Outpatient Hematopoietic Grafting in Multiple Sclerosis Employing Autologous Peripheral Blood Stem Cells

Multiple sclerosis (MS) is a chronic, inflammatory, debilitating disease that causes destruction of central nervous system (CNS) myelin, with varying degrees of axonal damage. It mainly affects young adults and is twice as common in women as in men (1). Studies published from the 1990s brought animal models and theoretical considerations of hematopoietic stem cell transplantation (HSCT) being useful in the prevention and treatment of autoimmune diseases, with clinical responses in some patients, suggesting that high-dose chemotherapy followed by HSCT rescue could "reset" the immunological changes through the control of autoreactive clones, followed by immunological tolerance after immune reconstitution (2); this led to the conclusion that HSCT may be a viable therapeutic option for MS (1-6). Autologous HSCT have been done in patients with MS since 1996 and more than 700 HSCTs have been performed around the world (1-6). Most patients have been treated in small trials or in multicenter studies. In retrospective analyzes, a progression-free survival of more than five years after transplant has been observed, the neurological outcomes being considerably more favorable in patients with the relapsing-remitting type and/or those who showed an inflammatory pattern in magnetic resonance imaging (MRI) during the pre-transplant screening. Reports of good results, particularly in the aggressive forms of MS reinforce the effectiveness HSCT in MS patients with prominent inflammatory activity. The risk of transplant related mortality in HSCT for MS was conventionally considered very high but has declined since 2001 to 1.3% (2-6), this probably being the result of the changes in the conditioning regimens, thus reducing toxicity. Recent data, with more than 700 autologous transplants for MS in Europe, showed an overall survival of 92% in five years and a progression-free survival of 46%, the main cause of mortality and morbidity being the recurrence of the autoimmune disease (2-6).