Role of the Lewis and ABO Blood Group Antigens in Helicobacter pylori Infection.

BACKGROUND Helicobacter pylori infection is a major risk factor for chronic gastritis and gastric cancer. Some findings show increased frequencies of these diseases in individuals with type O blood and in secretors (expressing Le(b) antigen), but other studies have not found any relationship between blood groups and this infection. Given that H. pylori infection and gastric cancer are common in Iran, the assessment of the pathogenesis of this infection in relation to these blood groups could be valuable. METHODS In a cross-sectional study, we determined the ABO and Lewis blood groups of participants using the tube method and evaluated the level of anti-H. pylori immunoglobulin G using an enzyme-linked immunosorbent assay. This study included 171 Iranian blood donors from Mashhad, Iran, during 2010. The significance of the differences in the frequencies of the Lewis and ABO phenotypes between individuals infected with and without H. Pylori infection were tested using the Chi-square test. A P-value < 0.05 was considered significant. RESULTS H. pylori infection was found in 76.6% of the study subjects (n = 131). The most common ABO blood group was O (33.9%), and the most common Lewis blood group was Le(a-b+) (54.7%). The frequencies of the ABO, Lewis, and secretion phenotypes were not significantly different between the infected and uninfected subjects. CONCLUSION We did not find any significant relationship between the Lewis, ABO, and secretion phenotypes and H. pylori infection.