The reason why the transplantation of haematopoietic cells is not used more frequently is a problem with haematopoietic cells source. Transplanted haematopoietic cells can come from the patient himself or from a donor. In both cases they are obtained from bone marrow. They can be direct harvested from the bone marrow or, with modern instruments, from peripheral (circulating) blood. In this case they are so called “peripheral blood stem cells” – below we will use abbreviation PBSC, it is only a technical term, biologically, PBSC correspond with what the general public calls bone marrow, but they have several advantages. This is the reason why this source of haematopoietic cells is used most often, and we cannot avoid it and still retain accuracy. The alternative source to bone marrow or PBSC is haematopoietic cells from umbilical cord blood. The advantage of transplant from the patients own umbilical cord blood is the fact that it could be readily available, a donor does not have to be sought, and transplant from own bone marrow or PBSC does not need to be prepared.

Own haematopoietic cells
Sibling’s haematopoietic cells
Unrelated donors haematopoietic stem cells
Own umbilical cord blood

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Own haematopoietic cells

          To obtain the haematopoietic cells from the patient’s bone marrow is the first possibility. This is impossible in some diseases (e.g. bone marrow failure), and if it is possible (e.g. breast cancer), the haematopoietic cells are often harmed by previous chemotherapy. Sometimes tumour cells are present in the bone marrow and they could be transferred back to the patient organism by transplantation. These are disadvantages of auto-transplantation, unless patient doesn’t have a transplant from his/her own umbilical cord blood.

Sibling’s haematopoietic cells

          The second possibility of how to obtain haematopoietic cells is to find matching bone marrow donor in the family. Here the problem with compatibility comes in. The bone marrow transplantation requires maximal match between donor and recipient, the match must be considerably more accurate than with kidney, heart, lungs or liver transplantation. Siblings are compatible donors of bone marrow for about 25% of patients - parents in less then one out of five thousand cases. But even in these cases is there a risk of serious post-transplantation reaction caused by inadequate compatibility, what can result into patient’s death. Umbilical cord blood does not cause such an intense post-transplant reaction as a bone marrow, so such a high level of compatibility is not required. As praxis results show, in case of emergency umbilical cord blood can be used for transplantation in another 10% of siblings (35% in total). However, the level of incompatibility already presents a very serious factor in the area of sibling pairs remarkably aggravating therapy prognosis.

          Sometimes when a child is suffering, the parents decide (at the doctors recommendation) to have another child. If the ill child lives until the sibling’s birth, there is a probability here that the umbilical cord blood of the born sibling will be suitable transplant for the ill child. It was in this way that the first umbilical cord blood transplantation was performed in the year 1988, by professor Elian Gluckman, in Paris. Unfortunately more often this ends in disappointment, either because the siblings are not compatible, or the ill child will not live until the birth of the sibling that might save his life.

Unrelated donors haematopoietic stem cells

          The third possibility is to find a compatible unrelated donor. The combined Bone Marrow Donor Registries register 8 million voluntary bone marrow donors and about 100 000 transplants from donated umbilical cord blood. The chance of finding a compatible donor or transplant for a patient is around 50%. If the compatible donor is found a haematopoietic cells transplantation could be done. In spite of high compatibility, one third of patients die due to the post-transplanting reaction caused by incompatibility between the donor’s haematopoietic cells and the cells of the patients organism.

          The new immune system recognises the foreign organism and, despite immune-suppression, starts to attack the patient’s own cells, as if they were infected, for inst. by a virus. In a very severe graft versus host reaction, the damage to the patient’s organs leads to his death.

Own umbilical cord blood

          The last option is to get a transplant from the patient’s own umbilical cord blood. It provides healthy haematopoietic stem cells for the patient. The advantage is the reliability of the transplant existence, its absolute compatibility (as the umbilical cord blood is child’s tissue not mother’s) and the security, that the haematopoietic stem cells are healthy and above all, that they have maximal vitality due to their juvenility. The problem is, however, that the transplant must be prepared at the childbirth as we can not estimate, which child will need its own transplant, so it must be prepared at random, with the hope that it will never be used.