AccuStat whole blood fingerstick test for Helicobacter pylori infection: a reliable screening method

Helicobacter pylori antibody testing is accurate for diagnosing untreated patients. Rapid serum testing is as accurate as formal enzyme-linked immunosorbent assay (ELISA) testing. As whole blood fingerstick tests may become the diagnostic method of choice if they are of similar accuracy, 51 patients were studied who had not taken antibiotics, bismuth, sucralfate, or proton pump inhibitors. Concordance between C-14 Urea Breath Testing and HM-CAP ELISA testing served as the study standard for H. pylori diagnosis. Rapid antibody testing was performed with the AccuStat whole blood (Boehringer Mannheim, Mannheim, Germany) and FlexSure HP (Smith Kline Diagnostics, San Jose, CA) serum tests. Antral biopsy for CLO testing and histological evaluation with thiazine staining were available for 18 (35.3%) and 20 patients (39.2%), respectively. Nineteen of 50 patients (38%) were infected. (One patient had discordant tests and was excluded.) FlexSure HP and AccuStat were each positive in 18 (36%) and 19 patients (38%) with sensitivity, specificity, and positive and negative predictive values of 89.5% and 89.5%, 96.8% and 93.5%, 94.4% and 89.5%, and 93.8% and 93.5%, respectively. There were two false-negative FlexSure HP and AccuStat tests and three false-positive tests--1 FlexSure and 2 AccuStat results. CLO test and histology concurred in every case tested. We conclude that both rapid antibody tests are accurate and suitable for screening patients not previously treated for H. pylori infection. Since the AccuStat has preserved diagnostic strength, is less costly, takes less time, and is less labor intensive, whole blood testing is the screening test of choice.