The potential use of adult stem cells for the treatment of multiple sclerosis and other neurodegenerative disorders.

No specific treatment exists for patients with multiple sclerosis (MS) who fail to respond to conventional immunosuppressive and immunomodulating modalities. Furthermore, no method is available for regeneration of existing defect in the central nervous system (CNS). The ultimate goals of MS treatment, similarly to other autoimmune diseases, are twofold: first, to eliminate self-reactive lymphocytes and to prevent de novo development of self-reactivity by induction of self-tolerance. Second, attempting regeneration and repair of existing damage. In the case of MS, there is a need to stop the ongoing process of inflammation against the CNS by self-reactive lymphocytes thus facilitating spontaneous re-myelinization while in parallel attempt to recover existing neurological deficits caused by the autoimmune process resulting in demyelinization. Cell therapy stands out as the most rationale approach for neurological regeneration. In the absence of clinically applicable approaches involving the use of embryonic stem cells, we are investigating the feasibility and efficacy of enriched autologous mesenchymal stromal cells (MSC) injected intrathecally and intravenously to induce in situ immunomodulation and neuroprotection and possibly facilitate repair of the CNS in patients with MS and other neurodegenerative disorders. Our preclinical results suggest that bone marrow cells may provide a source of stem cells with a potential for migration into inflamed CNS and differentiate into cells expressing neuronal and glial cell markers. Based on the preclinical data, we are currently evaluating the safety of a similar therapeutic approach in a small group of patients with MS and other neurodegenerative diseases.