Bilirubin: Worked Out Years Ago?

¹ Laboratory of Biochemistry, National Heart, Lung, and Blood Institute, National Institutes of Health, Bldg 3, Room 106, Bethesda, MD 20205

1. The free bilirubin theory proposes that unbound bilirubin binds to and enters cells. The theory is simple, reasonable, and attractive.

2. To date, there is no evidence to support the free bilirubin theory over other possible mechanisms.

3. The measurement of free bilirubin is now technically possible for mixtures of purified bilirubin and albumin. Measurement in serum is promising, but proven methods still elude current capabilities.

4. At present, there is no justification for the use of free bilirubin tests in the management of jaundice. This evaluation holds for related tests, regardless of aliases: reserve binding capacity, bilirubin binding capacity, albumin saturation, loosely bound bilirubin, gel bound bilirubin, and binding affinity.

5. For smaller prematures, the concentration of total bilirubin at which the risk of kernicterus exceeds the risk of treatment is unknown. There is no scientific basis to guide the clinician in deciding when to institute treatment of jaundice in these babies.

6. Hyperbilirubinemia can lead to kernicterus. Whether it causes other, milder forms of neurologic and developmental damage is unknown. At present, there is no basis for treating jaundice with the hope of preventing such damage.

This article has been cited by other articles:

				Y. Yilmaz, G. Alper, G. Kilicoglu, L. Celik, L. Karadeniz, and S. Yilmaz-Degirmenci Magnetic Resonance Imaging Findings in Patients With Severe Neonatal Indirect Hyperbilirubinemia J Child Neurol, June 1, 2001; 16(6): 452 - 455. [Abstract] [PDF]