Objectives: Patients with refractory myasthenia gravis (MG) have few treatment options. Autologous hematopoietic stem cell transplantation (HSCT) has been used to treat immune diseases; however, its use in the treatment of MG is not broadly considered. Our objective is to report on the efficacy and safety of HSCT in refractory MG.
Methods: Twenty-one patients who underwent HSCT for MG were retrospectively reviewed. All patients had severe MG refractory to multiple therapies. Stem cells were mobilized with cyclophosphamide and granulocyte colony-stimulating factor. The grafts were depleted of immune cells by selecting CD34+ cells. HSCT conditioning consisted of high-dose cytoreductive therapy and anti-thymocyte globulin. The primary efficacy outcome was achieving clinically stable remission or minimal manifestations without treatment and remaining as such until most recent follow-up.
Results: The median time from MG diagnosis to HSCT was 4.0 years. The primary outcome was reached in 16 of 18 evaluable patients (89%) at a median of 1.7 years and maintained with a median follow-up of 6.7 years (range 1.0-21.9 years). Three patients were not evaluable for the primary outcome: one due to confounding illness and two died within 12 months of transplant. The transplant-related mortality at 100 days was 9.5%. Two late deaths occurred, with uncertain relation to the HSCT.
Interpretation: After HSCT for refractory MG, most patients achieved sustained disease remission. However, HSCT-related mortality in medically complex MG patients may be high. Prospective studies investigating the efficacy and safety of HSCT in the treatment of refractory MG are warranted.
© 2024 The Author(s). Annals of Clinical and Translational Neurology published by Wiley Periodicals LLC on behalf of American Neurological Association.