Prevention of graft-versus-host disease (GVHD) by chemoseparation of marrow cells

If GVHD-creating lymphoid cells could be removed from the marrow inoculum prior to grafting, GVHD should theoretically be prevented and rapid hemopoiesis should be established. Selective inactivation or destruction of lymphoid cells in the bone marrow by incubating the marrow with chemotherapeutic agents should be possible, provided that the agents used preferentially inactivate lymphoid cells but preserve enough hemopoietic stem cells to permit engraftment. We chose two agents of the many available, cyclosporin A (CsA) and methylprednisolone (MP), agents that seemed to have this differential effect against lymphoid and hemopoietic cells. Furthermore, both of these agents have been used systemically in clinical marrow transplantation in attempts to either treat or prevent GVHD in the marrow recipient.