Blood tests in biliary disease

• blood tests generally include:
  • full blood count, urea and electrolytes, liver function test (LFT), calcium, albumin and international normalised ratio (INR)
• biliary disease typically produces a cholestatic picture – elevated alkaline phosphatase (ALP) and gamma-glutamyl transferase (GGT) with variable abnormalities of the transaminases (AST, ALT)
  • in the early stages of biliary obstruction - ALT rises before the ALP; cholestasis produces a conjugated hyperbilirubinaemia
    • INR and albumin indicate the synthetic function of the liver - these are good indicators of severity of disease in conjunction with bilirubin

If there are renal function abnormalities in the presence of liver disease then this generally indicates a worse prognosis.

Haematological investigations:

• leucocytosis with a neutrophilia if biliary sepsis
• anaemia of varying degrees may be present
  • iron deficiency - if there has been chronic gastrointestinal blood loss
  • macrocytosis - may occur secondary to alcohol abuse or small bowel diseases, eg bacterial overgrowth and parasitic infestations

Reference:

1. Prescriber 2003; 14(23):20-9.