[Clinical usefulness of lectin-reactive fraction of alpha-fetoprotein in hepatocellular carcinoma].

Alpha-fetoprotein (AFP) is well known as a tumor marker of hepatocellular carcinoma (HCC). AFP shows micro heterogeneity because of a structural variance in its sugar chain, and the sugar chain obtained from HCC patients has a high affinity to lectins such as Lens culinaris agglutinin. The lens culinaris agglutinin A-reactive fraction of alpha-fetoprotein (AFP-L3) was detected by a sensitive method using lectin-affinity electrophoresis coupled with antibody-affinity blotting. Of 62 HCC patients examined before initial therapy, 23 patients (37.1%) had an AFP-L3 level greater than 15%. In contrast, none of the patients with liver cirrhosis or chronic hepatitis tested were positive for AFP-L3. Seven (26.9%) of 26 patients with small HCC less than 2 cm in diameter measured on ultrasonography or computed tomography showed elevated AFP-L3 levels. Because there was no correlation observed between AFP-L3 and PIVKA-II, the combined measurement of these two complementary markers appeared to be useful in the diagnosis of HCC. When the results of both assays were combined, 34 (54.8%) of the 62 patients with untreated HCC showed elevated levels of one or both markers. The use of both markers together with imaging modalities during regular follow-up of chronic liver disease patients who are at high risk for HCC might be of great benefit.