Myasthenia gravis reflexive panel

Alphabetical Test listing

Myasthenia gravis reflexive panel-994

Test name:

Test number:

994

Excellian order number:

LAB994

Abbreviation:

MSO

Alternate names:

AChR Antibody
AChR reflex panel
Muscle nicotinic Acetylcholine Receptor (AChR) Binding Antibody
Muscle-Specific Kinase Antibody by RIA
Muscle-Specific Receptor Tyrosine Kinase
MuSK
MuSK Autoantibody
Myasthenia Gravis Antibodies
ACh receptor Myasthenia Gravis Antibodies Reflex

Tests included:

Acetylocholine receptor (AChR) binding and blocking antibodies with reflex to AChR modulating antibodies or MuSK antibodies.

If Acetylcholine Receptor Binding Antibody result is greater than 0.4 nmol/L or Acetylcholine Receptor Blocking Antibody result is greater than 26 percent, then Acetylcholine Receptor Modulating Antibody will be added. If Acetylcholine Receptor Binding Antibody result is less than or equal to 0.4 nmol/L, then Muscle-Specific Kinase (MuSK) Ab, IgG will be added.

Useful for:

Establish or confirm a clinical diagnosis of myasthenia gravis.

Specimen type:

Serum

Collection container:

Gold serum separator (SST) tube

Volume:

1.0 mL

Minimum volume:

0.5 mL

Collection instructions:

Immediatley following collection, mix sample by gently inverting 5 times

Processing instructions:

Allow sample to clot for a minimum of 30 minutes
Spin within two (2) hours of sample collection

Transport container:

Gold serum separator (SST) tube

Transport and stability:

Refrigerated (preferred) – 2 weeks

Ambient – 48 hours

Frozen – 1 month

Performing lab:

ARUP (3001869) via LabCorp (009985): R - NX

Days set up:

Daily

TAT:

8 days

Method:

Quantitative Radioimmunoassay/Semi-Quantitative Flow Cytometry

Reference ranges:

Acetylcholine Receptor Binding Antibody: Negative 0.0 - 0.4 nmol/L

Acetylcholine Receptor Blocking Antibody: Negative 0 - 26% blocking

Acetylcholine Receptor Modulating Antibody: Negative 0 - 45% modulating

Muscle-Specific Kinase (MuSK) Antibody, IgG: Negative 0.00 - 0.03 nmol/L

Clinical information:

Approximately 85 – 90% of patients with myasthenia gravis (MG) express antibodies to the acetylcholine receptor (AChR), which can be divided into binding, blocking, and modulating antibodies.

Binding antibody can activate complement and lead to loss of AChR
Blocking antibody may impair binding of acetylcholine to the receptor, leading to poor muscle contraction
Modulating antibody causes receptor endocytosis resulting in loss of AChR expression, which correlates most closely with clinical severity of disease

Approximately 10 - 15% of individuals with confirmed myasthenia gravis have no measurable binding, blocking, or modulating antibodies.

CPT codes:

83519
83516

if reflexed, add:
83516
83519

Date created:

11/24/2021

Revised date:

04/18/2023

Review date:

11/29/2021