Autologous hematopoietic stem cell transplantation (AHSCT) for aggressive multiple sclerosis - whom, when and how.

Multiple sclerosis (MS) is an autoimmune disease of the central nervous system that leads to an inflammatory process resulting in demyelination and axonal degeneration. The most common form of MS is the relapsing-remitting MS (RRMS) characterized by the presence of numerous relapses. After few years of disease course, 90% of those patients eventually develop a secondary progressive form. About 10% of patients may suffer from a slowly progressive MS form - the primary progressive. The current treatment of RRMS includes immunomodulatory and immunosuppressive agents, which are effective, but usually in earlier and more benign forms. The immunomodulatory treatment has limited efficacy in aggressive forms of RRMS, and relapses occur despite treatment continuation. AHSCT should be considered as a therapeutic approach for patients with aggressive relapsing-remitting and aggressive progressive MS who failed conventional therapy. The mechanism of action of AHSCT for MS results from resetting the aberrant patient's immune system and eliminating the autoreactive T-lymphocytes. AHSCT can serve as an effective and safe procedure only when strict neurological eligibility criteria are adhered. The procedure should be performed in highly specialized hematological centers. The aim of our paper is to summarize the current eligibility criteria for AHSCT in MS patients as well as to present data on efficacy and safety of this approach.