Isolation and infusion of donor CD34+ bone marrow cells in cadaver kidney transplantation

Background. Infusion of donor bone marrow cells induces tolerance in allograft models. CD34 + stem cells present in human bone marrow could be endowed with tolerogenic properties. Methods. CD34 + stem cells were isolated from bone marrow extracted from vertebral bodies of cadaveric donors. Donor CD34 + cells (0.6-3.7 x 10 6 /kg) were infused during surgery in 10 kidney transplant recipients receiving OKT3 as induction therapy. Chimerism was investigated using nested PCR for donor-specific HLA alleles. Results. The infusion of CD34 + stem cells was perfectly tolerated. Five patients remained free of acute rejection at follow-up, 47-325 days post-operatively. The five other patients underwent a single episode of corticosensitive acute rejection. Long-term chimerism was not induced in the seven patients investigated for the persistence of donor DNA. Conclusions. Infusion of donor CD34 + stem cells in kidney transplantation is safe. The clinical usefulness of the procedure remains to be established.