Acetylcholine Receptor Modulating Antibody

Test Code
ARABM (26141)

Quest Code
26474

CPT Codes
83519

Preferred Specimen
1 mL serum

Minimum Volume
0.5 mL

Transport Temperature
Room temperature

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
Radiobinding Assay (RBA)

Setup Schedule
Set up: Sun, Tues, Thurs; Report available: 2-7 days

Limitations
Antibodies may not be found in congenital myasthenia.

Reference Range
<32 % Inhibition

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. AChR modulating antibodies cross-link AChR molecules on cell surface, promoting internalization, and decreasing AChR surface density. The AChR binding and modulating antibody assays have similar sensitivities, but performing them together increases sensitivity of antibody detection by approximately 5%.

Performing Laboratory
Quest Diagnostics Nichols Institute
33608 Ortega Highway
San Juan Capistrano, CA 92675




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.