Sputum-to-serum hydrogen sulfide ratio in COPD. Issue 10 (17th July 2014)

• Record Type: Journal Article
• Authors: Saito, Junpei; Mackay, Alex J; Rossios, Christos; Gibeon, David; Macedo, Patricia; Sinharay, Rudy; Bhavsar, Pankaj K; Wedzicha, Jadwiga A; Chung, Kian Fan
• Is Part Of: Thorax. Volume 69:Issue 10(2014)
• Page Start: 903
• Page End: 909
• Publication Date: 2014-07-17
• Subjects: COPD Exacerbations; Chest -- Diseases -- Periodicals; Thorax; Chest -- Diseases; Periodicals; Periodicals; 617.54
• DOI: 10.1136/thoraxjnl-2013-204868
• Languages: English
• ISSNs: 0040-6376

Abstract

Abstract : Objectives: Hydrogen sulfide (H2 S) is a gas produced by respiratory cells including smooth muscle cells and may play a role as a cellular gasotransmitter. We evaluated whether H2 S levels in serum or sputum could represent a new biomarker of COPD in a cross-sectional study. Methods: H2 S levels in sputum and serum samples were measured using a sulfide-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 H2 S levels in AE-COPD subjects were higher than those in S-COPD, healthy smoking and non-smoking subjects (p<0.001), but serum H2 S levels in AE-COPD were lower than those in S-COPD (p<0.001). Thus, the sputum-to-serum ratio of H2 S (H2 S ratio) in AE-COPD subjects were higher than those in stable COPD, healthy smoking and non-smoking subjects (p<0.001). In 14 COPD subjects whose H2 S ratios were measured during and after an exacerbation, the mean ratio was increased during exacerbation (p<0.05). H2 S ratio was positively correlated with St. George's Respiratory Questionnaire score, sputum neutrophils and IL-6 and IL-8 levels in sputum and serum (p<0.01) but inversely correlated with sputum macrophages (%), FEV1 %predicted and FEV1 /FVC (p<0.01). The cut-off level of H2 S ratio to indicate an exacerbation was ≥0.44 (sensitivity of 93.1% and specificity of 84.5%). Conclusions: The ratio of sputum-to-serum levels of H2 S may provide a useful marker of COPD indicative of obstructive neutrophilic inflammation and of potential ongoing exacerbation.