ACETYLCHOLINE RECEPTOR BINDING ANTIBODY
- ACETYLCHOLINE RECEPTOR BINDING ANTIBODY
- Start Date
- Expiration Date
- AChR Binding Ab;Myasthenia Gravis Ab
- CPT Codes
- Reference Test
- Transport Info
Centrifuge and immediately transfer serum to separate plastic tube within 30 minutes of collection
- Fasting Required?
- Patient Instructions
- Reference Range
Negative = Less than or equal to 0.25 nmol/L
Equivocal = 0.26-0.49 nmol/L
Positive = Equal to or greater than 0.50 nmol/L
Useful as an aid in the differential diagnosis of Myasthenia Gravis (MG)
Myasthenia Gravis (MG) is a neuromuscular disorder characterized by muscle weakness, which in most cases is a result of autoantibody-mediated loss of functional acetylcholine receptors in the neuromuscular junction. More than 85% of MG patients express antibodies to acetylcholine receptors (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 AChR binding to the receptor and lead to poor muscle contraction.
• Modulating antibody causes receptor endocytosis resulting in loss of AChR expression.
The AChR binding antibody assay is the first choice of assay for confirming a diagnosis of acquired MG. AChR binding antibodies are characteristic of, but not diagnostic of, acquired MG. The test results must be interpreted by a physician in the context of other findings.