Experience with sephadex gel filtration in assessing the risk of bilirubin encephalopathy in neonatal jaundice

Recent progress in the prevention of significant neonatal hyperbilirubinemia either by enzyme induction or by phototherapy has not, so far, completely obviated the need for exchange transfusion. Moreover, kernicterus has not always been prevented. Kernicterus is seen particularly among severely ill, very small and immature infants who now can survive with the aid of modern respiratory and metabolic support. It is in this group that the authors' inadequacy in assessing the danger of kernicterus became obvious. Therefore, new methods for improving current criteria for exchange transfusion are urgently needed. It is generally agreed that the fraction of bilirubin which is not firmly bound to albumin ('unbound,' 'free' or 'loosely bound' bilirubin) is one of the main factors determining the development of bilirubin encephalopathy. Tests to assess bilirubin binding to serum have been suggested in order to improve the criteria for exchange transfusion. Sor far, none has proved to be of great clinical value. In the present work a simple and rapid Sephadex gel filtration test was used for assessing bilirubin binding in the serum of a large number of cases of neonatal jaundice, including 24 cases with bilirubin encephalopathy.