Antibodies to the muscle-specific receptor tyrosine kinase are involved in the pathogenesis of acetylcholine receptor (ACR) antibody-negative myasthenia gravis. Testing for these antibodies should be considered in the 20 % of patients with clinical symptoms of myasthenia gravis who do not demonstrate antibodies to the ACR.
Diagnosis of myasthenia gravis with or without equivocal anti-AChR findings
RST (rust top)
5-10 mL (1 mL serum)
Not currently performed in house; this test is referred to the Department of Immunology at the Churchill Hospital in Oxford.