THERAPEUTIC USE OF CORD-BLOOD STEM-CELLS

Human hematopoietic precursors stem cells are under extensive study, they are used for allogeneic or autologous transplantation, for positive or negative selection of some cell subsets, or for the introduction of new genes. Cord blood hematopoietic stem cells were shown to differ from adult bone marrow stem cells, because of their enrichment in immature progenitors. When compared to adult bone marrow stem cells, hemato,poietic stem cells from cord blood yield a higher number of bigger e a colonies, they survive and expand better in long term culture and they have a higher efficiency of gene transfer. Immunologically, they are immature and enriched in naive inactivated lymphoid cells. It has been demonstrated that a single unit of cord blood contains enough stem cells to engraft children with various malignant or non-malignant marrow disorders. Even, in HLA partially mismatched transplants, the number and severity of graft versus host disease has been limited. This has promoted the establishment of cord blood banks for use of unrelated stem cell transplants in children and perhaps in adults.