T. Shimoyama et al., EVALUATION OF HELICOBACTER-PYLORI VACA GENOTYPE IN JAPANESE PATIENTS WITH GASTRIC-CANCER, Journal of Clinical Pathology, 51(4), 1998, pp. 299-301
Aim-To examine the vacA genotypes of Helicobacter pylori strains in Ja
pan and to define whether any specific genotype was associated with ga
stric cancer. Methods-The allelic variation of vacA gene was studied u
sing a recently introduced polymerase chain reaction based vacA genoty
ping system. Results-80 H pylori strains were isolated from gastric bi
opsies of 40 patients with gastric cancer and 40 control subjects in a
Japanese population. All strains were s1/m1 subtype and 79 of 80 stra
ins were classified as sla subtype. Conclusions-The recently proposed
vacA genotyping system is applicable to Japanese H pylori strains and
most strains have the sla genotype, associated with increased virulenc
e. While the high frequency of s1a/m1 vacA genotype might play a role
in the increased incidence of atrophic gastritis and gastric cancer in
Japanese subjects, it precludes its use as a predictor of clinical ou
tcome of H pylori infection in Japan.