Validation of serological tests for Helicobacter pylori infection in an Irish population

Background Serological tests for Helicobacter pylori using laboratory and ' office' formats are commonly used, easy to perform. inexpensive and widely available. Local validation of test performance is required. Aims This study examined the performance of a laboratory and 'office' ELISA in a population of Irish dyspeptics presenting for endoscopy. Methods Consecutive patients presenting for endoscopy had blood drawn at se dation. Samples were analysed using two ELISA formats; a standard laborator y format and an 'office' ELISA test card. H. pylori infection was diagnosed by analysis of antral and corpus biopsies using the rapid urease test, cul ture and histology. A combination of two positive invasive tests was consid ered indicative of infection. Results The sensitivity and specificity of laboratory ELISA was 82.4% and 8 5% respectively while the values for the 'office' ELISA were 87.7% and 85.7 % respectively. In patients under 45 years sensitivities and specificities of the 'office' test exceeded 90%. The two serological tests agreed in 87.5 % of subjects. Conclusions Both tests performed satisfactorily. However, indeterminate res ults impaired the usefulness of the laboratory ELISA particularly when usin g a new cut-off. The 'office' ELISA performed particularly well in young pa tients. A simpler test using antigens from locally prevalent strains to opt imise accuracy is awaited.