Establish or confirm a clinical diagnosis of myasthenia gravis. Includes acetylocholine receptor (AChR) binding and blocking antibodies with reflex to AChR modulating antibodies or MuSK antibodies.
Quantitative Radioimmunoassay/Semi-Quantitative Flow Cytometry
New York DOH Approval Status
Serum Separator Tube (SST).
Separate from cells ASAP or within 2 hours of collection. Transfer 1 mL serum to an ARUP Standard Transport Tube. (Min: 0.5 mL)
Contaminated, hemolyzed, or severely lipemic specimens.
After separation from cells: Ambient: 48 hours; Refrigerated: 2 weeks; Frozen: 1 month (avoid repeated freeze/thaw cycles)
|Acetylcholine Binding Antibody||0.4 nmol/L or less|
|Acetylcholine Blocking Antibody||26 % blocking or less|
Approximately 85-90 percent of patients with myasthenia gravis (MG) express antibodies to the acetylcholine receptor (AChR), which can be divided into binding, blocking, and modulating antibodies. Binding antibody can activate complement and lead to loss of AChR. Blocking antibody may impair binding of acetylcholine to the receptor, leading to poor muscle contraction. Modulating antibody causes receptor endocytosis resulting in loss of AChR expression, which correlates most closely with clinical severity of disease. Approximately 10-15 percent of individuals with confirmed myasthenia gravis have no measurable binding, blocking, or modulating antibodies.
This test was developed and its performance characteristics determined by ARUP Laboratories. It has not been cleared or approved by the US Food and Drug Administration. This test was performed in a CLIA certified laboratory and is intended for clinical purposes.
|Acetylcholine Binding Antibody||0.0-0.4 nmol/L: Negative
0.5 nmol/L or greater: Positive
|Acetylcholine Blocking Antibody||0-26% blocking: Negative
27-41% blocking: Indeterminate
42% or greater blocking: Positive
Laboratory Developed Test (LDT)
If Acetylcholine Receptor Binding Antibody result is greater than 0.4 nmol/L or Acetylcholine Receptor Blocking Antibody result is greater than 26 percent, then Acetylcholine Receptor Modulating Antibody (ARUP test code 0099521) will be added. If Acetylcholine Receptor Binding Antibody result is less than or equal to 0.4 nmol/L, then Muscle-Specific Kinase (MuSK) Ab, IgG (ARUP test code 3001576) will be added. Additional charges apply.
83519; 83516; if reflexed, add 83516, 83519
|Component Test Code*||Component Chart Name||LOINC|
|0080009||Acetylcholine Binding Antibody||11034-6|
|0099580||Acetylcholine Blocking Antibody||42937-3|
- AChR Antibody
- AChR reflex panel
- Muscle nicotinic Acetylcholine Receptor (AChR) Binding Antibody
- Muscle-Specific Kinase Antibody by RIA
- Muscle-Specific Receptor Tyrosine Kinase
- MuSK Autoantibody
- Myasthenia Gravis Antibodies
- Myasthenia Gravis Antibodies Reflex