Leukemia Patients Survive With Stem Cell Transplant
STEM CELL THERAPIES TODAY
Did you know that several stem cell therapies are routinely used to treat disease today?
These include:
* Adult Stem Cell Transplant: Bone Marrow Stem Cells
* Adult Stem Cell Transplant: Peripheral Blood Stem Cells
* Umbilical Cord Blood Stem Cell Transplant
Adult Stem Cell Transplant: Bone Marrow Stem Cells
Perhaps the best-known stem cell therapy to date is the bone marrow transplant, which is used to treat leukemia and other types of cancer, as well as various blood disorders.
Why is this a stem cell therapy?
Leukemia is a cancer of white blood cells, or leukocytes. Like other blood cells, leukocytes are made in the bone marrow through a process that begins with multipotent adult stem cells. Mature leukocytes are released into the bloodstream, where they work to fight off infections in our bodies.
Leukemia results when leukocytes begin to grow and function abnormally, becoming cancerous. These abnormal cells cannot fight off infection, and they interfere with the functions of other organs.
Successful treatment for leukemia depends on getting rid of all the abnormal leukocytes in the patient, allowing healthy ones to grow in their place. One way to do this is through chemotherapy, which uses potent drugs to target and kill the abnormal cells. When chemotherapy alone can't eliminate them all, physicians sometimes turn to bone marrow transplants.
In a bone marrow transplant, the patient's bone marrow stem cells are replaced with those from a healthy, matching donor. To do this, all of the patient's existing bone marrow and abnormal leukocytes are first killed using a combination of chemotherapy and radiation. Next, a sample of donor bone marrow containing healthy stem cells is introduced into the patient's bloodstream.
If the transplant is successful, the stem cells will migrate into the patient's bone marrow and begin producing new, healthy leukocytes to replace the abnormal cells.
Adult Stem Cell Transplant: Peripheral Blood Stem Cell Transplant
While most blood stem cells reside in the bone marrow, a small number are present in the bloodstream. These multipotent peripheral blood stem cells, or PBSCs, can be used just like bone marrow stem cells to treat leukemia, other cancers and various blood disorders. Since they can be obtained from drawn blood, PBSCs are easier to collect than bone marrow stem cells, which must be extracted from within bones. This makes PBSCs a less invasive treatment option than bone marrow stem cells. PBSCs are sparse in the bloodstream, however, so collecting enough to perform a transplant can pose a challenge.
Umbilical Cord Blood Stem Cell Transplant
Newborn infants no longer need their umbilical cords, so they have traditionally been discarded as a by-product of the birth process. In recent years, however, the multipotent-stem-cell-rich blood found in the umbilical cord has proven useful in treating the same types of health problems as those treated using bone marrow stem cells and PBSCs.
Umbilical cord blood stem cell transplants are less prone to rejection than either bone marrow or peripheral blood stem cells. This is probably because the cells have not yet developed the features that can be recognized and attacked by the recipient's immune system. Also, because umbilical cord blood lacks well-developed immune cells, there is less chance that the transplanted cells will attack the recipient's body, a problem called graft versus host disease.
Both the versatility and availability of umbilical cord blood stem cells makes them a potent resource for transplant therapies.
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Leukemia Patients Survive With Stem Cell Transplant
"As many as 16,000 leukemia patients diagnosed each year require a bone marrow transplant, but have no matched relative or can't find a match in the national bone marrow registry," says Mary J. Laughlin, MD, lead author on the study and hematologist oncologist at Case Comprehensive Cancer Center and University Hospitals of Cleveland Ireland Cancer Center. "Umbilical cords that are normally discarded after birth could provide real hope for these patients."
Dr. Laughlin led an international team of researchers in collaboration with the International Bone Marrow Transplant Registry and the New York Blood Center National Cord Blood Program. They conducted an analysis and comparison of treatment results in more than 500 adult leukemia patients undergoing transplant.
Researchers directly compared patients who had cord blood stem cell transplants with two groups: patients who had fully-matched unrelated bone marrow transplants and patients who had one antigen-mismatched unrelated bone marrow transplants. The study included patient's ages 16 to 60 years who underwent transplants in the United States during a six-year period ending in 2001.
Survival rates were highest (33 percent) for those bone marrow transplants with matched unrelated donors. Survival rates were the same (22 percent) for cord blood and one antigen-mismatched unrelated bone marrow transplant patients--results that clearly indicate the efficacy of cord blood stem cells when bone marrow donors are unavailable, according to Dr. Laughlin, an Associate Professor of Medicine at Case Western Reserve University School of Medicine.
"These are very high risk patients who undergo cord blood transplants only as a last resort effort to stay alive," Dr. Laughlin says. "Even with a cord blood transplant, these patients often suffer from life-threatening infections. But the fact is, without attempting this innovative therapy, none of them would survive."
