Acetylcholine Receptor Blocking Autoantibody

Overview

  • EPIC Code:
  • LAB838
  • Soft Test Code:
  • ACRBA
  • Send Out Test Code:
  • 34459
Alternate Names
  • Acetylcholine Receptor, Blocking
  • ACHR Blocking Antibody
  • Myasthenia Gravis Evaluation
Clinical Significance

Myasthenia gravis (MG), the most common neuromuscular transmission disorder, is an antibody-mediated autoimmune disease that stems from a loss of acetylcholine receptors (AChR) at neuromuscular junctions. AChR autoantibodies are diagnostic of MG, and are found in 85-90% of MG patients. AChR binding autoantibodies are present most frequently in MG and provide the most reliable information for diagnostic screening. A small portion of patients with early onset or ocular restricted MG may only have AChR modulating autoantibodies, thus if AChR binding autoantibodies are absent in a patient with weakness or ocular symptoms consistent with MG, AChR modulating autoantibodies should be ordered. AChR blocking autoantibodies are directed against the neurotransmitter-binding site and may be the only AChR autoantibody in about 1% of MG patients.


Specimen Collection & Preparation

Specimen Requirements:

-OR-

1.0 mL Serum from a SST Gold Top Tube
Minimum Volume:
0.5 mL Serum
Rejection Criteria:

Microbially contaminated

Gross hemolysis

Grossly lipemic


Transport and Storage:
  • Ambient: 14 Days
  • Refrigerated: 14 Days
  • Frozen (-20 C or colder): 30 D

Clinical Interpretation

Reference Range:

< 15 % of inibition


Methodology:
  • Radioimmunoassay (RIA)

Clinical Significance

Myasthenia gravis (MG), the most common neuromuscular transmission disorder, is an antibody-mediated autoimmune disease that stems from a loss of acetylcholine receptors (AChR) at neuromuscular junctions. AChR autoantibodies are diagnostic of MG, and are found in 85-90% of MG patients. AChR binding autoantibodies are present most frequently in MG and provide the most reliable information for diagnostic screening. A small portion of patients with early onset or ocular restricted MG may only have AChR modulating autoantibodies, thus if AChR binding autoantibodies are absent in a patient with weakness or ocular symptoms consistent with MG, AChR modulating autoantibodies should be ordered. AChR blocking autoantibodies are directed against the neurotransmitter-binding site and may be the only AChR autoantibody in about 1% of MG patients.


Production Schedule

Sites Performed
  • Quest - Chantilly to San Juan Capistrano
Days Performed
Sunday
Tuesday
Thursday
Departments
  • Sendouts - Clinical
Turn Around Time

3 to 6 days


Coding & Compliance

CDM

00913519


CPT Coding

83519