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Information in brief
What is leukemia? Leukemia is a cancer disease that could be diagnosed at every age. The name of the disease comes form the symptom, i.e. the increased number of white blood cells (but this symptom does not always appear). In the course of the disease a lot of identical, irregular and disfunctional leukemia cells are produced in the bone marrow. On the other hand, the leukemia cells that reproduce beyond control obstruct the hematopoietic function of the regular bone marrow - no granulocytes, red blood cells, platelets are produced. The above leads to the development of the typical leukemia symptoms - weakness, paleness, recurring heavy infections, susceptibility to bleedings and bruises, small violet-red hemorrhages on the skin surface. Depending on the type of cancer cells, leukemia could be described as acute (gives clinical symptoms quicker) and chronic (may give no clinical symptoms and sometimes is diagnosed by accident). Each of the two above types may be further divided into myelogenous type and lymphocytic type. The myelogenous type of leukemia occurs when the new cell that would evolve to form a granulocyte is cancer-attacked. The lymphocytic type occurs when the new lymphocytes are malignantly transformed. Leukemia is treated by chemotherapy, i.e. administering drugs that destroy the cancer-attacked cells. In cases where the acute leukemias have been diagnosed, the treatment has to be taken up immediately, non-treated acute leukemias are terminal diseases. Similarly, the appropriate therapy has to be commenced quickly enough in case of chronic myelogenous leukemia, whereas in cases where chronic lymphocytic leukemias are diagnosed the therapy is initiated once the disease at an advanced stage. Why are bone marrow transplantations performed? Bone marrow transplantations are performed with acute leukemias and chronic myelogenous leukemias. Where the regular treatment is insufficient, the patients qualify for the transplantation. For such patients the bone marrow transplantation is the only hope for general recovery form the illness. The results of the transplantation vary depending on the type of leukemia, the stage of the disease and the general condition of the patient. Bone marrow is the substance of life. It is found inside the human bones, it is an extremely active substance. Every day it produces millions of blood cells. These are called erytrocytes (red blood cells), leukocytes (white blood cells) and platelets (also know as thrombocytes). It contains also so called stem cells, which account merely for 0,1% of all cells but are of great importance. Some of them have the ability of self-regeneration, some, by reproduction, give life to new generations of cells that finally produce the mature cells. A grown-up man has about 5 liters of bone marrow. Unfortunately, sometimes the bone marrow gets sick, as it is the case with leukemia. The sick bone marrow "pushes" numerous immature white blood cells into blood vessels or does not produce the red blood cells, white blood cells or platelets at all. There are more and more sick blood cells circulating in the blood vessels of a person suffering from leukemia and the number of healthy blood cells - able to transport oxygen and defend the body - is decreasing. It's not easy to treat the bone marrow diseases. Sometimes the only potential way to treat the disease is the bone marrow transplantation. The transplantation is done to treat patients with many diseases, e.g. proliferation diseases of the hematopoietic system (e.g. leukemia), Hodgkin's disease, malignant lymphomas, bone marrow cancer, aplastic anaemia, breast cancers, ovary cancer and other cancers, as well as small children with in-born disfunctions of bone marrow (e.g. grave complicated immune deficiency, in-born metabolism disorders - lisosomal diseases). How is bone marrow transplantation performed? The bone marrow transplantation consists in intravenous injection of hemopoietic cells to the sick person. The injected cells are transported with blood to the bone cavities. The procedure takes up to several hours and looks like administering fluids through a needle. But this administering decides on someone's life or death. This is because the sick person's own bone marrow needs to be destroyed before the donor's bone marrow is transplanted. Thus, the sick person is left with no immune system and is defenseless in case of every small infection. The procedure's professional name is ablation of bone marrow and its aim is to destroy the cancer cells as well as the bone marrow of the sick person. In order to do so, the whole body is subject to radiation and cytotoxical drugs are administered to the sick person. Such a brutal interference into the human body causes serious, but reversible side effects (most common are intense vomiting, loss of hair and taste, movement coordination disorders, conjunctiva and skin inflammation and other unpleasant side effects). The preparatory treatment is difficult to stand for the patient but it is also necessary, as it is a precondition for bone marrow transplantation. What happens to the patient after the transplantation? After the transplantation the patient has to remain isolated and live in the sterile environment. The food consumed must be sterile as well. The patient is kept in a room with a sterile air let into a room through the special filters keeping away bacteria, fungi and viruses. The hospital staff has to wear sterile clothing, masks and gloves and their contact with the patient is as minimal as possible. Nevertheless, the infections attack the weakened organism with the double force. It is often the case, that the bacteria, fungi or viruses that normally live in the donor's body, when transplanted, become the most feared enemy. As a rule these include the staphylococcus and