Allogeneic transplantation of peripheral blood progenitor cells.

Transplantation of autologous peripheral blood progenitor cells (PBPC) is now a well established method to reconstitute haematopoiesis after high-dose chemoradiotherapy. Allogeneic PBPCs have rarely been used as the sole measure to induce haematopoietic recovery after myeloablative therapy because of uncertainties regarding the durability of engraftment and the risk of acute and chronic graft-vs-host disease (GVHD). In addition, this technique requires the exposure of normal donors to granulocyte colony stimulating factor (G-CSF) in order to mobilise a sufficient number of PBPCs which can then be collected by leukapheresis. We report here our initial experience with allogeneic transplantation of PBPCs in order to demonstrate the feasibility and safety of harvesting sufficient numbers of PBPCs in healty donors. In addition, the early results presented in this communication show that allogeneic PBPCs can successfully be used to restore haematopoiesis in HLA-identical siblings of the donor without causing devastating graft-vs-host disease.