High seroprevalence of Helicobacter pylori in chronic bronchitis among Chinese population

An increased seroprevalence of Helicobacter pylori (H. pylori), especially high virulent cytotoxin-associated gene-A (CagA) positive strains, has been found in many extragastrointestinal disorders. Moreover, it has been reported that the risk of chronic bronchitis may be increased in H. pylori infected patients. However, until now there are no data regarding the relationship between H. pylori infection and chronic bronchitis among Chinese population. Therefore the aim of the present study was to assess the seroprevalence of H. pylori and in particular of CagA positive virulent strains in patients with chronic bronchitis among Chinese population. We evaluated 46 patients with chronic bronchitis, 48 age- and sex-matched patients with peptic ulcer and 48 healthy control subjects. All enrolled subjects underwent a serologic test for H. pylori IgG and CagA by enzyme linked-immunosorbent assay (ELISA). There was no significant difference in the seropositivity for these parameters between chronic bronchitis and peptic ulcer groups (86.9% vs 89.6% for anti-H. pylori IgG and 67.4% vs 72.9% for anti-H. pylori-CagA IgG). However, these serological parameters were significantly higher in the patients with chronic bronchitis or peptic ulcer than those in control group, who showed 60.4% for anti-H. pylori IgG seropositivity and 20.8% for anti-H. pylori-CagA IgG seropositivity. Among the patients with chronic bronchitis, no significant difference was found in these serological parameters between the current cigarette smokers and never smokers. This is the first report of a high seroprevalence of H. pylori infection in chronic bronchitis among Chinese population.