[Plasma level of endogenous hydrogen sulfide in patients with acute asthma]

To investigate the role of endogenous hydrogen sulfide (H2S) in patients with asthma.

Levels of serum H2S, lung function and cell differential count in induced sputum were studied in 44 patients with acute exacerbation of asthma, 33 patients with stable asthma and 12 health subjects. Of the 33 patients with stable asthma, 3 failed to achieve induced sputum.

The serum H2S level was (75.2+/-13.0) micromol/L in controls (12 cases), (55.8+/-13.6) micromol/L in patients with stable asthma (33 cases), (57.8+/-6.3) micromol/L in patients with mild of acute exacerbation asthma (9 cases), (40.8+/-5.1) micromol/L in that with moderate of acute exacerbation asthma (13 cases), and (31.3+/-2.9) micromol/L in that with severe of acute exacerbation asthma (22 cases, F = 44.592, P < 0.01). The level of serum H2S was significantly lower in smokers (45.4+/-19.5) micromol/L as compared with nonsmokers (52.7+/- 16.0) micromol/L (F = 4.804, P < 0.05). Status of the subjects (in good health, stable asthma, and exacerbation of asthma) was positively correlated with H2S in serum (r = 0.712, P < 0.01). H2S in serum was positively correlated with FEV1.0 % (r = 0.877, P < 0.01) and the percentage of sputum macrophages (r = 0.791, P < 0.01); and it was negatively correlated with count of sputum cells (r = -0.348, P < 0.01) and the percentage of sputumneutrophils (r = -0.906, P < 0. 01).

Endogenous H2S may be involved in the pathogenesis of airway obstruction in asthma and may be a noninvasive marker of disease activity and severity.