[Alpha-fetoprotein: diagnostic value in hepatic disorders]

The serum AFP concentration in man falls rapidly after birth and its synthesis in adult life is normally repressed. However, AFP is synthesized in large amounts by human hepatocellular carcinoma in greater than 70% of patients. Elevation of serum AFP in benign hepatic diseases such as acute and chronic viral hepatitis as well as toxic liver injury is associated with small transient increases in serum AFP. Therefore, quantification of serum alpha-fetoprotein (AFP) has been widely used as a diagnostic marker for hepatocellular carcinoma. Measurement of serum AFP levels have also been used in screening populations at high risk of human hepatocellular carcinoma such as those with cirrhosis or carriers of hepatitis B virus. However the specificity of the screening test in patients with only modestly raised AFP (below 400 ng/ml) is low, and false-positive results are frequent. A wide range of overlap in the distribution of serum AFP levels between hepatocellular carcinoma and chronic liver disease patients were observed mainly among HBsAg (+) patients. Therefore the specificity and predictive value of AFP are lower in HBsAg(+) than in HBsAg(-) patients, especially when AFP is between 25 and 200 ng/ml. In patients with chronic hepatitis B, the analysis of lectin reactivity of AFP has the advantages over quantification of serum AFP to detect HCC-specific variants in serum samples with only moderate raised AFP levels. Measurement of AFP serves as an important tool in the care and management of patients with benign and malignant hepatic disorders.