An enzyme immunoassay for the detection of IgM antibodies to Helicobacter pylori in serum. Helicobacter pylori is a spiral bacterium cultured from human gastric mucosa discovered by B.J. Marshall in 1982. Studies have indicated that the presence of H. pylori is associated with a variety of gastrointestinal diseases including gastritis, duodenal and gastric ulcers, non-ulcer dyspepsia, gastric adenocarcinoma, and lymphoma.

The organism is present in 95-98% of patients with duodenal ulcers and 60-90% of patients with gastric ulcers. The studies have also demonstrated that the removal of the organism by anti-microbial therapy is correlated with the resolution of symptoms and the cure of diseases. Patients who present clinical symptoms relating to the gastrointestinal tract can be diagnosed with H.

pylori infection by two methods: Invasive techniques – including biopsy followed by culture or histologic examination of biopsy specimen or direct detection of urease activity. Non-invasive techniques – include urea breath tests and serological methods. All of the testing performed on biopsy samples is subject to errors related to sampling and interference of contaminated bacteria. An ELISA test for the presence of H. pylori-specific IgM antibody is the technique of choice for serologic tests because of its accuracy and simplicity.

Purified H. pylori antigen is coated on the surface of microwells. Diluted patient serum is added to the wells, and the H. pylori IgM-specific antibody, if present, binds to the antigen. All unbound materials are washed away. Enzyme conjugate is added, which binds to the antibody-antigen complex.

Excess enzyme conjugate is washed off and a solution of TMB Reagent is added. The enzyme conjugate catalytic reaction is stopped at a specific time. The intensity of the color generated is proportional to the amount of IgM-specific antibodies in the sample. The results are read by a microwell reader and compared in a parallel manner with the calibrator and controls.