[An urease enzyme linked immunosorbent assay for detection of Helicobacter pylori infection]

A sensitive and specific serological diagnostic test for Helicobacter pylori infection has been developed and validated in 120 patients with dyspeptic symptoms undergoing endoscopy. This test is to use urease, a protein unique to H. pylori, as the basis for the enzyme linked immunosorbent assay (ELISA) that detects serum H. pylori urease antibodies. The ELISA mean optical density (OD) in H. pylori-positive group is higher than that in H. pylori-negative group (0.57 +/- 0.23 vs 0.24 +/- 0.15, P < 0.001), a cut-off 0.3 OD yields a sensitivity of 95% and a specificity of 93%. Serum absorption test showed that Escherichia coli, Klebsiella pneumonia, Proteus mirabilis, Yersinia enterocolotica, Pseudomonas aeruginosa cell lysate do not influence serum H. pylori urease antibody level, though they all have urease except E. coli. The result implied that H. pylori urease can be a good antigen to detect serum H. pylori antibody and it would be useful for epidemiological survey and routine diagnostic approach. Nearly half of the blood donors showed positive result with H. pylori urease antibody. It is suggested that H. pylori infection is quite common in the asymptomatic population.