Myasthenia gravis

Myasthenia gravis (MG) is caused by the failure of neuromuscular signal transmission. To confirm the diagnosis of MG the determination of acetylcholine receptors (ARAb) and muscle-specific receptor tyrosine kinase (MuSK) autoantibodies are needed. The ARAb Radioimmunoassay is the state-of-the-art diagnosis method for autoantibodies in the serum of 80-90 % of patients with generalized myasthenia gravis and in 55-70 % of patients with ocular myasthenia. In 10-20 % of the patients with generalized MG, and in up to 50 % of the patients with ocular MG these autoantibodies cannot be detected. In these cases, the disease is commonly referred to as seronegative MG (SNMG). The antibodies to the muscle-specific receptor tyrosine kinase can be detected and measured via MuSK-Ab ELISA.