Muscle-Specific Kinase (MuSK) Autoantibody, Serum
Use
This test is useful for the diagnosis of autoimmune muscle-specific kinase (MuSK) myasthenia gravis. It serves as a second-order test to aid in the diagnosis of autoimmune myasthenia gravis when first-line serologic tests are negative. Additionally, it is used for establishing a quantitative baseline value for MuSK antibodies that allows comparison with future levels if muscle weakness worsens.
Special Instructions
If not ordering electronically, complete and send one of the following forms with the specimen: Neurology Specialty Testing Client Test Request or General Request.
Limitations
Interpretation of serological and clinical status may be complicated by immunosuppressant therapy, which can cause false seronegativity. Furthermore, steroid-induced myopathy may obscure characteristic signs of myasthenia gravis.
New York Approved
Methodology
Immunoassay (RIA)
Biomarkers
LOINC Codes
- 51716-9
- 51716-9
Result Turnaround Time
3-10 days
Related Documents
For more information, please review the documents below
Specimen
Serum
Volume
1.5 mL
Minimum Volume
1 mL
Container
Red top or serum gel (submission in a plastic vial)
Collection Instructions
Centrifuge and aliquot serum into a plastic vial.
Causes for Rejection
Gross hemolysis, Gross lipemia, Gross icterus
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 72 hours |
| Refrigerated | 28 days |
| Frozen | 28 days |