Low prevalence of Helicobacter pylori in HIV-positive patients

Helicobacter pylori has been extensively studied and proven to be the main cause of chronic gastritis and peptic ulcer in the HIV-negative population.

Patients with chronic active gastritis have evidence of H pylori infection in over 90% of cases and in 70-100% of those with peptic ulcer disease. However, the reason for low incidence of H pylori infection in HIV-positive patients was still not very clear. A study examining this issue was recently reported in the November 7 issue of the World Journal of Gastroenterology because of its great significance for AIDS-related diseases.

The article describes 151 patients for gastrointestinal symptoms underwent endoscopic examination in Beijing You¡¯an Hospital, Capital Medical University, the largest referral center for the management of HIV infection and HIV-related complications in China, from January 2003 to March 2006. The HIV-positive patients in the present study, mainly from HeNan province, were infected through illegal blood plasma collection.

One conclusion reported by the investigators is that patients with HIV infection have a low prevalence of H pylori infection and peptic ulcer than that of HIV-negative patients with similar symptoms. The mechanism of chronic active gastritis in HIV-positive patients may be different from HIV-negative group that was closely related to H pylori infection. Various opportunistic infections of Upper gastrointestinal tract is likely to occur in HIV-positive patients with a CD4 lymphocyte counts less than 200/muL, such as CMV infection, Candida esophagitis.

Another interesting conclusion is that 84 % of HIV-positive patients co-infected with HCV and/or HBV infection. Endoscopic examination also revealed findings such as esophago-gastric varices and portal hypertensive gastropathy that was significantly different from previous reports.

The results of this study suggest a different mechanism of peptic ulcerogenesis and a different role of H pylori infection in chronic active gastritis and peptic ulcer in HIV-positive patients.