Acetylcholine Receptor Blocking Antibody
Ordering Recommendation
Initial diagnostic testing for myasthenia gravis. For reflexive panel, which contains binding, blocking, and modulating antibodies, refer to Acetylcholine Receptor Antibody Reflexive Panel (2001571).
New York DOH Approval Status
Specimen Required
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)
Refrigerated.
Contaminated, hemolyzed, or severely lipemic specimens.
After separation from cells: Ambient: 48 hours; Refrigerated: 2 weeks; Frozen: 1 year (avoid repeated freeze/thaw cycles)
Methodology
Semi-Quantitative Flow Cytometry
Performed
Mon-Sat
Reported
1-4 days
Reference Interval
Test Number |
Components |
Reference Interval |
---|---|---|
Acetylcholine Blocking Antibody | 26 or less blocking |
Interpretive Data
Approximately 85-90% 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% 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 Blocking Antibody | Negative: 0-26% blocking Indeterminate: 27-41% blocking Positive: 42% or greater blocking |
Laboratory Developed Test (LDT)
Note
Hotline History
CPT Codes
86042
Components
Component Test Code* | Component Chart Name | LOINC |
---|---|---|
0099580 | Acetylcholine Blocking Antibody | 42937-3 |
Aliases
- AChR Antibody
- ACHR blocking antibody
- Muscle nicotinic Acetylcholine Receptor (AChR) Blocking Antibody
- Myasthenia Gravis Antibodies