Acetylcholine Receptor Antibodies by Radioimmunoprecipitation
Use
This test assists in the diagnosis of autoimmune myasthenia gravis (MG) by detecting acetylcholine receptor (AChR) antibodies. It is the first-line test in the MG antibody panel, offered to facilitate the identification of AChR antibodies specific to MG cases. While a positive result strongly suggests MG, the absence of AChR antibodies does not conclusively rule out the condition, given that up to 10% of MG cases may not exhibit these antibodies. Therefore, this test is an essential initial diagnostic tool in assessing suspected cases of MG.
Special Instructions
Not provided.
Limitations
The test cannot identify causal antibodies in about 10% of MG cases. Additionally, the performance of the test may be affected if patients are undergoing immunomodulating treatments. The lack of FDA approval means its analytical accuracy is determined solely by Neurocode USA Inc., raising considerations about the test's diagnostic breadth and interpretation.
Methodology
Immunoassay
Biomarkers
Acetylcholine Receptor Antibodies
Protein
Result Turnaround Time
2-8 days
Related Documents
For more information, please review the documents below
Specimen
Serum
Volume
3 mL
Minimum Volume
0.5 mL
Container
Gel barrier or red-top tube
Collection Instructions
Draw blood in tube with SST activator (5 mL gold top or 8.5 mL tiger top). Invert tubes 8 times to ensure complete mixing. Allow sample 30 minutes to clot or 1 hour if using red-top tube. Centrifuge tubes at 1800 - 2200 x g for 10-15 minutes within 2 hours of collection. Draw off serum into aliquot tubes using a pipette.
Patient Preparation
No patient preparation is required for sample collection.
Storage Instructions
Store aliquot tubes in refrigerator (2°C - 8°C) until shipping.
Causes for Rejection
Grossly hemolytic, lipemic, or icteric samples. Samples arriving at room temperature.
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 7 days |
| Refrigerated | 4 weeks |
| Frozen | 4 weeks; 2 freeze/thaw cycles allowed |