Value of Liver Function Tests in Cirrhosis

Abstract

The liver comprises both parenchymal and non-parenchymal cells with varying functions. Cirrhosis is often complicated by the development of portal hypertension and its associated complications. Hence, assessment of liver in cirrhosis should include assessment of its structural, function of both hepatic and non-hepatic tissue and haemodynamic assessment of portal hypertension. There is no single test that can evaluate all functions of liver and assess prevalence and severity of portal hypertension. Commonly available tests like serum bilirubin, liver enzymes (alanine [ALT] and aspartate aminotransferase [AST], serum alkaline phosphatase [ALP], gamma glutamyl transpeptidase [GGT]), serum albumin and prothrombin time for assessment of liver functions partly assess liver functions. quantitative liver functions like indocyanine clearance tests [ICG-K], methacetin breath test [MBT] were developed to assess dynamic status of liver but has its own limitation and availability. Imaging based assessment of liver by transient elastography, MRI based 99 mTc-coupled asialoglycoprotein mebrofenin scan help the clinician to assess liver function, functional volume of liver left after surgery and portal hypertension [PH]. Hepatic venous pressure gradient still remains the gold standard for the assessment of portal hypertension but is invasive and not available in all centres. Combinations of blood parameters in form of various indices like fibrosis score of 4 [FIB-4], Lok index, scores like model for end stage liver disease (MELD) and Child-Turcotte Pugh score are commonly used for assessing liver function in clinical practice.

Keywords: 99mTc-GSA, technetium-99m galactosyl human serum albumin; ALP, alkaline phosphatase; ALT, alanine aminotransferase; ARFI, Acoustic Radiation Force Impulse; AST, aspartate aminotransferase; BUN, blood urea nitrogen; CLD, chronic liver disease; ESLD, end-stage liver disease; FIB-4, fibrosis score of 4; GGT, gamma glutamyl transpeptidase; HVPG, Hepatic venous pressure gradient; ICG-K, indocyanine clearance tests; INR, International normalised ratio; LFTs, liver function tests; MBT, methacetin breath test; NAFLD, non-alcoholic fatty liver disease; PBS, primary biliary cholangitis; PHT, portal hypertension; PSC, primary Sclerosing cholangitis; cirrhosis; liver function tests; portal hypertension.