Anti-Acetylcholine Receptor (ACh-R) and Muscle-Specific Kinase (MuSK) antibodies are associated with Myasthenia Gravis (MG), an autoimmune neuromuscular disorder.
- Anti-Acetylcholine Receptor (ACh-R) Antibodies:
- Most common in MG, found in about 85% of patients with generalized MG.
- These antibodies attack the acetylcholine receptors at the neuromuscular junction, impairing the transmission of signals from nerve to muscle.
- Their presence is diagnostic for MG, and their levels often correlate with disease severity.
- Muscle-Specific Kinase (MuSK) Antibodies:
- Found in a smaller percentage (40-50%) of MG patients, typically those who are negative for ACh-R antibodies.
- MuSK antibodies disrupt the function of MuSK protein, crucial for maintaining the neuromuscular junction.
- Patients with MuSK MG often have different clinical features and may respond differently to treatments compared to those with ACh-R antibodies.
Diagnosis and treatment strategies for MG are influenced by the presence of these antibodies.
Patients suspected to have MG should also have testing for B12, TSH and CT Chest (thymoma) +/- Tensilon test.