Myasthenia gravis profile with reflex
Myasthenia gravis profile with reflex-14217
- Acetylcholine receptor (AChR)-binding antibodies
- Acetylcholine Receptor (AChR)-blocking antibodies
- Acetylcholine Receptor (AChR)-modulating antibodies
- Striational antibodies
Reflex criteria:
If Acetylcholine Receptor (AChR)-binding, blocking and modulating antibodies are normal, will reflex to Muscle Specific Kinase (MuSK) Antibodies performed at Esoterix Endocrinology Laboratory.
Tests for the laboratory diagnosis of myasthenia gravis (MG).
In rare cases AChR antibodies can be found in patients with other autoimmune disorders or with thymoma without MG.1
The causative autoantibody cannot be identified in up to 10 percent of patients with MG.
No isotopes administered 24 hours prior to sample collection
- Allow sample to clot for a minimum of 30 to 60 minutes
- Spin within two (2) hours of sample collection
- Transfer 4.0 mL serum into two (2) a Transfer vial/tube with cap - 12mL (LabCorp), labelled as serum
Immediately following collection, mix sample by gently inverting 5 times
- Allow sample to clot for a minimum of 30 to 60 minutes
- Spin within two (2) hours of sample collection
Refrigerated (preferred) - 14 days
Ambient - 7 days
Frozen - 14 days
- Excessive hemolysis
- Chylous serum
- Recently administered radioisotopes
- Plasma specimen
AChR Binding Abs, Serum nmol/L
Negative: 0.00 - 0.24
Borderline: 0.25 - 0.40
Positive: >0.40
AChR Blocking Abs, Serum %
Negative: 0 - 25
Borderline: 26 - 30
Positive: >30
AChR Modulating Abs, Serum %
Negative: 0 - 45
Positive: >45
Striation Abs, Serum Negative
If MuSK Abs reflex:
Negative: <1.0; Positive: 1.0 or higher
Acetylcholine receptor autoantibodies are not typically found in congenital myasthenia gravis
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