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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

Serum

Specimen 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 days

Specimen Retention Time

28 days

Performing Laboratory

Mayo Clinic Laboratories in Rochester

CPT Code Information

86041

86043 (if appropriate)

86366 (if appropriate)