Insufficient validity of a rapid blood test for diagnosis of Helicobacter pylori infection

Objective: Rapid blood tests for diagnosis of Helicobacter (H.) pylori infection enable to detect antibodies against H. pylori instantly without laboratory equipment. Primary aim: to validate the Helisal Rapid Whole Blood Test (HRBT) with endoscopic bioptic methods as reference. Secondary aim: to compare the HRBT with ELISA IgG serology.

Methods: The HRBT was performed in 145 consecutive dyspeptic patients (median age 59 years) before undergoing esophagogastroduodenoscopy including biopsies from gastric antrum and corpus. A positive H. pylori status was defined by a positive culture or the combination of a positive rapid urease test and a positive histology. Serum for ELISA IgG testing was available from 92 patients.

Results: The H. pylori status was positive in 66% of the patients. The sensitivity of the HRBT resulted at 80%, the specificity at 82%. The sensitivity of the HRBT for a positive ELISA test amounted to 87%, the specificity to 96%.

Conclusions: The diagnostic validity of the HRBT is insufficient for clinical application. False test results add up by the general discrepancy between serological and bioptic methods and by diminished sensitivity compared to ELISA serology.