Noninvasive evaluation of Helicobacter pylori therapy: role of fasting or postprandial gastrin, pepsinogen I, pepsinogen II, or serum IgG antibodies.

Abstract

We evaluated the potential value of a change in serum IgG antibodies, fasting or meal-stimulated gastrin levels, and pepsinogen I (PGI) or pepsinogen II (PGII) levels for identifying Helicobacter pylori (H. pylori) status after antibiotic therapy. A total of 32 men and one woman with peptic ulcer disease and documented H. pylori infection were enrolled. Fasting and 30-min postprandial blood samples were obtained at 0, 2, 7, 11, 17, 23, 27, and 39 wk of the study and were analyzed for the factors evaluated. Treatment was successful in 25 patients and failed in seven. Serum IgG antibodies, meal-stimulated gastrin, and both fasting and meal-stimulated pepsinogen I and II levels fell throughout the study, and pepsinogen I:II ratios increased in those whose infection was cured. The mean levels at wk 0 versus wk 7 were: fasting gastrin (fmol/ml) 12.4 and 11, meal-stimulated gastrin 26.5 and 15.4, PGI (ng/ml) 83.7 and 59, PGII (ng/ml) 24.5 and 13.6, PGI/PGII 3.5 and 4.7, and enzyme-linked immunosorbent assay value 4.8 and 4.55. The sensitivity, specificity, and positive and negative predictive values for the data analyzed using different percent changes (e.g., 80%, 50%, and 20%) were calculated. The specificity and sensitivity remained <80% at all time points. Despite a significant fall in serum markers of H. pylori infection in groups of individuals, no marker tested could be used to reliably determine posttherapy H. pylori status for individual patients.