[Stem cell therapy in multiple sclerosis: a clinical update].

Promising results in an animal model of multiple sclerosis (MS; experimental autoimmune encephalomyelitis, EAE) have shown that immunosuppression followed by allogeneic bone marrow transplantation has the potential to significantly ameliorate the spontaneous course of the disease. Since 1995, emerging data on autologous hematopoietic stem cell transplantation (AHSCT) has supported a benefit also in patients with multiple sclerosis. To date, results on approximately 500 cases have been consecutively reported by the European Group for Blood and Marrow Transplantation (EBMT). These reports have not only proved a favourable outcome for many patients but also provided the rationale for the currently ongoing controlled trials on AHSCT in MS. At present, results from the ASTIMS study in particular, a multicenter active-controlled phase II study, are awaited. However, a number of critical issues remain unresolved. Furthermore, with upcoming new treatment compounds that to some extent act via lymphoablative properties, it remains essential to better select those patients who might profit most from stem cell therapy based on a justifiable benefit-to-risk ratio. Although transplant related mortality has dropped to 1%, mortality combined with concerns about long-term safety remain critical issues in a primarily non-life-threatening disease like MS.