Background: Allogeneic hematopoietic stem cell transplantation (HSCT) can lead to donor-specific tolerance. Patients reported in the literature that underwent kidney transplantation (KT) after a previous HSCT from the same haploidentical donor typically received short-term immunosuppression, mainly for safety reasons and concerns of triggering graft-versus-host disease.
Methods: We describe the case of a 22-year-old patient who developed chronic kidney failure after receiving haploidentical HSCT from his father for the treatment of metastatic rhabdomyosarcoma. Five years after HSCT, he received a preemptive kidney transplant from his father. Steroid treatment, which had been prescribed for the underlying kidney disease, was withdrawn within 2 months posttransplant, and no de novo immunosuppression was given. Donor-specific tolerance was assessed with mixed lymphocyte reaction and INF-γ ELISPOT before (D0) and after KT (D9). Furthermore, the exact level of donor-derived T cells was measured with real-time polymerase chain reaction before and 1 year after KT.
Results: In vitro assays (mixed lymphocyte reaction and ELISPOT) revealed donor-specific tolerance before and after transplantation, respectively. The number of recipient-derived T cells was low before KT and virtually did not change over time (0.0139% ± 0.0039 and 0.0120% ± 0.0067; P = NS). Graft function was excellent throughout the follow-up (36 months post KT: serum creatinine, 1.18 mg/dL). Protocol biopsies performed 1 and 12 months after transplantation confirmed the absence of rejection.
Conclusions: This is one of the first cases of kidney transplantation from the same donor after previous haploidentical HSCT with a corticosteroid taper alone. Our results suggest that immunosuppression can be avoided in such cases.