To better evaluate the future benefits of storing cord blood cells, it is imperative to understand the present knowledge of its clinical utilization. Every day, new studies are published, describing the potential of cord blood cells to treat various diseases. How do we know that a certain scientific claim regarding the clinical benefit of any technology is valid? The ultimate proof for any claimed benefit is its approved utilization by regulatory agency such as the FDA. However, the road to obtain such approval is long and costly.
Nonetheless, preliminary results in clinical studies, or even prove of concept in animal disease models, may provide a good indication on future potential of certain technology, if taken with caution. In this long road of proving clinical effectiveness, the earlier stages of research are usually experiments carried out in test tubes, or “ex vivo”, as termed for biological activities tested in artificial laboratory setup. Except for bone marrow transplantation (BMT), most of the claims attributing potential clinical benefit to cord blood cells are based today on these very early stages of test tube studies. This does not diminish the validity of such scientific data, but should be part of the considerations in any investment that an individual would like to commit.
Clinical utilization of cord blood cells may be divided into two major categories. The first is regeneration of ablated bone marrow, and the second is regeneration of many other tissues which are affected by numerous diseases. The first, bone marrow transplantation (BMT), which is the use of stem and progenitor blood cells to rebuild the damaged tissue responsible to produce all the blood cells in our body. BMT is widely used today for treatment of hematological malignancies. The second category is a broad range of diseases which occur more frequently in elderly people, and are associated with degeneration and malfunction of tissues such as heart, liver, blood vessels, bone, neural cells and others. It is believed that this category of diseases would be amenable to treatment with living cells, and especially with stem cells, an approach termed regenerative medicine.
Cord blood cells have been used in BMT for almost two decades to replace other sources of stem cells, such as bone marrow and mobilized peripheral blood. About 20,000 transplants were done with cord blood cells, compared to about 45,000 transplants done yearly worldwide using other cell sources. There are several limitations to cord blood, but on the other hand, there are also significant advantages. The limitations are gradually overcome today with the introduction of new technologies such as expansion of stem cells or using several cord units per patient. Still, the question remains, how effective is aulologous transplant (the patient receives his own cells); compared to allogeneic transplant (the patient receives cells from another donor, which may be found for example in the public cord blood banks).
For many, but not for all, hematological malignancies, it is better to use allogeneic transplant since the anti tumor effect seems to be stronger in such combination. If so, why should one store his baby’s cells? The answer is that for BMT indications, the cord stem cells can be used for family members as well. In this case, the allogeneic combination, together with the other advantages of cord blood cells, make it worth storing and using if necessary. In addition, a suitable donor is not always easy to find, and thus, the stored autologous cells present in such case a good alternative.
The most promising future utilization of cord blood cells are for the second category of clinical indications, namely for tissue regeneration. This category covers numerous deteriorating and life threatening diseases such as osteoporosis, Alzheimer’s disease, cardiac failure, muscle degeneration diseases, severe hepatitis and many other diseases for which there are numerous treatments, but no effective cure. The stem and progenitor cells that are found in cord blood have the potential to regenerate damaged tissues and thus present new emerging alternative to treat such diseases.
It should be emphasized however, that today, most of the studies demonstrating promising results were performed only in test tube or experimental animals’ laboratory models. Very few have gone through regulatory pathway of clinical development and non have yet been approved by FDA. We can also learn about the potential of cord blood stem cells from studies performed with adult stem cells obtained from other sources such as bone marrow, peripheral blood, fat tissue and others. Taking together, the potential of stem cells for treating many deteriorating conditions and diseases is overwhelming, but the real prove for their effectiveness will come from clinical studies, and is only in its very beginning.
If we consider specifically cord blood, it has been shown recently that in addition to blood stem cells, the cord blood contain additional very potent cell populations. Among them, cells like mesenchymal progenitors that can turn into bone and cartilage, cells like endothelial progenitors that can form blood vessels, pluripotent cells that can turn into many different cell types, including muscle, nerves and insulin producing cells. It was also demonstrated that the lymphoid cells of the cord blood can be used for immunotherapy of malignant diseases. Additional research and development, as well as clinical studies that will probably take years are required to bring such promising laboratory results into clinical applicability. The clinical potential however is tremendous, and increasing numbers of high quality scientific publications are accumulating constantly, and pointing to the right direction.