MYASTHENIA GRAVIS EVALUATION, PEDIATRIC

Reporting Title: MG Evaluation, Pediatric

Includes: Acetylcholine Receptor (Muscle AChR) Binding Antibodies and Acetylcholine Receptor (Muscle AChR) Modulating Antibodies

Recommended for initial investigation of patients presenting at less than age 20 with a defect of neuromuscular transmission.  Seropositivity distinguishes congential (ie, genetic) MG from acquired MG.  Seronegativity does not exclude the diagnosis of autoimmune MG.  A minority of patients lacking detectable AchR antibodies have the recently discovered muscle-specific receptor tyrosine kinase antibodies.  See “Myasthenia Gravis (MG) Tests in “Special Intructions.”

Methodology: Radioimmunoassay (RIA)

 

Test Performed At:

 

 

Mayo Medical Laboratories   #83371

 

Specimen Required:

 

 

Collect 4.0 mL (minimum 3.0 mL) of whole blood in a plain, red-top tube(s) or a serum gel tube(s).  

 

 

NOTE:

1.

Patient should have no general anesthetic or muscle-relaxant drugs in the previous 24 hours.

 

 

 

2.

Specimen will be rejected if hemolyzed.

 

Laboratory Notes:

 

 

Spin down and send 2.0 mL (minimum 1.5 mL) of serum refrigerated. 

 

 

NOTE:

Reject if hemolyzed.

 

Reference Values:

 

 

ACETYLCHOLINE RECEPTOR (MUSCLE) BINDING ANTIBODIES

 

 

 

£0.02 nmol/L

 

 

ACETYLCHOLINE RECEPTOR (MUSCLE) MODULATING ANTIBODIES

 

 

 

0-20% (reported as __% loss of AChR)

 

 

 

Day(s) Test Set Up:

 

 

Sunday - Friday

 

Cut-Off Time:

 

 

 

 

Turn Around Time:

 

 

4-6 days

 

CPT Code:

 

 

83519 -

muscle AChR binding antibodies

 

 

83519 -

muscle AChR modulating antibodies

 

KIDDOS Order Name:

 

 

Myasthenia Gravis Panel

 

Cerner Order Name:

 

 

Myasth Grav Pnl

 

Last Updated 09/09

Last Reviewed 03/10