Since 1998, advances in cord blood technology has allowed cord blood transplants to become an increasingly desirable alternative to traditional bone marrow transplants in patients requiring a stem cell transplant. And while bone marrow transplants continue be a more commonly performed procedure, there is evidence that suggests this may be changing. But is a cord blood transplant really a more effective procedure? The truth is, it depends on the circumstance.
What are Cord Blood and Bone Marrow Transplants?
Both bone marrow and cord blood stem cell transplants are designed to replace unhealthy cells with healthy ones; the most common sources of these healthy cells are bone marrow and umbilical cord blood.
Cord blood is blood that is collected from an infant’s umbilical cord after delivery, so that it may be tested, frozen, and subsequently stored in a cord blood bank for future use.
A bone marrow transplant, on the other hand, involves the use of bone marrow that is transplanted from a donor into the recipient in order to cultivate new stem cells. The marrow itself is a spongy tissue located inside the bones. Most commonly, marrow is extracted from either the breastbone, skull, hips, ribs or spine, as these contain stem cells which produce the following types of blood cells: white blood cells (leukocytes), which fight against infection; red blood cells (erythrocytes), which carry oxygen in order to eliminate waste from the organs and tissue; and platelets, which are responsible for making the blood clot.
In preparation for the transplant, bone barrow is removed while the donor is under a general anesthetic. It is then filtered, treated and either transplanted immediately into the recipient, or tested, frozen and stored for later use.
Cord Blood Transplant vs. Bone Marrow Transplant
There are many different criteria used to evaluate whether or not a cord blood transplant is right for you. When making your decision, it is important that both you and your doctor keep the following in mind:
| Evaluative Criteria | Transplant Preferred |
|---|---|
| Explanation | |
| Graft Versus Host Disease (GVHD) | Cord Blood Preferred |
| Graft Versus Host Disease is a potentially serious complication for any organ transplant. In fact, it is estimated to be fatal in up to 40% of patients. However, because cord blood is more primitive than bone marrow, there is a lower chance that these cells will attack the recipient’s body, resulting in a lower incidence of GVHD. | |
| HLA Matching | Cord Blood Preferred |
| Human Leukocyte Antigen (HLA) is a marker your immune system uses to recognize foreign cells. HLA tissue types are inherited, which is why it is recommended that a recipient’s bone marrow donor be a family member (ideally a brother or sister). This is a problem because 70% of donors do not have a suitable donor in their family. However, because cord blood stem cells are considered to be “purer” (and therefore more adaptable), there is generally no need to find an HLA match. | |
| Rich Source of Stem Cells | Cord Blood Preferred |
| Stem cells are found in greater proportions in umbilical cord blood. In fact, some experts say it contains nearly 10 times the amount of stem cells found in bone marrow. | |
| Regenerative Source | Cord Blood Preferred |
| It is believed that stem cells found in cord blood have greater regenerative properties since they are younger than bone marrow. | |
| Availability | Cord Blood Preferred |
| Stem cell transplants are in high demand, with over 30 000 individuals in line for the procedure each year. The problem is that waiting for a suitable donor can often inhibit an individual from having the procedure. In fact, for this very reason, 70% of these individuals cannot find a matching donor. Unfortunately, for some individuals, such as those with more severe types of cancer, this lack of treatment can be fatal. Cord blood banking, however, helps to alleviate this issue, as their storage facilities make cord blood readily available for those in need. | |
| Pain | Cord Blood Preferred |
| From a donor’s perspective, a cord blood transplant presents a much less invasive procedure, as the collection of cord blood stem cells happens directly after birth from the umbilical cord. Bone marrow transplants, on the other hand, are invasive procedures, requiring a general anesthesia so that bone marrow can be removed from the rear of the pelvic bone through a series of injections. | |
| Graft Rejection | Bone Marrow Preferred |
| Despite the numerous advantages of cord blood transplants, bone marrow transplants are still preferred in the case of graft rejection– or a case in which the recipient’s body attacks the donor’s stem cells. According to a recent study, some 11% of cord blood transplants were rejected, while this was the case in only 2% of bone marrow transplants. |
In addition, cord blood transplants are generally better suited for those younger than 30 years of age and who weigh less than 60 kilograms. Bone marrow transplants, on the other hand, are not recommended for individuals with kidney, lung, liver or heart diseases or disorders.
