Liver Function Testing
There are number of diagnostic parameters for investigating liver health and function,
including Bile Acids, Bilirubin, Hyaluronic Acid (HA), Aminotransferases, GLDH and other enzymes.
Whilst Hyaluronic Acid (HA) is the best single marker for liver fibrosis when it comes to distinguishing between the different stages of liver disease, a multiparameter approach may be beneficial. Recent developments have focused on disease modelling using several markers to assist with staging disease.
The Hepascore predictive model uses an algorithm to evaluate four clinical parameters alongside age and sex.
• Gamma glutamyl transferase and
Each of these parameters is an indicator of liver function but combination of these factors in the Hepascore model augments the predictive value of these non-invasive tests when staging liver disease.
Bilirubin for Neonatal Jaundice
Hyaluronic Acid for Liver Fibrosis
ALP and GGT for Bile Duct Disorders
Diazo methods for determination of Bilirubin have traditionally been widely used but are prone to interference from haemoglobin, which may result in under reporting, or ascorbic acid which can falsely elevate the test result. The Wako Direct and Total Bilirubin assays use a vanadation oxidation principle and offer excellent performance with minimal interference – giving clear, reliable answers when it matters.
Hyaluronic Acid Assay
Percutaneous liver biopsy is considered the gold standard for diagnosis and staging liver disease. However, this invasive procedure is costly and can be problematic, sample limitation may not give conclusive results and the procedure can result in pain, bleeding or even patient death. Serum Hyaluronic Acid is the current biomarker of choice for liver fibrosis presenting a cost-effective way to distinguish between cirrhosis and earlier stages of fibrosis. Using a cut-off concentration of 60 ng/ml, HA typically shows a negative predictive value of up to 100% and a positive predictive value of 61% for cirrhosis.
The introduction of the Wako HA LT kit means that the Hyaluronic Acid Assay can be automated in the routine clinical laboratory for the first time. In the Assay, the HA in the sample combines with Hyaluronic Acid Binding Protein (HABP). An insoluble aggregate is then made by adding latex particles, coated with anti-HABP antibody. The resulting increase in turbidity is proportional to the concentration of Hyaluronic Acid in the sample.