Alpha1-fetoprotein, an albumin - like glycoprotein with a molecular weight of 70000 daltons, is formed in the yolk sac, non - differentiated liver cells, and the fetal gastro - intestinal tract. 70‑95 % of patients with primary hepatocellular carcinoma have elevated AFP values.
The later the stage of non - seminomatous germ cell tumors, the higher the AFP values. Human chorionic gonadotropin (hCG) and AFP are important parameters for estimating the survival rate of patients with advanced, non - seminomatous germ cell tumors.
No correlation between the AFP concentration and tumor size, tumor growth, stage or degree of malignancy has so far been demonstrated. Greatly elevated AFP values generally indicate primary liver cell carcinoma. When liver metastasis exists, the AFP values are generally below 350‑400 IU/mL. As the AFP values rise during regeneration of the liver, moderately elevated values are found in alcohol - mediated liver cirrhosis and acute viral hepatitis as well as in carriers of HBsAg. The determination of AFP to screen the general population for cancer is, however, not to be recommended. Elevated AFP concentrations in maternal serum or amniotic fluid during pregnancy can indicate spina bifida, anencephalia, atresia of the oesophagus or multiple pregnancy.
Measurement of AFP makes a contribution to the risk assessment for trisomy 21 (Down syndrome) in the second trimester of pregnancy together with hCG+β and other parameters, such as exact gestational age and maternal weight. In a trisomy 21 affected pregnancy the maternal serum concentration of AFP is decreased whereas the maternal serum hCG+β concentration is approximately twice the normal median. The risk for a trisomy 21 affected pregnancy in the second trimester can be calculated by a suitable software.
SI units Conversion Calculator. Convert Alpha-fetoprotein (AFP) level to µg/L, ng/L, ng/dL, ng/100mL, ng%, ng/mL, IU/mL. Clinical laboratory units online conversion from conventional or traditional units to Si units. Table of conversion factors for Alpha-fetoprotein (AFP) unit conversion to µg/L, ng/L, ng/dL, ng/100mL, ng%, ng/mL, IU/mL.