Test Code MGMR Myasthenia Gravis Evaluation with Muscle-Specific Kinase (MuSK) Reflex, Serum
Ordering Guidance
This test should not be requested for patients who have recently received radioisotopes, therapeutically or diagnostically, because of potential assay interference. The specific waiting period before specimen collection will depend on the isotope administered, the dose given, and the clearance rate in the individual patient. Specimens will be screened for radioactivity prior to analysis. Radioactive specimens received in the laboratory will be held 1 week and assayed if sufficiently decayed or canceled if radioactivity remains.
Specimen Required
Patient Preparation: For optimal antibody detection, specimen collection is recommended prior to initiation of immunosuppressant medication or intravenous immunoglobulin treatment.
Supplies: Sarstedt Aliquot Tube, 5 mL (T914)
Collection Container/Tube:
Preferred: Red top
Acceptable: Serum gel
Submission Container/Tube: Plastic vial
Specimen Volume: 3 mL
Collection Instructions: Centrifuge and aliquot serum into a plastic vial.
Reflex Tests
Test ID | Reporting Name | Available Separately | Always Performed |
---|---|---|---|
ACMFS | AChR Modulating Flow Cytometry, S | No | No |
MUSK | MuSK Autoantibody, S | Yes | No |
Specimen Type
SerumSpecimen Minimum Volume
2 mL
Specimen Stability Information
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
Serum | Refrigerated (preferred) | 28 days | |
Frozen | 28 days | ||
Ambient | 72 hours |
Reject Due To
Gross hemolysis | Reject |
Gross lipemia | Reject |
Gross icterus | Reject |
Reference Values
Test ID |
Reporting Name |
Methodology |
Reference Value |
MGMRI |
MG with MuSK Interpretation, S |
Interpretation |
NA |
ARBI |
ACh Receptor (Muscle) Binding Ab |
Radioimmunoassay (RIA) |
≤0.02 nmol/L |
Reflex Information:
Test ID |
Reporting Name |
Methodology |
Reference Value |
ACMFS |
AChR Modulating Flow Cytometry, S |
Flow Cytometry |
Negative |
MUSK |
MuSK Autoantibody, S |
RIA |
≤0.02 nmol/L |
Day(s) Performed
Profile tests: Monday through Sunday; Reflex tests: Varies
Report Available
3 to 10 daysSpecimen Retention Time
28 daysPerforming Laboratory
Mayo Clinic Laboratories in RochesterCPT Code Information
86041
86043 (if appropriate)
86366 (if appropriate)