Myasthenia gravis profile with reflex

Alphabetical Test listing

Myasthenia gravis profile with reflex-14217

November 30, 2021

Due to reagent procurement issues at the performing laboratory, this test is currently not available to order. The suggested alternate test is the Myasthenia gravis reflexive panel (994/LAB994), referred to ARUP.

Myasthenia gravis profile with reflex
  • 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 at an additional charge

  • Diagnose 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

4.0 mL
  1. Allow a minimum clotting time of 30 to 60 minutes
  2. Spin within 2 hours of collection
  3. Transfer 4.0 mL serum into a Transfer vial/tube with cap - 12mL (LabCorp)



Refrigerated (preferred) - 14 days

Ambient - 7 days

Frozen - 14 days

Freeze/thaw cycles - stable x 3

One (1) week following testing
  • Excessive hemolysis
  • Chylous serum
  • Recently administered radioisotopes
  • Plasma specimen
LabCorp Burlington (165600): R-LC
Mo, We, Fr
14 days

See individual tests


AChR Binding Abs, Serum  nmol/L 0.00-0.24

 Negative: 0.00 - 0.24

 Borderline: 0.25 - 0.40

 Positive: >0.40

AChR Blocking Abs, Serum  % 0-25

 Negative: 0 - 25

 Borderline: 26 - 30

 Positive: >30

AChR Modulating Abs, Serum  % 0-20

 Negative: <21

 Equivocal: 21 - 25

 Positive: >25

Striation Abs, Serum   Neg:<1:40

If MuSK Abs reflex: 

  Negative: <1.0;   Positive: 1.0 or higher


Acetylcholine receptor autoantibodies are not typically found in congenital myasthenia gravis

False positives can occur in patients with serum drawn within 48 hours of administration of general anesthesia and muscle relaxants.
•Antibodies to alpha-bunarotoxin may sometimes be found in patients treated with snake venom.
Recently administered is
83519 x 3 - Acetylcholine receptor Abs
86255 - Striational Abs

Additional CPT codes (if appropriate:
83519 - Muscle specific kinase (MuSK) Abs