Test ID MGA1 Myasthenia Gravis (MG) Evaluation, Adult, Serum
Useful For
Initial evaluation of patients aged 20 or older with symptoms and signs of acquired myasthenia gravis (MG)
Bone marrow transplant recipients with suspected graft-versus-host disease, particularly if weakness has appeared
Confirming that a recently acquired neurological disorder has an autoimmune basis (eg, MG)
Providing a quantitative baseline for future comparisons in monitoring a patient's clinical course and the response to immunomodulatory treatment
Raising likelihood of neoplasia
Profile Information
Test ID | Reporting Name | Available Separately | Always Performed |
---|---|---|---|
MGEAI | MG Adult Interpretation, S | No | Yes |
ARBI | ACh Receptor (Muscle) Binding Ab | Yes | Yes |
ARMO | ACh Receptor (Muscle) Modulating Ab | No | Yes |
STR | Striational (Striated Muscle) Ab, S | Yes | Yes |
Reflex Tests
Test ID | Reporting Name | Available Separately | Always Performed |
---|---|---|---|
GD65S | GAD65 Ab Assay, S | Yes | No |
CRMWS | CRMP-5-IgG Western Blot, S | Yes | No |
GANG | AChR Ganglionic Neuronal Ab, S | No | No |
VGKC | Neuronal (V-G) K+ Channel Ab, S | No | No |
Testing Algorithm
If acetylcholine receptor (AChR) modulating antibodies are ≥90% and striational antibodies are ≥1:120, then AChR ganglionic neuronal autoantibody, glutamic acid decarboxylase autoantibody, neuronal voltage-gated potassium channel autoantibody, and CRMP-5-IgG Western blot will be performed at an additional charge.
See Myasthenia Gravis: Adult Diagnostic Algorithm in Special Instructions.
Special Instructions
Method Name
ARBI, ARMO, GANG, VGKC: Radioimmunoassay (RIA)
STR: Enzyme Immunoassay (EIA)
Reporting Name
MG Evaluation, AdultSpecimen Type
SerumSpecimen Required
Container/Tube:
Preferred: Red top
Acceptable: Serum gel
Specimen Volume: 3 mL
Additional Information: Patient should have no general anesthetic or muscle-relaxant drugs in the previous 24 hours.
Specimen Minimum Volume
2 mL
Specimen Stability Information
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
Serum | Refrigerated (preferred) | 28 days | |
Frozen | 28 days | ||
Ambient | 72 hours |
Day(s) and Time(s) Performed
ACh receptor (muscle) binding antibody:
Monday through Friday; 11 a.m., 6 p.m., 10 p.m.
Saturday; 6 a.m.
Sunday; 6 a.m., 10 a.m.
ACh receptor (muscle) modulating antibodies:
Monday through Thursday; 2 p.m.
Saturday; 8 a.m.
Striational (striated muscle) antibodies:
Monday through Friday; 4 a.m., 3 p.m.
Saturday; 6 a.m.
CRMP-5-IgG Western blot:
Monday, Wednesday, Friday; 8 a.m.
AChR ganglionic neuronal antibody:
Monday through Friday; 11 a.m., 6 p.m.
Saturday; 6 a.m.
Sunday; 6 a.m.
Neuronal VGKC autoantibody:
Monday through Friday; 11 a.m., 6 p.m.
Saturday; 6 a.m.
Sunday; 6 a.m.
GAD65 antibody assay:
Monday through Friday; 6 a.m., 4 p.m.
Performing Laboratory

CPT Code Information
83519 x 2
83520
83519 x 2 (if appropriate)
84182 (if appropriate)
86341 (if appropriate)
LOINC Code Information
Test ID | Test Order Name | Order LOINC Value |
---|---|---|
MGA1 | MG Evaluation, Adult | 53706-8 |
Result ID | Test Result Name | Result LOINC Value |
---|---|---|
34272 | MG Adult Interpretation, S | 69048-7 |
8338 | ACh Receptor (Muscle) Binding Ab | 11034-6 |
8879 | ACh Receptor (Muscle) Modulating Ab | 30192-9 |
8746 | Striational (Striated Muscle) Ab, S | 8097-8 |
NY State Approved
YesReference Values
ACh RECEPTOR (MUSCLE) BINDING ANTIBODY
≤0.02 nmol/L
ACh RECEPTOR (MUSCLE) MODULATING ANTIBODIES
0-20% (reported as __% loss of AChR)
STRIATIONAL (STRIATED MUSCLE) ANTIBODIES
<1:120
Forms
If not ordering electronically, complete, print, and send a Neurology Specialty Testing Client Test Request (T732) with the specimen.