Parents of a child who has been diagnosed in utero with a congenital heart defect, such as Hypoplastic Left Heart Syndrome (HLHS), often learn during pregnancy about banking the child’s umbilical cord blood. Susana Cantero Peral, M.D., a postdoctoral researcher who specializes in cord blood for the Todd and Karen Wanek Family Program for HLHS, talked with me about collecting, banking and the potential regenerative properties of cord blood.
When you decide to bank your baby’s cord blood, what is actually collected is the blood that remains in the blood vessels of the placenta and in the portion of the umbilical cord attached to it. Umbilical cord blood contains all of the normal elements of blood – red cells, white cells, platelets and plasma. It is also rich in hematopoietic (blood-forming) stem cells, similar to those found in bone marrow, which has been used to treat more than 80 different diseases, with leukemia being the most common disease category. Most of these transplants have been performed from unrelated cord blood units donated to public cord blood banks.
Umbilical cord blood was first used in transplant medicine in 1988, as an alternative source to bone marrow. At that time, the potential for these cells was not known, and some hematologists and transplants physicians regarded that new source of stem cells as “science fiction.” Today, clinical trials using umbilical cord blood for regenerative purposes are now becoming a reality in the field of regenerative medicine, and the HLHS program here at Mayo Clinic hopes to begin its own trials soon.
The HLHS program is doing ongoing research with the mononuclear cells found in cord blood. These cells are a subpopulation of leukocytes or white blood cells, which are important for fighting against infections. Mononuclear cells include lymphocytes and monocytes, and it is in this within this part of the blood that we can find the stem and progenitor cells.
“In addition to its use as an alternative to bone marrow for hematopoietic stem cell transplantation, cord blood has recently been used in a variety of regenerative medicine applications,” says Dr. Cantero Peral. “Some researchers have shown that cord blood contains a mixture of stem cells capable of giving rise to any cell of the body. Several cells of non-hematopoietic lineage, or which can differentiate into non-hematopoietic cells, have been identified in the mononuclear fraction.”
Preclinical investigations have employed umbilical cord blood mononuclear cells in the therapy of neurologic disease (stroke, spinal cord, or brain trauma, amyotropic lateral sclerosis), cardiac disease (myocardial infarction or ischemia, cardiac injury, valve repair), and tissue repair.
“Some ongoing clinical trials are studying mainly the safety and efficacy of autologous cord blood cells in diseases such as cerebral palsy, stroke in children, pediatric traumatic brain injury, neonatal hypoxic-ischemic encephalopathy, autism, peripheral vascular disease and type 1 diabetes,” says Dr. Cantero Peral.
It is the goal of the HLHS program to delay or prevent heart transplant for those affected with HLHS. One of the ways we hope to do that is by delivering cell based therapies to those affected with HLHS.
“Umbilical cord blood cells are unique in their ability to differentiate into many cell types and provide a nurturing environment that supports cell growth and development. By transplanting these cell types into damaged tissues such as the heart muscle, we believe the damaged tissue will be stimulated to undergo maximal regeneration or tissue renewal,” says Timothy Nelson, M.D., director of the Todd and Karen Wanek Program for HLHS. “Therefore, this type of cell may provide a readily available cell source for congenital heart disease patients and offer a new strategy to improve the strength and function of treated heart muscle.”