Acetylcholine Receptor Binding Antibody

Test Code

LAB836

Quest Code

206

Alias/See Also

ACRBA, ARBA

CPT Codes
86041

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
Radioimmunoassay (RIA)

Setup Schedule

Set up: Tues-Sat; 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.