DOES CAGA CONTRIBUTE TO ULCER PATHOGENESIS IN A DEVELOPING-COUNTRY, SUCH AS SUDAN

Background and Objective In Western populations, peptic ulcer disease is closely associated with Helicobacter pylori (H. pylori) strains exp ressing the CagA antigen. In Africa the prevalence of H. pylori infect ion and peptic ulcer disease is high, although information regarding p otential virulence factors is lacking. This study examines the prevale nce of antibodies to CagA both in African patients with dyspepsia who are undergoing gastroscopy, and in asymptomatic healthy African volunt eers. Methods Eighty two consecutive patients (median age 34 years, ra nge 15-73 years), attending for gastroscopy were studied, of whom 78 ( 95.1%) were subsequently found to be Helicobacter positive. Three antr al biopsies were obtained from each patient and 5 ml of blood was take n for determination of CagA seropositivity using western blot analysis . CagA seropositivity was also determined in 65 H, pylori positive hea lthy volunteers (median age 30 years, range 18-70 years), with no symp toms or previous history of gastroduodenal disease. Results Of the 78 H. pylori positive patients, CagA seropositivity was present in all 22 patients with active peptic ulcer disease (100%), in eight of nine pa tients with duodenitis (89%), in 15 of 19 patients with macroscopic ga stritis (78.9%), and in 24 of 28 patients with a normal endoscopy (85. 7%), On histological assessment, 46 patients had chronic active gastri tis, 29 patients had with atrophy and three patients had intestinal me taplasia. CagA seropositivity rates were 84.7%, 93% and 100%, respecti vely, for these groups. In the 89 healthy volunteers studied, 57 of th e 65 H. pylori positive subjects (87.7%) were seropositive for the Cag A protein. Conclusions As in Western countries, CagA seropositivity in this African population was closely related to endoscopic gastroduode nal disease, and to the presence of more advanced histological lesions in the antrum. However, there was also a high prevalence of CagA sero positivity in asymptomatic healthy individuals, suggesting that factor s other than CagA predominate in ulcer pathogenesis in this population . (C) 1998 Lippincott-Raven Publishers.