Myasthenia Gravis Panel W/Rflx

Test ID: 

705227

CPT code:

83519, 86255

Synonyms:

Myasthenia Gravis Evaluation Profile With Reflex

Clinical Use:

Diagnose acquired myasthenia gravis

Test Information:

Myasthenia gravis is an autoimmune disorder manifested by muscle weakness caused by the loss or dysfunction of acetylcholine receptors (AChR) of skeletal muscle. Autoantibodies (binding, blocking, and/or modulating) to postsynaptic AChRs are detectable in the serum of 90% of patients with generalized MG and in 55% to 70% of patients with ocular myasthenia. These autoantibodies interfere with normal neuromuscular function, causing muscle weakness and fatigue. Receptor antibody levels tend to rise several weeks before symptoms increase in patients with established MG. Remission after thymectomy is associated with a progressive decline in antibody levels. Consequently, measurements of AChR antibodies can be used in monitoring disease progression as well as the effects of treatment. Modulating antibodies are responsible for the degradation of AChR at the muscle cell surface. Modulating antibodies bind to two receptor molecules on the cell surface and accelerate internalization, triggering endocytosis and degradation. The relative increase in this degradation rate closely corresponds to the disease severity.

Specimen Type:

Serum

Requested Volume: 

2 mL

Minimum Volume: 

1 mL

Container Type: 

Red-top tube or gel-barrier tube

Collection:

Separate serum from cells within 45 minutes of collection. Send serum in plastic transport tube.

Storage Instructions:

Maintain specimen at room temperature; stable for seven days. Stable refrigerated for 14 days or frozen for two months.

Rejection Criteria:

Improper labeling; gross microbial contamination; specimen contaminated with anticoagulants; chylous serum; plasma specimen