Acetylcholine Receptor Blocking Antibody : 1002429

Test Code
ACHRBL or 1002429

Alias/See Also
Myasthenia Gravis Antibodies (Acetylcholine Receptor Blocking Antibody)

CPT Codes
83516

Instructions
Serum separator tube.

Transport Container
Centrifuge serum separator tube ASAP and transport 1 mL serum. (Min: 0.5 mL)

Transport Temperature
Refrigerated.

Specimen Stability
After separation from cells: Ambient: 2 hours; Refrigerated: 2 weeks; Frozen: 1 year (avoid multiple freeze/thaw cycles)

Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)
Severely lipemic, contaminated, or hemolyzed specimens.

Methodology
Semi-Quantitative Flow Cytometry

Setup Schedule
Monday - Saturday

Report Available
1-4 days (From receipt at performing laboratory)

Limitations
Approximately 85-90% of patients with myasthenia gravis (MG) express antibodies to the acetylcholine receptor (AChR), which can be divided into binding, blocking, and modulating antibodies. Binding antibody can activate complement and lead to loss of AChR. Blocking antibody may impair binding of acetylcholine to the receptor, leading to poor muscle contraction. Modulating antibody causes receptor endocytosis resulting in loss of AChR expression, which correlates most closely with clinical severity of disease. Approximately 10-15% of individuals with confirmed myasthenia gravis have no measurable binding, blocking, or modulating antibodies.

This test was developed and its performance characteristics determined by ARUP Laboratories. The U. S. Food and Drug Administration has not approved or cleared this test; however, FDA clearance or approval is not currently required for clinical use. The results are not intended to be used as the sole means for clinical diagnosis or patient management decisions.

Reference Range
Effective November 18, 2013
Negative: 0-26% blocking
Indeterminate: 27-41% blocking
Positive: 42% or greater blocking

Performing Laboratory
ARUP Laboratories



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.