BACKGROUND AND AIMS To assess the validity of biopsy-based tests (histology, culture, and urease test) and serology in detecting current H. pylori infection for the peptic ulcer patients who had gastric bleeding.

METHODS A total of 398 peptic ulcer patients were enrolled and divided into two groups, according to the presence or absence of bleeding. The diagnosis for current H. pylori infection was verified using the gold standard combining individual H. pylori tests. Sensitivity, specificity, and positive and negative predictive values of the culture, Campylobacter-like organism (CLO) test (urease test), histology, and serology were compared.

RESULTS Of the total study population (N = 398), 157 (39.4%) patients were categorized into the bleeding group. The sensitivities of the culture (40.0%) and CLO (85.0%) in the bleeding group were significantly lower than culture (58.1%) and CLO (96.4%) in the nonbleeding group (p = .012 and p < .001, respectively). In the bleeding group, the sensitivity of CLO (85.0%) was significantly lower than histology (92.5%) and serology (97.4%) (p = .013 and p = .002, respectively), which was not found in the nonbleeding group. The specificity of serology in the bleeding group (56.3%) was significantly lower than that of nonbleeding group (74.2%) (p = .038). Similarly, the specificity of serology was significantly lower than the other H. pylori tests in the bleeders.

CONCLUSIONS Bleeding decreased the sensitivity of H. pylori tests in patients with peptic ulcer, especially in urease test or culture. In contrast, histology was found to be a quite reliable test, regardless of the presence of bleeding.