Ordering Recommendation

Preferred reflexive panel for diagnosing myasthenia gravis. Includes acetylcholine receptor (AChR) binding and blocking antibodies with reflex to AChR modulating antibodies. 

New York DOH Approval Status

This test is New York state approved.

Specimen Required

Patient Preparation

Serum Separator Tube (SST).

Specimen Preparation

Separate from cells ASAP or within 2 hours of collection. Transfer 1 mL serum to an ARUP Standard Transport Tube. (Min: 0.5 mL)

Storage/Transport Temperature


Unacceptable Conditions

Contaminated, hemolyzed, or severely lipemic specimens.


After separation from cells: Ambient: 48 hours; Refrigerated: 2 weeks; Frozen: 1 year (avoid repeated freeze/thaw cycles)


Quantitative Radioimmunoassay/Semi-Quantitative Flow Cytometry




3-7 days

Reference Interval

Test Number
Reference Interval
  Acetylcholine Binding Antibody 0.4 nmol/L or less
  Acetylcholine Blocking Antibody 26 or less blocking

Interpretive Data

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.

Component Interpretation
Acetylcholine Receptor Binding Antibody Negative:
0.0-0.4 nmol/L
0.5 nmol/L or greater
Acetylcholine Receptor Blocking Antibody Negative:
0-26% blocking
27-41% blocking
42% or greater blocking

Compliance Category

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. Additional charges apply.

Hotline History


CPT Codes

86041; 86042; if reflexed, add 86043


Component Test Code* Component Chart Name LOINC
0080009 Acetylcholine Binding Antibody 11034-6
0099580 Acetylcholine Blocking Antibody 42937-3
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please click the sidebar link to access the Interface Map.


  • AChR Antibody
  • AChR reflex panel
  • Muscle nicotinic Acetylcholine Receptor (AChR) Binding Antibody
  • Myasthenia Gravis Antibodies
  • Myasthenia Gravis Antibodies Reflex
Acetylcholine Receptor Antibody Reflexive Panel