Test Details
Methodology
Electrochemiluminescence immunoassay (ECLIA)
Result Turnaround Time
Within 1 day
Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.
Use
The most important application of AFP testing in cancer management is for testicular cancer. Although not present in pure seminoma,1 elevated serum AFP is closely associated with nonseminomatous testicular cancer.2-4 The measurement of AFP in serum, in conjunction with serum hCG, is an established regimen for monitoring patients with nonseminomatous testicular cancer.5-8 In addition, monitoring the rate of AFP clearance from serum after treatment is an indicator of the effectiveness of therapy.9,10 Conversely, the growth rate of progressive cancer can be monitored by serially measuring serum AFP concentration over time.11 Serial serum AFP testing is a useful adjunctive test for managing nonseminomatous testicular cancer.
Special Instructions
If patient is pregnant, include approximate gestational age on the test request form and order test 010801. Values obtained with different assay methodologies should not be used interchangeably in serial testing. It is recommended that only one assay method be used consistently to monitor a patient's course of therapy. This procedure does not provide serial monitoring; it is intended for one-time use only. If serial monitoring is required, please use the serial monitoring number 480012 to order.
This test may exhibit interference when sample is collected from a person who is consuming a supplement with a high dose of biotin (also termed as vitamin B7 or B8, vitamin H, or coenzyme R). It is recommended to ask all patients who may be indicated for this test about biotin supplementation. Patients should be cautioned to stop biotin consumption at least 72 hours prior to the collection of a sample.
Limitations
The measured AFP value of a patient's sample can vary depending on the test procedure used. The laboratory finding must, therefore, always contain a statement on the AFP assay method used. AFP values determined on patient samples by different test procedures cannot be directly compared with one another and could be the cause of erroneous medical interpretations.
As with all tests containing monoclonal mouse antibodies, erroneous findings may be obtained from samples taken from patients who have been treated with monoclonal mouse antibodies or who have received them for diagnostic purposes.12 In rare cases, interference due to extremely high titers of antibodies to streptavidin and ruthenium can occur.12 The test contains additives, which minimize these effects.
For diagnostic purposes, the results should always be assessed in conjunction with the patient's medical history, clinical examination, and other findings.
Footnotes
Custom Additional Information
The Elecsys AFP assay is intended for the in vitro quantitative determination of α1-fetoprotein in human serum and plasma to aid in the management of patients with nonseminomatous germ cell tumors.12 The determination of AFP to screen the general population for cancer is, however, not to be recommended.
A1-fetoprotein, an albumin-like glycoprotein with a molecular weight of 70,000 daltons, is formed in the yolk sac, nondifferentiated liver cells, and the fetal gastrointestinal tract.13-15 Seventy percent to 95% of patients with primary hepatocellular carcinoma have elevated AFP values.16 The later the stage of nonseminomatous 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, nonseminomatous germ cell tumors.17-19
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 <350-400 IU/mL.20 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.20,21
Specimen Requirements
Specimen
Serum
Volume
1 mL
Minimum Volume
0.7 mL (Note: This volume does not allow for repeat testing.)
Container
Gel-barrier tube (preferred) or red-top tube
Collection Instructions
If a red-top tube is used, transfer separated serum to a plastic transport tube.
Stability Requirements
Temperature | Period |
---|---|
Room temperature | 14 days |
Refrigerated | 14 days |
Frozen | 14 days |
Freeze/thaw cycles | Stable x3 |
Reference Range
See table.
Age | Male | Female |
---|---|---|
AFP, Serum (ng/mL) | AFP, Serum (ng/mL) | |
0 to 7 d | 0.0–75265.8 | 0.0–75265.8 |
8 to 30 d | 0.0–32556.4 | 0.0–32556.4 |
1 m | 0.0–1747.8 | 0.0–1600.3 |
2 m | 0.0–391.1 | 0.0–550.0 |
3 m | 0.0–225.8 | 0.0–339.9 |
4 m | 0.0–230.6 | 0.0–230.6 |
5 m | 0.0–118.0 | 0.0–234.0 |
6 m | 0.0–97.2 | 0.0–97.2 |
7 to 11 m | 0.0–60.3 | 0.0–60.3 |
1 y | 0.0–21.4 | 0.0–21.4 |
2 y | 0.0 –9.4 | 0.0–10.1 |
3 to 4 y | 0.0–5.5 | 0.0–5.5 |
5 y | 0.0–3.6 | 0.0–4.2 |
6 to 12 y | 0.0–3.9 | 0.0–3.9 |
13 to 17 y | 0.0–4.3 | 0.0–4.3 |
18 to 30 y | 0.0–5.7 | 0.0–4.7 |
31 to 50 y | 0.0–6.9 | 0.0–6.4 |
51 to 80 y | 0.0–8.4 | 0.0–9.2 |
>80 y | 0.0–6.4 | 0.0–8.7 |
Reference Interval developed by in-house study. Normal values apply only to males and to nonpregnant females. These results are not interpretable for pregnant females. |
Storage Instructions
Room temperature
Causes for Rejection
Citrate plasma specimen; improper labeling
LOINC® Map
Order Code | Order Code Name | Order Loinc | Result Code | Result Code Name | UofM | Result LOINC |
---|---|---|---|---|---|---|
002253 | AFP, Serum, Tumor Marker | 53962-7 | 002266 | AFP, Serum, Tumor Marker | ng/mL | 53962-7 |
Order Code | 002253 | |||||
Order Code Name | AFP, Serum, Tumor Marker | |||||
Order Loinc | 53962-7 | |||||
Result Code | 002266 | |||||
Result Code Name | AFP, Serum, Tumor Marker | |||||
UofM | ng/mL | |||||
Result LOINC | 53962-7 |