Acetylcholine Receptor Modulating Antibody

Test Code

26474

Preferred Specimen

1 mL serum

Minimum Volume

0.5 mL

Transport Container

Transport tube

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)

FDA Status
This test was developed and its analytical performance characteristics have been determined by Quest Diagnostics. It has not been cleared or approved by FDA. This assay has been validated pursuant to the CLIA regulations and is used for clinical purposes.

Setup Schedule

Set up: Sun, Tues, Thurs; Report available: 3-8 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-San Juan Capistrano, CA

33608 Ortega Highway

San Juan Capistrano, CA 92675-2042

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.