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.
Analyte Specific Reagent (ASR)
|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