Hematopoietic cells transplantation
Many diseases cause the failure of hematopoiesis in bone marrow. This means that the production of red and white blood cells and platelets is stopped. The only way to save the patients is to give them healthy hematopoietic stem cells. Therefore the transplantation of hematopoietic stem cells is the restoration of blood formation.
If the patient’s own cells are used it is called an autologous transplantation. If the cells come from a different person it’s an allogenic transplantation. The choice between an autologous and allogenic transplantation depends on the disease. Stem cells could be derived from either bone marrow or cord blood. It is possible to obtain so-called peripheral blood stem cells from the bone marrow after being treated with certain growth factors.
With autologous transplantations you could say that the patients “donate” stem cells to them selves. As the cells are their own there is no risk of post-transplantation complications. The advantage of cells from cord blood for an autologous transplantation is that they are collected at the time of birth and so are young and “clean”; not affected by therapy or the aging process. Cells from bone marrow are isolated from the already ill patient during the disease’s remission. However those cells can contain remains of tumorous cells or could be damaged by chemotherapy.
The amount of autologous transplantations is twice that of allogenic transplantations. Autologous hematopoietic cells are often used in diagnoses where a donor's cells wouldn't be used due to possible post-transplantation complications. This is usually the case if the actual disease is less harmful than transplantation from a donor.
Allogenic transplantations are used when it is impossible to use your own stem cells as the origin of the disease is or may be present in the hematopoietic cells. For allogenic transplantation it is necessary to find a donor compatible in certain tissue types - HLA antigens. First the donor is searched for in the immediate family – there is a 25% chance that a sibling will be HLA-compatible. In that case it is called sibling transplantation. If the patient has no compatible sibling then the public cord blood registry is searched. This is called an unrelated allogenic transplantation.
Hematopoietic stem cell transplantation can be used to treat more than 80 disorders