Etiologic Role of Helicobacter pylori in the Pathogenesis of Histological Chronic Gastritis

Abstract

The aims of this study were 1) to investigate the prevalence rate of H.pyloriassociated chronic gastritis in patients with non-ulcer dyspepsia (NUD), 2) to observe the effect of eradication of H.pylori on the improvement in histological findings of chronic gastritis, 3) to detect and measure the specific antibody to H.pylori in patients' sera with ELISA, and 4) finally to study the immune response of serum IgG against H.pylori according to the severity of histological gastritis with immunoblot. Out of total 77 patients, 54 had H.pylori in their gastric antral mucosa. 48 had moderate-to-severe chronic gastritis, and the remaining 6 had normal-to-mild. In contrast, out of 23 patients without H.pylori, 17 had normal-to-mild chronic gastritis. and only 6 had moderateto- severe. After treatment with colloidal bismuth subcitrate (CBS) alone or CBS and amoxicillin, H.pylori cleared up in 61.5% and 83.3% of the patients, respectively. In the placebo group, however, not a single case lost H.pylori. When H.pylori was successfully eradicated. improvement in histological gastritis was found in 88.8%. while it was 30% when not eradicated (P(0.002) in repeated biopsies. The detection rate of antiH. pylori by ELISA in patients with H.pylori was significantly higher (90.7%) than in patients without H.pylori (21.7%) (P(0.001). Moreover, the levels of IgG antibody in patients with H.pylori were significantly different between the patients with normal-tomild (median:0.52) and those with moderate-to-severe gastritis (median: 1.28) (P(0.005). Major protein bands of acid glycine extract of H.pylori on SDS-PAGE were 62 kD, 33 kD. 25 kD. 20 kD. and 14 kD, while protein bands reacting with patient's sera were 62 kl). 33 kD, and 14 kD. Sera from patients with H.pylori and severe gastritis commonly reacted with 62 kl), 33 kD, and 14 kD antigen. However. sera from patients with H.pylori and normal-to-mild gastritis showed a faint band with only 62 kD. In conclusion. it was strongly suggested that H.pylori playa causative role in the pathogenesis of histological chronic gastritis. ELISA in this study using acid glycine extract of H.pylori may be useful in the diagnosis of H.pylori-associated histologically moderate-to-severe gastritis. In some cases. H.pylori was detected from normal gastric mucosa, where negligible antigen-antibody reaction between serum IgG and H.pylori was identified by immunoblot.