A PRACTICAL SINGLE-SAMPLE DRY LATEX AGGLUTINATION-TEST FOR HELICOBACTER-PYLORI ANTIBODY DETECTION

Assessment of a single serum sample for Helicobacter pylori antibodies is frequently requested in routine diagnostic laboratories. Current e nzyme linked immunosorbent assay (ELISA) kits are not ideal for testin g small numbers of serum samples and some have low sensitivities, spec ificities or large grey zones. A panel of 90 serum samples from patien ts who had presented for routine upper endoscopy was used to compare t hree kits for the detection of H pylori antibodies: (1) Pyloriset Dry, total antibody latex agglutination, Orion Diagnostica, Espoo, Finland , (2) Pyloriset enzyme immunoassay (EIA), IgG ELISA, Orion; and (3) He l-p, IgG ELISA, Amrad, Kew, Victoria, Australia. Diagnosis of H pylori positivity was made if culture results and either rapid urease test o r histopathology were positive. The sensitivity, specificity, positive , and negative predictive value for each test was as follows: Orion: l atex 93.3%, 95.6%, 95.5%, 93.3% respectively; Orion: EIA-G 94.4%, 97.8 %, 97.4%, 84.4%, respectively; and Amrad: EIA-G 100%, 88.9%, 90%, 100% , respectively. The latex test performed better than the EIAs with res pect to sensitivity and specificity.