Serum anti-Helicobacter pylori immunoglobulin G titer correlates with grade of histological gastritis, mucosal bacterial density, and levels of serum biomarkers.

OBJECTIVE. Clinical implications of serum anti-Helicobacter pylori immunoglobulin G (IgG) titer were unclear. This study investigated the associations of serum anti-H. pylori IgG titer with grade of histological gastritis, mucosal bacterial density and levels of serum biomarkers, including pepsinogen (PG) I, PGII, PGI/II ratio and gastrin-17. MATERIAL AND METHODS. Study participants were from a screening program in northern China. Serum anti-H. pylori IgG measurements were available for 5922 patients with superficial gastritis. Serum anti-H. pylori IgG titer and serum biomarkers were measured using ELISA, and gastric biopsies were evaluated using standardized criteria. RESULTS. In patients with mild, moderate or severe superficial gastritis, the mean serum anti-H. pylori IgG titers were 17.3, 33.4 and 54.4 EIU (p for trend < 0.0001), respectively. As mucosal H. pylori density score increased from 0 to 3, the mean serum anti-H. pylori IgG titers also increased from 24.7 to 44.8 EIU (p for trend < 0.0001). Serum anti-H. pylori IgG titer was associated positively with serum PGI, PGII and gastrin-17 concentrations and negatively with PGI/II ratio, and the association was the strongest for PGII. The mean PGII concentration of the patients in the highest quartile of IgG titer was twice the mean concentration of the patients in the lowest quartile (17.2 vs. 8.6 EIU, p < 0.0001). CONCLUSIONS. Our results suggest that serum anti-H. pylori IgG titer was associated positively with grade of histological gastritis, mucosal bacterial density and concentrations of serum PGI, PGII and gastrin-17, and negatively with PGI/II ratio.