Comparison of 4 laboratory methods for detection of Helicobacter pylori

OBJECTIVE: To compare the usefulness of 4 commonly used tests in the diagnosis of Helicobacter pylori H. pylori infection in Saudi patients with dyspepsia.

METHODS: Patients presenting with dyspepsia at the gastroenterology clinic of Aseer Central Hospital, Abha, Kingdom of Saudi Arabia between October 2005 to May 2006, who consented to participate in the study were enrolled. Patients who received anti-Helicobacter treatment or proton pump inhibitors within 30 days, or in whom endoscopy revealed cancer or gastro-esophageal reflux, were excluded from the study. Stool sample for H. pylori stool antigen HpSA were tested using the enzyme immunoassay technique 2-7 days before endoscopy. At endoscopy, gastric antrum mucosal biopsies were taken for campylobacte-like organism CLO test, histology and culture.

RESULTS: There were 72 males and 43 females, age range from 18-75 years, mean age 40.09 ± 15.68. Seventy-nine patients out of the 115 68.7% samples were positive for H. pylori, by culture. Culture and histology agreed in 112 cases 97.4% and disagreed in 3 cases 2.6%. The sensitivities and specificities % of histology were 97.5 and 97.2, of HpSAg were 91.9 and 98.6, and of CLO were 79.7 and 97.2 tests against culture.

CONCLUSION: Culture, histology, and H. pylori stool antigen tests all have comparable results, and there is no need to use all 3 at the same time, for the diagnosis of H. pylori infection. The CLO test is less sensitive, and of low negative predictive value.