Alpha-fetoprotein

Keywords: AFP

Specimen:

5 mL blood in plain tube.

Method:

Immunoassay.

Reference Interval:

Method dependent.

Non-pregnant adult:< 16 µg/L.

Normal pregnancy: varies with gestational age, results may be expressed as multiples of the median.

See Down syndrome antenatal risk test.

Application:

Detection and monitoring of hepatocellular carcinoma and germ cell tumours, particularly for recurrence after treatment.

Assessment of risk for neural tube and other defects in utero, including Down syndrome (one of the components of the 'triple test').

Interpretation:

Hepatocellular carcinoma is usually associated with very high levels of α-fetoprotein, but a normal level does not exclude this diagnosis, nor of germ cell tumour.

Moderate increases may occur with non-malignant disease associated with liver cell regeneration.

In pregnancy increased levels have high sensitivity and low specificity for fetal abnormalities. Low maternal levels are associated with Down syndrome pregnancies; results must be interpreted in conjunction with other tests -consult pathologist.

See Down syndrome antenatal risk test.

Reference:

Benn PA. Clin Chim Acta 2002; 323: 1-16.

Nguyen MH, Keeffe EB. J Clin Gastroenterol 2002; 35: 86-91.