Multiple sclerosis (MS) is a chronic, demyelinating disease of the CNS. Onset typically occurs in early adulthood. Patients present with intermittent symptoms that are partially reversible; this form is termed relapsing-remitting (RRMS). Over time, most patients develop secondary-progressive MS (SPMS) which manifests as irreversible and gradual neurological impairments that often progress without acute relapses. Beta-interferons or glatiramer acetate represents the first line therapeutic option for RRMS. Clinical trials confirm that show partial efficacy, though they do not prevent the onset of secondary progression. SPMS, is the consequence of axonal loss and neurodegeneration and no current therapy has been effective. Stem cell therapy show great promise and is rapidly developing as alternative therapeutic strategy. Clinical indications for adult stem cells, which can be safely harvested and normally behave well without formation of tumours, are rapidly increasing. The majority of human stem cell trials have focused on clinical applications for haematopoietic stem cells (HSC), mesenchymal stem cells (MSC), or both, which can be easily obtained in clinically sufficient numbers from peripheral blood, bone marrow, adipose tissue, or umbilical cord blood and placenta. MSC can readily be isolated from a small sample of bone marrow and rapidly expanded so as to generate large numbers of cells for autologous therapies. When administered intravenously have an immune suppressive effect that can ameliorate animal autoimmune diseases. MSC transplantation significantly improves clinical outcome in experimental allergic encephalitis (EAE), the animal model of MS. When intravenously injected, MSC may migrate to inflammatory brain lesions and promote survival of brain-resident cells. Several disease models demonstrate axonal neuroprotection following MSC therapy, with some evidence that this is potentially mediated through the production of neurotrophic/growth factors, and/or immunomodulatory effects of MSC. For that reasons, MSC have become the focus of research as a potential cell therapy for inducing neuroprotection in human neurodegenerative diseases such as MS.

A growing body of literature confirms the therapeutic MSC biological properties, and provide a plausible mechanism of action to guide clinical trial design with a number of phase I/II trials in MS patients now underway. Experimental clinical trials in MS are being considered or have recently been initiated by several research groups, which are testing the therapeutic potential of different sources of MSC. Learning from previous clinical studies, and taking advantage of the potential that adult BM-MSC may stimulate repair and remyelination, to plan a clinical trial in patients with inflammatory MS seems reasonable. We propose a safety trial of a single intravenous injection of autologous bone marrow-derived MSC into 8 subjects with RRMS. The trial proposed here will enable us to ascertain whether autologous BM-MSC transplantation is a safe procedure, and whether BM-MSC therapy during the relapsing-remitting phase of MS can establish a immunomodulatory and regenerative microenvironment and reverse neurological disability in RRMS patients.