Role ofHelicobacter pylori serology in evaluating treatment success

Duodenal ulcer recurrence and gastritis are reduced with successfulHelicobacter pylori treatment. Serology is accurate in the diagnosis ofH. pylori, but its value in determining eradication is unproved. To evaluate the usefulness of serology in monitoring treatment, we measured serial serum antibodies in three patient groups: eradication success (N=57), eradication failure (N=19), and untreated patients (N=24). Eradication was determined by Warthin Starry staining of antral biopsies and repeat¹³C breath tests at six weeks. Subsequent¹³C breath tests were then performed at three-month intervals to monitor eradication. IgG antibody concentrations toH. pylori were determined by a commercially available ELISA kit. Serology concentrations remained constant throughout the study period in the untreated patients. IgG concentrations decreased slightly in the treatment failure group at six weeks but thereafter remained at baseline values. In the eradicated group, serum IgG concentrations decreased 26% by three months, 43% by six months and 55% at nine and 12 months (P<0.001). A 20% reduction in IgG concentrations by six months was associated with successful treatment (sensitivity 86% and specificity 88%). We conclude that serology is a potentially useful way to monitorH. pylori treatment success.This work was presented in part in a poster at the May 1992 meeting of the American Gastroenterology Association.[¹³C]urea was kindly provided by Cambridge Isotope Laboratories, Boston, Massachusetts. Reagents and equipment to perform ELISA supplied by Bio Whittaker, Inc., Walkersville, Maryland.