November 10, 2011 the Food and Drug Administration approved the first product using umbilical cord blood for stem cell transplant. The product is called Hemacord and it was developed by the New York Blood Center.
Stem cell transplant are used for treatment of certain types of blood cancer and inherited immune system disorders. Umbilical cord blood stem cell transplant may also be called simply stem cell transplant or bone marrow transplant depending on where the stem cells came from. Bone marrow transplant has been utilized since the late 1960s.
What is stem cell transplant?
A stem cell transplant is the infusion of healthy stem cells into the body. A stem cell transplant (or bone marrow transplant) is used to help the body produce blood cells and decrease the risk of life-threatening infections, anemia, and bleeding.
Bone marrow transplants are considered when a person’s bone marrow stops working or does not produce enough healthy stems cells on its own. The stem cell for transplant can be either autologous (from the persons own body) or allogeneic (from a donor).
Stem cells can be from the umbilical cord, bone marrow, or peripheral blood.
How does the stem cell transplant work?
The stem cells are infused into the patient and they are absorbed into the bone marrow. Once in the bone marrow they reproduce. These reproduced cells mature and move into the blood stream. Once in the blood stream they can help strengthen the immune system, decrease anemia, and decrease bleeding risk.
A stem cell transplant is often the last hope of a dying patient.
New York Blood Center's single largest registry group is from the Fire Department of New York. Over 8,000 firefighters are registered and more than 130 have been donors - and some have been donors twice and one has donated three times to three different patients.
Caucasians in need of a stem cell/marrow transplant have as much as an 80% chance of finding a match through donor registries, but for minorities the percentage drops dramatically.
The ideal donor is between the ages of 25 to 40 and male. However, potential bone marrow donors can be between the ages of 18 to 60, male or female. Testing will determine if someone is healthy enough to be a bone marrow donor and also verify if a qualified match exists between donor and patient.
–New York Blood Center
What is umbilical cord blood?
Cord blood is the remaining blood in the placenta and the cut umbilical cord after a baby is born. It contains the same elements as blood. It contains red blood cells, white blood cells, platelets, and plasma.
Cord blood is also rich in hematopoietic (blood-forming) stem cells similar to those found in bone marrow. Cord blood stem cells can be used for transplantation as an alternative to bone marrow in some cases. More than 80 different diseases have been treated with unrelated cord blood transplants.
Currently scientists are still researching the use of cord blood to replace cells of other tissues such as nerve or heart cells.
What are stem cells and where do they come from?
"Stem cells: The body's master cells Stem cells are the body's raw materials — cells from which all other cells with specialized functions are generated. Under the right conditions in the body or a laboratory, stem cells divide to form more cells, called daughter cells. These daughter cells either become new stem cells (self-renewal) or become specialized cells (differentiation) with a more specific function, such as blood cells, brain cells, heart muscle or bone. Stem cells are unique — no other cell in the body has the natural ability to generate new cell types." – Mayo Clinic
There are three types of stem cells:
Embryonic stem cells: These are stem cells from and embryo four to five days old. At that time the embryo is called a blastocyst and contains about 150 cells.
The embryotic stem cells are called pluripotent stem cells. Pluripotent stem cells can divide into more stem cells or they can divide into specialized cells. Stem cells dividing into specialized cells have the highest potential for use in regenerate or repair diseased tissue and organs.
Embryonic stem cells are harvested from donated eggs that were fertilized at in vitro clinics, but not utilized or implanted.
Adult stem cells: These stem cells are found in smaller numbers in most adult tissue. Adult stem cells can also be found in children, placentas, and umbilical cords. The majority of adult stem cells are found in bone marrow. Adult stem cells are not at versatile as embryonic stem cells, less durable, and more likely to contain abnormalities.
"Adult cells altered to have properties of embryonic stem cells (induced pluripotent stem cells). Scientists have successfully transformed regular adult cells into stem cells using a technique called nuclear reprogramming. By altering the genes in the adult cells, researchers can reprogram the cells to act similarly to embryonic stem cells. This new technique may help researchers avoid the controversies that come with embryonic stem cells, and prevent immune system rejection of the new stem cells. But, it's not yet known if altering adult cells will cause adverse effects in humans. Researchers have been able to take regular connective tissue cells and reprogram them to become heart cells. The new heart cells were injected into mice with heart failure, where they improved heart function and survival time." –The Mayo Clinic
Amniotic fluid stem cells: Stem cells are found in amniotic fluid; however, more study is needed to fully understand their potential.
What is bone marrow?
There are two types of bone marrow.
Red marrow (consists of hematopoietic tissue, red blood cells, white blood cells, and platelets.) and Yellow marrow (consists of mostly fat cells.) Both types of bone marrow contain numerous vessels and capillaries.
At birth all of a persons marrow is red, but by adulthood only about half of a persons bone marrow remains red.
Bone marrow contains three types of stem cells.
Hematopoietic stem cells become Leukocytes, erythrocytes and thrombocytes.
- White blood cells (also called Leukocytes) can be further divided into five types of cells that fight infections. Without white blood cells our bodies would be under constant strain of bacteria and sickness. White blood cells are very important for our immune system.
- Red blood cells (also called erythrocytes) among other responsibilities carry oxygen around the body. A person can have all the oxygen in the world, but if there are no red blood cells to carry it through the body and to the organs it remains unused.
- Platelets (also called thrombocytes) are a major part of what our body uses to clot our blood. Someone with too few platelets is Thrombocytopenic which means blood clotting is severely compromised. A person with low platelets will have trouble stopping a wound from bleeding and may even spontaneously bleed internally.
Mesenchymal stem cells are found around the central sinus in the bone marrow. They become osteoblasts (bone cells), chondrocytes (cartilage cells), myocytes (muscle cells) and other types of cells. Endothelial stem cells are multipotent or progenitor cells similar to hematopoietic stem cells, but they have limited lineage.
What are peripheral blood stem cells?
Once the mature stem cells leave the bone marrow and enter the blood stream they can be collected during a process called apheresis.
What are stem cell lines?
Stem cell lines are a group of stem cells that all extend from a single original stem cell that does not specialize. These stem cell lines can be frozen and kept or shared with other scientists. With the use of stem cell lines in research there may be no need to collect stem cells from an embryo.
A list of conditions that qualify for the use of stem cell transplants can be found on the national blood cord program site.
For more information about Hemacord or the New York Blood Center please visit their web site.
Questions about stem cell transplants visit The Mayo Clinic’s web site.
A stem cell diagram from The Mayo Clinic.
Any questions about bone marrow please visit The bone marrow foundation’s web site.
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