Letter to the Editor
Conditioning regimens for hematopoietic stem cell transplantations (HSCT) for autoimmune disease have generally been derived from intensive myeloablative protocols used for transplantation for hematological disorders. These include BEAM (comprising BCNU [1,3-bis(2-chloroethyl)-1-nitrosourea], cytosine arabinoside, etoposide, and melphalan) with antithymocyte globulin [1] and several total body irradiation-based regimens [2,3]. However, as multiple sclerosis (MS) is chiefly an immune-mediated disorder, it is believed that immunomodulation, rather than myeloablation, is necessary [4,5]. To minimize the toxic effects of intensive chemo/radiotherapy while maximizing the immunoablative effects of potent lymphoid-active drugs, we adopted a "FluCy" conditioning regimen with fludarabine added to a backbone of cyclophosphamide conditioning. We present here our first 3 patients with severe MS who successfully underwent autologous HSCT with this conditioning regimen in the Singapore General Hospital.
After obtaining Ethics Committee approval for autologous HSCT for autoimmune diseases including MS and systemic lupus erythematosus, 3 patients received transplants for secondary progressive MS that had continued to relapse/ progress despite established therapy with interferon and immunosuppression. Patients received a stem cell mobilization regimen comprising intravenous (IV) cyclophosphamide 2 g/m 2 on day 1 and subcutaneous (S/C) granulocyte colony-stimulating factor (G-CSF) 10 g/kg from day 4. Peripheral blood stem cell (PBSC) collection via apheresis was carried out following neutrophil recovery after cyclophosphamide. CD34 selection of the PBSC product was performed via a Clinimacs column in 1 of the 3 patients. The