Acetylcholine Receptor (AChR) Antibodies, Complete Profile With Reflex to MuSK Antibodies
Also known as: ACHALL, AG, MYESTTH, Reflex Musk
Use
Test for the laboratory diagnosis of myasthenia gravis (MG)
Special Instructions
The test includes measurements for AChR-binding, AChR-blocking, and AChR-modulating antibodies. If AChR-binding and blocking results are normal, it will reflex to Muscle Specific Kinase (MuSK) antibodies. Patient specimens testing positive may indicate other autoimmune disorders or thymoma without MG.
Limitations
The test has not been cleared or approved by the FDA, and the performance characteristics have been determined by LabCorp. In rare cases, AChR antibodies can be found in patients with other autoimmune disorders or with thymoma without MG. About 10% of MG patients may not have the causative autoantibody identified, and 15% of MG patients may have no measurable AChR antibodies, but instead have antibodies against MuSK.
Methodology
Immunoassay
Biomarkers
LOINC Codes
- 11034-6
- 11561-8
- 99062-2
- 11034-6
- 11561-8
- 99062-2
Result Turnaround Time
2-7 days
Related Documents
For more information, please review the documents below
Specimen
Serum
Volume
4 mL divided into two tubes
Minimum Volume
2 mL
Container
Red-top tube or gel-barrier tube
Collection Instructions
Allow a minimum clotting time of 30 to 60 minutes with serum separation within 2 hours of collection. Send serum samples in a plastic transport tubes.
Patient Preparation
No isotopes administered 24 hours prior to venipuncture.
Storage Instructions
Refrigerate.
Causes for Rejection
Excessive hemolysis; chylous serum; recently administered radioisotopes; plasma specimen
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 13 days |
| Refrigerated | 13 days |
| Frozen | 13 days |