Analysis of vacA/cagA genotypes/status in Helicobacter pylori isolates from Iranian children and their association with clinical outcome


Abstract: More than 50% of Iranian children are infected with Helicobacter pylori; however, no data exist about the association of vacA/cagA genotype/status with disease outcomes in them. We analyzed association of vacA/cagA genotypes/status of children's isolates with gastric inflammation status as the first step in H. pylori pathogenesis. Materials and methods: Antral biopsies for culture and histopathology were taken from 328 children in 1997-2009. vacA (s, m) alleles and cagA statuses of the isolates were determined by PCR. Histopathology was performed according to the Sydney system; gastritis was scored as normal, mild, moderate, severe, and follicular. Results: A total of 159 culture-positive cases, with no mixed infections, were enrolled in the study. Of them, 60% were cagA-positive; 21.4%, 37.1%, 16.3%, and 25.2% cases were s1m1, s1m2, s2m1, and s2m2, respectively. Histopathology showed normal (4.4%), mild-chronic (31.4%), moderate-chronic (38.4%), severe-chronic (10.7%), and follicular gastritis (15.1%) cases. Thirty-four (21.4%) of the children had ulcers. Correlation (P < 0.05) was observed between more severe (moderate, severe, follicular) status and both vacAs1 allele and cagA-positive status. No significant relation was observed between genotype/status of vacA/cagA and ulcers (P > 0.05). Conclusion: vacAs1 and cagA are associated with more severe gastric inflammation in Iranian children. Association of vacAs1 and cagA with more severe pathology in Iran may be similar to that of other parts of the world.

Keywords: Helicobacter pylori, children, gastritis, cagA, vacA, ulcer, Iran

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