Establishment of assay kits for the determination of microheterogeneities of alpha-fetoprotein using lectin-affinity electrophoresis.

Diagnostic kits for determination of alpha-fetoprotein (AFP) carbohydrate chain microheterogeneity were developed using lectin affinity electrophoresis with Lens culinaris agglutinin-A (LCA-A) and erythro-agglutinating phytohemagglutinin-E4 (PHA-E4). Separated AFP bands by electrophoresis were detected with high sensitivity by antibody-affinity blotting and immunoenzymatic amplification. Densitometry was used to apportion lectin reactive AFPs. The within-run S.D. for proportions of AFP bands was below 3%. Band intensity was linearly related to AFP concentration between 2 and 200 ng/ml. Profiles of lectin reactive AFPs were compared in serum samples from 55 patients having liver diseases. The average values of lectin reactive AFPs for chronic hepatitis and liver cirrhosis patients were both below 13%, but those of hepatocellular carcinoma patients were above 25%. Correlation of data with disease states suggests that the methods can greatly facilitate the discrimination between benign and malignant liver diseases.