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Cell therapy is the transplantation of human or animal cells to replace or repair damaged tissue.
The purpose of cell therapy is to introduce cells into the body that will grow and replace damaged tissue. Cell therapy differs from conventional stem cell therapy in that the cells injected into the body in cell therapy are already differentiated (e.g., muscle cells, gland cells), whereas conventional stem cell therapy utilizes undifferentiated, usually embryonic cells. Cell therapy has long been used by alternative medicine practitioners who have claimed great benefits; these have not been replicated by conventional medical practitioners.
The theory behind cell therapy has been in existence for several hundred years. The first recorded discussion of the concept of cell therapy can be traced to Phillippus Aureolus Paracelsus (1493-1541), a German-Swiss physician and alchemist who wrote in his Der grossen Wundartzney (Great Surgery Book) in 1536 that "the heart heals the heart, lung heals the lung, spleen heals the spleen; like cures like." Paracelsus and many of his contemporaries agreed that the best way to treat an illness was to use living tissue to restore the ailing. In 1667, at a laboratory in the palace of Louis XIV, Jean-Baptiste Denis (1640-1704) attempted to transfuse blood from a calf into a mentally ill patient. Since blood transfusion is, in effect, a form of cell therapy, this could be the first documented case of this procedure. However, the first recorded attempt at non-blood cellular therapy occurred in 1912 when German physicians attempted to treat children with hypothyroidism (underactive thyroid gland), with thyroid cells.
In 1931, Dr. Paul Niehans (1882-1971), a Swiss physician, became known as "the father of cell therapy" quite by chance. After a surgical accident by a colleague, Niehans attempted to replace a patient's severely damaged parathyroid glands with those of a steer. When the patient began to rapidly deteriorate before the transplant could take place, Niehans decided to dice the steer's parathyroid gland into fine pieces, mix the pieces in a saline solution, and inject them into the dying patient. He reported that immediately the patient began to improve and, in fact, lived for another 30 years.
Cell therapy as alternative medicine
Cell therapy as performed by alternative medicine practitioners is very different from the controlled research done by conventional stem cell medical researchers. Alternative practitioners refer to their form of cell therapy by several other different names including xenotransplant therapy, glandular therapy, and fresh cell therapy. The procedure involves the injection of either whole fetal xenogenic (animal) cells (e.g., from sheep, cows, pigs, and sharks) or cell extracts from human tissue. Several different types of cells may be administered simultaneously.
Just as Paracelsus's theory of "like cures like," the types of cells that are administered correspond in some way with the organ or tissue in the patient that is failing. In other words, the cells are not species specific, but only organ specific. Alternative practitioners cannot explain how this type of cell therapy works, but proponents claim that the injected cells travel to the similar organ from which they were taken to revitalize and stimulate that organ's function and regenerate its cellular structure. Supporters of cellular treatment believe that embryonic and fetal animal tissue contain active therapeutic agents distinct from vitamins, minerals, hormones, or enzymes. This theory and these claims are rejected by practitioners of conventional medicine.
Proponents of cell therapy claim that it has been used successfully to rebuild damaged cartilage in joints, repair spinal cord injuries, strengthen a weakened immune system, treat autoimmune diseases such as AIDS, and help patients with neurological disorders such as Alzheimer's disease, Parkinson's disease, and epilepsy. Further claims of positive results have been made in the treatment of a wide range of chronic conditions such as arteriosclerosis, congenital defects, and sexual dysfunction. The therapy has also been used to treat cancer patients at a number of clinics in Tijuana, Mexico. Most of these claims are anecdotal. None of these application is supported by well-designed, controlled clinical studies.
Cell therapy as conventional medicine
Cell therapy in conventional medicine is still in the research and early clinical trial stage. This research is an outgrowth of stem cell research, and is performed in government-regulated laboratories by traditionally trained scientists. Embryonic stem cells are cells taken from an embryo before they have differentiated (specialized) into such specific cell types as muscle cells, nerve cells, or skin cells. In laboratory test tube and animal experiments, stem cells often can be manipulated into differentiating into specific types cells that have the potential to replace differentiated cells in damaged organs. For example, in early 2008, researchers at the Diabetic Research Institute at the University of Miami in Florida were able to convert embryonic stem cells into insulin-producing cells and use them to treat insulin-dependent diabetes in mice.
Stem cells also have been found in bone marrow, and work is underway to see if other cells can be manipulated into transforming into differentiated cells. In January 2009, researchers at Northwestern University's Feinberg School of Medicine in Chicago announced that they had used a patient's own bone marrow stem cells to improve early symptoms of multiple sclerosis. Researchers noted improvement only in patients with early symptoms; in earlier research those with advanced symptoms had not improved. Other researchers are working on treating symptoms of muscular dystrophy with fully differentiated myoblasts (a kind of muscle cell) with mixed results. Still other are working with using cartilage cells (chondrocyte cells) to repair cartilage in joints such as the knee.