"Techniques that extend the availability of stem cell transplantation to those patients in desperate need are an important and valuable step in the right direction," said Marshall Lichtman, MD, The Leukemia & Lymphoma Society's Executive Vice President. "Dr. Laughlin's study gives renewed hope to adult patients without a sibling stem cell donor. Continued research is needed, however, to improve the outlook for the large proportion of patients who do not yet benefit from these approaches." The Society helped fund the study.
Cord blood transplantation provides leukemia patients with stem cells, enabling them to produce healthy blood cells in a procedure previously shown to be highly effective in children with the disease. As a stem cell source, umbilical cord blood is not controversial and readily available; in fact, cord blood is normally discarded after a baby's birth.
New mothers can donate cord blood immediately after delivery. Ordinarily, the placenta (the afterbirth), and the cord blood it contains, is discarded. Now a trained technician can collect the cord blood which remains in the placenta after the baby is born and the cord is cut. The donated cord blood is processed and frozen and stored for any patient in the future that might need a transplant.
The availability of cord blood makes it a logical choice for doctors and their patients when a matching bone marrow donor cannot be found. A patient's best chance for survival comes from a bone marrow donor who is related to the patient and matches the patient's tissue type. A bone marrow transplant from an unrelated donor may be an option when there is no donor available in the family, but offers a poorer chance for survival, even when fully matched.
"The fact is, approximately 20,000 leukemia patients nationwide need transplants but only 20 percent of them have a sibling match, so there remains a large group--about 16,000 patients--who are forced to seek donors from a marrow donor registry in hopes of finding a match from donors who aren't related to them," Dr. Laughlin says. "But only a small percentage of patients are lucky enough to find a transplant match at the registry, which is why the cord blood transplant is so important."
University Hospitals of Cleveland collaborates with the New York Blood Center National Cord Blood Program (a public cord blood bank that was the source of most of the cord blood units reported in the study) to collect cord blood donated for future patients. Recently, cord blood donated by the mother of a newborn baby at UHC proved a lifesaving option for a two-year-old leukemia patient.
The study was funded by the National Cancer Institute, the National Institute of Allergy and Infectious Diseases, the National Heart Lung and Blood Institute, the Abraham and Phyllis Katz Foundation, The Leukemia & Lymphoma Society, American Society of Clinical Oncology and the Children's Leukemia Research Association.
© Mukto Samadder
STEM CELL THERAPIES TODAY
Did you know that several stem cell therapies are routinely used to treat disease today?
These include:
* Adult Stem Cell Transplant: Bone Marrow Stem Cells
* Adult Stem Cell Transplant: Peripheral Blood Stem Cells
* Umbilical Cord Blood Stem Cell Transplant
Adult Stem Cell Transplant: Bone Marrow Stem Cells
Perhaps the best-known stem cell therapy to date is the bone marrow transplant, which is used to treat leukemia and other types of cancer, as well as various blood disorders.
Why is this a stem cell therapy?
Leukemia is a cancer of white blood cells, or leukocytes. Like other blood cells, leukocytes are made in the bone marrow through a process that begins with multipotent adult stem cells. Mature leukocytes are released into the bloodstream, where they work to fight off infections in our bodies.
Leukemia results when leukocytes begin to grow and function abnormally, becoming cancerous. These abnormal cells cannot fight off infection, and they interfere with the functions of other organs.
Successful treatment for leukemia depends on getting rid of all the abnormal leukocytes in the patient, allowing healthy ones to grow in their place. One way to do this is through chemotherapy, which uses potent drugs to target and kill the abnormal cells. When chemotherapy alone can't eliminate them all, physicians sometimes turn to bone marrow transplants.
In a bone marrow transplant, the patient's bone marrow stem cells are replaced with those from a healthy, matching donor. To do this, all of the patient's existing bone marrow and abnormal leukocytes are first killed using a combination of chemotherapy and radiation. Next, a sample of donor bone marrow containing healthy stem cells is introduced into the patient's bloodstream.
If the transplant is successful, the stem cells will migrate into the patient's bone marrow and begin producing new, healthy leukocytes to replace the abnormal cells.
Adult Stem Cell Transplant: Peripheral Blood Stem Cell Transplant
While most blood stem cells reside in the bone marrow, a small number are present in the bloodstream. These multipotent peripheral blood stem cells, or PBSCs, can be used just like bone marrow stem cells to treat leukemia, other cancers and various blood disorders. Since they can be obtained from drawn blood, PBSCs are easier to collect than bone marrow stem cells, which must be extracted from within bones. This makes PBSCs a less invasive treatment option than bone marrow stem cells. PBSCs are sparse in the bloodstream, however, so collecting enough to perform a transplant can pose a challenge.
