A review of previously published research suggests that stem cells harvested from an adult's blood or marrow may provide treatment benefit to select patients for some autoimmune diseases and cardiovascular disorders, according to an article in the February 27 issue of JAMA: The Journal of the American Medical Association.
In broad terms, there are two types of stem cells, embryonic stem cells and adult stem cells. Human embryonic stem cells are isolated from a 4- to 5-day-old postfertilization blastocyst (an early form in the development of an embryo). Adult stem cells are located in tissues throughout the body and function as a reservoir to replace damaged or aging cells. Stem cell therapy is rapidly developing and shows great promise, “but clinical application has lagged due to ethical concerns or difficulties in harvesting or safely and efficiently expanding sufficient quantities. In contrast, clinical indications for blood-derived (from peripheral or umbilical cord blood) and bone marrow-derived stem cells, which can be easily and safely harvested, are rapidly increasing,” the authors write.
Richard K. Burt, M.D., of the Northwestern University Feinberg School of Medicine, Chicago, and colleagues conducted a review of articles regarding clinical indications and outcomes for use of blood- and bone marrow-derived stem cells. A search of databases identified 323 reports that were examined for feasibility and toxicity, and 69 that were evaluated for outcomes. These studies were published between January 1997 and December 2007.
For autoimmune diseases, 26 reports representing 854 patients reported treatment-related mortality 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).