten by B. burgdorferi s.l.-infected ticks were divided into (1) those later developing clinical LB, (2) those who developed anti-B. burgdorferi s.l. antibodies but not clinical LB, (3) those who neither developed antibodies nor clinical LB. A fourth group consisted of bitten study subjects without development of antibodies or clinical LB. Two sets of samples, both comprising all four groups, were collected in order to repeat the analyses and confirm the data. Sera or plasma collected a few days after the tick bite were analysed for 18 biomarkers (IL-1β, IL-6, CXCL8/IL-8, IL-12p70, IL-17A, IL-27, TNF, CCL18, CCL20, CCL22, CXCL1, CXCL9, CXCL10, CXCL11, calprotectin, MMP-3, MMP-8, MMP-9) by multiplex bead assay and ELISA. In the first set of samples, the neutrophil activation marker calprotectin was increased in subjects who developed clinical LB compared with subjects who developed antibodies against B. burgdorferi s.l. but did not develop LB. However, the finding could not be confirmed in the second set of samples, thus the study failed to identify an early prognostic marker for development of clinical LB. Interestingly, both sets of samples showed increases in two different Th1-associated markers, CXCL10 and IL-12p70, respectively, in subjects who following a bite by a B. burgdorferi s.l.-infected tick developed antibodies against B. burgdorferi s.l. but did not develop LB compared with subjects who developed clinical LB, thus supporting the hypothesis of an early strong Th1-response being important for optimal resolution of B. burgdorferi s.l. infection.

Resolution of Lyme borreliosis has previously been shown to be associated with a strong initial Th1 response, followed by a subsequent Th2 response,  shutting off inflammation. We mapped markers for Th1, Th2, Th17, cytotoxic and T regulatory subsets in a murine model, where the outcome of Borrelia (B.) burgdorferi sensu stricto (s.s.) infection was altered by immune-deviation towards Th2 by exposure to a subtoxic dose of mercury. Twenty-one B. burgdorferi s.s.-infected (Bb), 21 immune-deviated B. burgdorferi s.s.-infected (BbId), and seven control C3H/HeN mice were sacrificed on days 15, 28 and 43 post-infection (p.i.) with B. burgdorferi s.s. BbId mice had increased joint swelling compared with Bb at the height of the disease (28 p.i.), and also showed a trend for increased spirochaetal load that became significant on day 43 p.i. BbId had an increased histopathology score on day 28 p.i. compared with both earlier and later time points. mRNA expression of IL-4 (p=0.018), IL-10 (p=0.018) and EBI-3 (p=0.009) decreased in Bb mice, but not in BbId, over the course of infection. A trend for higher expression of IL-12p40 mRNA in Bb mice compared with BbId was seen late in the disease course, while BbId showed trends for higher levels of Foxp3 and GM-CSF. At the protein level, BbId showed decreased levels of CXCL9 compared to the Bb group on day 15 p.i (p=0.007). Bb mice showed increases of CXCL9 and CXCL10 at all time points compared with day 0 p.i. (p≤0.014), whereas BbId mice showed an initial decrease in both chemokines at day 15 p.i. compared with day 0 (p≤0.008). In conclusion, both the clinical signs of infection and the trends for increased expression of pro-inflammatory GM-CSF and T-regulatory marker Foxp3 in BbId mice suggested ongoing inflammation. Although our findings support the need for a strong Th1 response followed by anti-inflammatory response for optimal resolution, the anti-inflammatory response seems to be more complex than only dampening the inflammation by a Th1-antagonistic Th2 response.

Objectives: The risk of developing Lyme borreliosis (LB) from Borrelia burgdorferi sensu lato (Bb)-infected ticks in Sweden is largely unknown. In the current study, we investigated the prevalence of Bb in ticks that had bitten humans and the risk of developing LB from Bb-infected ticks. Methods: Health questionnaires, blood samples, and ticks were collected from 394 tick-bitten study subjects in the County of Ostergotland, Sweden, at the time of the tick bite. Questionnaires and blood samples were also collected 3 months later. Ticks were screened for Bb DNA with PCR, while sera were analyzed for antibodies against Bb using two ELISA assays. Seroconversion, i.e., an at least two-fold increase in anti-Bb antibodies after 3 months, was confirmed using a Strip-Immunoassay. Results: Seventy-five of 397 ticks collected from the study subjects were determined to be Bb-positive. Sixty-four of the tick-bitten subjects had been bitten by Bb-infected ticks. Four of them showed seroconversion and were therefore considered to have an active Bb infection. None of these four subjects had sought health care due to symptoms, but one reported symptoms. Conclusions: Our data suggest that the risk of developing LB after being bitten by a Bb-infected tick is low, and asymptomatic Bb infections appear to be more frequent than symptomatic infections.

