Semiquantitative Assay of Serum Lipoprotein-X in Differential Diagnosis of Neonatal Hepatitis and Congenital Biliary Atresia

Sera from 83 infants with biliary atresia or neonatal hepatitis were examined for the presence of lipoprotein-X (Lp-X). All the infants examined with biliary atresia were positive for Lp-X. Forty-three percent of infants with neonatal hepatitis were positive for Lp-X. The semiquantitative assay of serum Lp-X revealed that it was higher in the group of biliary atresia than in the group of neonatal hepatitis. Out of 37 infants with biliary atresia 18 were positive for Lp-X in an eight-fold or greater dilution of serum. On the other hand, only one of 46 infants with neonatal hepatitis was Lp-X positive in the same dilution. The semiquantitative values of Lp-X were well correlated with quantitative levels of Lp-X, and the sera positive for Lp-X in eight-fold or greater dilutions had Lp-X levels of higher than 300 mg/100 ml. From these results the semiquantitative assay of serum Lp-X may be of value in helping to differentiate biliary atresia from neonatal hepatitis, especially in the early stage of the disease.