A Validated LC-MS/MS Assay for the Quantification of Cholate Isotopes in Human Serum

Area of Science:

• Biochemistry
• Analytical Chemistry
• Hepatology

Background:

• Current liver evaluation methods are indirect, relying on nonspecific tests or invasive procedures.
• There is a need for direct measures of liver function and physiology.
• This study introduces a novel assay for assessing liver health.

Purpose of the Study:

• To analytically validate a sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) assay.
• To validate a dual-sample oral (DuO) cholate challenge test for liver function assessment.
• To quantify serial serum concentrations of cholate isotopes in liver disease patients.

Main Methods:

• Analytical validation of the cholate assay for accuracy, precision, sensitivity, specificity, and range.
• Validation using human serum samples with quality controls and calibrators.
• DuO test parameters validated in 48 subjects with diverse liver disease etiologies.

Main Results:

• Assay accuracy showed mean biases from 0.1% to 3.7%.
• Total imprecision for all analytes ranged from 2.3% to 8.4%.
• The DuO test met all validation acceptance criteria, demonstrating reliable performance.

Conclusions:

• Method validation established performance characteristics for the LC-MS/MS cholate assay and DuO test.
• The validated assay and test provide accurate and precise measurements of liver function.
• This offers a promising new tool for evaluating liver physiology in clinical settings.