Systemic and mucosal humoral responses to Helicobacter pylori in gastric cancer (original) (raw)

The systemic IgG response to Helicobacter pylori was examined in 70 patients with gastric cancer. H pylori IgG antibodies were assayed by enzyme linked immunosorbent assay (ELISA), and serological recognition of Hpylori antigens was characterised by western blotting. A percentage of 78-5 were seropositive by ELISA. Two of five patients under age 50 were seronegative. Positivity was unrelated to age, sex, tumour type, or site. Ninety one per cent of ELISA positive cancer patients recognised the H pylon cytotoxin associated 120 kilodalton (kD) protein, significantly more than a control group of 47 ELISA positive patients with non-ulcer dyspepsia (72%). Four of 15 ELISA negative cancer patients also showed recognition of this protein in western blots. Mucosal IgA responses to H pylori were examined by immunoblotting supernatants of in vitro cultured resected antral mucosa in an overlapping group of 19 gastric cancer patients. Eighteen had a positive response, including 10 of 11 negative for H pylori by biopsy urease testing. The systemic and local immunoblotting results show that the high seroprevalence ofH pylori antibodies detected by ELISA is nevertheless an underestimate of past infection. Dyspepsia screening policies based solely on H pylori ELISA would miss some young patients with gastric cancer. Further study of the relation of the H pylon cytotoxin to gastric precancerous lesions is warranted. 1 Dixon MF. Helicobacter pylori and peptic ulceration: histopathological aspects. J Gastroenterol Hepatol 1991; 6: 125-30. 2 Wyatt JI, Dixon MF. Chronic gastritispathogenetic approach. J Pathol 1988; 154: 113-24. 3 Rauws EAJ, Langenberg W, Houthoff HJ, Zanen HC, Tytgat GNJ. Campylobacter pyloridis-associated chronic active antral gastritis. Gastroenterology 1988; 94: 33-40. 4 von Wulffen H, Grote HJ, Gatermann S, Loning T, Berger B, Buhl C. Immunoblot analysis of immune response to Campylobacter pyloni and its clinical associates. J Clin Pathol 1988; 41: 653-9. 5 Jones DM, Eldridge J, Fox AJ, Sethi P, Whorwell PJ. Antibody to the gastric campylobacter-like organism (Campylobacter pyloridis) -clinical correlations and distribution in the normal population. J Med Microbiol 1986; 22: 57-62.