Objective: In recent years, salivary alpha-amylase (sAA) has beenproposed as a reliable proxy for sympathetic activity. This study aimed at testing the association between sAA to a broad range of psychosocial factors, self rated health, cardiovascular risk factors and inflammatory markers in a normal population sample.

Methods: 30 participants, all men between 50 and 54 years old, were randomly selected from a normal population based study. Saliva samples were collected at awakening, 30 minutes after awakening and just before going to bed. sAA was measured by a calorimetric method using Phadebas amylase test. Linear regression models were used to test associations between sAA levels and a broad spectrum of psychosocial factors (e.g. depressive symptamology, vital exhaustion, mastery and sense of coherence) self rated health and inflammatory markers (e.g. C-reactive protein). Adjustments were made for physical exercise, smoking, blood  lipids and  time point  when  sample was collected.

Results: sAA levels at awakening were positively associated with depressive symptamology (p = 0.046), vital exhaustion (p = 0.025) and negatively associated with sense of coherence (p = 0.034). It was further associated positively associated with levels of C-reactive protein (p = 0.024)  and  negatively associated with  self  reported general health (p = 0.010). Samples taken just before going to bed were showing similar results, whereas samples taken 30 minutes after awakening only showed a few significant associations.

Conclusions: The associations found give further support for the use of salivary alpha amylase as a psychoneuroendocrinological bio- marker. Assessment just after awakening or just before going to bed seems to be more reliable than samples 30 minutes after awakening.

Objective: The aim of this study was to establish three-dimensional cultures originating from muscle biopsies and evaluate the viability and morphology. Method: Muscle biopsies from patients with suspected neuromuscular disorders were obtained and established as primary muscle tissue cultures. Tissue pieces, 1-2 mm of diameters, were placed in culture medium and subjected to sporadic stirring to prevent attachment and outgrowth as monolayer cells. Morphology and ability to attach to the surface were investigated by light microscopy. Viability was evaluated by Tc-99m-tetrofosmin uptake. After 1 month, histology was evaluated by light microscopy and immunocytochemistry. The findings of a healthy muscle and a dystrophic muscle were compared. Results: Initially, the tissue pieces were unshaped but formed spheroid-like structures during the culture period. For dystrophic muscle, attachment capacity to the surface was initially potent and decreased during the culture period, whereas control muscle showed weak attachment from the start that increased during the culture period. The uptake of Tc-99m-tetrofosmin increased in control muscle, while it decreased in dystrophic muscle, during the culture period. The histological investigation demonstrated larger destruction of myofiber, weaker satellite cell activation and reduced myofiber regeneration in the dystrophic muscle as compared to the control muscle. Conclusion: The cellular components of the muscle tissue can survive and proliferate as spheroid-like primary cultures. The cellular composition resembles the in vivo condition, which allows studies of degeneration of the original fibers, and activation and proliferation of the satellite cells. The culture system may provide better understanding of the degeneration and regeneration processes in different muscle disorders and allow investigations of pharmacological interventions.

