Aggressive multiple sclerosis-is there a role for stem cell transplantation?

Conventional drugs, including disease-modifying drugs, various cytostatic regimens and steroids, are unable to control disease activity in a small group of patients with "malignant" multiple sclerosis (MS). This group of patients could be offered aggressive therapies, such as high-dose immunosuppression followed by haematopoietic stem cell transplant (HSCT). Bone marrow or peripheral blood HSCT has been proposed for the treatment of autoimmune diseases because of its immunosuppressive and immunomodulatory effects, and recapitulation of lymphocyte ontogeny may stabilise or improve the course of MS in some patients. There have been a few small studies conducted using high-dose immunoablation and HSCT. A recent clinical trial of 85 patients treated by HSCT revealed that more than 60% of patients may benefit from this procedure. Due to the perceived risks associated with HSCT, only patients with malignant MS who no longer benefit from more conventional therapies were enrolled. HSCT is thus a justified and feasible treatment in certain patient groups, although transplant-related mortality must be reduced.