Hepatic panel
Total / direct bilirubin
Heme-degradation product; pattern reveals pre-, intra-, or post-hepatic disease.
Sample
Serum (protect from light)
Clinical reference range
0.2 to 1.2 mg/dL
Total
Conv: 0.2–1.2 mg/dL
Biology
What it measures
Indirect (unconjugated) is lipid-soluble, bound to albumin. Conjugated in hepatocytes by UGT1A1. Direct (conjugated) is water-soluble, excreted in bile.
Clinical use
Why we order it
Diagnose hemolysis (indirect), Gilbert (indirect, isolated), cholestasis (direct), and parenchymal liver disease.
Lens · Clinical
Interpretation by lens
Clinical interpretation
Direct bilirubin >50% of total → consider hepatobiliary obstruction; <20% → consider hemolysis or Gilbert.
Differential
Causes of abnormal values
Causes of HIGH
- ↑Hemolysis (indirect, with low haptoglobin)
- ↑Gilbert syndrome (indirect, isolated, fasting/stress)
- ↑Hepatocellular disease (mixed)
- ↑Cholestasis / biliary obstruction (direct)
- ↑Crigler-Najjar (rare, severe)
Pitfalls
Pre-analytic & interpretation traps
- !Hemolysis in vitro falsely lowers measured bilirubin via interference; protect samples from light to avoid degradation.
Related