Secondary diagnostic testing for patients with generalized or ocular myasthenia gravis and no detectable antibodies to acetylcholine receptor (AChR).
One 4 mL Plain Red or Serum Separator Tube (SST).
Separate from cells ASAP or within 2 hours of collection. Transfer 2 mL of serum to an ARUP Standard Transport Tube. (Min: 0.5 mL)
Grossly lipemic, icteric, or hemolyzed specimens.
After separation from cells: Ambient: 48 hours; Refrigerated: 2 weeks; Frozen: 1 month (avoid multiple freeze/thaw cycles)
|Positive||0.04 nmol/L or greater|
Muscle-specific kinase (MuSK) antibody is found in a subset of patients with myasthenia gravis, primarily those seronegative for muscle acetylcholine receptor (AChR) antibody. Decreasing antibody levels may be associated with therapeutic response; therefore, clinical correlation must be strongly considered. A negative test result does not rule out a diagnosis of myasthenia gravis.
Compliance Statement A: For laboratory developed tests using a manufacturer labeled ASR as the reagent providing the specificity of the assay. Analyte Specific Reagent. This test was developed and its performance characteristics determined by ARUP Laboratories. The U. S. Food and Drug Administration has not approved or cleared this test; however, the FDA has determined that such clearance or approval is not necessary.
|Component Test Code*||Component Chart Name||LOINC|
|3001577||Muscle-Specific Kinase (MuSK) Ab, IgG||51716-9|
- Muscle-Specific Kinase Antibody by RIA
- Muscle-Specific Receptor Tyrosine Kinase
- MuSK Autoantibody