Liver function tests (LFTs) are the central test when investigating jaundice and often point towards the cause (Table 1).
Table 1 Liver function tests
| | Normal range notes |
Alkaline phosphatase | ALP 25-115U/L | Considerably raised in extrahepatic and intrahepatic biliary disease |
Transaminases | AST 10-40U/LALT 5-40U/L | Usually highly raised in hepatocellular disease |
Gamma glutaryl transferese | Male: <50 U/LFemale: <32 U/L | Sensitive but not specific for alcohol intake, raised GGT and ALP suggest cholestasis |
Other blood tests include:
- Full blood count
- Raised reticulocyte count and schistocytes on blood film indicate haemolysis
- Coombs test will be positive
- Amylase if raised may indicate pancreatitis
- Hepatitis serology (for viral hepatitis)
- Autoimmune markers
- Markers such as anti-nuclear antibodies and anti-smooth muscle antibodies may indicate autoimmune disease
- The majority of patients with PBC are positive for anti-mitochondrial antibody
- Up to 85% of patients with PSC are positive with perinuclear staining anti-nuclear cytoplasmic antibody
- Alpha 1 antitrypsin
- Deficiency may proceed to liver cirrhosis
- Copper/Ceruloplasmin
- Deficiency may indicate Wilsons disease
- Ferritin
- Levels >1000 ng/ml and transferrin saturation >50% will indicate haemochromatosis