Detection of Helicobacter pylori CagA EPIYA in gastric biopsy specimens and its relation to gastric diseases

Abstract

CagA of Helicobacter pylori undergoes tyrosine phosphorylation in a region containing differing numbers of repeat sequences (EPIYAs), which can result in a modulation of the inflammatory response. This study investigated whether the presence of CagA EPIYA variations in strains of H. pylori that are positive for this region contributes to differing degrees of disease severity in the gastric mucosa. In this study, 157 H. pylori-positive patients were included, and of those, 40.8% (64/157) were infected with cagA-positive strains, which were assayed for the presence of CagA EPIYA-ABC, EPIYA-ABCC, and EPIYA-ABCCC. Peptic ulcers were significantly more prevalent in patients infected with strains containing CagA EPIYA-ABCC/ABCCC than in those with CagA EPIYA ABC strains (P=0.044). This suggests that the number of repetitions of EPIYA-C influences the development of gastroduodenal lesions, highlighting the importance and usefulness of evaluating the cagA gene sequence when making therapeutic intervention decisions in patients infected with H. pylori.

Keywords: Amino acid repeat sequence; Gastritis; Helicobacter pylori; Peptic ulcer; cagA protein.