other bacteria, cythomegalic and zoster viruses, adenoviruses, yeast viruses as well fungus named aspergillus. This is why the patient has to take antibiotics, anti-fungi and anti-virus medicines for a long time after the transplantation. What is a "graft vs host disease" (GvHD)? New white blood cells that appear in the patient's blood after the transplantation signal the reproduction of the regular blood cells by the grafted bone marrow that filled the bone cavities. Usually this process begins 2-4 weeks after the bone marrow was transplanted. The so-called graft vs. host disease (GvHD) is the most serious disease of the period. The transplanted bone marrow "discovers" that it is inside somebody else's body and decides to defends itself. The bone marrow seems to "reject" the organism it was transplanted into. Regardless of the preventive actions undertaken with respect to this disease, the GvHD afflicts significant part of patients and has various results. Unfortunately, it happens that the disease is a cause of patient's death. When the disease appears the patient has to take additional immunosuppressive medicines (reducing immunity), including high doses of steroids. Sometimes the GvHD has a chronic form and lasts for the whole life, the patient may also go through acute phases of the disease, the disease may have also progressive character. In most of the cases, owing to the proper treatment, the GvHD may be effectively stopped, the transplanted donor's cells become tolerant to the patient's tissues, thus the patient may slowly turn back to his normal life. What types of transplantations are performed? The bone marrow transplantation may be divided into two groups: Autologous - when the bone marrow is transplanted form the patient himself, thus the patient is a donor and a recipient at the same time. In this case, the bone marrow transplantation is possible because high doses of medicines destroying the cancer cells are administered (megachemiotherapy). The bone marrow is collected before this therapy in the remission period of the disease, i.e. in the period when the cancer cells are not detected in the patient's body no matter what detection method is applied. Colloquially we say that the disease has entered into a remission stage. The administered medicines destroy the residual cancer cells, but damage the remaining bone marrow permanently as well. At this time healthy and collected in the remission period bone marrow is transplanted to the patient Allogenic - bone marrow is collected for another person - a related or unrelated donor. In this case, before the transplantation is made the patient takes high doses of medicines as well, sometimes the radiation of the whole body is necessary. Such treatment destroys the patient's bone marrow as well as his immune system and the cancer cells, thus preparing the body to receive the donor's bone marrow. The first allogenic transplant form an unrelated donor was carried out in Poland in 1997 and the recipient was Urszula Jaworska, the founder of the largest Bone Marrow Donors Registry, that operates at the Urszula Jaworska's Foundation. Why is the matching of donor so important? As the bone marrow may not be produced outside the human body, in order to treat the sick person, the right donor has to be found. The person that would like to help disinterestedly and share his life and his health. Donating bone marrow, just like donating blood is done gratuitously and is a safe procedure for the donor. The collected bone marrow is regenerated in the donor's body within a couple of weeks. Bone marrow may be donated by the same person many times. Who may become a bone marrow donor? The bone marrow donor is potentially every healthy person aged 18-50. The donor may not be HIV, hepatitis B or C positive and may not have suffered form hepatitis A, tuberculosis, any hematological diseases or cancer. After making decision, the potential bone marrow donor is asked to undergo medical examination. The examination is simple: the blood sample is taken. Next, the genetic data (referring to the so called human leukocyte antigen - HLA) of the donor are entered into the Bone Marrow Donors Registry. If it turns out, that the sick person has the same antigens as the potential donor, the person will be asked to donate the bone marrow. The bone marrow may be donated GRATUITOUSLY and disinterestedly exclusively. The donor and the recipient do not meet each other for at least one year after the graft. After this period, should both sides wish to know each other, the data may be disclosed and the meeting arranged. The representatives of the Registry and the transplantation center are also present during the meeting. How is the bone marrow harvested? The bone marrow is collected in the operating room under general or epidural anesthesia by sucking the marrow with the use of a needle inserted into the upper crest of the pelvic bone. Each time the needle is inserted into the bone cavity, up to 5 ml of bone marrow is sucked out. Usually after the bone marrow collection the donor has several dots on the skin in the area of pelvic bones. The total quantity of bone marrow collected depends on the situation and is determined first of all by the weight of the recipient (as well as the donor) and the number of cells in the harvested bone marrow. Usually up to 1000 ml (rarely more than 1500 ml) of bone marrow is collected form the donor. The procedure takes up to 45-90 min. The bone marrow is deposited in a special container filled with anti-coagulant. The bone marrow is then filtered and, if necessary, subject to further processing. As a rule, a dozen or so days before the bone marrow harvesting takes place the donor is asked to visit a blood-collecting station where his own blood is taken for autotransfusion purposes. This blood will be given to the donor after the bone marrow collection. The