ABSTRACT
Myasthenia gravis (MG), which means severe muscle weakness, is due to antibody mediated loss of motor end plate acetylcholine (ACh) receptors. 1 , 2 In normal muscle, acetylcholine released from a nerve ending binds to the acetylcholine receptor (AChR) on the post synaptic motor end plate of muscle inducing a depolarization potential. 2 , 3 If enough AChR depolarizations occur, the firing threshold is exceeded and an action potential or contraction of the muscle follows. AchR antibody reduce the number of ACh receptors causing loss of synaptic folds on the motor end plate and impaired neuromuscular transmission. Ex vivo transfer of ACh receptor antibody induces disease across a wide range of species. 4 , 5 While in utero, transplacental transfer from mother to fetus causes neonatal MG. 6-8 The clinical manifestations are muscular fatigue and weakness. 9 , 10 Treatment of MG includes acetylcholine esterase inhibitors and immune suppressive or immune modulating medications. 11-15 For patients with severe disease, HSCT may be considered. In fact, the first animal hematopoietic stem cell transplantation (HSCT) for an autoimmune disease was reported in 1983 for experimental autoimmune myasthenia gravis (EAMG). 16 Syngeneic HSCT cured EAMG related muscle weakness.
