THE DIAGNOSTIC-VALUE OF ENZYME-IMMUNOASSAY AND IMMUNOBLOT IN MONITORING ERADICATION OF HELICOBACTER-PYLORI

55 patients with severe ulcer disease and H. pylori infection, success fully treated with antimicrobials, were followed-up with repeated bloo d samples for up to 32 months. Sera were analysed by enzyme immunoassa y (ETA) for IgG and IgA antibodies and by IgG immunoblot. The EIA for IgG antibodies showed a high sensitivity (100%), while IgA antibodies above the cut-off level were found in 55% of the patients. At a median of 77 days after onset of treatment, approximately 50% of the patient s showed a significant decrease (greater than or equal to 50%) of IgG or had titres below the cut-off level. All patients but 1 had a signif icant decrease of IgG after 6-12 months. The decrease was slower for I DA. The Ii. pylori-specific 116 kDa and 19.5 kDa bands were found in a ll pre-treatment samples, but the decrease in median intensity of the bands was slower than for the Ige EIA. In the 32-months post-treatment samples, both bands had an intensity still above 50% of the pre-treat ment value. The study showed that the Ige EIA is a useful method for m onitoring eradication of H. pylori. Immunoblot can detect previous H. pylori infection in EIA negative individuals.