The Clinical Usefulness of Serum Pepsinogens, Specific IgG Anti‐HP Antibodies and Gastrin for Monitoring Helicobacter pylori Treatment in Older People

Abstract

To evaluate the clinical usefulness of Pepsinogen A (PGA) and C (PGC), PGA/PGC ratio, gastrin, and specific IgG anti-HP antibodies (anti-HP Ab) in monitoring the effect of cure for Helicobacter pylori (HP) infection in older people. We studied the changes in serum parameters (PGA, PGC, PGA/PGC ratio, gastrin and anti-HP Ab) in older patients before and 2 months after stopping therapy for the cure of HP infection. Eighty-eight older patients (M = 43, F = 45, mean age = 73.3, range = 60-89) with chronic gastritis (42), gastric ulcer (14) or duodenal ulcer (32) were found HP-positive by histology of gastric antral and body biopsies and the rapid urease test. Two different associations of antibiotics and antiulcer drugs (omeprazole, metronidazole, azithromycin, or clarithromycin) for 2-4 weeks. At the beginning of the study and 2 months after treatment withdrawal, the subjects were studied by upper G.I. endoscopy with at least two antral and two body gastric biopsies (Giemsa stain and rapid urease test for HP); serum PGA (RIA method, microgram/mL), PGC (RIA method, microgram/mL), PGA/PGC ratio, gastrin (RIA method, picogr/mL), and anti-HP Ab (ELISA method, Biolife, MU/mL) were also determined. Statistical analysis was based on either the Wilcoxon test, for paired data, the chi-square test, the Kruskal Wallis test, or the Mann-Whitney test for unpaired data. The choice of the best cut-off value in the different parameters was performed by receiver operating characteristics curves (ROC) and by Youden index. The correlation between HP density in the gastric mucosa and gastritis activity was verified by Spearman rank correlation test. After therapy, 56/88 patients proved HP-negative (HP-eradicated: M = 30, F = 26, mean age = 73.0, range = 60-87 years), whereas 32/88 were not cured (HP-persistent: M = 13, F = 19, mean age = 73.0, range = 60-89 years). After therapy, in HP-eradicated cases, a statistically significant change was found in anti-HP Ab (75.23 +/- 8.94 vs 47.32 +/- 5.26, P < .001), PGC (21.58 +/- 1.97 vs 14.34 +/- 1.75, P < .001), and PGA/PGC ratio (8.46 +/- 0.68 vs 11.54 +/- 0.89, P < .001), but not in PGA and gastrin. On the other hand, in HP-persistent cases, anti-HP Ab, PGA, PGC, PGA/ PGC ratio and gastrin did not change after therapy. The sensitivity and specificity were, respectively, 0.62 and 0.56 for anti-HP Ab and 0.75 and 0.56 for the PGA/PGC ratio, which demonstrated the best diagnostic accuracy (68%). The eradication of HP from the stomach of older patients induces a rapid and significant decrease in serum levels of IgG anti-HP antibodies and PGC, with an increase in PGA/PGC ratio but not in gastrin. Unchanged serum levels of IgG anti-HP antibodies, PGC, and PGA/PGC ratio 2 months after completing HP eradication therapy are indicative of ongoing HP infection. The PGA/PGC ratio showed the best diagnostic accuracy among serum measures tested.