Test ID ARBI Acetylcholine Receptor (Muscle AChR) Binding Antibody, Serum
Useful For
Supporting the diagnosis of autoimmune myasthenia gravis (MG) in adults and children
Distinguishing autoimmune from congenital MG in adults and children or other acquired forms of neuromuscular junction transmission disorders
An adjunct to the test for P/Q-type calcium channel binding antibodies as a diagnostic aid for Lambert-Eaton myasthenic syndrome
Special Instructions
Method Name
Radioimmunoassay (RIA)
Reporting Name
ACh Receptor (Muscle) Binding AbSpecimen Type
SerumOrdering Guidance
For the initial diagnostic workup of patients with suspicion of myasthenia gravis, one of the following testing algorithms is recommended:
-Myasthenia Gravis Evaluation with MuSK Reflex Algorithm
-Myasthenia Gravis/Lambert Eaton Syndrome Diagnostic Algorithm
Standalone testing ARBI / Acetylcholine Receptor (Muscle AChR) Binding Antibody, Serum is recommended in certain situations.
This test should not be requested in patients who have recently received radioisotopes, therapeutically or diagnostically, because of potential assay interference. The specific waiting period before specimen collection will depend on the isotope administered, the dose given, and the clearance rate in the individual patient. Specimens will be screened for radioactivity prior to analysis. Radioactive specimens received in the laboratory will be held for 1 week and assayed if sufficiently decayed or canceled if radioactivity remains.
Specimen Required
Patient Preparation: For optimal antibody detection, specimen collection is recommended prior to initiation of immunosuppressant medication.
Supplies: Aliquot Tube, 5 mL (T465)
Collection Container/Tube:
Preferred: Red top
Acceptable: Serum gel
Submission Container/Tube: Plastic vial
Specimen Volume: 1.5 mL
Specimen Minimum Volume
1 mL
Specimen Stability Information
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
Serum | Refrigerated (preferred) | 28 days | |
Frozen | 28 days | ||
Ambient | 72 hours |
Reference Values
≤0.02 nmol/L
Day(s) Performed
Monday through Sunday
Performing Laboratory

CPT Code Information
83519
LOINC Code Information
Test ID | Test Order Name | Order LOINC Value |
---|---|---|
ARBI | ACh Receptor (Muscle) Binding Ab | 97558-1 |
Result ID | Test Result Name | Result LOINC Value |
---|---|---|
8338 | ACh Receptor (Muscle) Binding Ab | 97558-1 |
Test Classification
This test was developed, and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the US Food and Drug Administration.Testing Algorithm
This is the primary diagnostic test for myasthenia gravis.
For information see:
Myasthenia Gravis Evaluation with MuSK Reflex Algorithm
Myasthenia Gravis/Lambert Eaton Syndrome Diagnostic Algorithm
Report Available
3 to 6 daysNY State Approved
YesForms
If not ordering electronically, complete, print, and send a Neurology Specialty Testing Client Test Request (T732) with the specimen.