Immunosuppression

The authors show that bone marrow–derived mesenchymal stem cells (BM-MSC) can reverse stroke-induced thymic atrophy, restore thymic structure, and normalize peripheral T-cell populations in a mouse tMCAO model.

OBJECTIVE To assess in multiple sclerosis (MS) the effect of intense immunosuppression followed by autologous hematopoietic stem cells transplantation (AHSCT) vs mitoxantrone (MTX) on disease activity measured by MRI. METHODS We conducted a multicenter, phase II, randomized trial including patients with secondary progressive or relapsing-remitting MS, with a documented increase in the last year on the Expanded Disability Status Scale, in spite of conventional therapy, and presence of one or more gadolinium-enhancing (Gd+) areas. Patients were randomized to receive intense immunosuppression (mobilization with cyclophosphamide and filgrastim, conditioning with carmustine, cytosine-arabinoside, etoposide, melphalan, and anti-thymocyte globulin) followed by AHSCT or MTX 20 mg every month for 6 months. The primary endpoint was the cumulative number of new T2 lesions in the 4 years following randomization. Secondary endpoints were the cumulative number of Gd+ lesions, relapse rate, and disability progression. Safety and tolerability were also assessed. Twenty-one patients were randomized and 17 had postbaseline evaluable MRI scans. RESULTS AHSCT reduced by 79% the number of new T2 lesions as compared to MTX (rate ratio 0.21, p = 0.00016). It also reduced Gd+ lesions as well as the annualized relapse rate. No difference was found in the progression of disability. CONCLUSION Intense immunosuppression followed by AHSCT is significantly superior to MTX in reducing MRI activity in severe cases of MS. These results strongly support further phase III studies with primary clinical endpoints.