Reliability of biopsy-based diagnostic tests for Helicobacter pylori after treatment aimed at its eradication.

ABSTRACT

OBJECTIVE: Recurrence of Heliobacter pylori after apparently successful treatment mostly represents resurgence of the infection, rather than a new one. Therefore, the reliability of biopsy-based tests after treatment was investigated. METHODS: Four weeks or more after treatment, antral biopsy samples were taken for culture, histology, urease test and polymerase chain reaction (PCR), and a corpus specimen for culture. Treatment failure was defined as > or = 2 tests positive. If one test was positive, a 13C-urea breath test was performed and considered conclusive. RESULTS: One hundred and ninety-seven patients were evaluated. Endoscopy was performed 53 days (27-92 days) after treatment. Twenty-one patients with missing test results and 19 patients on acid-suppressive drugs were excluded. In 140 of 156 patients (89.7%), H. pylori was eradicated. Sensitivity and specificity of culture of antrum were, respectively, 100% and 100%; culture of corpus, 100% and 100%; rapid urease test, 87% and 99%; haematoxylin/eosin stain, 94% and 95%; Giemsa stain, 81% and 99%; and PCR, 88% and 100%. CONCLUSION: Although all biopsy-based tests are reliable after treatment, culture is the biopsy-based test of first choice as it is the most accurate and gives additional information on antibiotic resistance.