An enzyme-linked immunosorbent assay (ELISA) has been developed for the measurement of anti-gliadin antibodies (AGA), thereby providing a practical and cheap assay for use in the diagnosis of coeliac disease (CD). Since gliadin is a common food antigen for most people, a large group of apparently healthy blood donors (n=l866) was analysed, as well as children and adults with symptoms more or less suggesting CD. The effects of various cut-offvalues on the sensitivity, specificity and predictive value (PV) of the test were calculated, both alone and together with anti-endomysium antibodies (EMA). A high prevalence value, of at least 1/256 (7!1866), for gluten enteropathy (GE) was found in the blood donor population. Moreover, a high frequency of CD among fanners with diffuse symptoms, conceivably due to a high exposure to gluten by inhalation, was also observed. It was impossible to combine high sensitivity with high specificity for both IgA- and IgG AGA, and vice versa, in adults. A significant increase in the mean lgA AGA level with age was seen when the blood donors were divided into age groups. A positive PV of 18-25% was found for IgA-AGA, depending on how-the cut-off value was defined. For IgG-AGA the positive PV was 0% (0/35) among asymptomatic subjects. IgA-EMA yielded both high specificity and a high positive PV, but a lower sensitivity than IgA-AGA, especially in children younger than 2 years, with signs of CD. When screening for GE in a population with expected low prevalence, measurement of IgA-AGA is suggested as a primary test because of fairly good sensitivity, technical simplicity, and low cost. Sera found to be positive are then re tested with IgA-EMA, which gives a positive PV close to 100%. For populations with a moderate or high expected prevalence for CD, our results indicate that different tests should be used depending on the age of the population studied. In younger children ( < 2 years old) lgA-AGA yielded a high sensitivity (lOO%) and a high specificity (86%). fu older children (> 2 years old) and adults the use of IgA-EMA seems more suitable, because of the high specificity (99-100%) and positive PV (95-100% ). Since, however, the negative PV was not 100%, a negative test result does not exclude CD.

Objective: The impact of present disease-modifying treatments (DMTs) in multiple sclerosis (MS) on nerve injury and reactive astrogliosis is still unclear. Therefore, we studied the effect of natalizumab treatment on the release of 2 brain-specific tissue damage markers into cerebrospinal fluid (CSF) in MS patients. Methods: CSF samples from 92 patients with relapsing forms of MS were collected in a prospective manner prior to natalizumab treatment and after 6 or 12 months. In 86 cases, natalizumab was used as second-line DMT due to breakthrough of disease activity. The levels of neurofilament light (NFL) and glial fibrillary acidic protein (GFAP) were determined using highly sensitive in-house developed enzyme-linked immunosorbent assays. Results: Natalizumab treatment led to a 3-fold reduction of NFL levels, from a mean value of 1,300 (standard deviation [SD], 2,200) to 400 (SD, 270) ng/l (p andlt; 0.001). The later value was not significantly different from that found in healthy control subjects (350ng/l; SD, 170; n = 28). Subgroup analysis revealed a consistent effect on NFL release, regardless of previous DMT or whether patients had relapses or were in remission within 3 months prior to natalizumab treatment. No differences between pre- and post-treatment levels of GFAP were detected. Interpretation: Our data demonstrate that natalizumab treatment reduces the accumulation of nerve injury in relapsing forms of MS. It is anticipated that highly effective anti-inflammatory treatment can reduce axonal loss, thereby preventing development of permanent neurological disability.

During pregnancy, the woman carries a fetus partly foreign to her immune system, because of the expression of paternal antigens. Despite this, the fetus is normally tolerated and not rejected, as is often the case with organs in allogeneic transplantations. Systemic changes in maternal blood occur during pregnancy but, perhaps of greater importance, are changes in tissues locally in the uterus. The pregnant uterine endometrium, the decidua, is infiltrated by large numbers of leukocytes, mainly natural killer (NK) cells but also macrophages and T lymphocytes. Further, various cytokines are known to be secreted at the fetomaternal interface. However, the functions of these cells and the cytokine networks are not fully understood. The aim of this thesis was to investigate the local immune balance in normal human pregnancy decidua, both in the early phase of pregnancy and at parturition.

First trimester decidual mononuclear cells, NK cells and macrophages were all shown to secrete IFN-γ, IL-4 and IL-10, as detected by ELISPOT. The secretion was not mirrored in blood from the same subjects. A significantly larger number of decidual macrophages secreted IL-10 than did their blood counterparts, indicating potential regulatory functions of this cell type.

Further examination of early pregnancy decidual macrophages by microarray revealed 120 genes being differentially regulated at the transcriptional level in decidual compared to blood monocytes/macrophages. Several genes were associated with alternative activation/M2 polarization of macrophages, including CCL-18, CD209, IGF-1, MRC-1 and FN-1. Genes connected to immune regulation and tissue remodelling were common, in line with the potential functions for this cell type in utero. In addition, some molecules not previously connected to decidual macrophages, such as TREM-2, A2M and PGDS, were found to be upregulated, gaining new insights into the regulatory functions of decidual macrophages.

