Evaluation of the FlexSure HP whole blood antibody test for diagnosis of Helicobacter pylori infection

Abstract

Objective: Rapid, inexpensive, reliable tests are needed to facilitate the diagnosis of Helicobacter pylori infection. We evaluated the accuracy of the new FlexSure HP whole blood test (SmithKline Diagnostics, Inc.), a rapid, qualitative in-office test for the detection of antibodies to H. pylori utilizing whole blood obtained from a fingerstick.

Methods: Five North American sites enrolled patients not previously treated for H. pylori who underwent upper endoscopy. Patients had not received antibiotics, bismuth, or proton pump inhibitors within 4 wk before study enrollment. Bacterial infection was established by the presence of H. pylori in gastric biopsies (minimum of two) or positive rapid urease test of antral tissue. The presence of IgG antibodies was determined using FlexSure HP whole blood tests with blood obtained by fingerstick and FlexSure HP serum and ELISA (HM-CAP) tests with serum obtained from venipuncture.

Results: Three hundred ninety-three patients were enrolled (56% male; mean age, 46.8 +/- 16.0 yr). H. pylori infection was present in 187 (48%). Compared with the standard of histology and rapid urease test, sensitivity for FlexSure HP whole blood, FlexSure HP serum, and HM-CAP EIA were, respectively, 84%, 90%, and 95% (p < 0.05 compared with FlexSure HP whole blood). There were no statistical differences in specificity or overall accuracy between the three tests.

Conclusions: FlexSure HP whole blood demonstrated an accuracy not significantly different from the FlexSure HP serum test but had sensitivity significantly lower than the HM-CAP EIA. FlexSure HP whole blood may be useful for in-office H. pylori diagnosis.