Factors for Negative Result in Serum Anti-Helicobacter pylori IgG Antibody Test in Adult Subjects With Nodular Gastritis: A Single-center Study.

Aim Nodular gastritis has been demonstrated to be strongly associated with Helicobacter pylori infection. The present retrospective study was performed to elucidate factors related to a negative serum antibody test result in adults with nodular gastritis. Materials and methods We investigated 116 H. pylori-positive subjects endoscopically diagnosed with nodular gastritis and subjected to a serum anti-H. pylori immunoglobulin G (IgG) antibody test. The degree of gastric mucosal atrophy and the presence of spotty redness in the gastric body and fornix were carefully determined by observations of endoscopic images. Results Of the 116 investigated subjects, 108 were positive and 8 negative in serum anti-H. pylori IgG antibody test results. The degree of gastric mucosal atrophy was mild in seven among eight seronegative cases. The levels of pepsinogen II in serum in patients with negative antibody test findings were significantly lower as compared to those found positive, while the pepsinogen I/II ratio tended to be higher in subjects shown negative by the test. Only 1 of 69 with spotty redness was negative in serum anti-H. pylori IgG antibody testing, while 7 of 47 without spotty redness were negative. Multiple logistic regression analysis of subjects with a negative test result revealed that the absence of spotty redness shown by endoscopy was a significant risk factor. Conclusion The absence of spotty redness, which may reflect the degree of gastric body inflammation, is a significant factor indicating increased risk for a negative serum anti-H. pylori IgG antibody test result in subjects with nodular gastritis.