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Exhaled Breath Condensate in Obstructive Lung Diseases: A Methodological study
Linköpings universitet, Hälsouniversitetet. Linköpings universitet, Institutionen för medicin och hälsa, Klinisk fysiologi. Östergötlands Läns Landsting, Hjärtcentrum, Fysiologiska kliniken.
2009 (Engelska)Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
Abstract [en]

Asthma and chronic obstructive pulmonary disease (COPD) are two common inflammatory airway diseases characterized by airway inflammation and mucus hypersecretion. Prediction of the outcome of these diseases may not be performed and the need for non-invasive diagnostic tools capable of identifying inflammation in asthma and COPD becomes therefore obvious. Validation, sensitivity and specificity of most non-invasive methods to detect and monitor inflammatory responses in airways are poor and there is a great need to identify and standardize less invasive, or non-invasive methods for investigation of airway inflammation.

Epithelial lining fluid (ELF) covers the airway surface and contains soluble and insoluble inflammatory cell products and plasma proteins originating and passively transferred from the underlying tissue. Airborne aerosol particles containing ELF saturated with water may be recovered in exhaled air by allowing the air to pass a cold surface, creating exhaled breath condensate (EBC). EBC may then be analysed for various components of interest.

The aims of this thesis were (1) to explore whether a certain profile of inflammatory cell markers in EBC, saliva or serum may be identified in patients with allergic asthma or COPD, (2) to evaluate the efficacy and reproducibility of a measurable marker in EBC using either of the two condensers ECoScreen or RTube and (3) to evaluate the value of chlorine concentrations in EBC as well as reproducibility of assessments of certain compounds in EBC.

Material and methods: Thirty-six patients with asthma, 49 smokers or ex-smokers and 25 healthy volunteers participated in three clinical studies. In addition, efficacy, reproducibility and comparison of the two condensers were studied in an ex vivo set up using aerosols of solutions of saline, myeloperoxidase (MPO) or human neutrophil lipocalin (HNL). Aerosol boluses were transferred by means of a servo ventilator to either of the two condensers. Concentrations of chlorine (presumed to be a marker of mucous secretion) in EBC or saliva were analyzed by means of a sensitive coulometric technique (AOX). The inflammatory cell markers histamine, MPO, HNL, lysozyme, cysteinyl-leukotrienes (CysLT) and eosinophil cationic protein (ECP) were analysed in EBC, saliva and/or serum by means of ELISA, RIA, EIA or immunochemical fluorescence methods, respectively. Lung function tests, including diffusion capacity were measured by standard techniques according to clinical routines.

Results and Conclusions: Chlorine measurements served as the main tool in our tests and intra-assay variability <10% was recorded. However, flow dependency, temperature dependency, substance dependency and concentration dependency characterized yields of EBC. Despite acceptable analytical precision, low concentration levels of inflammation markers, biological variability and occasionally contamination with saliva mean that the feasibility of the EBC method is limited. Despite biological variability, concentrations of chlorine in EBC were significantly higher during than after a mild pollen season, suggesting that chlorine concentrations in EBC are a sensitive marker of allergic airway inflammation. A vast number of confounding factors made interpretations of EBC data obtained from COPD and non-COPD patients difficult and traditional diagnostic tools, such as diffusion capacity (DLCO) and serum lysozyme appeared to best discriminate between COPD and non-COPD.

Ort, förlag, år, upplaga, sidor
Linköping: Linköping University Electronic Press , 2009. , s. 72
Serie
Linköping University Medical Dissertations, ISSN 0345-0082 ; 1091
Nationell ämneskategori
Medicin och hälsovetenskap
Identifikatorer
URN: urn:nbn:se:liu:diva-16294ISBN: 9789173937269 (tryckt)OAI: oai:DiVA.org:liu-16294DiVA, id: diva2:133637
Disputation
2009-02-06, Elsa Brännströmssalen, Campus US, Linköpings Universitet, Linköping, 13:00 (Engelska)
Opponent
Handledare
Tillgänglig från: 2009-01-13 Skapad: 2009-01-13 Senast uppdaterad: 2017-12-15Bibliografiskt granskad
Delarbeten
1. Quantitative Assessment and Repeatability of Chlorine in Exhaled Breath Condensate: Comparison of Two Types of Condensators
Öppna denna publikation i ny flik eller fönster >>Quantitative Assessment and Repeatability of Chlorine in Exhaled Breath Condensate: Comparison of Two Types of Condensators
2005 (Engelska)Ingår i: Respiration, ISSN 0025-7931, E-ISSN 1423-0356, Vol. 72, nr 5, s. 529-536Artikel i tidskrift (Refereegranskat) Published
Abstract [en]

Background: Airway condition is presumably reflected in epithelial lining fluid (ELF). Exhaled breath condensate (EBC) has been used as a surrogate marker of the composition of ELF.

