[Allogeneic haematopoietic stem cell transplantation - an overview]

Allogeneic haematopoietic stem cell transplantation is an effective treatment option for chemotherapy-refractory or relapsed haematological malignancies such as leukaemias and lymphomas. After conditioning with chemotherapy with or without total body irradiation, donor cells are infused to reconstitute haematopoiesis. Donor-derived immune cells induce immune reactions to control or eradicate the underlying disease, thereby going beyond the effect of chemotherapy. This graft-versus-tumour effect (GvT) is often accompanied by detrimental graft-versus-host reactions (graft-versus-host disease, GvHD), which substantially influence the mortality and morbidity after transplantation. The balance between GvHD and GvT, implementing various parameters such as donor selection, stem cell source, conditioning, immune reconstitution and immunosuppressive regimens, represents the challenge in the field of allogeneic stem cell transplantation.