ROLE OF THE THYMUS IN RADIATION-INDUCED LUNG DAMAGE AFTER BONE-MARROWTRANSPLANTATION

Pneumonitis developing after total-body irradiation and bone marrow tr ansplantation can be a serious complication of this form of therapy, I n this study, the incidence of lung damage in a murine syngeneic trans plant model was found to be decreased by prior removal of the thymus, indicating that thymus-derived cells, even in the absence of complicat ing factors such as graft-versus-host disease and opportunistic pathog ens, can contribute to radiation-induced lung damage, It is suggested that the increased damage is due to a syngeneic graft-versus-host reac tion mediated by a regenerating lymphoid system, If this concept is co rrect, new strategies can be identified that might be employed in alte ring the incidence of this serious transplant-related complication. (C ) 1997 by Radiation Research Society.