ARUP's Laboratory Test Directory

Acetylcholine Receptor Modulating Antibody : 0099521

Mnemonic: ACHRMOD

Methodology: Semi-Quantitative Flow Cytometry
Performed: Sun-Fri
Reported: 2-7 days
Specimen Required: Collect: Serum separator tube.

Specimen Preparation: Separate serum from cells ASAP or within 2 hours of collection. Transfer 0.5 mL serum to an ARUP Standard Transport Tube. (Min: 0.3 mL)

Storage/Transport Temperature: Refrigerated.

Unacceptable Conditions: Contaminated, hemolyzed, or severely lipemic specimens.

Stability (collection to initiation of testing): After separation from cells: Ambient: 2 hours; Refrigerated: 2 weeks; Frozen: 1 year (avoid repeated freeze/thaw cycles)

Reference Interval:
Negative: 0-45% modulating
Positive: 46% or greater modulating

Effective August 20, 2012
Interpretive Data: Approximately 85-90 percent 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 percent of individuals with confirmed myasthenia gravis have no measurable binding, blocking, or modulating antibodies.

See Compliance Statement B: www.aruplab.com/CS
CPT Code(s): 83516
Cross References: Myasthenia Gravis Antibodies (Acetylcholine Receptor Modulating Antibody)