Reference range : ≤7 micro;g/l
turnround : <3 days
AFP is a glycoprotein homologous to albumin. Normally produced during gestation by the fetal liver,
Malignancies with elevated levels:
Mainly confined to three malignancies, ie
- Hepatocellular carcinoma - elevated in 70 - 90% cases
- Non-seminomatous germ cell tumours of testis, ovary and other sites - elevated in 40 - 60% of patients with testicular germ cell tumours. Rarely elevated in patients with stage one testicular cancer.
- Hepatoblastoma (in children, extremely rare in adults)
Physiological causes for raised AFP:
AFP is high in newborns with levels declining to adult values by one year of age. AFP is also elevated in pregnancy.
Benign conditions which may have elevated levels:
Hepatitis, cirrhosis, biliary tract obstruction, alcoholic liver disease and ataxia telangiectasia.
20-40% of adult patients with hepatitis or cirrhosis have raised AFP levels and AFP concentrations up to 1000 µg/l may occur in benign conditions. AFP concentrations >50µg/L should be referred for specialist hepatobiliary interpretation.
Main clinical applications:
In general, AFP should only be requested in patients with established cirrhosis or in whom a hepatic lesion has been demonstrated by imaging
- Diagnostic aid for hepatocellular carcinoma. An AFP concentration between 400 - 500 µg/l is now generally accepted as the optimal decision point to distinguish hepatocellular carcinoma from chronic liver disease. In general, a sustained rise in AFP is suggestive of malignancy, while stable or decreasing results make it less likely. A rising concentration over a period of time is more significant than the absolute concentration e.g. a doubling from 10µg/L to 20µg/L and then a rise to 50µg/L is much more suggestive of malignancy than a single value of 80µg/L.
- Screening for hepatocellular carcinoma in high risk disease groups eg
haemochromatosis, alcoholic cirrhosis (if abstinent) cirrhosis due to hepatitis C
hepatitis B surface antigen positive carriers with chronic active hepatitis / cirrhosis
males with primary biliary cirrhosis)
Small hepatocellular tumours are AFP negative in up to 40% cases. In these instances, the tumour can only be detected by ultrasound. Lesions undetectable by imaging are likely to reach 2cm in diameter in about 4 -12 months, so in order to detect tumours below 2cm, the suggested interval for surveillance in cirrhotic patients is 6 months, using both serum AFP and ultrasound.
- In combination with HCG, for monitoring patients with non-seminomatous germ cell tumours.
- Independent prognostic marker for non-seminomatous germ cell tumours
- Diagnosis of hepatoblastoma
Additional information on
AFP and its clinical use can be found here: AFP.
AFP: new reference interval 01/05/21.
RLH service users: results unaffected.
AUH service users: AFP now reported in ug/L, values 20 % higher than previously.
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