Diagnosis of hepatocellular carcinoma by concanavalin a affinity electrophoresis of serum alpha-fetoprotein

Background Concanavalin A (Con A) affinity electrophoresis of serum alpha-fetoprotein (AFP) can distinguish hepatocellular carcinoma (HCC) from other malignancies when the serum AFP concentration is elevated. However, Con A has not been able to distinguish HCC from benign chronic liver disease such as cirrhosis or chronic hepatitis. Methods The Con A affinity electrophoresis of serum AFP was analyzed in patients with a serum AFP concentration greater than 50 ng/mL by antibody affinity electrophoresis and Western blotting in an attempt to distinguish hepatocellular carcinoma from benign chronic liver disease. Before the assay, the serum AFP concentrations were adjusted between 100 ng/ml and 300 ng/ml by concentrating or diluting the samples. Results Of 180 patients with HCC, 44 (24%) had a single band and 91 (51%), 35 (19%), and 10 (6%) had 2, 3, and 4 bands, respectively. All 35 patients with chronic hepatitis had a single band. All but 1 of 72 patients with cirrhosis had a single band. Multiple AFP bands on Con A affinity electrophoresis appear to be diagnostic of HCC. This method has a sensitivity of 76%, a specificity of 99%, a positive predictive value of 99%, and a negative predictive value of 71% for detecting HCC. The number of AFP bands correlated with serum AFP concentration and tumor size in patients with HCC. Conclusions This assay is useful for distinguishing HCC from benign chronic liver diseases.