Serological assessment of Helicobacter pylori eradication in peptic ulcer patients

Background: Measurement of changes in serum antibodies is an excellent pred ictor of Helicobacter pylori eradication after antibiotic treatment. Aim: T o measure the changes in serum antibody titers to Helicobacter pylori, befo re and after treatment. Material and methods: IgG antibodies to H. pylori w ere prospectively evaluated in 107 duodenal ulcer patients treated either w ith antibiotics (amoxicillin, metronidazole and bismuth subsalicylate) plus omeprazole alone. IgG antibody levels were determined using an "in house" ELISA in sera from 49 eradicated patients that received quadruple therapy a nd 58 non-eradicated patients (12 in whom antibiotic therapy failed and 46 that received omeprazole alone). Endoscopy, urease test, microscopy, and cu lture of gastric biopsies confirmed H. pylori eradication. Results: Patient s in whom H. pylori was eradicated, showed a maintained drop in serum antib ody titers that ranged from 15%, 62%, 74% to 76% at 28 days, 4, 8 and 12 mo nths respectively. Such reduction was not observed in patients treated with omeprazole. Patients, in whom quadruple therapy failed to eradicate H. pyl ori, showed a discrete and transient decrease in antibody titers. By the fo urth month, patients in whom eradication with quadruple therapy was not ach ieved, irrespective of whether they received quadruple therapy or omeprazol e alone. Conclusions: A 45% decrease in IgG titer after 4 months is indicat ive of therapeutic success in H. pylori eradication. Therefore, serology ma y be useful to monitor the outcome of antibiotic therapy (Rev Med Chile 200 0; 128: 1119-26).