next day after the harvesting the donor may turn back to his everyday activities. Even small children may donate their bone marrow. What is hematopoietic cells collection from the peripheral blood? Another method of hematopoietic cells collection is their separation form the peripheral blood. However, the donor has to be appropriately prepared for this procedure. The medicine (Filgastrin, Neupogen) that increases the number of hematopoietic cells in the blood is administered. The medicine is taken subcutaneously once or twice a day (every 12 hours). Then, the hematopoietic cells are separated from the peripheral blood in the course of the procedure called apheresis. The procedure is carried out in the special medical centre by means of cell separator and no general anesthesia is required. The blood is taken from one vein and is mixed with anti-coagulant outside the donor's body. The cells separator separates the hematopoietic cells from the blood. The remaining blood comes back to the donor through a needle inserted into another vein. Usually two needles are inserted for apheresis (one into left and one into right elbow vein). Technically this procedure is the same as standard platelets collection done in the blood-collecting station. The difference lies in the cells that are being separated. As a rule two aphereses are necessary within 2 consecutive days. The procedure requires no general anesthesia. What should I do to become a potential bone marrow donor? Please contact the Urszula Jaworska's Foundation - the largest Bone Marrow Donors Registry under the tel. no -22 870-05-21. The participation declaration is also available on-line. The completed declaration should be sent to the Foundation address (Warszawa, ul. Międzynarodowa 61), than you should await the invitation for the blood examination. You may also go with the completed declaration directly to one of the laboratories carrying out genetic tests. This tests are free of charge. The costs are covered by the Foundation. The tests consist in collecting a small sample of your blood. Then, the genetic data are entered into the Bone Marrow Donors Registry. From then on, the coded genetic data of the donor may be made available to the transplantation centers in the whole world, thus the donor may be asked to donate his bone marrow. What is a Bone Marrow Donors Registry? The Bone Marrow Donors Registries are databases, where the information on the antigens (HLA) is provided. The antigens are the places or substance in the cell that stimulate the production of antibodies. The 1st class HLA test is the lowest level of testing that allows the donor to be entered into the Registry. The Registry data are legally protected and are made available at the request of transplantation centres looking for the bone marrow donors for their patients as well as at the request of the sick persons and their families. Finding the right donor is very difficult. The donor's antigens have to be identical or very similar to those of the patient. Thanks to the antigens the organism distinguishes between its own cells and hostile cells, viruses and bacteria. The organism accepts the first cells and eliminates the latter. If the patient got the transplant of the bone marrow from the dissimilar person, his organism would recognize the graft as an enemy. The patient would die. The probability of finding the right donor is like 1:25 000. This is like looking for a needle in a haystick. Still, some genetic combinations of antigens repeat and thus finding the donor genetically similar to the patient is possible. Every nation has characteristic genetic combinations, this is why it would be easier to find the Polish donor for the Polish patient. Every donor, whose genetic data are on the Register has his identification number and such unidentified, coded data are provided to the transplantation centers. The security of the data is guarded by the Registry. The Registry is responsible for the information and may not provide them without justified reason. Urszula Jaworska's Foundation is the largest, by number of registered persons, Bone Marrow Donors Registry in Poland. Presently over 11 200 donors are registered. It is also the only register in Poland that succeeded in several bone marrow transplantations from the registered donors. The next genetically similar donors are matched for the patients in the whole world. The main aim of the Foundation is helping to the patients suffering from leukemia and other blood cancers, conducting educational and information campaigns on the Bone Marrow Donors Registry and bone marrow transplantations in the press via radio and TV, as well as winning new potential bone marrow donors.
The bone marrow transplantation is for many patients the procedure that may save their lives. Unfortunately, the related donor may help in 25-30% of the cases. The rest of the patients may survive if they find unrelated, genetically similar donor. The probability of finding the appropriate, unrelated donor is higher if the register is larger, thus the more potential bone marrow donors, the more patients could be saved. In the countries where the registers have hundred thousands of donors, the probability of matching the donor reaches 40%. This is why it is so important that our registers have as many potential bone marrow donors as possible. It's a shame that in a country of 40 million people the potential bone marrow donors registers have in total around 15-16 thousands of those willing to help (there are up to 8 million of registered donors in the world, 4 million in the US only). As a matter of fact, up till now the most of Polish bone marrow transplantations from unrelated donors could be carried out owing to foreign donors. This situation should be changed. It would improve quickly, if we had more potential bone marrow donors. Prepared by:
Translation: Maria Kukawska |
