Korean J Intern Med.  2001 Mar;16(1):8-13.

Relevance of vacA Genotypes of Helicobacter pylori to cagA Status and Its Clinical Outcome

• Park SM
• Park J
• Kim JG
• Yoo BC

Abstract

BACKGROUND: Determination of vacA mosaicism may be important because specific Helicobacter pylori vacA genotype can be used to predict different clinical outcome. The aim of this study was to assess the relationship of vacA genotypes of Helicobacter pylori to cagA status and its development of peptic ulcer diseases in Korean patients.
METHODS
Gastric biopsy specimens were obtained from 53 patients with gastric ulcer(GU), 57 with duodenal ulcer (DU) and 26 with chronic gastritis(CG) patients; all patients were infected with Helicobacter pylori. Bacterial mRNAs in the gastric mucosa were amplified by RT-PCR, using synthetic oligonucleotide primers specific for the vacA and the cagA gene. Patients with vacA s1 subtype were further examined to determine whether they had s1a or s1b subtype.
RESULTS
There was no correlation in frequency of vacA s1 and/or s1a genotype between CG and either GU or DU, as the vacA s1 and s1a/m1 were present in the majority of strains independent of clinical status(s1 ; 100.0% versus 94.3 % or 93.0 % and s1a/m1 ; 76.9% versus 62.3% or 64.9%, res pectively). Likewise, there was no difference in the prevalence of the cagA gene between CG and either GU or DU patients (92.3% versus 90.6% or 98.2%, respectively). In addition, the cagA-negative status did not predict the presence of vacA s2 genotype.
CONCLUSION
These results strongly suggest that either cagA or vacA s1 and/or s1a is not proved to be a useful marker to distinguish disease-specific Helicobacter pylori strains for the development of peptic ulcer diseases in Korean patients.

Keyword

vacA; cagA; Chronic gastritis; Peptic Ulcer

MeSH Terms

Adolescence
Adult
Aged
Aged, 80 and over
Bacterial Proteins/analysis*
Base Sequence
Biopsy, Needle
Chi-Square Distribution
Chronic Disease
Duodenal Ulcer/pathology
Duodenal Ulcer/genetics
Female
Gastritis/pathology
Gastritis/genetics
Genotype
Helicobacter Infections/pathology
Helicobacter Infections/genetics*
Helicobacter pylori/genetics*
Human
Korea
Male
Middle Age
Molecular Sequence Data
Peptic Ulcer/pathology
Peptic Ulcer/genetics*
Polymerase Chain Reaction
Probability
Prognosis
Sensitivity and Specificity
Stomach Ulcer/pathology
Stomach Ulcer/genetics
Support, Non-U.S. Gov't
Tissue Culture