Differences in the structure of alpha-fetoprotein and its clinical use in pediatric surgery.

Techniques have been studied which distinguish two variants of human alpha-fetoprotein (AFP) on the basis of characteristics of the carbohydrate moiety of this glycoprotein. AFP in serum samples from six children with tumors of yolk sac origin showed little concanavalin-A (Con A) binding. In contrast, Con A binding of AFP was almost complete in serum samples from 14 other subjects with elevated AFP, including two with liver-cell tumors, eight with neonatal cholestasis, and four normal newborn infants. Differences were confirmed by immunoelectrophoretic studies. Thus, AFP from cells of yolk sac origin can be distinguished from AFP from liver cells or from tumors of hepatic cell origin.