Serum alpha-fetoprotein and its lectin reactivity in liver diseases: a review.

Increased serum concentration of alpha-fetoprotein (AFP) can be found in benign and malignant liver diseases, in yolk sac tumors, and in several nonhepatic neoplasms at advanced stage. The frequency and level of elevated serum AFP are highest in hepatocellular carcinoma (HCC) and yolk sac tumors. Most levels of serum AFP in HCC are greater than 500 ng per mL, whereas the serum AFP in most of the benign liver diseases is only moderately elevated and is transient in nature. Determination of lectin reactivity of serum AFP is helpful for the differentiation of HCC from other diseases associated with elevated serum AFP. Determination of Len culinaris agglutinin (LCA) reactivity of serum AFP is useful for the differentiation of HCC from benign liver diseases, and for early detection of hepatoma. Determination of concanavalin A (Con A) nonreactive AFP variant is useful for the differentiation of HCC from yolk sac tumors and may also allow for the differentiation of HCC from nonhepatic neoplasms. However, reaction with several lectins may be required if differentiation among various nonhepatic neoplasms is needed.