Serum hydrogen sulfide as a novel marker predicting bacterial involvement in patients with community-acquired lower respiratory tract infections

Background and objective: Endogenous hydrogen sulfide (H(2)S) may be involved in the pathogenesis of systemic inflammation. It was investigated whether serum H(2)S levels differed among patients with community-acquired pneumonia, those with exacerbations of COPD or control subjects, and whether H(2)S may be used as a surrogate marker of the need for antibiotic treatment. Methods: Serum H(2)S levels were measured in 129 patients with pneumonia or COPD exacerbations and in 72 healthy control subjects. Results: The mean serum H(2)S concentration was 36% lower in patients with pneumonia (22.7 +/- 14.6 mu mol/L) than in control subjects (35.4 +/- 5.3 mu mol/L) (P < 0.01). Serum H(2)S concentration did not differ between patients with acute exacerbations of COPD (33.8 +/- 18.6 mu mol/L) and control subjects. Within the COPD group, patients with Anthonisen type 1 exacerbations had a lower serum H(2)S concentration (22.5 +/- 11.6 mu mol/L) than control subjects, and those with type 3 exacerbations had a higher serum H(2)S concentration (54.2 +/- 21.3 mu mol/L) than control subjects. There was no difference between patients with type 2 exacerbations (41.7 +/- 8.4 mu mol/L) and control subjects. In patients requiring antibiotics, serum H(2)S concentration was 41% lower than in those not requiring antibiotics. The area under the receiver operating characteristic curve for H(2)S as a surrogate marker of the need for antibiotics was 0.862 (95% confidence interval: 0.805-0.919, P < 0.01). Serum H(2)S levels were inversely correlated with serum CRP levels (r = -0.337, P < 0.01). Conclusions: Serum H(2)S levels may be used as a marker in lower respiratory tract infections. Further studies are required to validate the role of serum H(2)S levels in guiding antibiotic selection.http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000268061300018&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=8e1609b174ce4e31116a60747a720701Respiratory SystemSCI(E)PubMed20ARTICLE5746-7521