Bone marrow transplantation

What is bone marrow?
Bone marrow are present in the bone marrow cavity of long bones and flat bones of the cancellous bone between the mesh of a sponge-like organizations, to produce blood cells in bone marrow slightly red, as red bone marrow. Some of the adult bone marrow cavity of bone marrow fat cells contain a lot of yellow, and can not produce blood cells, known as the yellow bone marrow. Human birth, the body cavity filled with bone marrow red bone marrow, with age, bone marrow, fat cells increase, a considerable number of red bone marrow yellow bone marrow was replaced only last almost flat bone in the cancellous bone have red bone marrow. Such changes are possible because not all adult hematopoietic bone marrow cavity, some of the bone marrow cavity blood had been necessary to add enough blood cells. Severe ischemia, when the body, some can be transformed into yellow marrow red bone marrow, blood's ability to resume.

What is the role of bone marrow?
Human blood components in a constant metabolism, the old cells are removed, to generate new cells, bone marrow function is essential to generate a variety of cells produce stem cells, these stem cells through differentiation and then to generate a variety of blood cells such as red blood cells, interleukin platelets, lymphocytes and so easy to say that is the role of bone marrow hematopoietic function. Therefore, the bone marrow to maintain the life of the body and immunity is very important.

What is Bone Marrow Transplantation?
An organ transplant, is a treatment that infusion of normal bone marrow to replace abnormal bone marrow in patient. For the treatment of hematopoietic function, immune function defects, hematological malignancies and other malignant tumors. With this therapy may improve efficacy, to improve the prognosis, the long survival and even cure.

Which types of Bone Marrow Transplantation are there?
One is allogeneic bone marrow transplantation. It has to be patient human leukocyte antigen (HLA) matching for the importation of pulp by the allogeneic bone marrow, or among family members of bone marrow transplantation. Another type is autologous bone marrow transplantation (ABMT). Later to carry out such a bone marrow transplant. Use their own bone marrow, not for the pulp, and this method is simple, easy to promote, can be used for one child, and without the occurrence of GVHD. For leukemia, lymphoma and various solid tumor treatment.

Human leukocyte antigen (HLA) loci simultaneously exist in two No. 6 of the short arm of chromosome, each closely linked up and by the complexity of the composition of the gene locus. Each site, or by some dozens of alleles in a component. HLA was first as a human major histocompatibility complex (MHC) was found, and its expression of genes encoding the antigen, involved in control of immune recognition and the interaction between lymphocyte subsets, the HLA match is not on the graft and by those organizations influential mutually exclusive. On the one hand, can produce clinical graft explants should not live on the other hand, can have varying severity of acute and chronic graft-versus-host disease, manifested as skin, liver and gastrointestinal diseases, severe cases can cause death. Therefore, HLA typing of the organization's selection for the pulp and the success of bone marrow transplantation is one important aspect.

About 60% of adult patients with acute leukemia after allogeneic bone marrow transplantation or with up to 3 years longer survival time, and some have reached more than 5 to 6 years. Chronic myeloid leukemia in chronic phase, about 80% of patients can survive for more than 3 years, some have survived for more than 5 to 6 years can be described as radical. It was only compared with conventional chemotherapy United, not bone marrow transplantation for acute leukemia, only 10 ~ 15% of people survived to 3 years, the average survival time of only about a year. Chronic myeloid leukemia average survival time of 3 ~ 4 years, although the slow course of disease, but chemotherapy is currently no possible cure. Therefore, bone marrow transplantation achieved better effects than conventional chemotherapy. Of lymphoma and other solid tumors application of autologous bone marrow transplantation can be achieved without radical purposes.

Principle of Bone Marrow Transplantation
Select appropriate patients, the right time. With leukemia as an example: adult acute leukemia in first complete remission (at this time there is still ≤ leukemia cells in vivo), CML in chronic phase, with large doses of chemotherapy and radiotherapy for pre-processing, so that patients further to kill the leukemia cells out. At the same time, the patients immune system and bone marrow function extremely inhibited, so that the latter difficult to restore their own, and then for those who (for acute and chronic myeloid leukemia) or removed prior autologous bone marrow (for acute leukemia in complete remission) by intravenous infusion to patients can be rescued, and attention may arise during infection, such as bleeding complications, to take effective measures and wait for the normal function of hematopoietic reconstruction in a few weeks to achieve cure.

Outlook of Bone Marrow Transplantation
Allogeneic and autologous bone marrow transplantation have advantages and disadvantages, ABMT biggest disadvantage for the high recurrence rate, therefore, must be removed with acute leukemia and bone marrow of patients with advanced solid tumors in the residual tumor cells or leukemia. Removal of the current study means there is: the use of monoclonal antibodies plus complement, monoclonal antibodies add plant lectin, monoclonal antibodies and magnetic micro-particles, and the long-term bone marrow culture, the special training system for selectively normal hematopoietic cell growth, and to kill residual leukemia or tumor cells, or interfere with its growth in order to achieve the purpose of purification.

Allo-BMT, in order to eliminate or reduce the occurrence of GVHD, the first recipient and donor HLA typing of want accurate, reliable in addition to conventional HLA-A,-B,-C,-DR matching, the two sides should make further mixed lymphocyte culture in order to know the HLA-D with other currently can not detect other human leukocyte antigen between the degree of consistency and to further estimate the potential of bone marrow transplant can not be excluded or live-sik graft the extent of anti-versus-host disease. Cyclosporine A is a strong prevention of antigen to stimulate T cells in response to the drug. At the same time, monoclonal antibodies can also be used for the removal of T lymphocytes in the marrow, so as to reduce or avoid the cause for which they are the occurrence of GVHD, reducing the number of deaths.

Which diseases can be treated by bone marrow transplantation?
Bone marrow transplant is a very advanced method of treatment, mainly for the treatment of acute and chronic leukemia, severe aplastic anemia, Mediterranean anemia, lymphoma, multiple myeloma and is now trying to further the treatment of metastatic breast cancer and ovarian cancer .