Assessment of the performance of a dual-sample oral cholate challenge test: The HepQuant DuO test

Liver health is currently evaluated using nonspecific blood tests, fibrosis surrogates, and invasive procedures, none of which directly measure liver function and physiology. The validated HepQuant SHUNT test quantifies liver function and physiology and is linked to clinical outcomes. Herein we present the reliability of a simplified version, the dual-sample oral cholate challenge (HepQuant DuO) test.

Samples from the SHUNT-V study representing various liver disease etiologies were used in experiments to assess test reliability. We compared the HepQuant DuO test analyte measurements relative to the previously validated HepQuant SHUNT test. Precision and imprecision (%CV) of analyte measurements and HepQuant DuO test parameters were evaluated over four days, with two runs per day and three replicates per run, using two-way nested hierarchical ANOVA. Analytical specificity was evaluated in samples spiked with endogenous ¹²C-cholic acid.

All samples met the prespecified method comparison acceptance criteria with a mean bias of 2.6 %, demonstrating equivalency between the analytical methods of HepQuant DuO and SHUNT. Total imprecision across all HepQuant DuO test parameters, for both 13C- and d4-cholate, ranged from 0.6 % to 2.1 %. Samples spiked with high concentrations of ¹²C-cholic acid demonstrated lack of interference with a percent change relative to controls of 3.2 % or less.

The studies described herein established the reliability of the HepQuant DuO test in terms of precision, analytical specificity, and agreement with the validated HepQuant SHUNT test. Reportable ranges and reference intervals are also described.