Test Background AFP is a single chain glycoprotein of 591 amino acids that is structurally related to albumin. Synthesis of AFP occurs primarily in the liver and yolk sac of the fetus. It is secreted into fetal serum, reaching a peak at about 13 weeks gestation and gradually declining thereafter. After birth, circulating concentrations decrease with a half-life of 5 days to adult levels by 8-10 months of age. The higher values in early childhood must be considered when using AFP measurement in testicular yolk sac tumour, the commonest testicular neoplasm in infants. Elevated circulating levels of AFP are observed in several malignant diseases, most commonly in hepatocellular carcinoma (HCC) and germ cell tumours where measurement is an important part of management. AFP is also used in the diagnosis of hepatoblastoma. Elevated serum AFP occurs in pregnancy and transient increases in serum AFP may occur in liver regeneration, hepatitis, chronic liver disease and cirrhosis (especially in hepatitis), biliary tract obstruction, alcoholic liver disease, ataxia telangiectasia and hereditary tyrosinaemia.
Clinical Indications Testicular and other germ cell tumours (GCT)
Adult serum (non-pregnant): <14 µg/L
Non-infant CSF (>2 months of age): <3 µg/L
Sample Required SST (gold top) preferred, serum (red top) accepted
Sample Volume 0.5 mL
Turnaround Time 4 days
Notes Abbott Alinity