Lethal graft-versus-host reaction induced in x-irradiated F1 hybrids by parental strain leukocytes.

The experimental findings show that the injection of parental strain (A or L strain) whole blood, containing 15 x 10/sup 6/ nucleated cells, into sublethally x-irradiated (500 r) LAf/sub 1/ mice, results in delayed deaths, i.e., from 8 to 39 days post irradiation. The reneral appearance of these injected mice, thcir body weight loss, and the histological evidence as specific lymphoid tissue atrophy indicate that thc syndrome produced is entirely analogous to that observed previously following spleen cell injection. The effect is referable to the leukocytes and not to the erythrocytes or scrum. Since lymph node cells, as well as spleen cells elicit these delayed deaths, it is reasonable to postulate that the responsible cells are those of the lymphoid series. These results imply that peripheral blood contains immunologically competent cells. On this basis, it is suggested that the administration of whole blood or agranulocytic leukocytes from non-isologous donors to heavily irradiated recipients constitutes a potentially hazardous procedure. (auth)