Term decidual mononuclear cells spontaneously secrete IFN-γ, TNF, IL-4, IL-10, and TGF-β. No differences were seen between tissues obtained before and after the onset of labour, indicating that decidual mononuclear cells are not the main cell population responsible for plausible cytokine regulation in the process of labour induction. Placental and fetal membranes as well as cells in the maternal systemic circulation may instead contribute to a possible shift in immune balance prior to pregnancy termination.

In conclusion, decidual leukocytes, including NK cells and macrophages, are potential producers of both Th1-like/pro-inflammatory and Th2-like/anti-inflammatory cytokines in early pregnancy as well as at parturition. Decidual macrophages are of a specialized phenotype with effector functions contributing to a proper invasion of the placenta and to immunological protection of the semi-allogeneic fetus. This thesis adds new knowledge on local immune balance during normal human pregnancy, however, the clinical significance of the presented data needs to be clarified.

Cytokines are believed to be important in maintaining pregnancy and in the process of labour induction in humans. The aim of this study was to investigate the secretion of the cytokines interferon-γ (IFN-γ), interleukin-4 (IL-4), IL-10, transforming growth factor-β (TGF-β) and tumour necrosis factor-α (TNF-α) in decidual tissue with or without labour.

Decidual tissue was collected from 32 healthy women undergoing elective caesarean sections before the onset of labour (n = 17) or after normal vaginal delivery (n = 15). Mononuclear cells were analysed for cytokine secretion with ELISPOT. To validate the widely used method of tissue collected at caesarean sections and after vaginal deliveries as a representative of before and after labour, respectively, placenta biopsies were collected from 12 healthy women to study the expression of the prostaglandin pathway enzymes cyclooxygenase-2 (COX-2) and microsomal prostaglandin E₂ synthase (mPGES).

Decidual mononuclear cells from term human pregnancy spontaneously secrete IFN-γ, IL-4, IL-10, TGF-β and TNF-α. No difference was seen in cytokine secretion with or without labour, indicating that decidual leukocytes are not the main cell population responsible for plausible cytokine regulation in the process of termination of pregnancy. Placental tissues obtained after vaginal delivery showed a higher mRNA expression of the prostaglandin regulating molecules COX-2 and mPGES than tissues from caesarean sections before the onset of labour, validating that the model can be used as a representative of the state before and after labour.

Background: Although uterine macrophages are thought to play an important regulatory role at the maternal-fetal interface, their global gene expression profile is not known.

Methodology/Principal Findings: Using micro-array comprising approximately 14,000 genes, the gene expression pattern of human first trimester decidual CD14+ monocytes/macrophages was characterized and compared with the expression profile of the corresponding cells in blood. Some of the key findings were confirmed by real time PCR or by secreted protein. A unique gene expression pattern intrinsic of first trimester decidual CD14+ cells was demonstrated. A large number of regulated genes were functionally related to immunomodulation and tissue remodelling, corroborating polarization patterns of differentiated macrophages mainly of the alternatively activated M2 phenotype. These include known M2 markers such as CCL-18, CD209, insulin-like growth factor (IGF)-1, mannose receptor c type (MRC)-1 and fibronectin-1. Further, the selective up-regulation of triggering receptor expressed on myeloid cells (TREM)-2, alpha-2-macroglobulin (A2M) and prostaglandin D2 synthase (PGDS) provides new insights into the regulatory function of decidual macrophages in pregnancy that may have implications in pregnancy complications.

Conclusions/Significance: The molecular characterization of decidual macrophages presents a unique transcriptional profile replete with important components for fetal immunoprotection and provides several clues for further studies of these cells.

Background: Laboratory diagnostics in Lyme neuroborreliosis need improvement. We hereby investigate 4 new recombinant or peptide Borrelia antigens in cerebrospinal fluid in children with neuroborreliosis to evaluate their performance as diagnostic antigens.

Methods: An enzyme-linked immunosorbent assay was used to detect IgG antibodies to recombinant decorin binding protein A (DbpA), BBK32, outer surface protein C (OspC), and the invariable region 6 peptide (IR6). The recombinant antigens originated from 3 pathogenic subspecies; Borrelia afzelii, Borrelia garinii, and Borrelia burgdorferi sensu stricto. Cerebrospinal fluid and serum from children with clinical features indicative for neuroborreliosis (n = 57) were analyzed. Classification of patients was based on clinical symptoms and laboratory findings. Controls were children with other neurologic diseases (n = 20) and adult patients with no proven infection (n = 16).

