Validation of a novel point‐of‐care test for alanine aminotransferase measurement: A pilot cohort study

Background Alanine aminotransferase (ALT) measurement is essential for evaluation of liver disease. We validated a novel rapid point‐of‐care (POC) test for ALT1 against laboratory ALT. Methods Stored plasma samples from adults with chronic liver disease (Test cohort n = 240; Validation cohort n = 491) were analysed using the BioPoint® antigen immunoassay POC ALT1 lateral flow test, which provides quantitative ALT results (Axxin handheld reader) or semi‐quantitative results (visual read, cut off 40 IU/ml). The accuracy of POC ALT1 to detect ALT > 40 IU/L was determined by ROC analysis. In patients with chronic hepatitis B, treatment eligibility (EASL criteria) was determined using POC ALT1 and compared to laboratory ALT. Results POC ALT1 test had good accuracy for laboratory ALT > 40 IU/L: AUROC 0.93 (95% CI: 0.89–0.96) in the Test cohort and AUROC 0.92 (95% CI: 0.88–0.95) in the Validation cohort. POC ALT1 cut off of 0.8 for ALT > 40 IU/L maximised sensitivity (97%) and specificity (71%) in the Test cohort (42% laboratory ALT > 40 IU/L) and yielded PPV 84% and NPV 91% in the Validation cohort (19% laboratory ALT > 40 IU/L). Semi‐quantitative POC ALT1 had good accuracy for laboratory ALT in the Validation cohort (AUROC 0.85, 95% CI: 0.81–0.99; sensitivity 77% and specificity 93%). Combined with HBV DNA and transient elastography, both quantitative and semi‐quantitative POC ALT1 tests had good accuracy for excluding hepatitis B treatment needs (sensitivity 96%, specificity 78% and NPV 99%). Conclusion The POC ALT1 test had good accuracy for elevated ALT levels and for determining treatment eligibility among people with chronic hepatitis B.