Acetylcholine Receptor Binding Antibody

Test Code
ACHRBI


Quest Code
206


Alias/See Also
206


CPT Codes
83519

Preferred Specimen
1 mL serum


Minimum Volume
0.5 mL


Transport Temperature
Refrigerated


Specimen Stability
Room temperature: 14 days
Refrigerated: 14 days
Frozen: 30 days


Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)
Gross hemolysis • Grossly lipemic • Microbially contaminated


Methodology
Radioimmunoassay (RIA)

Setup Schedule
Set up: Tues-Sat; Report available: 1-2 days


Report Available
Report available: 1-2 days


Limitations
Antibodies may not be found in congenital myasthenia.


Reference Range
Negative ≤0.30 nmol/L
Equivocal 0.31-0.49 nmol/L
Positive ≥0.50 nmol/L


Clinical Significance
Myasthenia Gravis (MG) is an autoimmune neuromuscular disorder characterized by muscle weakness, most commonly due to autoantibody-mediated loss of functional acetylcholine receptors (AChR) in the neuromuscular junction. AChR binding autoantibodies are diagnostic of MG, and are found in 85-90% of MG patients. This assay aids in the differential diagnosis of conditions with MG-like muscle weakness and in monitoring therapeutic response. If binding antibodies are negative, assays for modulating and blocking antibodies should be considered.


Performing Laboratory
Quest Diagnostics Nichols Institute
33608 Ortega Highway
San Juan Capistrano, CA 92690-6130



The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.