Kidney transplantation following treatment with cyclophosphamide and bone marrow grafting.

Canine cyclophosphamide (CY) chimeras permanently accept kidney and skin grafts as do radiation chimeras. Three of five dogs with reversion of chimerism rejected their kidney grafts within 11-16 days, while two of them retained their kidney grafts permanently. These results suggest that the reversion of chimerism in CY chimeras may be due to different mechanisms, either immunologic rejection or a nonimmunologic substitution of the grafted marrow by the host's own hemopoiesis.