Exhaled hydrogen sulfide in patients with chronic airway inflammatory disease

Background: Chronic obstructive pulmonary disease (COPD) and asthma are two common chronic airway inflammatory diseases. Recent studies showed that endogenous hydrogen sulfide (H 2 S) might be the third signaling gasotransmitter playing a important role in inflammation. Objective: To investigate whether exhaled H 2 S level is related to airway inflammation in COPD and asthma. Methods: Clinical data, inflammatory cell in induced sputum, plasma level of TNF-α, IL-8 and LTB4, exhaled and plasma H 2 S level were studied in 41 patients with AECOPD, 36 with stable COPD, 50 with acute exacerbation of asthma, 24 with stable asthma, and 11 healthy subjects. Results: Exhaled H 2 S level were lower by 20.63% and 37.81%, respectively, in patients with stable COPD and AECOPD than healthy controls ( P 2 S level was decreased by 21.64% in patients with AECOPD than stable COPD patients ( P 2 S was positively correlated with the percentage of predicted inspiratory capacity ( r =0.321, P =0.026), negatively correlated with plasma H 2 S levels ( r =-0.384, P =0.021) and SGRQ activity score (r=-0.226, P =0.05). Exhaled H 2 S levels were decreased by 29.5% and 31.4%, respectively, in patients with stable and acute exacerbation of asthma than healthy controls (all P 2 S levels than non-smokers ( P 2 S in asthma was negatively correlated with plasma LTB4 ( r =-0.627, P =0.05). Conclusions: Exhaled hydrogen sulfide was decreased in patients with COPD and asthma. Its alteration in level may be connected with airway inflammation. The study is funded by NSFC (No. 30871127), NCET (No. 985-2-082-113), and Chinese Medical Association CRD Grant (No. 08020370115).