Validation of leukotriene B 4 measurements in exhaled breath condensate

116

Biomarkers in chronic obstructive pulmonary disease may be useful in aiding diagnosis, defining specific phenotypes of disease, monitoring exacerbations and evaluating the effects of drugs. Exhaled breath condensate is a noninvasive means of sampling the airways, allowing biomarkers of airway inflammation and oxidative stress to be measured. In the present review, the use of exhaled breath condensate biomarkers in chronic obstructive pulmonary disease is explored and potential applications in diagnosis, disease phenotyping, exacerbation monitoring and clinical trials are considered. Exhaled breath condensate biomarkers are comprehensively reviewed in terms of method validation, reproducibility, disease specificity and sensitivity to detect changes in airway inflammation.The commonly used exhaled breath condensate methodologies in chronic obstructive pulmonary disease patients are shown to have considerable variability, due to technical issues concerning both sample collection and analysis. Despite these issues, there is still data to support the use of exhaled breath condensate biomarkers for monitoring chronic obstructive pulmonary disease exacerbations and the response to pharmacological intervention. Further improvements to sample collection and analysis methods will improve the sensitivity of these biomarkers. The use of cytokine arrays, mass spectrometry and nuclear magnetic resonance profiling of exhaled breath condensate has opened a new avenue for analysis, as hypothesis generation from such profiling may lead to further selection of biomarkers for specific analysis.

Section: Discussionmentioning

confidence: 99%

Section: Gas Standardisationmentioning

confidence: 99%

Exhaled breath condensate biomarkers in COPD

Borrill¹,

Roy²,

Singh³

2008

116

“…In one study authors could not detect cys-LTs at all in EBC [73]. The specificity of the immunoreactivity of the LTB 4 EIA assay was confirmed by using reverse-phase high performance liquid chromatography [133]. The correlation coefficient for two repeated LTB 4 measurements was 0.76 [133].…”

Section: Sourcementioning

confidence: 96%

Exhaled breath condensate: methodological recommendations and unresolved questions

Ho¹,

Hunt²,

Barnes³

2005

Self Cite

1,159

1,315

Collection of exhaled breath condensate (EBC) is a noninvasive method for obtaining samples from the lungs. EBC contains large number of mediators including adenosine, ammonia, hydrogen peroxide, isoprostanes, leukotrienes, nitrogen oxides, peptides and cytokines. Concentrations of these mediators are influenced by lung diseases and modulated by therapeutic interventions. Similarly EBC pH also changes in respiratory diseases.The aim of the American Thoracic Society/European Respiratory Society Task Force on EBC was to identify the important methodological issues surrounding EBC collection and assay, to provide recommendations for the measurements and to highlight areas where further research is required.Based on the currently available evidence and the consensus of the expert panel for EBC collection, the following general recommendations were put together for oral sample collection: collect during tidal breathing using a noseclip and a saliva trap; define cooling temperature and collection time (10 min is generally sufficient to obtain 1-2 mL of sample and well tolerated by patients); use inert material for condenser; do not use resistor and do not use filter between the subject and the condenser. These are only general recommendations and certain circumstances may dictate variation from them.Important areas for future research involve: ascertaining mechanisms and site of exhaled breath condensate particle formation; determination of dilution markers; improving reproducibility; employment of EBC in longitudinal studies; and determining the utility of exhaled breath condensate measures for the management of individual patients. These studies are required before recommending this technique for use in clinical practice.

“…Correction for the variable dilution is one approach [560]. Assays are usually performed using ELISA and these assays have been validated using gas chromatography-mass spectrometry for some mediators [561,562].…”

Section: Problemsmentioning

confidence: 99%

Outcomes for COPD pharmacological trials: from lung function to biomarkers

Cazzola¹,

MacNee²,

Martínez³

et al. 2008

Self Cite

750

566

The American Thoracic Society/European Respiratory Society jointly created a Task Force on “Outcomes for COPD pharmacological trials: from lung function to biomarkers” to inform the chronic obstructive pulmonary disease research community about the possible use and limitations of current outcomes and markers when evaluating the impact of a pharmacological therapy. Based on their review of the published literature, the following document has been prepared with individual sections that address specific outcomes and markers, and a final section that summarises their recommendations.