Standard Venipuncture vs a Capillary Blood Collection Device for the Prospective Determination of Abnormal Liver Chemistry

Abstract

Background: Abnormal liver function is a common manifestation of human disease and may also occur in approved and investigational medications as drug-induced liver injury (DILI). Capillary blood collection devices may allow for more frequent and convenient measurement outside of the clinic. Validation of such approaches is lacking. Methods: This prospective, biospecimens collection study evaluated the Tasso+ in patients with abnormal liver tests (NCT05259618). The primary objective was to define the concordance of alanine aminotransferase (ALT) obtained via Tasso+ compared to standard venipuncture. Secondary objectives included measurement of 14 other analytes and patient surveys. At the time of venipuncture, 2 Tasso+ samples were collected: one was centrifuged and shipped, and the other was refrigerated and shipped as whole blood. Results: Thirty-six patients with elevated ALT values were enrolled. In total, 100 venipuncture, 50 Tasso+ centrifuged, and 48 Tasso+ whole blood samples were obtained. Tasso+ centrifuged samples demonstrated concordance correlation coefficients (CCC) of >0.99 for ALT, alkaline phosphatase (ALP), aspartate aminotransferase (AST), and total bilirubin and CCC >0.95 for albumin, chloride, enzymatic creatinine, serum glucose, magnesium, and phosphorus. Tasso+ whole blood showed CCC of >0.99 for AST, bilirubin total, and enzymatic creatinine and CCC >0.95 for ALT, ALP, albumin, magnesium, and phosphorus. Hemolysis was comparable across the 3 sample types, but its impact was reflected in the Tasso+ potassium data. Patient feedback indicated a very favorable patient experience. Conclusions: The capillary blood collection device, Tasso+, showed substantial to almost perfect concordance to standard venipuncture for measurement of abnormal liver function. Studies are ongoing to validate longitudinal sampling outside of the clinic.