AFP is a 70 kD major fetal serum glycoprotein with an unknown function that is synthesized in the liver, yolk sac and fetal gastrointestinal tract. Serum elevations are seen in either pregnant women or patients with cirrhosis and hepatitis. Increases in serum levels aid in diagnosis, classification and monitoring of non-seminomatous testicular cancer as well as primary hepatocellular carcinoma. This antigen is derived from a liver tumor cell and not human cord serum. It contains the correct isoform percentage of AFP-L3 (approximately 70% as compared to 10% in human cord serum).
AFP has three isoforms (AFP-L1, AFP-L2 and AFP-L3) of which the AFP-L3 form is associated with germ cell and liver tumors.
Approved clinical uses includes diagnosis, classification and monitoring of non-seminomatous testicular and heptacellular carcinomas.