Failure of allogeneic bone marrow transplantation to arrest disease activity in multiple sclerosis.

Multiple sclerosis (MS) is thought to be an autoimmune disease in which activated T-cells initiate a macrophage mediated destruction of CNS myelin. Bone marrow transplantation (BMT) is currently being evaluated in the treatment of MS in patients with aggressive disease activity. Autologous BMT could potentially reset the immune response to myelin antigens leading to immune tolerance and decreased disease activity. Allogeneic transplantation could reconstitute the immune system potentially arresting the progression of autoimmune disease. The purpose of this paper is to report a patient with MS who underwent allogeneic BMT for chronic myelogenous leukemia (CML) and showed continued evidence of active demyelinating disease by clinical and radiologic criteria over a period of two years. While this is only a single case report with inherent limitations, it suggests that the immune mediated destruction of CNS myelin in MS may not be prevented or aborted by immune system reconstitution, and is consistent with the idea that immune mediated tissue destruction in MS could be targeted against an abnormal antigen.