ROLE OF HELICOBACTER-PYLORI SEROLOGY IN EVALUATING TREATMENT SUCCESS

Duodenal ulcer recurrence and gastritis are reduced with successful He licobacter pylori treatment. Serology is accurate in the diagnosis of H. pylori but, its value in determining eradication is unproved. To ev aluate 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 bio psies and repeat C-13 breath tests at six weeks. Subsequent C-13 breat h tests were then performed at three-month intervals to monitor eradic ation. IgG antibody concentrations to H. pylori were determined by a c ommercially available ELISA kit. Serology concentrations remained cons tant throughout the study period in the untreated patients. IgG concen trations decreased slightly in the treatment failure group at six week s but thereafter remained at baseline values. In the eradicated group, serum IgG concentrations decreased 26% by three months, 43% by six mo nths 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 monitor H. pylori treatment success.