Stem cells are primitive or unspecialized cells that exist in the different tissues and organs of the body. They are versatile cells that can replicate very fast and transform into a variety of cell types. In case of damage to the tissues and organs where they are present, they serve as source of new functional cells.
Stem cells are numerous in the embryo, but they progressively diminishin number as the individual ages such that there are very few in adults. Thus, the regenerative power of the different body tissues and organs in adults is very limited because there are not enough stem cells that can transform into functional cells. Consequently, heart attack victims are not able to replace the damage area of their heart with new muscle cells, Alzheimer patients are not able to regenerate new neurons to replace the ones they lost, etc.
Stem cell therapy involves harvesting stem cells, culturing them to increase their number and then injecting them into the patient being treated. In the patient, the stem cells transform into specialized cells that replace those that have been lost in the various tissues and organs because of disease or the aging process.
Stem cells can be harvested from embryos (embryonic stem cells) or the patient himself (adult stem cells). Embryonic stem cells are more numerous and more versatile than adult stem cells, but when injected into a patient, there is a possibility of a rejection reaction because they do not come from the same human body. Also, harvesting embryonic stem cells is not allowed in many countries for ethical reasons. Adult stem cells, on the other hand, are safer to use, but very few can be harvested from the individual and they are not very versatile, they can transform into several types of cells only. Most stem cell therapies that are currently performed in humans involve adult stem cells.
Stem cell therapy has tremendous potentials. Conceivably, it can treat cancer, strokes and other neurological disorders including Alzheimer’s disease and Parkinson’s disease, heart attacks and cardiac failure, diabetes mellitus, Huntington’s disease, celiac disease, muscle damage and many others. It can also possibly delay or even reverse the aging process by replacing cells that have been lost or have become senescent.
Is stem cell therapy therefore the panacea and fountain of youth that humanity has been seeking for since time immemorial? It is too early to tell. Most stem cell therapies for specific diseases and conditions are only in their experimental stage. In fact, in the US, the only currently FDA approved application for stem cell therapy is for bone marrow transplant in patients with dysfunctional bone marrow, multiple myeloma and leukemias (cancers of the blood).
Nevertheless, despite the admonition of many experts that more research is necessary to understand stem cell behavior before stem cell therapeutics can be applied in the clinical setting, many doctors and medical facilitiesworldwide, including the US and the Philippines, are already offering adult stem cell therapy for the treatment of all forms of cancers, a variety of other ailments and for reversing the aging process. And there are many takers despite the prohibitive cost—upwards of US$ 10,000 (PhP 2-3 million, in the Philippines). Fortunately, adult stem cell therapy does not appear to have any serious short or medium-term adverse effects (the long-term effects are still unknown). Hence, if the patient does not derive any benefit from the procedure, the only thing he/she loses is money.
By EDUARDO GONZALES, MD