Evaluation of two new tests for the detection of Helicobacter pylori in stool specimens

Abstract number: 1734_104

Blanco S., Lacoma A., Forne M., Prat C., Latorre I., Cuesta M., Viver J., Ausina V., Dominguez J.

Objectives:

1. To evaluate the usefulness of 2 new stool antigen assays, a immunochromatographic tests Letitest H. pylori CARD (Laboratorios leti, Madrid, Spain) and an EIA test Immundiagnostik ELISA (Immunodiagnostik AG, Bensheim, Deutschland) in the diagnostic of Helicobacter pylori infection and to confirm H. pylori eradication after treatment.

2. To compare their accuracy with four stool antigen assays: ImmunoCard STAT! HpSA and Premier Platinum HpSA (Meridian Diagnostics, Cincinnati, OH), Amplified IDEIA Hp StAR and RAPID Hp StAR (DakoCytomation, Cambridge, UK).

Methods: We evaluated stool samples from 80 patients diagnosed with H. pylori infection and from 40 patients without infection. To confirm H. pylori eradication we evaluated 40 patients who received H. pylori treatment, eradication was confirmed with 13C-urea breath test 6 weeks later.

The assays were performed according to the specifications of the manufacturer. Sensitivity, specificity, and positive and negative predictive values were calculated.

Results: The sensitivity, specificity, and positive and negative predictive values of the tests are shown in the table. In the 40 patients evaluated 6 weeks after eradication therapy, the overall agreement between urea breath test and the antigen tests were: Letitest 85%, ImmunoCard STAT! HpSA 82.5%, RAPID Hp StAR 75%, Immundiagnostik ELISA 82.5%, Amplified IDEIA Hp StAR 90% and Premier Platinum HpSA 75%.

Conclusions: Our results indicate that Letitest and Immundiagnostik ELISA are helpful procedures to determine H. pylori infection. Compared to the 13C UBT, both new test shows a comparably good correlation to assess the success of eradication therapy.