Serum alpha-fetoprotein. 8. Serum levels during diethylnitrosamine poisoning of baboons

[Carcinofetal antigens. I. alpha-fetoprotein (author's transl)]

Alpha-fetoprotein (AFP) is an alpha1-glycoprotein (M.W. about 65000) appearing in the fetal serum of most mammals including man during the early stages of pregnancy; 4 weeks after birth it disappears altogether or exists at very low concentrations as in the normal adult. AFP is formed in the yolk sac, the fetal liver and the gastro-intestinal tract. One of its physiological functions in fetal life is supposed to be the protection of the fetus from maternal oestrogens (oestrophilic property). The clinical significance of AFP is based on the regular and increasing production in primary liver cell carcinoma, less frequently in teratogenetic tumors where it serves as a control of therapy and course of the disease. Less frequent, minor and temporary increases in the AFP serum level occur in several primary tumors with secondary liver involvement, and in inflammatory gastro-intestinal diseases, e.g. of the liver (hepatitis, cirrhosis). AFP has an increasing importance in gynecology (gestational age, fetal distress syndrom, malformations, hydatidiform mole/chorion carcinoma). The physico-chemical properties of AFP are widely known. Both fetal and tumor AFP appear to be immunologically and biochemically identical, as are that of tissue and biological fluids. The differences observed (variants, microheterogeneity) depend mainly on the different content of sialic acid. An antigenetic relationship exists, between the AFP of most species. The immunodiffusion (Ouchterlony) is the most frequently used but relatively insensitive test (1-5 mug/ml) in finding AFP, whereas the radioimmunoassay is the most sensitive one (up to 0,25 ng/ml) and permits the determination of normal serum levels in adults (below 20 ng/ml). The serum concentration in healthy pregnant women lies up to 500 ng/ml, in patients with hepatitis, liver cirrhosis and other liver diseases mostly under 3 mug/ml, whereas in those with primary liver cell carcinoma levels up to and above 600 mg-percent have been found.

Serum alpha-fetoprotein levels in acute viral hepatitis

Serum alpha-fetoprotein levels were measured serially by radioimmunoassay in 32 patients with acute viral hepatitis. With one exception, the levels were increased during the course of the illness. Raised concentrations of the protein occurred almost equally in patients with and without the hepatitis-B antigen. In the majority of patients the rise was modest but in seven levels were reached at which alpha-fetoprotein could be detected by immunodiffusion. Very high levels were more likely to occur in children. In eight patients the concentration increased as the serum glutamic pyruvic transaminase (SGPT) level, used as an index of hepatocyte damage, was returning to normal, a pattern which favoured increased synthesis of the protein during hepatocellular regeneration. In the remainder, the alpha-fetoprotein level paralleled that of SGPT, suggesting rather an acutephase reaction to liver injury.