CLEVELAND, Sept. 16, 2011 /PRNewswire/ -- Recent advances in regenerative medicine show stem cell therapy may ultimately be used to create new blood vessels (angiogenesis), improve heart function and reduce the risk of amputation in patients with peripheral vascular disease.
Yet an obstacle stands in the way of realizing the promise of these breakthroughs: Autologous endothelial progenitor stem cells (i.e., adult "self" stem cells) compose a very small fraction of the cells in the blood (<0.002 percent), and it is difficult to obtain sufficient quantities of these cells to actually replace damaged cells in tissues such as the heart or muscle.
Researchers at University Hospitals (UH) Case Medical Center, however, have developed a novel method to isolate sufficient numbers of autologous endothelial progenitor stem cells (stem cells that express the CD34 receptor) that can be used to renew damaged heart or muscle tissue. Such stem cells have the advantage of being derived directly from the individual patient. This eliminates not only the ethical questions that surround the use of embryonic and non-autologous (i.e., non-self) stem cells but also the health-related complications that could arise by using stem cells from other sources, cell lines or individuals.
Marco Costa, MD, PhD, Director, Interventional Cardiovascular Center and Research & Innovation Center, UH Case Medical Center, reports there are two methods for obtaining the stem cells.
"One way is to give the patients granulocyte stimulating factor," Dr. Costa said. "This increases the number of stem cells in the blood, and then we can collect a large number of these cells by apheresis, the process of removing a specific component from blood and returning the remaining components to the donor, in order to collect more of one particular part of the blood than could be separated from a unit of whole blood. The alternative, and the method we prefer, is to obtain a small number of cells from the patient's blood and expand them for seven days in culture media, which is a kind of 'health spa' for the cells."
The culturing procedure expands the cell population to obtain enough autologous endothelial progenitor stem cells to use for treatment.
"Because of our ability to add cytokines and growth factors to control the growth environment," Dr. Costa said, "these cells are healthier than those in the original cell population derived from patients with advanced diseases."
Upcoming Clinical Trials
Studies remain in the research phase, but Dr. Costa's group has shown the procedures to culture stem cells and inject them into target tissues for treatment are feasible in animal models. He and his group are participating in Phase I-III clinical trials of bone marrow-derived and peripheral blood-derived stem cells for the treatment of patients with ischemic and non-ischemic cardiomyopathy, advanced coronary artery disease, and recent myocardial infarction (3-21 days).
The patients who may ultimately benefit from this novel method to amplify and fortify autologous endothelial progenitor stem cells include those with advanced coronary artery disease, heart failure, acute myocardial infarction or peripheral arterial disease. Dr. Costa notes the physicians at UH Case Medical Center are eager to evaluate individuals who might benefit from this procedure.
"Patients who come to UH Case Medical Center will find that they have many treatment options," he said. "Some may benefit from other procedures that we already offer. If they meet inclusion criteria, however, some patients could be recruited to participate in stem cell trials that are actively enrolling patients or in exciting upcoming clinical trials."
SOURCE University Hospitals Case Medical Center