Clinical significance of serum alpha-fetoprotein subfractionation in pediatric diseases.

Serum alpha-fetoprotein (AFP) subfraction profile is a predictive indicator for the discrimination of hepatic malignancies, benign liver diseases and yolk sac tumor in adults. In the present study, AFP subfractions were examined in AFP-positive sera from 59 patients of less than 15 years of age. Fractionation of AFP was carried out by lectin affinity crossed-line immunoelectrophoresis. Concanavalin A, Lens culinaris hemagglutinin and phytohemagglutinin E were used as lectins. Fifty-four of 59 (91.5%) AFP subfraction profiles in patients with pediatric diseases were classified into three common types: (1) benign liver disorder, (2) hepatic malignancy and (3) yolk sac tumor. An atypical AFP subfraction profile resembling hepatic malignancy type was found in 5 of 59 (8.5%) infants. It was concluded that estimation of serum AFP subfraction profiles facilitates differential diagnosis of various AFP-positive pediatric diseases, such as hepatoblastoma, hepatoma, hepatic cirrhosis, hepatitis or germ cell tumors.