Myasthenia gravis after allogeneic bone marrow transplantation for lymphoblastic lymphoma

A 31-year-old female with lymphoblastic lymphoma developed myasthenia gravi s (MG) 26 months after receiving an allogeneic bone marrow transplant (BMT) from an HLA-identical sister. She presented with classic symptoms and elec tromyographic evidence of the disorder approximately 2 weeks after electing to abruptly discontinue her immunosuppressive medications. She initially r esponded to steroids and acetylcholinesterase inhibitors. Her subsequent co urse has been characterized by episodes of moderately severe weakness that respond to intravenous immunoglobulin and prednisone, This case of post-tra nsplant MG is only the second reported to have occurred in association with BMT for lymphoblastic lymphoma. Potential risk factors for the development of post-transplant MG are discussed including underlying hematological dis order, HLA phenotype, family history of MG, the presence of chronic GVHD, a nd recent cessation of immune suppression.