Evaluation of endoscopy-based diagnostic methods for the detection of Helicobacter pylori.

ABSTRACT

BACKGROUND: Helicobacter pylori is an etiological factor in duodenal ulcer. Few studies have objectively assessed the accuracy of diagnostic methods for the detection of H. pylori. METHODS: The sensitivity and specificity of histology, touch smear, rapid urease test (RUT) and brush cytology of endoscopic antral biopsy from patients with duodenal ulcer were compared. Forty-nine patients were evaluated before, and 34 after, eradication therapy. Each time, sampling was done for all 4 tests. The infection status for each sample was established by a positive concordance of results of three of four tests. RESULTS: The highest degree of agreement was between RUT and cytology (kappa = 0.69). Brush cytology (100%) followed by RUT (94.5%) were the most sensitive tests. Histology had the highest specificity (89.3%). A combination of RUT or brush cytology with histology had the maximum chance of detecting H. pylori. As single tests, brush cytology and touch smear had high diagnostic accuracies with a Youdin J value of 1.79 and 1.78, respectively. CONCLUSION: The best method for diagnosis of H. pylori is a combination of the rapid urease test or brush cytology with histology. Brush cytology or touch smear are diagnostic tests of choice if a single test is desired.