SHORT-TERM FOLLOW-UP BY SEROLOGY OF PATIENTS GIVEN ANTIBIOTIC-TREATMENT FOR HELICOBACTER-PYLORI INFECTION

Helicobacter pylori serology and in particular enzyme-linked immunosor bent assays for the measurement of immunoglobulin G (IgG) antibody tit ers form an accurate means of diagnosing H. pylori infection in patien ts before treatment. H. pylori serology is of limited value in monitor ing treatment because of the slow decline in antibody titers. In the p resent study we aimed to measure the most suitable moment after antibi otic treatment at which serology should be used to monitor treatment. Sixty-four patients who had nonulcer dyspepsia and H. pylori infection and who underwent upper gastrointestinal endoscopy because of persist ent dyspeptic symptoms were included in the study, H. pylori cure was confirmed by histology and culture 5 weeks after the completion of the antibiotic treatment. Serological examination was performed before th erapy and at 5 weeks, 10 weeks, and 1 year after the completion of ant ibiotic treatment. Diagnostic performance was assessed by receiver-ope rating characteristic analysis. The areas under the receiver-operating characteristic curves of the H. pylori antibody titers at 5 weeks, 10 weeks, and 1 year after the completion of treatment were 0.53 (95% co nfidence interval [CI], 0.36 to 0.69), 0.60 (95% CI, 0.43 to 0.76), an d 0.78 (95% CI, 0.63 to 0.93), respectively. The areas under the recei ver-operating characteristic curves of the changes in H. pylori IgG an tibody titers at 5 weeks, 10 weeks, and 1 year after the completion of treatment in comparison with the pretreatment titers were 0.85 (95% C I, 0.72 to 0.97), 0.96 (95% CI, 0.89 to 1.0), and 1.0 (95% CI, not est imable), respectively. We conclude that serology forms a useful means of monitoring treatment in patients with nonulcer dyspepsia and H. pyl ori infection as early as 10 weeks and maybe even sooner after the com pletion of treatment for the infection.