What are stem cells?
When umbilical cord blood stem cells are called stem cells derived from umbilical cord blood or umbilical cord blood after cutting the umbilical cord of the child.
Since the late 1980s, we know that cord blood is rich in stem cells, which are able to restore the hematopoietic system. The reason is the migration of blood formation, which is a resident during fetal development in the liver and spleen, the bone marrow. This walk takes place in the last trimester of pregnancy through the bloodstream of the child. As a result, can be found at the time of birth in the blood of the child and thus also in the rest of umbilical cord blood and placenta extraordinary number of stem cells.
Cord blood stem cells have been used medicinally first time in 1988 by the French doctor Eliane Gluckman in Paris to treat a child with Fanconi anemia. By 2011, more than 20,000 times umbilical cord blood stem cells, predominantly as a foreign transplant, been used (→ stem cell transplantation), and more than 600,000 donations were kept. Only NETCORD reported 10,434 transplants.
Properties
Benefits of cord blood stem cells compared with bone marrow stem cells:
-To attract risk-poor
-Storage of stem cell preparations for ethnic minorities and children of mixed ethnicity
-Low contamination with latent viruses and tumor cells
-Immediate availability of long-term storage (cryopreservation)
-Better compatibility if the HLA characteristics of donor and recipient do not match
-Easy to deploy when needed instead of a complex coordination between bone marrow collection center and the transplant center
-High proliferation potential of stem cells
-High differentiation potential of stem cells
-Lower risk for acquired chromosomal alterations and mutations
Has already demonstrated the ability of cord blood stem cells to develop not only blood cells but also nerve, liver, blood vessel, muscle, bone, cartilage and islet cells. This property is used in biotechnology for the regeneration of body tissues. This has not previously been used in humans.
Recent research has also shown that cord blood cells are well suited for reprogramming to induced pluripotent stem cells. Compared to the previously used for reprogramming of adult cells as in the skin, they have the advantage that they do not exhibit age-related genetic and epigenetic changes, and no loss of telomerase activity.
Disadvantages of cord blood stem cells compared with bone marrow stem cells:
-limited Stock
-To win the birth of a child
-Longer aplasia of hematopoiesis, compared with bone marrow stem cells
-Genetic defects which such. As for leukemia, or diabetes mellitus can lead, are also present in cord blood
Furthermore, there is criticism that the donation bind unnecessary personnel resources in maternity hospitals. An early cord clamping for cord blood donation is contrary to current standards and leads to a drop in the child's blood volume.
Application of umbilical cord blood
Treatment of children and adults
The disadvantage with the transplantation of umbilical cord blood stem cells as compared to bone marrow is located in the lower amount of stem cells is available. Only through a sufficient number of cells the treatment of adult patients is possible. Stem cell transplant doctors currently recommend a minimum cell dose is between 10 and 30 million nucleated cells (mononuclear cells, MNC) per kilogram of body weight of the recipient when the donor and recipient are not identical (allogeneic transplant). If the recommended dose to treat adult cell is not reached, can be an alternative simultaneous transplantation of two cord blood specimens.
However, given the benefits of cord blood as the better tolerability and the immediate availability of cord blood transplantation in adults is also gaining in importance. Currently used in the United States, for example, 20% of all stem cell cord blood, cord blood in Japan the rate for children and adults together is already at 50%.
Allogeneic transplantation (foreign transplant)
Allogeneic transplantation of umbilical cord blood is currently the norm. In this case, the patient is transferred cord blood stem cells, which do not come from him but a suitable donor. If it is not a directed donation, while cord blood stem cells from stem cell registries. Allogeneic umbilical cord blood stem cells are currently used primarily for leukemia, blood formation disorders and genetic diseases. Slightly more than a third of all allogeneic transplant Nabelschnurblute been used in adults.
Autologous transplantation (self-transplantation)
So far, about 130 cases of autologous umbilical cord blood transplants are known. The first application of autologous cord blood stem cells was in 1999 in a child with neuroblastoma in Brazil. In addition to tumor diseases such as neuroblastoma or retinoblastoma also cases of bone marrow failure (aplastic anemia), type 1 diabetes and neonatal brain damage with private cord blood have been treated according to data of autologous cord blood banking.
2009, a cerebral palsy in a 2.5-year-old boy was first successfully treated with autologous cord blood at the University Hospital in Bochum.
Side effects
Observed in 2011, a study of 104 patients after stem cell from umbilical cord blood. Around 10% developed chronic histological tangible colitis often with granulomatous inflammation.
