The cardioprotector dexrazoxane augments therapeutic efficacy of mitoxantrone in experimental autoimmune encephalomyelitis.

The present study investigates the immunological effects of a combination treatment of mitoxantrone and the cardioprotector dexrazoxane in experimental autoimmune encephalomyelitis (EAE). Mitoxantrone, an anthracycline-derived immunosuppressive drug has been approved recently for treatment of very active multiple sclerosis (MS). Its prolonged use is limited due to its cardiotoxic properties. Dexrazoxane (DZR (S)-(+)-1,2-bis (3,5.dioxopiperazinyl)propane, ICRF-187) is an iron III chelator which in animal models and in cancer patients reduces anthracycline and mitoxantrone induced cardiotoxicity when given immediately before these agents. We examined the immunological effects of dexrazoxane in combination with mitoxantrone in experimental autoimmune encephalomyelitis (EAE) in Lewis rats. EAE was induced by active immunization with myelin basic protein (MBP) or by adoptive transfer of MBP specific T cells (AT-EAE). The clinical course, spinal cord pathology, activity of metalloproteinases (MMP-2 and MMP-9) and T cell apoptosis were assessed. Monotherapy with DZR ameliorated slightly the course of actively induced EAE and AT-EAE. The combination of DZR and mitoxantrone was superior to mitoxantrone given alone. Clinical amelioration ran in parallel with the marked reduction of inflammatory infiltration which was nearly abolished by the combination treatment. DZR did not affect the activity of metalloproteinase 9 and did not increase the proportion of apoptotic lymph node cells ex vivo or T cells in situ. We conclude that in addition to its cardioprotective role, DZR augments mitoxantrone-mediated immunosuppressive effects in animal models of human central nervous system (CNS) autoimmune disease. Clinical trials in MS patients are warranted to evaluate the unexpected immunosuppressive efficacy of DZR as add-on treatment.