Relationship between Gene Subtype of Helicobacter pylori Virulence Factor and Upper Gastrointestinal Diseases

Lee, Jin Woo; Jeong, Seok; Kim, In Han; Kwon, Kye Sook; Choi, Won; Lee, Don Haeng; Cho, Hyeon Guen; Kim, Pum Soo; Kim, Hyung Gil; Shin, Yong Woon; Kim, Young Soo; Choe, Yon Ho; Hwang, Tae Sook; Choi, Mi Sook

Abstract

BACKGROUND/AIMS: Clinical outcome of Helicobacter pylori (H. pylori) infection may be associated with specific virulence-related bacterial genotypes. The present study aimed to assess the relationship between the H. pylori virulence factors such as cagA, vacA, iceA and severity of upper gastrointestinal diseases.
METHODS
PCR was used to examine cagA, vacA, and iceA genotypes of H. pylori isolates obtained from 92 infected patients with different clinical presentations (14 cases of nonulcer dyspepsia, 26 cases of gastric ulcer, 30 cases of duodenal ulcer, 22 cases of gastric cancer). If sl was positive, DNA sequence was analyzed for its subtype.
RESULTS
The positive rate of cagA varies from 78.6% to 96.7% in the clinical subcategories. The positive rates of iceA1 and iceA2 were 88.5% and 0% in patients with gastric ulcer, 86.7% and 3.3% in patients with duodenal ulcer, 72.7% and 13.6% in patients with gastric cancer, and 92.9% and 0% in patients with nonulcer dyspepsia, respectively. No significant difference was found in the prevalence of cagA and iceA among these groups. The vacA genotype slc and ml were predominant in most subjects irrespective of the clinical outcome and we could not find slb and s2 subtypes. The genotype of cagA+ iceAl vacA slc-ml was predominant in Korean H. pylori strains.
CONCLUSIONS
We could not confirm the previous reports of relationship between the cagA, vacA, iceA status and clinical outcome of patients with upper gastrointestinal diseases. Further study is needed to examine the specificity of H. pylori strains in Koreans.