Prevalence of Helicobacter pylori cagA, vacA, iceA, babA2 genotypes in Polish children and adolescents with gastroduodenal disease.

Abstract

Infection with Helicobacter pylori is a major cause of chronic gastritis and peptic ulcer disease in children and its consequences in adulthood can lead to serious complications, including in particular the development of gastric cancer. Our aim was to analyze the relationship between the occurrence of selected genes such as cagA, vacA, iceA, and babA2 determining pathogenicity of H. pylori strains and clinical outcome in children. The study was performed on H. pylori strains isolated from biopsies taken from 130 children and adolescents with non-ulcer dyspepsia (NUD), gastric and duodenal ulcers (PUD) and gastroesophageal reflux disease (GERD). Genes such as cagA, vacA (allelic variants: s1/ s2, m1/m2), iceA (allelic variants: iceA1, iceA2) and babA2 were determined by polymerase chain reaction (PCR). The cagA gene was detected in 79/130 (60.8%) H. pylori isolates. The presence of the cagA gene was significantly associated with duodenal ulcer (p<0.05). The vacAs1/m1 genotype as more frequent in children with ulcers than in other groups, whereas the vacAs2/m2 genotype was more frequent in patients with gastritis and GERD. The iceA1, iceA2 and babA2 genes were present in 59/130 (45.4%), 27/130 (21%) and 30/130 (23.1%) of the strains, respectively. The vacAs1/cagA+ genotype was most frequently observed in strains isolated from children with PUD. The predominant genotype in children with NUD and GERD was vacAs2/cagA-/iceA1+/babA2-. The study showed a high incidence of strains with increased virulence, possessing cagA, vacAs1 and iceA1 genes in symptomatic children with H. pylori infection.