Conjugated hyperbilirubinemia is defined biochemically as a conjugated bilirubin level of ≥ 2 mg/dL (>25 μmol/L) and > 20 % of the total bilirubin.
CAUSES
- Intrauterine infection TORCH
- Neonatal hepatitis
- Biliary atresia
- Cholydochal cyst
- Parenteral nutrition related
- Metabolic: Galactosemia, cystic fibrosis, α1-antitrypsin deficiency
- Intrahepatic cholestasis: familial & syndromic
INVESTIGATIONS
A-INVESTIGATIONS TO ESTABLISH THE PRESENCE OF CHOLESTASIS:
- Increased total & direct serum bilirubin (conjugated hyperbilirubinemia)
- Increased liver enzymes: ALT,AST,GGT,alkaline phosphatase.
- Decrease liver synthetic functions: Serum proteins, albumin, prothrombin time & INR
B- INVESTIGATIONS TO IDENTIFY THE CAUSE OF CHOLESTASIS:
- Liver biopsy is the most reliable method for differentiation between idiopathic hepatitis and extrahepatic biliary atresia.
- HIDA scan
- TORCH screening by specific IgM antibodies and may be PCR
- Reducing substance in urine → galactosemia
- Sepsis screen → sepsis
- Metabolic workup: Galactose 1-phosphate uridyl transferase, Serum antitrypsin level