Helicobacter pylori cagA,iceA and vacA genotypes in patients with gastric cancer in Taiwan

AIM: Helicobacter pylori( H pylori) has been linked to chronic gastritis, peptic ulcer, gastric cancer and MALT-lymphoma.The link of genotypes of Hpylorito gastric cancer remains controversial. The aim of this study was to investigate the Hpylori vacA alleles, cagA and iceA in patients with gastric cancer in Taiwan.METHODS: Patients with gastric cancer, peptic ulcer and chronic gastritis were enrolled in this study. We obtained biopsy specimens from the stomach at least 2 cm away from the tumor margin in patients with gastric cancer, and from the antrum of stomach in patients with peptic ulcer or chronic gastritis. 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 (gastric ulcer: 77, duodenal ulcer: 66, and chronic gastritis: 25) were found to have positive PCR results of the biopsy specimens from patients with peptic ulcer and chronic gastritis. We found positive cagA (139/168, 83%), m2 (84/168, 50%) and iceA1 (125/168,74%) strains in the majority of patients. In patients with gastric cancer, the vacA sla and slc subtypes were less commonly found than those in non-cancer patients (35/66 vs 127/168, P= 0.0001 for sla and 13/66 vs93/168, P<0.0001 for slc). In the middle region, the mlT strain in patients with gastric cancer was more than that of non-cancer patients(23/66 vs 33/168, P = 0.02).CONCLUSION: In Taiwan, H pylori with positive vacA sla,cagA and iceA1 strains are found in the majority of patients with gastric cancer or non-cancer patients. In patients with gastric cancer, the vacA s1a and slc subtypes are less and m1T is more than in patients with peptic ulcer and chronic gastritis.

Genotypes of Helicobacter pylori in patients with peptic ulcer bleeding

AIM:Helicobacter pyloricauses 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, nonbleeding 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 iceA1 (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, Hpylori vacA s1a and m1T prevent bleeding complication.