Histopathologic Analysis of Helicobacter pylori-associated Chronic Gastritis between cagA-positive and cagA-negative Strains

ABSTRACT

Infection with Helicobacter pylori (H. pylori) leads to gastritis, but the majority of infected persons are asymptomatic, and it has been recently described that the ability of H. pylori to cause more severe disease is related to the presence of the cytotoxin-associated gene A (cagA). We investigated the prevalence of cagA-bearing strains in a group of H. pylori-positive gastritis, and compared the morphologic differences between cagA-positive and cagA-negative cases on H&E stained slides. Polymerase chain reaction (PCR) assays for detection of H. pylori and cagA of 62 gastric biopsy specimens were performed. All the slides were analyzed by the updated Sydney system. Forty eight (77.4%) were PCR positive for H. pylori and thirty four (54.8%) were positive for cagA. There were no significant differences in numbers of H. pylori, degree of infiltration of mononuclear cells and degree of atrophy between cagA-positive and cagA-negative groups. The rates of neutrophilic infiltration and intestinal metaplasia were significantly higher in cagA-positive group than in cagA-negative group. In conclusion, the detection of H. pylori by PCR method is more sensitive than that of microscopic examination and H. pylori strains possessing cagA are associated with an enhanced induction of severe gastritis.