Acetylcholine Receptor Binding Antibody

Test Code
206X

CPT Codes
83519

Specimen Container
No additive (red-top). SST is acceptable.

Preferred Specimen
1 mL serum (0.2 mL minimum)

Instructions
Serum is the only acceptable sample.

Transport Temperature
Room temperature

Methodology
Radioimmunoassay

Reference Range

Negative:	< or = 0.30nmol/L
Equivocal:	0.31-0.49 nmol/L
Positive:	> or = 0.50nmol/L

Clinical Use
Myasthenia gravis (MG) is a neuromuscular disorder characterized by muscle weakness, most commonly due to autoantibody-mediated loss of functional acetylcholine receptors (AChR) in the neuromuscular junction. This assay aids in the differential diagnosis of MG-like muscle weakness, in differentiating between generalized MG and ocular MG, and in monitoring therapeutic response. If binding antibodies are negative, assays for blocking and modulating antibodies should be considered.

Performed By
Quest Diagnostics Nichols Institute