Cell therapy (also called cellular therapy or cytotherapy) is therapy in which cellular material is injected into a patient; this generally means intact, living cells. For example, T cells capable of fighting cancer cells via cell-mediated immunity may be injected in the course of immunotherapy.
Cell therapy originated in the nineteenth century when scientists experimented by injecting animal material in an attempt to prevent and treat illness. Although such attempts produced no positive benefit, further research found in the mid twentieth century that human cells could be used to help prevent the human body rejecting transplanted organs, leading in time to successful bone marrow transplantation.Today two distinct categories of cell therapy are recognized.The first category is cell therapy in mainstream medicine. This is the subject of intense research and the basis of potential therapeutic benefit. Such research can be controversial when it involves human embryonic material.
The second category is in alternative medicine, and perpetuates the practice of injecting animal materials in an attempt to cure disease. This practice, according to the American Cancer Society, is not backed by any medical evidence of effectiveness, and can have deadly consequences.