[Analysis of lectin-affinity of alpha fetoprotein-diagnostic approach]

Lectin affinities of AFP were analyzed using Con A sepharose chromatography and crossed immuno-affino-electrophoresis. With Con A, AFP was divided into three subfractions, nonbound, loosely-bound and tightly-bound by chromatography, or two subfractions, nonbound and bound by electrophoresis. Con A nonbound subfraction was small in percentage in hepatocellular carcinoma (HCC), neonatal hepatitis, congenital biliary atresia (CBA), liver cirrhosis (LC) and cord sera. In contrast with these, the increase of Con A non-bound AFP was observed in yolk sac tumor (YST) and metastatic liver cancer (Meta). With LCA, AFP was divided into three subfractions: nonbound, loosely bound and tightly bound. Loosely bound fraction was very small in every specimen. AFPs from cord sera and LC showed uniform LCA affinity pattern, but AFPs from HCC were not uniform. Our data suggest that the analyses of lectin affinity of AFP serve as a diagnostic tool in differentiating (1) HCC from YST, (2) HCC from Meta, (3) CBA or neonatal hepatitis from YST and (4) LC from some cases of HCC.