Assessment of clinical activity of and initial diagnostic testing for myasthenia gravis. For reflexive panel, which contains binding, blocking, and modulating antibodies, refer to Acetylcholine Receptor Antibody Reflexive Panel (2001571).
Semi-Quantitative Flow Cytometry
Serum Separator Tube (SST).
Separate from cells ASAP or within 2 hours of collection. Transfer 0.5 mL serum to an ARUP Standard Transport Tube. (Min: 0.3 mL)
Contaminated, hemolyzed, or severely lipemic specimens.
After separation from cells: Ambient: 48 hours; Refrigerated: 2 weeks; Frozen: 1 year (avoid repeated freeze/thaw cycles)
Effective August 20, 2012
|Positive||46% or greater modulating|
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.
Laboratory Developed Test (LDT)
|Component Test Code*||Component Chart Name||LOINC|
|0099521||Acetylcholine Modulating Antibody||30192-9|
- AChR Antibody
- ACHR modulating antibody
- Muscle nicotinic Acetylcholine Receptor (AChR) Modulating Antibody
- Myasthenia Gravis Antibodies