Results: Sensitivity for DbpA was 82%, for BBK32 70%, for OspC 58% and for IR6 70%. Specificities were 94%, 100%, 97%, and 97%, respectively. No single antigen was superior. When new antigens were combined in a panel, sensitivity was 80% and specificity 100%. The reference flagella antigen showed a sensitivity of 60% and a specificity of 100%. Over all, the B. garinii related antigens dominated.

Conclusions: Recombinant DbpA and BBK32 as well as the peptide antigen IR6 perform well in laboratory diagnostics of neuroborreliosis in children. New antigens seem to improve diagnostic performance when compared with the routine flagella antigen. If different antigens are combined in a panel to cover the antigenic diversity, sensitivity improves further and a specificity of 100% can be achieve.

Background: Evaluation of children with clinically suspected neuroborreliosis (NB) is difficult. With a prospective study design we wanted to characterize children with signs and symptoms indicative for NB, investigate clinical outcome and, if possible, identify factors of importance for recovery.

Material/Methods: Children being evaluated for NB (n = 177) in Southeast Sweden were categorized into 3 groups: "confirmed neuroborreliosis" (41%) with Borrelia antibodies in the cerebrospinal fluid, "possible neuroborreliosis" (26%) with pleocytosis but 110 Borrelia antibodies in the cerebrospinal fluid, and "not determined" (33%) with no pleocytosis and no Borrelia antibodies in the cerebrospinal fluid, Antibiotic treatment was given to 69% of children. Patients were followed during 6 months and compared with a matched control group (n = 174).

Results: Clinical recovery at the 6-month follow-up (n = 177) was generally good and no patient was found to have recurrent or progressive neurologic symptoms. However, persistent facial nerve palsy caused dysfunctional and cosmetic problems in 11% of patients. Persistent nonspecific symptoms, such as headache and fatigue, were not more frequently reported in patients than in controls. Influence on daily life was reported to the same extent in patients and controls. Consequently, persistent headache and fatigue at follow-up should not be considered as attributable to NB. No prognostic factors could be identified.

Conclusions: Clinical recovery was satisfactory in children being evaluated for NB although persistent symptoms from facial nerve palsy occurred. Persistent nonspecific symptoms, such as headache and fatigue, were not more frequently reported in patients than in controls.

Background and Objectives: Monoclonal gammopathy of undetermined significance (MGUS) of IgM isotype is a condition with clonally expanded B cells, recently suggested having an infectious origin. MGUS is frequently associated with polyneuropathy and antibodies against myelin protein zero (P0), whereas the role of the T cells remains largely unknown. Here we have analyzed P0-specific B cells, as antigen-presenting cells, and their capacity to activate T helper cells.

Design and Methods: We used a well-characterized MGUS-derived B cell line, TJ2, expressing anti-P0 IgM. The ability of TJ2 cells to bind, endocytose, process, and present P0 was investigated by receptor-clustering and immunofluorescence. The activation of P0-specific autologous T cells was studied by measuring IL2 and IFNγ with flow cytometry, immunobeads, and ELISPOT.

Results: Surface-receptor clustering and endocytosis of receptor-ligand (IgM/P0) complexes were pronounced after P0 exposure. Naturally processed or synthetic P0 peptide (194-208)-pulsed TJ2 cells significantly induced IL2 secretion from autologous T cells compared to control antigen pulsed cells (p<0 .001). The numbers of IFNγ producing T helper cells, including CD4+/CD8+ cells, were also significantly increased (p=0.0152). Affinity-isolated naturally processed myelin peptides were potent IFNγ stimulators for autologous PBMCs, but not for control PBMCs.

Interpretation and conclusions: We show for the first time that myelin P0 is naturally processed in IgM MGUS B cells, acting as aberrant antigen-presenting cells in activation of patients T helper cells. Our findings cast new light on the important role of autoreactive P0-specific B cells in he induction of the pathogenic T cell responses found in nerve lesions of MGUS patients with peripheral neuropathy.

