Relevance of vacA genotypes of Helicobacter pylori to cagA status and its clinical outcome

• Published in: The Korean journal of internal medicine Vol. 16; no. 1; pp. 8 - 13
• Main Authors: Park, S M, Park, J, Kim, J G, Yoo, B C
• Format: Journal Article
• Language: English
• Published: Korea (South) Korean Association of Internal Medicine 01.03.2001
• Subjects: Adolescent; Adult; Aged; Aged, 80 and over; Bacterial Proteins - analysis; Base Sequence; Biopsy, Needle; Chi-Square Distribution; Chronic Disease; Culture Techniques; Duodenal Ulcer - genetics; Duodenal Ulcer - pathology; Female; Gastritis - genetics; Gastritis - pathology; Genotype; Helicobacter Infections - genetics; Helicobacter Infections - pathology; Helicobacter pylori - genetics; Humans; Korea; Male; Middle Aged; Molecular Sequence Data; Original; Peptic Ulcer - genetics; Peptic Ulcer - pathology; Polymerase Chain Reaction; Probability; Prognosis; Sensitivity and Specificity; Stomach Ulcer - genetics; Stomach Ulcer - pathology; Korea
• ISSN: 1226-3303; 2005-6648
• DOI: 10.3904/kjim.2001.16.1.8

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. 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. 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%, respectively). 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. 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.