Objective: We compared three whole blood antibody tests for Helicobacter pylori (H. pylori) in a United States, multicenter trial.
Methods: Patients referred for EGD at three medical centers were recruited. During EGD, biopsies were taken for histology and rapid urease testing (RUT). Immediately after endoscopy, patients underwent the antibody tests (FlexPack HP, Abbott Diagnostics; QuikVue, Quidel Corporation; AccuMeter, ChemTrak) using whole blood obtained by two to three fingersticks. Performance characteristics were calculated for each antibody test using the biopsy-based methods as a gold standard.
Results: A total of 131 patients participated; 50 (38%) patients had histological evidence of H. pylori infection. Using histology as a gold standard, the sensitivities of FlexPack HP, QuikVue, and Accumeter were 76%, 78%, and 84%, respectively. Specificity was 79% with FlexPack HP and 90% with QuikVue and Accumeter. There were no significant differences in the performance of the three antibody tests though there was a trend toward superior performance for AccuMeter compared to FlexPack HP (p = 0.019). However, RUT proved superior to FlexPack HP using histology as a gold standard (p = 0.008). Using either concordant histology and RUT results or a positive histology or RUT to define active H. pylori infection, there was no statistically significant difference between the antibody tests.
Conclusions: There were no statistically significant differences in the performance of the three antibody tests. These tests proved only marginally sensitive in detecting patients infected with H. pylori. Clinicians should be aware of the limitations of these tests, particularly when using them as a sole means of testing for H. pylori.