Objectives: This study aimed at assessing the technical repeatability of chlorine measurements in EBC and comparing two separate condensators (Ecoscreen® and R Tube) regarding recovery and repeatability. Furthermore, the association between condensate recoveries and variations in the airway status were scrutinized.

Methods: EBC was collected using two condensators from 10 healthy volunteers. In addition, 13 asthmatic patients produced EBC with or without an added resistance of 5 cm H2O (Res5), applied to the outflow tract of Ecoscreen. All tests were done in random order. Chlorine levels (analyzed by a coulometric technique) in EBC served as a tool for investigation.

Results: Chlorine was measurable in all samples. The coefficient of repeatability of chlorine measurements was <10%. Chlorine levels were higher in EBC obtained from R Tube (p < 0.001), and differences in recoveries and variability in chlorine levels were presumably related to technical differences in the condensators and not to the repeatability of chlorine measurements per se. Air-flow-dependent chlorine levels were obtained from healthy volunteers. Application of Res5, recruiting additional alveoli, resulted in increased recovery of the EBC volume, but not of chlorine, from those that had the most pronounced airway obstruction (p = 0.05).

Conclusion: We conclude that by employing a sensitive analysis technique, chlorine is repeatedly measurable in EBC. We suggest that the bulk of chlorine in EBC originates from large airways and not from the alveolar area. Both condensators were comparable regarding repeatability but differed regarding chlorine recover

Nyckelord
Asthma, Chlorine, Exhaled breath condensate, Repeatability, Volunteers
Nationell ämneskategori
Medicin och hälsovetenskap
Identifikatorer
urn:nbn:se:liu:diva-16289 (URN)10.1159/000087679 (DOI)
Tillgänglig från: 2009-01-13 Skapad: 2009-01-13 Senast uppdaterad: 2017-12-14Bibliografiskt granskad
2. Chlorine in Breath Condensate: A Measure of Airway Affection in Pollinosis?
Öppna denna publikation i ny flik eller fönster >>Chlorine in Breath Condensate: A Measure of Airway Affection in Pollinosis?
2007 (Engelska)Ingår i: Respiration, ISSN 0025-7931, E-ISSN 1423-0356, Vol. 74, nr 2, s. 184-191Artikel i tidskrift (Refereegranskat) Published
Abstract [en]

Background: Infiltration of inflammatory cells in bronchial mucosa and glandular hypersecretion are hallmarks of asthma. It has been postulated that exhaled breath condensate (EBC) mirrors events in epithelial lining fluid of airways, such as presence of local inflammation as well as glandular hypersecretion. It is also well known that eosinophil cationic protein (ECP) and cysteinyl-leukotrienes (cys-LT) are released by circulating inflammatory cells when triggered by antigen stimulation in asthma patients.

Objectives: The aim of this study was to evaluate whether chlorine and/or cys-LT in EBC would reflect changes of exposure of airborne pollen in patients with asthma.

Methods: EBC and serum were collected from 23 patients with allergic asthma during a pollen season and repeated 5 months later during a period with no aeroallergens. Chlorine was measured by means of a sensitive coulometric technique and cys-LT by an EIA technique. Serum ECP was measured and lung function tests were performed and symptoms noted during both occasions.

Results: Significantly higher concentrations of chlorine in EBC (p = 0.007) and ECP in serum (p = 0.003) were found during the pollen season compared to post-season. Chlorine levels tended to be higher in patients who reported of chest symptoms compared to those who denied symptoms during the pollen season (p = 0.06). Areas under the receiver-operated characteristic curves (AUCROC) were compared and similar discriminative power to identify exacerbations of asthma was recorded by chlorine in EBC (range 0.67-0.78) and ECP in serum (range 0.64-0.78).

Conclusion: It is concluded that chlorine in EBC and ECP in serum decreased significantly post-season, and this is suggested to mirror the decrement in airborne antigen. It is furthermore proposed that chlorine in EBC and ECP in serum tend to have a similar capacity to identify seasonal variations in airborne pollen in patients with asthma.

Ort, förlag, år, upplaga, sidor
Karger, 2007
Nyckelord
Pollen season, Allergic asthma, Exhaled breath condensate, Serum eosinophil cationic protein, Chlorine
Nationell ämneskategori
Medicin och hälsovetenskap
Identifikatorer
urn:nbn:se:liu:diva-16291 (URN)10.1159/000091300 (DOI)000244565600010 ()
Tillgänglig från: 2009-01-13 Skapad: 2009-01-13 Senast uppdaterad: 2017-12-14Bibliografiskt granskad
3. Efficacy of Two Breath Condensers: An in Vitro Comparative Study
Öppna denna publikation i ny flik eller fönster >>Efficacy of Two Breath Condensers: An in Vitro Comparative Study
2008 (Engelska)Artikel i tidskrift (Refereegranskat) Submitted
Abstract [en]

Examination of exhaled breath condensate (EBC) has been suggested to give information about inflammatory airway diseases.

