Treating leukemia with cord blood is dependent on having access to a source of cord blood. Cord blood refers to blood that is found within the umbilical cord. The umbilical cord is the tube that connects the baby’s navel to the mother’s placenta and womb, allowing nutrients to pass from mother to child. Umbilical cords contain just a small amount of blood, but scientists believe that this blood is a rich source of stem cells, cells that have the capability to grow into other types of cells. Having an understanding of the relationship between leukemia and cord blood and knowledge of how to find cord blood donors also impacts successful treatment of leukemia with cord blood.
Leukemia is a type of cancer that affects the bone marrow and blood. Bone marrow is the soft, jelly-like substance found within the core of the bones that is responsible for producing blood cells. In individuals with leukemia, the bone marrow begins to produce abnormal white blood cells, those responsible for defending against infections. When white blood cells are behaving normally, they grow old and die before being replaced with new cells. Abnormal white blood cells, however, do not die off; instead, they continue to multiply, making it difficult for healthy blood cells to reproduce and fight off infections.
To address the damage done to white blood cells, leukemia may be treated with cord blood. Like other forms of cancer, however, leukemia typically involves a multi-stage treatment process. Characteristically, treatment for leukemia includes some combination of radiation and chemotherapy to destroy abnormal white blood cells and suppress the immune system. Then a cord blood transplant is done using an intravenous line to reintroduce healthy stem cells into the bone marrow. These healthy cells can then go on to produce new white blood cells and restore the immune system's capability to protect against infections.
The process of treating leukemia with cord blood requires collecting available stem cells for transplant. These stem cells can come from the healthy bone marrow of a family member like a sibling or through a donor with a similar human leukocyte antigen (HLA) type. HLA types refer to protein markers within the cells, and a viable donor will have similar protein markers to reduce the likelihood of the transplant being rejected. In the United States, a national registry is available that transplant centers or patients can use to search for cord blood unit matches.
Cord blood transplantations for treating leukemia with cord blood are done more often on children than adults due to the larger size of adult patients and the limited amount of blood cells contained in a core blood unit. In general, cord blood donors do not have to be as closely matched as bone marrow donors. This may make a cord blood treatment a more viable alternative for patients suffering from acute leukemia, and often these individuals cannot afford to wait to find a bone marrow donor match. As a precaution against stem cell related diseases, some parents are also choosing to have their newborns' umbilical cord blood stored at a private bank or donated to help others. If needed in the future, a treatment of leukemia with cord blood could be done using an individual’s own stored cord blood.