Bone marrow transplantation is sometimes difficult to practice due to lack of donors. Faced with this problem, researchers are testing another method, i.e., the transplantation of stem cells extracted from the umbilical cord of newborns. These immature cells are able to regenerate the bone marrow, and it is best when HLA (Human Leucocyte Antigen) compatibility is observed.
These immature cells decrease the graft rejection phenomenon. Moreover, their ability to proliferation is superior to adult bone marrow cells. Finally, it is a very important source because, until this, the umbilical cord was just a “waste”.
Many therapeutic advances, have been noted in children with leukemia, in the field of cord blood transplantation. In adults, this kind of transplant is also possible in some cases. Thousands have been done in the world until 2004, and even more currently.
This transplant which does not require absolute histocompatibility, allows to shorten the waiting time for transplantation, which may be very important in case of emergency (e.g., acute leukemias requiring immediate intervention), because often no compatible bone marrow samples are available readily.
Some studies are continuing in this field, because it would seem that perfect compatibility is not essential for a successful transplant, which gives great hope especially for patients with leukemia waiting for a compatible marrow.
Most diseases benefiting from the therapeutic input of stem cells are treated using bone marrow transplantation or cord blood stem cell transplant (i.e., placental blood). Transplants of Hematopoietic stem cells derived from umbilical cord blood are growing, because of the quite interesting properties characterizing this type of cells, i.e., their immunological immaturity and the advantage of providing a readily available source of cells.