Affinity chromatographic separation of alpha-fetoprotein variants: development of a mini-column procedure, and application to cancer patients.

This is an affinity chromatographic procedure for separating variants of alpha-fetoprotein in 0.1 mL of serum on a disposable mini-column containing 0.9 mL of concanavalin A-Sepharose, at pH 6.4 and with a flow rate of 5 mL/h. The binding capacity of the column is 52 micrograms. Analytical recovery was 90%. Between-run CVs varied from 2.0% for samples with a high percentage of concanavalin A nonreactive fraction to 13% for samples with a low percentage. The mean proportion of nonreactive alpha-fetoprotein was 13.4% for patients with hepatocellular carcinoma, 62.2% for testicular carcinoma, and 8.9% for nonmalignant liver diseases. This suggests that the alpha-fetoprotein variants could be used to distinguish hepatocellular carcinoma from other carcinomas. Serial determination of the concanavalin A nonreactive fraction in such patients showed a relatively constant percentage. This indicates that monitoring variants in patients with hepatocellular carcinoma throughout their clinical course may not provide useful information additional to that provided by the values for total serum alpha-fetoprotein.