For patients suffering from leukemia, lymphoma, aplastic anemia and other hematological malignancies, a cord blood transplant may be required to save their life.
A cord blood transplant uses blood collected from the umbilical cord and placenta after a baby is born. It is then frozen, and stored at a cord blood bank until needed.
According to Dr. Zartash Gul, assistant professor of medicine for hematology and blood and marrow transplantation at UK Healthcare, the first cord blood transplants were performed in the 1980s, when researchers were looking for an alternative for patients who did not have a perfect match for a stem cell transplant. Researchers found that cord cells were able to tolerate more discrepancies when it came to the Human Leukocyte Antigens (HLA) matching a donor to a recipient. Instead of having to match all 10 HLA points for a stem cell transplant, patients could transplant successfully with only six points matched for cord blood. “That realization opened up a lot of options for people who otherwise did not have an option for a stem cell transplant,” says Dr. Gul.
Since there is more flexibility in a match with cord blood, Dr. Gul says it normally allows doctors to perfect the transplant in a much shorter time frame than the six to eight weeks it may take to prepare for a stem cell transplant. “Right now there are around 600,000 cord blood units already banked and ready to go.”
When a patient is indicated for a cord blood transplant, they first undergo chemotherapy to try to clear as much of the disease from their body as possible. “They have to come to the transplant already in remission, so to speak,” Dr. Gul explains. Also during that time, the patient is matched to a cord blood unit, which is shipped in and processed.
Patients usually surprised to realize the word “transplant” is a misnomer. The cord blood is infused into the patient through a central line, “just like a blood transfusion”. Dr. Gul says the cells in the cord blood have “baby stem cells” that go through the bloodstream and find their way to the patient’s bone marrow. “They find their niche, start making a home for themselves there, and then multiply.”
Dr. Gul says complications for a cord blood transplant may include standard complications of a blood transfusion, such as a blood clot or risk of infection. Patients that undergo a cord blood transplant are without white blood cells for the 21 to 28 days it takes for the cord blood to engraft, giving them a higher risk of infection.
Another potential complication is graft versus host disease. During a transplant, the donated cord blood will regard any disease in a patient’s body as foreign and will attack it, which is why patients undergo as much chemotherapy as possible prior to the transplant. However, sometimes there is something left behind, causing the donor cord blood to attack and create a new immune system. This new immune system may in turn see the patient as foreign and begin to attack them as well.
By Corrie Pelc