[Physiopathology and possible clinical use of hematopoietic stem cells. Recent advances].

Studies carried out during these last years have lead to a considerable improvement in the understanding of the biology of hematopoietic stem cells. The development of hematopoietic stem cell transplantation had a considerable impact on the therapy of leukemias. The improvement in transplantation protocols allowed the development of allogenic transplantations in which the graft versus tumor contributes to the anti-tumor effects. In parallel many growth factors acting on hematopoietic cells have been isolated and used in clinic to stimulate hematopoietic recovery and stem cell mobilization. Finally, malignant stem cells have been isolated and characterized in acute and chronic leukemias: these cells are responsible for the development and maintenance of the leukemic process and must be eradicated to obtain an effective treatment of leukemias.