Genotypes of Helicobacter pylori in patients with peptic ulcer bleeding.

Aim: Helicobacter pylori causes chronic gastritis, peptic ulcer, gastric cancer and MALT-lymphoma. Different genotypes of Helicobacter pylori are confirmed from diverse geographic areas. Its association with bleeding peptic ulcer remains controversial. The aim of this study was to investigate the Helicobacter pylori vacA alleles, cagA and iceA in patients with bleeding peptic ulcer.

Methods: We enrolled patients with bleeding, non-bleeding peptic ulcers and chronic gastritis. Biopsy specimens were obtained from the antrum of the stomach for rapid urease test, bacterial culture and PCR assay. DNA extraction and polymerase chain reaction were used to detect the presence or absence of cagA and to assess the polymorphism of vacA and iceA.

Results: A total of 168 patients (60.4%) (25 patients with chronic gastritis, 26 patients with bleeding gastric ulcer, 51 patients with non-bleeding gastric ulcer, 26 patients with bleeding duodenal ulcer, and 40 patients with non-bleeding duodenal ulcer) were found to have positive PCR results between January 2001 and December 2002. Concerning genotypes, we found cagA (139/278, 50%), vacA s1a (127/278, 45.7%), and ice A1 (125/278, 45%) predominated in all studied patients. In patients with bleeding peptic ulcers, vacA s1a and m1T were fewer than those in patients with non-bleeding peptic ulcers (37/106 vs 69/135, P=0.017, and 4/106 vs 21/135, P =0.002).

Conclusion: In patients with peptic ulcers, H pylori vacA s1a and m1T prevent bleeding complication.