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HelpTest Code L3AFP Alpha-Fetoprotein (AFP) L3% and Total, Hepatocellular Carcinoma Tumor Marker, Serum
Reporting Name
AFP-L3% and Total AFP, SUseful For
Distinguishing between hepatocellular carcinoma and chronic liver disease
Monitoring individuals with hepatic cirrhosis from any etiology for progression to hepatocellular carcinoma
Surveillance for development of hepatocellular carcinoma in individuals with a positive family history of hepatic cancer
Surveillance for development of hepatocellular carcinoma in individuals within specific ethnic and sex groups who do not have hepatic cirrhosis but have a confirmed diagnosis of chronic infection by hepatitis B acquired early in life, including:
-African men above the age of 20
-Asian men above the age of 40
-Asian women above the age of 50
Method Name
Isotachophoresis with Laser-Induced Fluorescence
Performing Laboratory
Mayo Clinic Laboratories in Rochester
Specimen Type
SerumSpecimen Required
Collection Container/Tube:
Preferred: Serum Gel
Acceptable: Red Top
Submission Container/Tube: Plastic vial
Specimen Volume: 0.5 mL
Collection Instructions: Centrifuge and aliquot serum into a plastic vial.
Specimen Minimum Volume
0.2 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Serum | Frozen (preferred) | 180 days | |
| Refrigerated | 5 days |
Reject Due To
| Gross hemolysis | Reject |
| Gross lipemia | OK |
| Gross icterus | OK |
Reference Values
TOTAL ALPHA-FETOPROTEIN (AFP):
<4.7 ng/mL
AFP %L3:
<10%
Day(s) Performed
Monday through Friday
CPT Code Information
82107
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| L3AFP | AFP-L3% and Total AFP, S | 96451-0 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| TAFP | Total AFP, S | 1834-1 |
| L3 | %L3 | 42332-7 |
| INT67 | Interpretation | 69048-7 |
Clinical Information
Worldwide, hepatocellular carcinoma is the third leading cause of death from cancer.(1) While hepatocellular carcinoma can be treated effectively in its early stages, most patients are not diagnosed until they are symptomatic and at higher grades and stages, which are less responsive to therapies. Alpha-fetoprotein (AFP) is the standard serum tumor marker utilized in the evaluation of suspected hepatocellular carcinoma. However, increased serum concentrations of AFP may be found in chronic hepatitis and liver cirrhosis as well as in other tumor types (eg, germ cell tumors),(2) decreasing the specificity of AFP testing for hepatocellular carcinoma. Furthermore, AFP is not expressed at high levels in all hepatocellular carcinoma patients, resulting in decreased sensitivity, especially in potentially curable small tumors.
AFP is differentially glycosylated in several hepatic diseases. For example, uridine diphosphate-alpha-(1->6)-fucosyltransferase is differentially expressed in hepatocytes following malignant transformation.(3) This enzyme incorporates fucose residues on the carbohydrate chains of AFP. Different glycosylated forms of AFP can be recognized following electrophoresis by reaction with different carbohydrate-binding plant lectins. The fucosylated form of serum AFP, which is most closely associated with hepatocellular carcinoma, is recognized by a lectin from the common lentil (Lens culinaris). This is designated as AFP-L3 (third electrophoretic form of lentil lectin-reactive AFP). AFP-L3 is most useful in the differential diagnosis of individuals with total serum AFP of 200 ng/mL or below, which may result from a variety of benign pathologies, such as chronic liver diseases.
AFP-L3 should be utilized as an adjunct to high-resolution ultrasound for surveillance of individuals at significant risk for developing hepatic lesions.
Interpretation
Alpha-fetoprotein (AFP)-L3 results of 10% or above are associated with a 7-fold increased risk of developing hepatocellular carcinoma. Patients with AFP-L3 at this level should be monitored more intensely for evidence of hepatocellular carcinoma according to current practice guidelines.
A total serum AFP above 200 ng/mL is highly suggestive of a diagnosis of hepatocellular carcinoma. In patients with liver disease, a total serum AFP at this level is near 100% predictive of hepatocellular carcinoma. With lower total AFP levels, there is an increased likelihood that chronic liver disease, rather than hepatocellular carcinoma, is responsible for the AFP elevation.
AFP concentrations over 100,000 ng/mL have been reported in normal newborns, and the values rapidly decline in the first 6 years of life.
Cautions
Tumor marker tests are not specific for diagnosis of malignancy. Some hepatocellular tumors do not synthesize alpha-fetoprotein (AFP). AFP or AFP-L3 should, therefore, not be relied upon alone. Concomitant clinical assessment or imaging is recommended in hepatocellular carcinoma surveillance of high-risk patients and for hepatocellular carcinoma diagnosis.
Test results for AFP are not interpretable if the individual is pregnant.
Alpha-Fetoprotein and L3% values are not interpretable during pregnancy for the investigation of malignant disease.
Higher AFP values are found in newborns and pregnant women.
Values obtained with different assay methods or kits cannot be used interchangeably. The total AFP test value must be obtained using this method (uTASWako i30 AFP-L3 kit) in order to determine the percent AFP-L3. Mayo Clinic Laboratories other AFP tumor marker test, AFP / Alpha-Fetoprotein (AFP) Tumor Marker, Serum; is not suitable for use with AFP-L3 values.
In rare cases, some individuals can develop antibodies to mouse or other animal antibodies (often referred to as human anti-mouse antibodies [HAMA] or heterophile antibodies), which may cause interference in some immunoassays. Caution should be used in interpretation of results and the laboratory should be alerted if the result does not correlate with the clinical presentation.
Method Description
Total alpha-fetoprotein (AFP) is measured by laser-induced fluorescence, with separation of the lentil lectin-reactive AFP-L3 and lectin nonreactive forms of AFP by isotachophoresis of their immune-complexes. Results are expressed as the percent ratio of AFP-L3 to total AFP.(Package insert: uTASWako i30 AFP-L3 18.07.18K13. Wako Diagnostics; 07/2018)