The aim of the present study was to compare efficacy and variability in gain of two commercially available condensers, ECoScreen® [E] and RTube [R] in an in vitro experimental set up.

Methods: Test-fluids containing myeloperoxidase (MPO) or human neutrophil lipocalin (HNL) in addition to saline and bovine serum albumin (BSA) were nebulized. The aerosol was intermittently driven forward by a servoventilator fed by room tempered air, to reach the condenser. Two different concentrations of saline were also dispensed via the same equipment. Analyses of MPO, HNL and chlorine were done by means of ELISA, RIA or a modified adsorbed organic halogen technique (AOX), respectively.

Results: Significantly higher volumes were recovered by ECoScreen than by RTube during 20-minutes experiments (p<0.001) but not in ten-minute experiments (p>0.05). Based on changes of source concentrations in the nebulizer cup, resulting from nebulization per se, recoveries of HNL tended to be higher by E than by R (p<0.05). In contrast there were no significant differences between condensers in recoveries of MPO or chlorine. The spread of data was wide regarding all tested compounds and of similar degree for both condensers, despite acceptable inter-assay coefficients of variations of all analyses.

Conclusion: Condensing efficacy tended to be larger using E than R but there was a large variability in results from both condensers. Individual biomolecules may have their specific characteristics, and this must be taken into consideration when planning studies on EBC. We suggest that further methodological studies of the EBC method are warranted.

Nyckelord
Chlorine, HNL, MPO, Exhaled Breath Condensate, efficacy
Nationell ämneskategori
Medicin och hälsovetenskap
Identifikatorer
urn:nbn:se:liu:diva-16292 (URN)
Tillgänglig från: 2009-01-13 Skapad: 2009-01-13 Senast uppdaterad: 2009-08-17Bibliografiskt granskad
4. Can we predict development of COPD?
Öppna denna publikation i ny flik eller fönster >>Can we predict development of COPD?
2008 (Engelska)Artikel i tidskrift (Refereegranskat) Submitted
Abstract [en]

Background: Cigarette smoking is one of the main causes of chronic obstructive pulmonarydisease (COPD). Chronic inflammation of airways may start years before manifestation ofclinical symptoms, thus early identification of smokers at risk to develop COPD is crucial.Objectives: To evaluate if a single breath test for diffusion capacity (DLCO) or concentrationsof certain biomarkers in exhaled breath condensate (EBC), saliva or serum could identifysubjects with COPD or non-COPD smokers and ex-smokers supposed to be at risk to developCOPD, as suggested by rapid decline of forced expiratory volume in one second (FEV1) during afive year period.

Methods: Twenty-nine symptom free smokers/ex-smokers, 16 smokers/ex-smokers with COPDand 19 matched healthy non-smoking volunteers were studied by means of spirometry, DLCO,and analyses of EBC, saliva and serum [chlorine, lysozyme, eosinophil cationic protein (ECP)and myeloperoxidase (MPO)]. Area under a receiver operated curve (AUCROC) was used toassess sensitivity and specificity of measurements to identify manifest or risk to get COPD.

Results: Only DLCO could identify subjects with COPD or risk to develop COPD, as judged byAUCROC (0.85 or 0.75, respectively). Lower DLCO (p=0.003) and higher serum concentrationsof lysozyme (p=0.011) were recorded in those with COPD than non-COPD subjects.Furthermore, concentration of chlorine was higher in EBC from COPD subjects than fromhealthy volunteers (p<0.05). Except for chlorine, none of the remaining biomarkers weredetected in EBC and there was a vast variability of concentrations of biomarkers in saliva.

Conclusion: DLCO was the most effective discriminator of COPD and rapid decline of lungfunction. Serum concentration of lysozyme was the second strongest discriminator, confirmingprevious findings on involvement of neutrophils in the disease process. The use of EBC as a toolto measure exhaled biomarkers involved in COPD is dubious due to large variability and lowconcentrations of markers in EBC.

Nyckelord
Exhaled Breath Condensate, serum, DLCO, COPD, lysozyme and chlorine
Nationell ämneskategori
Medicin och hälsovetenskap
Identifikatorer
urn:nbn:se:liu:diva-16293 (URN)
Tillgänglig från: 2009-01-13 Skapad: 2009-01-13 Senast uppdaterad: 2009-09-18Bibliografiskt granskad

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