Suppressive effect of cyclophosphamide on the progression of lethal graft-versus-host disease in mice--a therapeutic model of fatal post-transfusion GVHD.

In this paper, we examine in a murine system whether cyclophosphamide (CY) could prevent the development of fatal GVHD and furthermore whether it could be used to treat on-going GVHD. (C57BL/6xDBA/2)F1 (BDF1) mice were injected with spleen cells from B6 donors and their thoraces were opened to mimic cardiac operation. These mice lost body weight gradually and most of them died during 2-4 weeks post-transfusion. They showed splenomegaly, thymic atrophy and marked bone-marrow aplasia. When CY was administered at 100 mg kg-1 on days 0, 2, 7 and 9, all mice were relieved of GVHD and their organs were almost free of signs of GVHD. CY (100 mg kg-1) administered on days 7 and 9 also save mice from lethal GVHD. Moreover, CY administered at a dose of 20 mg kg-1 on days 9 and 11 when GVHD became apparent was also effective. These data suggest that CY might be used as a therapeutic agent for lethal post-transfusion GVHD.