KINETICS OF SPECIFIC IGG ANTIBODIES FOR MONITORING THE EFFECT OF ANTI-HELICOBACTER-PYLORI CHEMOTHERAPY

A total of 104 patients with recurrent duodenal ulcer were treated wit h either ranitidine plus amoxicillin plus metronidazole or ranitidine plus placebo. To study the effect of the eradication of Helicobacter p ylori on the systemic immune response in an IgG ELISA, sera were drawn from all patients before the onset of therapy and at 6, 16 +/- 2, 32 +/- 2, and 60 +/- 2 weeks after therapy. In patients with eradication of the organism, a significant (P < .001) reduction of the specific Ig G titer occurred. This was not observed in patients without bacterial eradication. If a titer reduction of >50% was taken as an indicator fo r eradication of H. pylori, the sensitivity of the serologic test was 97.6%-99.7%. Its specificity increased with the interval to the onset of chemotherapy from 56.3% to 97.6%. Serologic tests are simple to per form and cause very little discomfort to the patient.