acetylcholine (nicotinic) Ab antibody in serum

Indications

• evaluation of myasthenia gravis

Reference interval

< 0.03 nmol/L

Clinical significance

• occurs in patients with myasthenia gravis (MG).
• occasionally occur in association with:
  • amyotrophic lateral sclerosis (ALS)
  • Lambert-Eaton myasthenic syndrome
  • pernicious anemia
• does NOT occur with congenital myasthenia gravis
• occurs in only 15% of patients with ocular myasthenia gravis

Methods

Radioimmunoassay (RIA)

False positives may occur with muscle relaxants:

• metocurine
• succinylcholine

Acetylcholine receptor antibody is more sensitive for detection of MG than electromyography (EMG) & is useful for following the response of MG to therapy. If negative & clinical suspicion of MG is high, acetylcholine receptor blocking & acetylcholine receptor modulating antibodies are used as 2nd & 3rd line tests.

Specimen

• serum
• store refrigerated or frozen without preservative
• do NOT use plasma
• stable at -20 degrees C

More general terms

• serology

More specific terms

• acetylcholine (nicotinic) receptor binding Ab in serum
• acetylcholine (nicotinic) receptor modulating Ab in serum

Component of

• Acetylcholine receptor modulating Ab/Acetylcholine receptor Ab total in Serum