A strong initial inflammatory response is important in neuroborreliosis. Since complement is a main player in early inflammation, we monitored the concentration and activation of complement in plasma and cerebrospinal fluid from 298 patients, of whom 23 were diagnosed with neuroborreliosis. Using sandwich ELISAs, we found significantly elevated levels of C1q, C4, C3, and C3a in cerebrospinal fluid, but not in plasma, in patients with neuroborreliosis. This finding indicates that complement plays a role in the human immune response in neuroborreliosis, that the immunologic process is compartmentalized to the CNS, and that complement activation may occur via the classical pathway.

Background: Previous studies indicate that successful resolution of Lyme neuroborreliosis (NB) is associated with a strong T helper (Th) 1-type cytokine response in the cerebrospinal fluid (CSF) followed by a down-regulating Th2 response, whereas the role of the recently discovered Th17 cytokine response is unknown. Methods: To investigate the relative contribution of different Th associated cytokine/chemokine responses, we used a multiple bead array to measure the levels of CXCL10 (Th1 marker), CCL22 (Th2 marker), IL-17 (Th17 marker) and CXCL8 (general inflammation marker), in serum and in CSF from untreated patients with confirmed NB (n = 133), and non-NB patients (n = 96), and related the findings to clinical data. Samples from patients with possible early NB (n = 15) and possible late NB (n = 19) were also analysed, as well as samples from an additional control group with orthopaedic patients (n = 17), where CSF was obtained at spinal anaesthesia. Results: The most prominent differences across groups were found in the CSF. IL-17 was elevated in CSF in 49% of the patients with confirmed NB, but was not detectable in the other groups. Patients with confirmed NB and possible early NB had significantly higher CSF levels of CXCL10, CCL22 and CXCL8 compared to both the non-NB group and the control group (p andlt; 0.0001 for all comparisons). Patients in the early NB group, showing a short duration of symptoms, had lower CCL22 levels in CSF than did the confirmed NB group (p andlt; 0.0001). Furthermore, patients within the confirmed NB group showing a duration of symptoms andlt; 2 weeks, tended to have lower CCL22 levels in CSF than did those with longer symptom duration (p = 0.023). Cytokine/chemokine levels were not correlated with clinical parameters or to levels of anti-Borrelia-antibodies. Conclusion: Our results support the notion that early NB is dominated by a Th1-type response, eventually accompanied by a Th2 response. Interestingly, IL-17 was increased exclusively in CSF from patients with confirmed NB, suggesting a hitherto unknown role for Th17 in NB. However, for conclusive evidence, future prospective studies are needed.

We studied retrospectively the medical records of all patients (n = 150) diagnosed, by cerebrospinal fluid (CSF) analysis, with neuroborreliosis (NB) in Jonkoping County, Sweden during 2000-2005. The number of NB cases increased from 5/100 000 to 10/100 000 inhabitants/year. In 17% of the patients, anti-Borrelia antibodies were found in CSF but not in serum at the time of diagnosis. Facial palsy, headache and fever were frequent manifestations in children, whereas unspecific muscle and joint pain were the most commonly reported symptoms in older patients. Post-treatment symptoms persisting for more than 6 months occurred in 13%, and the patients concerned were significantly older, had longer-lasting symptoms prior to treatment, had higher levels of Borrelia-specific IgG in CSF, and more often had radiculitis. The total cost of NB-related healthcare was estimated to be euro500 000 for the entire study group (euro3300 per patient), and the cost of social benefits was estimated to be euro134 000 (euro2000 per patient). CSF analysis is necessary for the diagnosis of NB, because some patients develop antibodies in serum later than in CSF. Early diagnosis of borreliosis would result in reduced human suffering and in economic gain.

