Helicobacter pylori infection, histopathological gastritis and gastric epithelial cell apoptosis in children

Aim: Features of gastritis and gastric epithelial cell apoptosis in children infected with Helicobacter pylori genotypes are seldom studied. Therefore, we investigated the relationship between vacA genotypes and the severity of gastritis, and gastric epithelial cell apoptosis in H. pylori -infected children. Methods: Antral biopsies from 52 children infected with H. pylori vacA genotypes (s1a/m1 = 17, s1a/m2 = 21 and s2/m2 = 14) were analysed for severity of gastritis on histopathology. Fifteen biopsies infected with different vacA genotypes were studied for gastric epithelial cell apoptosis by terminal uridine deoxynucleotidyl nick-end labelling. Results: Children infected with the s1a/m1 and s1a/m2 vacA genotypes had higher severity of chronic inflammation than the s2/m2 genotype (s1a/m1 vs s2/m2, p =0.05; s1a/m2 vs s2/m2, p =0.01). The vacA s1a allele was more independently associated with severe chronic inflammation than the s2 allele ( p =0.02). Children infected with the s1a/m1 and s1a/m2 strains had higher gastric epithelial cell apoptosis than the s2/m2 strain (s1a/m1 or s1a/m2 vs s2/m2, p </0.0001). Conclusion: The s1a/m1 and s1a/m2 H. pylori vacA genotypes have significantly higher association with severe chronic gastritis and gastric epithelial cell apoptosis than the s2/m2 genotype in children. The role of H. pylori vacA genotypes and their allelic subtypes in relation to pathogenicity and disease potential in children needs further studies.