Skin transplantation to monitor clinical donor-related tolerance in mixed hematopoietic chimerism.

Mixed hematopoietic chimerism usually carries with it the tolerance to any other tissue from the same donor. Consequently, the establishment of a sustained chimerism may allow long-term acceptance of transplanted organs without immunosuppression. We report a girl with refractory severe aplastic anemia who developed low recipient level hematopoietic chimerism following transplantation of maternal highly purified CD34+ cells without prophylactic immunosuppression. Renal thrombotic microangiopathy led to chronic renal failure and she received skin allografts from her mother in view of a future kidney donation. The maternal skin grafts were accepted without immunosuppression and the hematopoietic chimerism remained stable. Skin transplantation may be a helpful and easily applicable tool to monitor donor-related tolerance in hematopoietic chimerism clinically. It should contribute to minimize the risks of subsequent solid organ transplantation from the same donor without immunosuppression.