Stem Cell Transplantation

A stem cell transplant is a treatment for some types of cancer. For example in the case if person might have leukemia, multiple myeloma, or some types of lymphoma. It also treat some blood diseases with stem cell transplants. During those day, patients who needed a stem cell transplant received a bone marrow transplant because the stem cells were collected from the bone marrow but today stem cells are usually collected from the blood instead of the bone marrow. This is reason why now more commonly called as stem cell transplants.

Stem cell transplants are used to replace bone marrow that has been destroyed by cancer or destroyed by the chemo or radiation that is used to treat the cancer and cancers, such as certain leukemias, multiple myeloma, and some lymphomas. Stem cell transplant can be an important part of treatment. High doses of chemo sometime work better than standard doses to kill cancer cells. But when high doses are use than it can also kill all the stem cells and cause the bone marrow to completely stop making blood cells in which need to live. The transplanted stem cells replace the body stem cells after the bone marrow and its stem cells have been destroyed by treatment. Transplant lets doctors use much higher doses of chemo to try to kill all of the cancer cells. Blood cells in body start out as young or is immature cells called hematopoietic stem cells.

Even though they called stem cells but they are not the same as the embryo stem cells that are studied in cloning and other types of research. Stem cells mostly live in the bone marrow at the spongy center of certain bone and this is where they divide to make new blood cells. Once blood cells mature, they leave the bone marrow and enter the bloodstream. A small number of stem cells also get into the bloodstream and these are called peripheral blood stem cells. Stem cell transplants are used to give back stem cells when the bone marrow has been destroyed by disease chemotherapy or radiation.

History

First human bone marrow transfusion was given to a patient with aplastic anemia in 1939. This patient received daily blood transfusions and attempt to raise her leukocyte and platelet counts. It was made using intravenous injection of bone marrow. After World War II and the use of the atomic bomb, researchers tried to find ways to restore the bone marrow function in aplasia caused by radiation exposure and in the 1950s, it was proven in a mouse model that marrow aplasia secondary to radiation can be overcome by syngeneic marrow graft. In 1956, Barnes and colleagues published their experiment on two groups of mice with acute leukemia and both groups were irradiated as anti leukemic therapy and both were salvaged from marrow aplasia by bone marrow transplantation. The first group received a syngeneic marrow ( from mice of the same strain ) however, most of the mice died from leukemia relapse. The second group received an allogeneic marrow from a different strain and none of the mice in this group experienced disease relapse. Another breakthrough took place with the first transplantation done from an HLA matched unrelated donor. Hematopoietic stem cell transplantation from an unrelated donor dramatically increased the odds for finding a match. For example, it rose from 25% to 75% for Caucasian patient. International collaboration was mandatory for the establishment of transplantation centers around the world and for a global donor registry. In 1972 the International Bone Marrow Transplant Registry ( IBMTR ) was established for documenting HSCT outcome data and by that time, transplantations were done in 12 centers performing about 50 procedures a year altogether. In 1974, the European Group for Blood and Marrow Transplantation ( EBMT ) was established for European collaboration in the field of HSCT. The first unrelated donor transplantation inspired in 1986 the foundation of the National Marrow Donor Program ( NMDP ), and in 1988 Bone Marrow Donors Worldwide ( BMDW ) was founded, this organization unifies more than 23 million donors registered in 73 countries and 600,000 cord blood units from cord blood banks in 32 countries

Discussion

Stem cells make the 3 main types of blood cells. Red blood cells, white blood cells, and platelets and we need all of these types of blood cells to keep us alive. For these blood cells to do their jobs, need to have enough of each type in blood. Red blood cells ( RBC ) carry oxygen away from the lungs to all of the cells in the body and they bring carbon dioxide from the cells back to the lungs to be exhaled. A blood test called a hematocrit show how much of blood is made up of RBC. The normal range is about 35% to 50% for adults. People that have hematocrit below this level have anemia ( Low level of RBC ). This can make them look pale and feel tired, short of breath, and weak. White blood cells ( WBC ) help fight infections caused by fungi, viruses and bacteria. There are different type of WBC that is neutrophils are the most important type in fighting bacterial infections. Absolute neutrophil count(ANC) is a measure of the neutrophils in blood. When ANC drops below 1,000 per cubic millimeter (1,000/mm3) means patient might have neutropenia, and have a higher risk of infection. The danger is greatest when levels are below 500/mm3. Next is lymphocytes are another type of white blood cell. There are different kinds of lymphocytes, such as T lymphocytes, B lymphocytes, and natural killer cells. Some lymphocytes make antibodies to help fight infections and the body depends on lymphocytes to recognize its own cells and reject cells that are foreign to the body. Example are invading germs or cells that are transplanted from someone else. Platelets are pieces of cells that seal damaged blood vessels and help blood to clot, both of which are important in stopping bleeding. A normal platelet count is between 150,000/cubic mm and 450,000/cubic mm. A person whose platelet count drop below normal is said to have thrombocytopenia, and may bleed longer, bruise more easily, and have bleeding gum or nosebleed. Spontaneous bleeding ( bleeding with no known injury ) can happen when a person platelet count drops lower than 20,000/mm3. Can be seen in hemorrhagic dengue fever. This are dangerous if bleeding occurs in the brain or if blood begins to leak into the intestine or stomach.

Source

There are two major sources of stem cells. The type that gets into all forms of media daily are embryonic stem cells which are over hyped and are never used clinically because illegal. The legal, moral and ethically correct type of stem cells are bone marrow derived stem cells and umbilical cord stem cells that almost never receive any publicity. All forms of stem cells are essentially very similar and differ only in fairly minor ways. Adult Stem Cells have been found in nearly every tissue in the body. In addition, umbilical cord stem cells are categorized as adult stem cells because they have grown beyond the embryonic stage and adult stem cells in fact have been used in transplants for over 30 years

Storage,collection and processing blood stem cells can be moved or mobilized out of the bone marrow into the bloodstream ( peripheral blood ) where they can be easily collected. Most transplants these days use stem cells collected from the bloodstream. Receive injections of a drug such as filgrastim or plerixifor over a four to five day period. These drugs move stem cells out of the bone marrow into the bloodstream. Most people tolerate these drugs well although mild flu like symptoms are common. Symptoms end a few days after the injections stop. If collecting stem cell for own transplant, chemotherapy drugs may be used to help move the stem cells out of bone marrow into the bloodstream. Procedure used to collect bone marrow for transplant is called a bone marrow harvest. It is a surgical procedure that takes place in a hospital operating room and typically done as an outpatient procedure because only takes 30 minutes to be done. While under anesthesia, a needle will be inserted into rear pelvic bone where a large quantity of bone marrow is located. The bone marrow will be extracted with a syringe, several skin and bone punctures are required to extract sufficient bone marrow for transplant. There are no surgical incisions involved and only skin punctures where the needle was inserted. A sterile bandage will be applied to the site when the collection end.

Risk

After the surgery might feel tired or weak and have trouble walking for a few days. The area where the bone marrow was taken out might feel sore for a few days but doctor will ask patient to take a pain reliever for the discomfort. Normal cases, likely be able to get back to normal routine within a couple of days but it may take a couple of weeks before feel fully recovered. Because of newer modern technologies and past experience, a fatal risk are minimize.