Liver function assessment

Among the existing biomarkers for liver function, ALT and AST are general indicators of hepatocellular injury. Increases in Alkaline Phosphatase (ALP), Aspartate Aminotransferase (AST) and Total Bilirubin are often also associated with liver disfunction. The range of tests available is complemented by Gamma Glutamyltransferase (GGT), Glucose dehydrogenase (GLDH) and cholinesterase, being all these useful tools to detect liver disfunction. Bile acids are also important markers, since those present in serum represent the bile acids not cleared by the liver due to impaired hepatic function. Bile acid stimulation test is also available. A decrease in urobilinogen in urine levels may also be a sign of biliary obstruction. Other typical measurements are albumin and globulin.

Perturbations in the coagulation cascade are frequently associated with liver disfunction, since the liver is the primary site of synthesis of nearly all coagulation factors. Thus, clotting time will increase with severe liver injury. The fall in clotting factor levels is accompanied by a parallel fall in anticoagulant proteins. The status of the coagulation system can also be checked with tests such as prothrombin time (Quick’s test) and activated partial thromboplastin time (APTT). 

High von Willebrand factor levels are associated with liver cirrhosis. Inflammation occurs in some chronic liver diseases, which is often reflected by an increase in cytokine levels. For instance, tumour necrosis factor-α (TNFα) is an inflammatory cytokine involved in liver inflammation. Sustained liver inflammation leads to liver fibrosis.

Finally, fatty liver disease is related to obesity and diabetes, so monitoring glucose, Triglycerides (TGs) and cholesterol may be useful. Glycosylated haemoglobin (HbA1c) is often measured to determine the diabetic stage of the animal: a high HbA1c value means that the animal has too much sugar in blood. IDEXX BioAnalytics is currently developing this test for dogs and rodents.

*In bold, IDEXX BioAnalytics tests and services available

 
 

*In bold, IDEXX BioAnalytics tests and services available