(Science: protein tumour marker) a protein substance that is normally produced by the liver cells.
It is one of the first alpha-globulins to appear in mammalian sera during development of the embryo and the dominant serum proteins in early embryonic life. They reappear in the adult serum during certain pathologic states.
measurement of the alpha-fetoprotein level in the bloodstream has been used as a early detection test for some forms of cancer (hepatocellular carcinoma). Alpha-fetoprotein can also be an important marker in the fluid obtained by amniocentesis for the prenatal diagnosis of anencephaly and other open neural tube defects such as spina bifida.
Elevated in: wrong dates for a pregnancy, multiple gestation, midline closure (neural-tube) defects, encephalocele, anencephaly, liver tumours, hepatoblastoma, haemangioendothelioma (occasionally, mild), hepatocellular carcinoma (HCC, hepatoma). The level produced by liver tumours (hepatomas), germ Cell tumours (teratocarcinoma and embryonal cell carcinomas) permits the monitoring of response to treatment of these tumours.
Decreased in: wrong dates fo
r a pregnancy, chromosome abnormality (including down syndrome)