Transfusions of syngeneic blood do not seem to induce suppressive effect on antitumor or transplantation immunity in mice

There was no prolongation of allogeneic heart survival or acceleration of tumor development in mice pretransfused with syngeneic blood. Analogous transfusion of donor-specific (allogeneic) blood, without additional immunosuppression, resulted in prolongation of allogeneic heart survival. These results argue against participation of some immunologically unspecific mechanisms in immunosuppressive effect of blood transfusion on transplantation immunity in this model.