Acetylcholine Receptor Blocking Antibody : 34459

Test Code
ACHRBL or 34459

CPT Codes
83519

Instructions
Serum separator tube.

Transport Container
Centrifuge serum separator tube and transport 1 mL serum (Min: 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
Sunday & Tuesday & Thursday

Report Available
3-6 days  (From receipt at performing laboratory)

Reference Range
<15 % 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 blocking autoantibodies prevent inter-action of binding antibodies with the AChR. Fewer than 1% of patients have blocking antibodies without binding antibodies. Blocking antibodies are present in about 50% of patients with MG, but rare in other conditions. Therefore, blocking antibodies have utility in ruling out a possible false positive binding assay and detecting the rare patient without AChR binding antibodies.

Performing Laboratory
Quest Diagnostics



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.