[Mesenchymal stem cells. Basic science and future clinical use].

Mesenchymal stem cells can be obtained from a bone marrow aspirate taken from the iliac crest of adult humans. The cells can be ex vivo expanded to large numbers and retain the ability of differentiate to cardiac, bone, adipocytes and muscle cells in vitro and in vivo. Undifferentiated mesenchymal stem cells produce large numbers of growth factors that control hematopoiesis and modulate lymphocyte function. Mesenchymal stem cells are well tolerated when transplanted to humans and animals. After transplantation, the differentiation appears to be controlled by local factors in the respective tissues. When co-transplanted together with hematopoietic cells in a stem-cell transplantation setting, mesenchymal stem cells appear to enhance engraftment of the hematopoietic cells as well as reduced the incidence and severity of graft-versus-host disease.