Acetylcholine Receptor Binding Antibody with reflex to Muscle-Specific Kinase (MuSK) Ab, IgG
3001868
Ordering Recommendation

Initial diagnostic test when suspicion of myasthenia gravis is high.

Mnemonic
ACHR BIN R
Methodology
Quantitative Radioimmunoassay
Performed
Sun-Sat
Reported
2-8 days
New York DOH Approval Status
This test is New York DOH approved.
Submit With Order
ARUP Consult®
Disease Topics
Specimen Required
Patient Preparation
 
Collect
Serum Separator Tube (SST). 
Specimen Preparation
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) 
Storage/Transport Temperature
Refrigerated. 
Unacceptable Conditions
Plasma. Contaminated, hemolyzed, or severely lipemic specimens. 
Remarks
 
Stability
After separation from cells: Ambient: 48 hours; Refrigerated: 2 weeks; Frozen: 1 month (avoid repeated freeze/thaw cycles) 
Reference Interval
Test Number
Components
Reference Interval
0080009Acetylcholine Receptor Binding Antibody
Negative0.0-0.4 nmol/L
Positive0.5 nmol/L or greater

3001576Muscle-Specific Kinase (MuSK) Antibody, IgG
Negative0.00-0.03 nmol/L
Positive0.04 nmol/L or greater


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.

Statement B: Compliance Statement B: For laboratory developed tests not using a RUO kit, and for FDA approved, cleared or 510(k) exempt assays with alterations. This test was developed and its performance characteristics determined by ARUP Laboratories. The U. S. Food and Drug Administration has not approved or cleared this test; however, FDA clearance or approval is not currently required for clinical use. The results are not intended to be used as the sole means for clinical diagnosis or patient management decisions.

Note
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.
Hotline History
View Hotline History
CPT Code(s)
Components
Component Test Code*Component Chart NameLOINC
0080009Acetylcholine Binding Antibody11034-6
* 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 view this test within the Laboratory Test Directory found at www.aruplab.com
Aliases
  • AChR Antibody
  • ACHR blocking antibody
  • Muscle nicotinic Acetylcholine Receptor (AChR) Binding Antibody
  • Muscle-Specific Kinase Antibody by RIA
  • Muscle-Specific Receptor Tyrosine Kinase
  • MuSK
  • MuSK Autoantibody
  • Myasthenia Gravis Antibodies