Usefulness of the unbound serum bilirubin for predicting neonatal bilirubin encephalopathy / 国际儿科学杂志

ABSTRACT

Bilirubin encephalopathy is still one of the challenges for neonatal society.In recent years,the incidence in Europe and North America is 1/100 000 ～ 1/40 000,while it is 1.13‰ in China.The current guideline for neonatal hyperbilirubinemia is based on total serum bilirubin (TSB),combined with gestational age,birth weight,age and risk factors.TSB is used as a main index for phototherapy and exchange transfusion.However,only unbound serum bilirubin (UB) can cross blood brain barrier and neuron membrane to cause neurotoxicity,so it is important to monitor UB.In view of the difficulties to measure UB directly,it has been proposed to measure serum albumin (SA),the TSB/SA ratio,TSB/SA molar ratio and the affinity of SA for TSB in addition to monitor TSB,but their clinical practice value is limited.Previously,the methods for direct detection of UB such as oxidase method,modified peroxidase method and photometric method have not been accepted nor routinely used.Recently Martelanc has piloted to use high performance liquid chromatography to directly measure UB with precision up to pmol/L.This recent progress offers reference for measuring UB in neonates,but the threshold of UB predicting bilirubin encephalopathy needs to be further studied.This article will review the important role of UB in predicting bilirubin encephalopathy,predicting experimental parameters of neonatal bilirubin encephalopathy,current methodologies for direct detection of UB.