Diagnosis of Helicobacter pylori infection using urease rapid test in patients with bleeding duodenal ulcer: influence of endoscopic signs and simultaneous corporal and antral biopsies.

INTRODUCTION The sensitivity of invasive diagnostic methods for Helicobacter pylori (H. pylori) infection, particularly of urease rapid test, is decreased in cases of gastroduodenal ulcer and upper gastrointestinal bleeding. OBJECTIVES To assess the influence of blood in the stomach or recent bleeding endoscopic signs in the diagnostic sensitivity of urease rapid test among patients with bleeding duodenal ulcer, as well as the influence of simultaneously collecting corporal and antral biopsy samples. PATIENTS AND METHODS 120 patients, 85 male and 35 female, with an average age of 62 (18-88) years, who were admitted to our Hospital due to bleeding duodenal ulcer and who received an endoscopic diagnosis within 24 hours of admission were included. None of the patients had been under treatment with non-steroideal antiinflammatory drugs, proton-pump inhibitors or antimicrobial drugs in the two weeks prior to the bleeding event, and none had received eradicating therapy for H. pylori. In this group of selected patients an H. pylori infection rate nearing 100% was assumed. H. pylori infection was ruled out using antral biopsy (69 cases) or both antral and fundic biopsies (51 cases) for urease rapid testing (Jatrox-H.p.-Test). Patients were classified in three groups according to their endoscopic bleeding signs: a) presence of blood in the stomach or recent bleeding ulcer (21 cases); b) ulcer showing non-recent bleeding signs (38 cases); and c) ulcer without bleeding signs (61 cases). The sensitivity of the urease rapid test was compared between patient groups. Similarly, urease test results with an antral biopsy sample were compared in 100 patients with non-bleeding duodenal ulcer. RESULTS Urease test was positive in 93% of patients with non-bleeding duodenal ulcer, and in 83% of patients with upper gastrointestinal bleeding, which reached statistical significance (p = 0.019). This test was positive in 82.6% of patients with an antral biopsy, and in 82.3% of patients with combined antral and fundic biopsies. In group A, urease test was positive in 90.5% of patients; in group B, it was positive in 89.5% of patients, and in group C, the test turned positive in 75.4% of patients. Statistical differences were only reached when patients in group C were compared to patients in groups A and B together (p = 0.037). CONCLUSIONS 1. The presence of either blood in the stomach or recent bleeding endoscopic signs appeared not to be the conditioning factor for the decreased sensitivity of urease test among patients with bleeding duodenal ulcer. 2. The decreased sensitivity of this test in patients with upper gastrointestinal bleeding is more evident during the resolution stage, and it does not seem to occur because of H. pylori migration from the antrum to the corporal gastric region.