Narrative review of bilirubin measurement and binding

Abstract

: It is well accepted that infants with an imbalance in bilirubin production and excretion and/or poor plasma bilirubin binding have an increased risk of bilirubin-induced neurological dysfunction (BIND). The objective of this narrative review is to provide current literature on bilirubin measurement and bilirubin binding in premature and term infants with unconjugated hyperbilirubinemia. We provide evidence to support the notion that both total serum bilirubin (TSB) and bilirubin binding measurement contribute critical information about the risk of BIND in premature and term infants. We have reviewed and provided the evidence supporting the usefulness of free or unbound bilirubin as a better predictor of BIND compared to TSB in premature and term infants. We have also discussed promising newer developing technologies as point-of-care (POC) methods for bilirubin and bilirubin binding measurement. Overall, the improved knowledge of bilirubin binding over the last 20 years and recent development of promising newer point of care technologies for bilirubin and binding measurement augur well for development of pragmatic intervention trials to reduce mortality and morbidity associated with unconjugated hyperbilirubinemia in premature and term infants.