Serologic IgG recognition of Helicobacter pylori cytotoxin-associated protein, peptic ulcer and gastroduodenal pathology in childhood

Objective: To assess seropositivity to Helicobacter pylori cytotoxin-associated proteins in a group of children with H. pylori gastritis and to correlate seropositivity to their disease characteristics, in a prospective study. Patients and methods: Sera were collected from 68 children with H. pylori gastritis and IgG recognition of H. pylori cytotoxin-associated proteins was assessed by western blotting. Endoscopic and histologic findings, severity of antral inflammation, mucus gel layer thickness, symptom severity, serum pepsinogen I and gastrin levels of seropositive and seronegative children were compared. Results: Forty-four children (64.7%) had serum IgG antibodies that recognized the 130 kDa cytotoxin-associated protein. In seropositive children, the antrum was more frequently nodular at endoscopy (P < 0.01) and duodenal ulcer was more, common (P < 0.05). Gastritis was more frequently active (P < 0.01), inflammatory infiltrate was heavier (P < 0.02) and serum pepsinogen I levels were higher (P < 0.001). All children with duodenal ulcer, but only one out of five with gastric ulcer, were seropositive. Conclusions: Infection with H. pylori strains which do or do not express the cytotoxin-associated protein may partly account for the difference in disease severity seen in H. pylori gastritis.