TY - JOUR T1 - Hydrogen sulfide (H<sub>2</sub>S) in sputum and serum as a novel biomarker of COPD JF - European Respiratory Journal JO - Eur Respir J VL - 44 IS - Suppl 58 SP - P3984 AU - Junpei Saito AU - Alexander Mackay AU - Christos Rossios AU - David Gibeon AU - Patricia Macedo AU - Rudy Sinharay AU - Pankaj Bhavsar AU - Mitsuru Munakata AU - Jadwiga Wedzicha AU - Kian Fan Chung Y1 - 2014/09/01 UR - http://erj.ersjournals.com/content/44/Suppl_58/P3984.abstract N2 - Objectives: Hydrogen sulphide (H2S) is a gas produced by respiratory cells including smooth muscle cells and may play a role as a cellular gasotransmitter. The aim of the study is to evaluate whether H2S levels in serum or sputum could represent a new biomarker of COPD in a cross-sectional study.Methods: H2S levels in sputum and serum samples were measured using a sulphide sensitive electrode in 64 patients with stable COPD (S-COPD), 29 COPD subjects during acute exacerbation (AE-COPD), 14 healthy smokers, and 21 healthy non-smokers.Results: Sputum H2S levels in AE-COPD subjects were higher than those in S-COPD, healthy smoking and non-smoking subjects (p&lt;0.001), but serum H2S levels in AE-COPD were lower than those in S-COPD (p&lt;0.001). Thus, the sputum-to-serum ratio of H2S (H2S ratio) in AE-COPD subjects were higher than those in S-COPD, healthy smoking and non-smoking subjects (p&lt;0.001). In 14 COPD subjects where concomitant sputum and serum H2S levels were measured at baseline and during an exacerbation, the mean ratio was increased during exacerbation (p&lt;0.01). Both sputum and serum H2S levels correlated inversely with the degree of airflow obstruction measured as FEV1 %predicted and FEV1/FVC. Additionally, there were positive relationships between sputum neutrophils and H2S levels in sputum as well as serum (p&lt;0.01). Finally, the optimal cut-off level of H2S ratio to predict an exacerbation was ≥0.44 (sensitivity of 93.1%, and specificity of 84.5%).Conclusion: The ratio of sputum-to-serum levels of H2S may provide a useful marker of COPD indicative of obstructive neutrophilic inflammation and of potential future risk of exacerbation. ER -