Comparison of invasive and noninvasive tests for detecting Helicobacter pylori infection in bleeding peptic ulcers.

BACKGROUND: Eradication of Helicobacter pylori infection has been shown to prevent recurrent bleeding from peptic ulcers. However, the detection rate for H pylori infection seems to be underestimated in this group of patients and has been scarcely investigated.

METHODS: Eighty patients with bleeding peptic ulcer were studied for evidence of H pylori infection. Seventy-seven of these patients were enrolled as having H pylori infection after any one of the following 3 tests were positive: culture, histologic study, or any 2 of rapid urease test (CLO test), carbon 13-labeled urea breath test (UBT), and serologic examination. Fresh blood or blood-containing material in the gastric antrum was noted by panendoscopy in 22 patients (group A). In the remaining 55 cases there was no blood in the antrum (group B).

RESULTS: The sensitivities of the CLO test, bacterial culture, histologic study, 13C-labeled UBT, and immunoglobulin G serologic test were 45.5%, 36.4%, 77.2%, 95.4%, and 100% in group A, respectively, and 70.9%, 40.0%, 70.9%, 92.7%, and 96.4%, respectively, in group B. There was a statistically significant difference between the sensitivities found for CLO test and 13C-labeled UBT (p < 0.05). Of these 5 tests, only the sensitivity of the CLO test showed a statistically significant difference between groups A and B (p < 0.05). A delayed positive CLO test result was recorded in 13 patients (3 in group A, 10 in group B).

CONCLUSION: Noninvasive tests seemed to be more sensitive than invasive tests in detecting H pylori infection in patients with bleeding peptic ulcers. Blood in the antrum might reduce the sensitivity of the CLO test but have no effect on the other tests. The CLO test should be observed for more than 24 hours because of the possibility of a delayed positive result in some patients with bleeding peptic ulcers.