Umbilical Cord Blood Stem Cell Transplant
Newborn infants no longer need their umbilical cords, so they have traditionally been discarded as a by-product of the birth process. In recent years, however, the multipotent-stem-cell-rich blood found in the umbilical cord has proven useful in treating the same types of health problems as those treated using bone marrow stem cells and PBSCs.
Umbilical cord blood stem cell transplants are less prone to rejection than either bone marrow or peripheral blood stem cells. This is probably because the cells have not yet developed the features that can be recognized and attacked by the recipient's immune system. Also, because umbilical cord blood lacks well-developed immune cells, there is less chance that the transplanted cells will attack the recipient's body, a problem called graft versus host disease.
Both the versatility and availability of umbilical cord blood stem cells makes them a potent resource for transplant therapies.
==============
Leukemia Patients Survive With Stem Cell Transplant
"As many as 16,000 leukemia patients diagnosed each year require a bone marrow transplant, but have no matched relative or can't find a match in the national bone marrow registry," says Mary J. Laughlin, MD, lead author on the study and hematologist oncologist at Case Comprehensive Cancer Center and University Hospitals of Cleveland Ireland Cancer Center. "Umbilical cords that are normally discarded after birth could provide real hope for these patients."
Dr. Laughlin led an international team of researchers in collaboration with the International Bone Marrow Transplant Registry and the New York Blood Center National Cord Blood Program. They conducted an analysis and comparison of treatment results in more than 500 adult leukemia patients undergoing transplant.
Researchers directly compared patients who had cord blood stem cell transplants with two groups: patients who had fully-matched unrelated bone marrow transplants and patients who had one antigen-mismatched unrelated bone marrow transplants. The study included patient's ages 16 to 60 years who underwent transplants in the United States during a six-year period ending in 2001.
Survival rates were highest (33 percent) for those bone marrow transplants with matched unrelated donors. Survival rates were the same (22 percent) for cord blood and one antigen-mismatched unrelated bone marrow transplant patients--results that clearly indicate the efficacy of cord blood stem cells when bone marrow donors are unavailable, according to Dr. Laughlin, an Associate Professor of Medicine at Case Western Reserve University School of Medicine.
"These are very high risk patients who undergo cord blood transplants only as a last resort effort to stay alive," Dr. Laughlin says. "Even with a cord blood transplant, these patients often suffer from life-threatening infections. But the fact is, without attempting this innovative therapy, none of them would survive."
"Techniques that extend the availability of stem cell transplantation to those patients in desperate need are an important and valuable step in the right direction," said Marshall Lichtman, MD, The Leukemia & Lymphoma Society's Executive Vice President. "Dr. Laughlin's study gives renewed hope to adult patients without a sibling stem cell donor. Continued research is needed, however, to improve the outlook for the large proportion of patients who do not yet benefit from these approaches." The Society helped fund the study.
Cord blood transplantation provides leukemia patients with stem cells, enabling them to produce healthy blood cells in a procedure previously shown to be highly effective in children with the disease. As a stem cell source, umbilical cord blood is not controversial and readily available; in fact, cord blood is normally discarded after a baby's birth.
New mothers can donate cord blood immediately after delivery. Ordinarily, the placenta (the afterbirth), and the cord blood it contains, is discarded. Now a trained technician can collect the cord blood which remains in the placenta after the baby is born and the cord is cut. The donated cord blood is processed and frozen and stored for any patient in the future that might need a transplant.
The availability of cord blood makes it a logical choice for doctors and their patients when a matching bone marrow donor cannot be found. A patient's best chance for survival comes from a bone marrow donor who is related to the patient and matches the patient's tissue type. A bone marrow transplant from an unrelated donor may be an option when there is no donor available in the family, but offers a poorer chance for survival, even when fully matched.
"The fact is, approximately 20,000 leukemia patients nationwide need transplants but only 20 percent of them have a sibling match, so there remains a large group--about 16,000 patients--who are forced to seek donors from a marrow donor registry in hopes of finding a match from donors who aren't related to them," Dr. Laughlin says. "But only a small percentage of patients are lucky enough to find a transplant match at the registry, which is why the cord blood transplant is so important."
University Hospitals of Cleveland collaborates with the New York Blood Center National Cord Blood Program (a public cord blood bank that was the source of most of the cord blood units reported in the study) to collect cord blood donated for future patients. Recently, cord blood donated by the mother of a newborn baby at UHC proved a lifesaving option for a two-year-old leukemia patient.
The study was funded by the National Cancer Institute, the National Institute of Allergy and Infectious Diseases, the National Heart Lung and Blood Institute, the Abraham and Phyllis Katz Foundation, The Leukemia & Lymphoma Society, American Society of Clinical Oncology and the Children's Leukemia Research Association.
© Mukto Samadder
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