[Transplant of hemopoietic progenitors].

In the second half of the XX century, the transplant of hemopoietic progenitors ceased to be a desperate treatment with a high incidence of complications implying a high mortality, and became a curative treatment for thousands of patients with hematological neoplasias and other diseases. Since then understanding of the hemopoietic stem cells has increased, peripheral blood has replaced bone marrow as a source of progenitors, cord blood has been established as a viable source of progenitors and the realisation of unrelated transplants is a reality for many patients. The improvement of conditioning regimes and the introduction of new non-myeloablative treatments have reduced relapses. The new diagnostic techniques and the new anti-microbial treatments have reduced infectious complications and their mortality. There has been an advance in knowledge in determining minimal residual disease and the anti-tumour effect of the lymphocytes of the donor, which has made it possible to widen the indications. Besides, new understanding of the immunobiology of the transplant has, on the one hand, improved the options for controlling one of the principal complications, the graft-versus-host disease, and, on the other, a better use is made of the immunotherapeutic effect of the transplant.