A breakdown product of haemoglobin metabolism.
Tube
01 (SE) – Serum Gel
ID
Tests&Tubes0020
Additional information
UNCONJUGATED HYPERBILIRUBINAEMIA: Unconjugated bilirubin is lipid soluble and can cross the blood brain barrier where its toxic effects cause irreversible brain damage (kernicterus). Severe hyperbilirubinaemia is treated first with phototherapy and then with exchange transfusion.
PHYSIOLOGICAL JAUNDICE – Transient unconjugated hyperbilirubinaemia presenting with jaundice on the 2nd or 3rd day of life and persisting for 2 weeks. In the premature infant physiological jaundice may last as long as 4 weeks. Neonates have increased levels of unconjugated bilirubin. This is a result of the increased synthesis of bilirubin (due to the decreased half life of red cells and the presence of large amounts of red cell precursors) and the reduced clearance (due to reduced membrane uptake and ligand production, immaturity of the enzyme UDP glucuronyl transferase which is involved in hepatic conjugation, inefficient bile acid metabolism and transport). In cases of persistent neonatal unconjugated hyperbilirubinaemia consider other pathological causes such as haemolytic disease (Rhesus incompatibility, deficiency of the enzyme glucose 6-phosphatase dehydrogenase, toxins,infection), Gilbert’s syndrome, Crigler-Najjar (inherited disorder of bilirubin conjugation).
CONJUGATED HYPERBILIRUBINAEMIA: Defined as a conjugated plasma bilirubin > 15% of total. Tends to be characterised by pale stools and dark urine. Can be intra or extra hepatic. ALP tends to be raised in extrahepatic causes. In neonates consider biliary atresia as an extrahepatic cause.
Turn around
A&E: N/A
Day Case: N/A
In-Patient: 6 Hours
Out-Patient: 24 Hours
GP: N/A
Send to
Blood Sciences Cross Site
Contact
For further details please contact Leeds Pathology customer services: [email protected].
Collection Con
Minimum volume: 500µl serum
Instructions for Lab Staff: Standard lab processing- No special requirements
Sample REQ
Blood
Ref. Range Notes
Blood Sciences reference ranges are available through the useful information and links page: [LINK]
Units
umol/L