Muscle Specific Kinase MuSK Autoantibody, Serum (Referred Out)- Saskatoon
Discipline
Overview
Description
- If Acetylcholine Receptor Antibodies ordered in conjunction with MuSK Antibodies and/or LRP4 Antibodies, refer to Myasthenia Gravis Autoantibodies Reflex Panel
Test Ordering Requirements
Forms Required
- Specimen must arrive at SPH laboratory with copy of requisition
- UBC-Neuro-Immunology Laboratory Requisition
Specimen Information
Specimen types accepted
- Serum
Specimen collection container
- Preferred Collection Container: Gold (gel)
- Alternative Collection Container: Red (non-gel)
Required volume
- Optimal Volume: 5.0 mL Full collection tube
- Minimum Volume: 1 mL serum
(Submitting the minimum volume makes it impossible to repeat the test or perform confirmatory/reflex testing. In some situations, a minimum volume may require a second collection)
Transport and stability
- Refrigerated: 1 week
- Frozen: 2 months
Rejection criteria
- Specimens received where the collection protocols were not followed
- Grossly hemolyzed samples
- Grossly lipemic samples
- Pathology and Laboratory Medicine Acceptance and Rejection Criteria
Performance
Days/times performed
Availability |
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Testing Site |
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Maximum laboratory time
- 2-4 week turnaround time by testing laboratory
Other information
Additional Comments
- Diagnosis of autoimmune muscle-specific kinase (MuSK) myasthenia gravis
- Second-order test to aid in the diagnosis of autoimmune myasthenia gravis when first-line serologic tests are negative
- Establishing a quantitative baseline value for MuSK antibodies that allows comparison with future levels if weakness is worsening
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As per the Medical Services Commission (MSC) guidelines, if this test is to be billed through provincial health services, it must be requested by a neurologist, ophthalmologist, or a neuro-ophthalmologist and the patient has to have been found AchR Ab negative within the last 18 months with BC Neuroimmunology or with another lab, in which case, a copy of the results from the other lab must be attached or stated on the requisition by the ordering physician. The MSC does not cover repeat testing for patients previously negative for MuSK Ab within 18 months of the last test date. For MuSK Ab that is ordered as reflex testing to AchR Ab, MuSK testing is performed after AchR Ab testing and will not be done if the patient is AchR Ab positive.
Last Updated: October 10, 2024