Preservation of umbilical cord blood
As a donation to a stem cell registry
The donation of a stem cell registry is used to establish a pool of stem cell preparations that can be accessed when needed to oncologists and hematologists. By cryopreservation, it is also possible to stockpile stem cells for patients with relatively rare occurring genetic endowment or of mixed ethnicity, and so to reduce the donor search in the application.
The donation is free for the parents because the costs are covered by donor funds (eg from the José Carreras Foundation) and delivery fees paid by the insurance company of the patient.
Umbilical cord blood can be donated in Germany at the stem cell registry in Dusseldorf, Mannheim, Munich, Freiburg, Erlangen, Dresden, Hanover. These registers are working together in many German cities with about 75 hospitals. Only in those cooperating hospitals is currently possible removal. In Switzerland clinics in Basel, Bern, Geneva, Lugano and Liestal are set up for the cord blood donation.
As a (directed) donation for treatment of an infected family member
Stem cells of a close relative, preferably siblings are very suitable in the present agreement of the tissue compatibility for transplantation. For this purpose, the cord blood is collected targeted for future treatment of patients already present illness and processed. According to an analysis of around 500 cord blood transplants between HLA-identical siblings Eurocord concludes that the method shows good results.
The (directed) cord blood donation is free for parents and is offered by both the stem cell registries and private cord blood banks. Thus, the cord blood donation for family members is everywhere possible.
As treasury preservation of private provision
The own preservation of umbilical cord blood (autologous storage) for private provision is controversial: main criticism is that the probability to need their own stem cells in childhood is very low. In addition, it must be examined in haematological diseases of the child, whether the stem cells already contain the predisposition to developing the disease. The use of cord blood to treat disease in adults holds the German Medical Association in its 1999 directive nor speculative. Considerable criticism is also the chairman of the German Society of Hematology and Oncology, Gerhard Ehninger, which holds the commercial freezing of umbilical cord blood for "profiteering".
As in cord blood but also pluripotent stem cells are proliferative and, on the other hand, there is reason to hope that it grow in the future specific tissue or cell clusters to treat serious diseases and can develop new stem cell-based therapies. In mid-August of 2012 was registered with the National Institutes of Health, United States, already more than a dozen studies with their own cord blood. One focus is the treatment of children with cerebral palsy and other infantile brain damage. Since 2005, patients at Duke University, Durham, USA, treated with their own cord blood. A South Korean pilot study of 20 patients is 2012 on the conclusion that the transfusion of one's own cord blood in cerebral palsy is feasible and safe. However, the neurological improvements in children with diplegia and hemiplegia were significantly higher than in those with tetraplegia. In addition, the International Juvenile Diabetes Research Foundation in cooperation with the University of Florida, Gainsville, USA, a study for the treatment of diabetes mellitus type 1 started. According to initial estimates, the therapy with cord blood could help preserve the insulin production in the body of the patient. Overall, these therapies in the very early experimental stage with an uncertain outcome.
Private cord blood banks experienced in recent years, an increasing number of transplants. So embedded stem the German Stem Cell Bank Vita have been already used 34 to the company 27 times for treatment. The Cord Blood Registry, USA, has a total of 127 people treated solely by its own account until October 2009. In 71 cases, the child received their own cord blood, in other cases, a close relative, usually a sibling. According to the independent information portal Parent's Guide to Cord Blood Foundation are to February 2009 the world a little more than 130 autologous transplants carried out. Information on the success rate is missing.
The self-preservation of umbilical cord blood is a charge for the parents. The costs in Germany about 1200 up to 2500 € for the first twenty years of storage. So far only a few cases are known in which the costs were paid back by health insurance. The self-preservation is largely coverage possible in Germany.
As a donation for stem cell research
In cord blood donation for stem cells research be used to investigate their effectiveness and to gain new stem cell-based therapies for the treatment of diseases.
The donation for stem cell research is offered by stem cell registries, academic institutions, and private cord blood bank. It is free for the parents, but not everywhere possible.
A donation can not be performed if the mother has received in the weeks before the birth of blood products. This includes the anti-D prophylaxis for rhesus incompatibility.
Long term storage of stem cells
Studies have shown that cord blood stem cells hold more than 20 years without losing their vitality and proliferation ability. According to the Fraunhofer Institute for Biomedical Engineering in St. Ingbert near Saarbrucken stem cells are theoretically be stored for several centuries without sacrificing potential.
The reason is that the life processes fully come inside cells at temperatures below -130 ° C to a halt. Theoretically, the stem cells are so indefinitely. "The only limit on the storage time is due to the cosmic rays that constantly exceeds the cell samples in a frozen state and in stainless steel tanks."