Diagnosis of Helicobacter pylori infection from antral biopsies in pediatric patients is urease test that reliable?

Our objectives were to determine if the urease (CLO) test alone is a reliable diagnostic test for H. pylori gastritis in children and if the density of H. pylori influences the CLO test result. We performed a combined retrospective and prospective study reviewing the results of CLO-test and histology of gastric mucosal biopsy from 67 patients (35 females) with H. pylori gastritis. Two antral biopsies were inoculated on the CLO-test and two processed for histology to grade the severity of gastritis and H. pylori density. The mean age of patients was 11 years (SD +/- 4.53). Only 50 patients tested positive for H. pylori on CLO-test, whereas all patients were positive on histology. The sensitivity of the CLO-test was 75%. There was a significant association between CLO-test positivity and the density of H. pylori organisms on histology (P < 0.01), and with the severity of gastritis (P < 0.001) by the Pearson chi-square test. However, there was no association between the density of H. pylori and severity of gastritis. In conclusion, the CLO-test is not reliable as a sole diagnostic test for H. pylori gastritis in children because of a significant number of false negatives. Histologic examination of gastric mucosal biopsy is superior to the CLO-test in diagnosing H. pylori infection.