Background: A post marketing surveillance study was conducted to evaluate safety and efficacy of natalizumab in Swedish multiple sclerosis (MS) patients since its introduction in August 2006 until March 2010. Methods: Patients were registered in the web-based Swedish MS-registry at 40 locations and evaluated every 6 months. Adverse events and clinical outcomes were recorded. Results: One thousand one hundred and fifty-two patients were included (71.4% female) and 149 patients stopped treatment; the main reason was planned pregnancy. Anti-natalizumab antibodies were found in 4.5% (52 patients) of which 1.6% displayed persistent antibodies. Serious adverse events were rare, but included three cases with progressive multifocal leukoencephalopathy (PML). There were seven fatal cases, probably unrelated to the natalizumab treatment. For relapsing-remitting MS patients (n = 901), mean Expanded Disability Status Scale (EDSS, -10.7%), Multiple Sclerosis Severity Scale (MSSS, -20.4%), Multiple Sclerosis Impact Scale (MSIS-29, physical -9.9%, psychological -13.3%) and Symbol Digit Modalities Test (SDMT, +10.7%) all showed significant improvements during 24 months of treatment with natalizumab. The Swedish web-based MS quality registry proved to function as a platform for post-marketing MS drug surveillance, providing long-term data regarding drug effects and adverse events beyond clinical trials. Conclusions: Our results indicate that natalizumab is generally well tolerated and has sustained efficacy for patients with active MS, though the risk of PML is still an important concern.

Lyme borreliosis was first described some 30 years ago in the USA. Today, it is the most common vector borne disease in Europe and the USA. The disease can have multiple stages and symptoms can manifest from various parts of the body; joints, skin heart and nervous system. In Europe, neuroborreliosis is the most frequent late stage diagnosis. Although Lyme borreliosis is treatable with antibiotics and the causative spirochete has not been shown to be resistant to drugs, some patients do not recover completely. They have persistent symptoms and are diagnosed with chronic or persistent Lyme borreliosis. The mechanism behind the lingering symptoms is unclear but might be due to tissue damage caused by the immune system. The aim of this thesis was to study the immunological differences between patients with different outcome of Lyme borreliosis, i.e. chronic, subacute and asymptomatic, and various factors that might influence the course of the disease.

The Borrelia-specific IFN-γ and IL-4 secretion was detected in blood and cerebrospinal fluid from patients with chronic and subacute neuroborreliosis during the course of the disease. Blood samples were also obtained from patients with erythema migrans (EM) and acrodermatitis chronicum atrophicans. An early increase of IFN-γ with a later switch to an IL-4 response was observed in patients with a subacute disease course whereas the IFN-γ secretion continued to be elevated in chronic patients.

The Borrelia-specific Th1-response was further investigated in chronic, subacute and asymptomatic individuals by studying the expression of the Th1-marker IL-12Rβ2, on a protein and mRNA level. The cytokine secretion and Foxp3, a marker for regulatory T-cells, were also analyzed. Chronic patients had a lower IL-12Rβ2 expression on CD8+ T-cells and a lower number of Borrelia-specific IFN-γ secreting cells compared to asymptomatic individuals. Chronic patients also displayed a higher expression of Borrelia-specific Foxp3 than healthy controls.

The conclusions for these tow studies were that a strong Th1-response early in the infection with a later switch to a Th2-response is beneficiary whereas a slow or weak Th1-response corresponds to a prolonged disease course.

The influence of a previous infection with another pathogen, seen to suppress the immune response in animals, and the possible gender difference in immune response was also investigated. Patients with EM were screened for antibodies to Anaplasma phagocytophilum (Ap) as a sign of a previous exposure to these tick-borne bacteria. Blood lymphocytes from Ap seronegative, Ap seropositive and healthy controls were stimulated with Borrelia antigen and the secretion of IL-4, IL-5, IL-12, IL-13 and IFN-γ was detected by ELISPOT. Ap seropositive patients had a lower number of cells responding with IL-12 secretion compared to the other groups which might indicate an inhibited Th1-response.

Reinfections with Lyme borreliosis was in a previous study, done by Bennet et al, found to be more frequent in postmenopausal women than in men. To investigate if there was an immunological explanation to the gender discrepancy, blood lymphocytes from individuals reinfected with Lyme borreliosis and individuals infected only once were stimulated with various antigens. The cytokine secretion was detected by ELISPOT, ELISA and Immulite. There were no differences between reinfected and single infected individuals. However, women, regardless of times infected, displayed a Th2-derived and anti-inflammatory spontaneous immune response compared to men.

A previous infection with the bacteria Ap might possibly have a long term effect on the immune system and might be of disadvantage when mounting a Th1-response to a Borrelia infection. Also, the Th2-derived response displayed by postmenopausal women could indicate why more women than men get reinfected with Borrelia burgdorferi.