A research review conducted by the scientists of Northwestern University Feinberg School of Medicine explored the wide range of possibilities in treating cardiovascular and autoimmune diseases with adult stem cells.
There are two types of stem cells, embryonic stem cells and adult stem cells. Human embryonic stem cells are harvested from embryos four to five days after fertilization. Adult stem cells are located in tissues throughout the body and provide a reservoir for replacement of damaged or aging cells.
Dr. Richard K. Burt, of the Northwestern University Feinberg School of Medicine, and colleagues examined hundreds of studies of blood- or bone marrow derived stem cells that were conducted between January 1997 and December 2007 -- 323 assessed feasibility and toxicity, and 69 looked at patient outcomes.
The review found that in 26 studies involving a total of 854 patients with autoimmune diseases there was a treatment-related death rate of less than one percent (2/220 patients) for nonmyeloablative (not causing bone marrow suppression), less than two percent (3/197) for dose-reduced myeloablative, and 13 percent (13/100) for intense myeloablative regimens, i.e., those including total body irradiation or high-dose busulfan, a drug used in the treatment of some types of chronic leukemia.
"While all trials performed during the inflammatory stage of autoimmune disease suggested that transplantation of hematopoietic [formation of blood or blood cells] stem cells (HSCs) may have a potent disease-remitting effect, remission duration remains unclear, and no randomized trials have been published," the researchers said.
In 17 studies of 1,002 patients with cardiovascular diseases, 16 studies of 493 patients with chronic coronary artery disease, and three meta-analyses, there was evidence suggesting that adult stem cell transplantation might help lead to modest improvements in cardiac function among people with coronary artery disease.
"Stem cells harvested from blood or marrow, whether administered as purified HSCs or mesenchymal [cells that develop into connective tissue, blood vessels and lymphatic tissue] stem cells or as an unmanipulated or unpurified product can, under appropriate conditions in select patients, provide disease-ameliorating effects in some autoimmune diseases and cardiovascular disorders," the researchers said.
Clinical trials are needed to determine the most appropriate cell type, dose, method, timing of delivery, and adverse effects of adult HSCs for these and other nonmalignant disorders," the researchers added.
The review is published in the February 27 issue of JAMA.