Basic knowledge on cord blood stem cells
Stem cells are primitive cells with the potential for self-duplication and multi-directional differentiation. They are the source of organ cells that form the various tissues and organs in the human body.
Hematopoietic stem cells are the source for blood and immune cells, with the ability for self-renewal, multi-directional differentiation and homing (directed movement towards hemopoietic tissue and organs). Hematopoietic stem cells primarily reside in bone marrow, fetal liver, umbilical cord blood and mobilized peripheral blood. They can not only differentiate into red blood cells, white blood cells, platelets but can also be involved in cross-system differentiation into the cells of various tissues and organs. Hence, they are pluripotent stem cells.
Cord blood is the blood remaining in the umbilical cord and placenta after a baby is born and the umbilical cord is cut. The cord blood contains large quantities of stem cells and is one of the main sources of an individual's stem cells. Compared to bone marrow stem cells and peripheral blood stem cells, the cord blood stem cells have a lower incidence of rejection, a weaker immunogenicity and their rate of renewal is 10-20 times higher than the former.
This service is available to expectant mothers, so long as they are physically healthy, with no family hereditary diseases. Expectant healthy mothers can store cord blood stem cells for their newborn babies.
Following the signing of "Agreement on cord blood stem cells storage" by pregnant clients and timely settlement of certain medical expenses, the cord blood stem cells of their newborns will immediately be stored in the storage facilities. During the 18 year contractual period of storage, we offer free medical insurance policy. The stored cord blood belongs to the depositor at all time, and they could only be used on other family members or a third party after the consents of the owner/guardians is received.
The cord blood stem cells can be kept under normal temperature conditions (4-25°C) for 48 hours with no notable impact on their viability, but in any case should not exceed 72 hours (3 days).
- Special storage containers to keep and transport cord blood stem cells (temperature maintained at 4 -25°C) are to be used.
- Ensuring that cord blood stem cells are unexposed to X-ray radiation and remote from radiation is a must.
Stem cell transplants have a history of 50 years. However, before the 1980s, the transplants carried out surgically primarily involved bone marrow. Later on, peripheral blood stem cell transplants emerged. In the 1990s, cord blood stem cells became another new source of hematopoietic stem cells and its importance is growing. According to statistics, there are now 8 million people who have registered at bone marrow registry, but the actual utilization rate only amounts to 0.196%-0.2%. As for cord blood banks, there are 200,000 registrations and within a few short years, its utilization rate has now reached about 3%.
As genetic engineering advances, cord blood stem cells transplants will not only cure the above diseases, and hopefully, also are capable to cure diabetes, anemia, liver disease and nerve disorders. Cord blood can also be used as the future source of cellular and immune treatments and vehicle for gene therapies, for skin transplants for patients with accidental and radiation injuries, for the repair of muscles, bones and cartilage damages as well as for replacements of hips and knee joints; and for the treatments of cancer patients following removal of tissues or organs and their replacements.
After cord blood is collected and transported to the processing centre, the first step to be taken is to establish an identification archive of the collected units based on the maternal information. Subsequently, the cord blood will be sent to the laboratory for testing, as well as for separation. Cryprotectants will be added on the units to protect the cells during the cyro-preservation. Finally, it will be stored in liquid nitrogen containers at -196°C.
Our cord blood storage process features a computerized bar-coding system, which identifies cord blood units in all steps. At the same time, for every critical process, it is carried out and verified immediately by more than two officers, so as to ensure accuracy of cord blood unit registration numbers. In addition, the results of every test conducted will be validated by more than two officers, so as to ensure their accuracy. Every liquid nitrogen container is equipped with a computerized, automated liquid-nitrogen replenishing system and electronic automated alarm system. Every day, staff will check and document the liquid nitrogen volume of each container to ensure the safety standards being met at all time. Before the frozen cord blood unit is used, we will carry out genotype verification checks to ensure the safety of the units as well as the validation of the identity of the stored cord blood units.
HLA means human leukocyte antigens, which are found on the surface of various types of nucleated cells in the human body. In the human anatomy, they are akin to an "identity card", inherited from one's parents and could distinguish "self" and "nonself", through which the wholeness of an individual can be maintained. Therefore, HLA plays a critical role, determining the success or failure of hematopoietic stem cell transplants. In these transplants, matching HLA types of the donor and recipient is required.
The compatibility rate of identical twins conceived from the same egg (same genotype) is 100%. For non-identical twins or siblings conceived from different eggs (different genotypes), the HLA matching rate is 25%. The HLA matching rate among unrelated human individuals varies from one in a few hundred to one in ten thousand. Among the relatively rare HLA types, the matching rate is only one in tens of thousands. Due to the one-child policies in China, the matching success rate within China is even lower.