Stem cell therapy has potential to treat a wide range of diseases and disorders, but it is, for the most part, still in the test tube and animal research stage of development. Because of the ethical questions raised when the harvesting of stem cells destroys embryos, the United States has placed restrictions on some human stem cell research. These restrictions, however, do not apply to research that does not destroy embryos. However, much stem cell research is being carried out in other countries, especially Thailand, South Korea, and China, where fewer restrictions are placed on obtaining human stem cells for experimentation. A list of FDA-approved clinical trials involving stem cell therapy can be found at http://www.clinicaltrials.gov.
Alternative practitioners use several processes to prepare cells for use. One procedure involves extracting cells from the patient and then culturing them in a laboratory until they multiply to the level needed for transplantation back into the same patient. Another procedure uses freshly removed fetal animal tissue that has been processed and suspended in a saline (salt water) solution. The preparation of fresh cells then may be either injected immediately into the patient or preserved by being freeze-dried or deep-frozen in liquid nitrogen before being injected. Injected cells may or may not be tested for pathogens, such as bacteria, viruses, or parasites, before use. Conventional cell therapy researchers work in laboratories where the growing environment of the cells is highly controlled and monitored to prevent contamination.
Many forms of cell therapy in the United States are highly experimental procedures. Patients should approach any cell therapy treatments with extreme caution, inquire about their proven efficacy and legal use in the United States or their home country, and should only accept treatment only from a licensed physician who should educate the patient completely on the risks and possible side effects involved with cell therapy. These same cautions apply for patients interested in participating in FDA-approved clinical trials of cell therapy treatments.
Because cell therapy encompasses a wide range of treatments and applications and many of these treatments are unproven and highly experimental, the full range of possible side effects of the treatments is not yet known. Anaphylactic shock, immune system reactions, and encephalitis are just a few of the known reported side effects in some patients to date.
Patients undergoing cell therapy treatments which use cells transplanted from animals or other humans run the risk of cell rejection, in which the body recognizes the cells as a foreign substance and uses immune system cells to attack and destroy them. Some forms of cell therapy use special coatings on the cells in an attempt to trick the immune system into recognizing the new cells as native to the body. There is also the chance of the cell solution transmitting a bacterial, viral, fungal, or parasitic infection to the patient. Careful screening and testing of cells for pathogens can reduce this risk.
Research and general acceptance
Cell therapy as alternative healers practice it is generally rejected as effective by the traditionally-trained scientific community. Most of the claims made for these therapies are based on anecdotal evidence and are not backed by controlled clinical trials. While some mainstream cell therapy procedures have shown some success in clinical studies, others are still largely unproven, including cell therapy for cancer treatment. Until large, controlled human clinical studies are performed on cell therapy procedures, they will remain fringe treatments.
For Your Information
- Steenblock, David and Anthony G. Payne.Umbilical Cord Stem Cell Therapy: The Gift of Healing from Healthy Newborns. Laguna Beach, CA: Basic Health Publications, 2006.
- Pollack, Andrew. "Stem Cell Therapy Controls Diabetes in Mice." New York Times. February 21, 2007 [cited February 2, 2009] http://www.nytimes.com/2008/02/21/health/research/21stem.html.
- "Cellular Therapy." Quackwatch. 2003 [cited February 2, 2009]. http://www.quackwatch.com/01QuackeryRelatedTopics/Cancer/cellular.html.
- " Multiple Sclerosis 'Reversed' with Stem Cell Therapy." New Scientist Health. January 30, 2009 [cited February 2, 2009]. http://www.newscientist.com/article/dn16509-multiple-sclerosis-reversed-with-stem-cell-therapy.html.
- Alternative Medicine Foundation. P. O. Box 60016, Potomac, MD 20859. (301) 340-1960. http://www.amfoundation.org.
- Center for Cell and Gene Therapy. Baylor College of Medicine. One Baylor Place N1002, Houston, TX 77030 (713) 798-1246. http://www.bcm.edu/genetherapy.
Gale Encyclopedia of Medicine. Copyright 2008 The Gale Group, Inc. All rights reserved.
(1) Live cell therapy
(2) The injection of cellular material from organs, foetuses, or embryos of animals to stimulate healing, counteract the effects of ageing, and treat a variety of degenerative diseases such as arthritis, Parkinson’s disease, atherosclerosis, and cancer; methods include the use of live cells, freeze-dried cells, cells from specific organs, and whole embryo preparations
(1) Gene therapy, see there
(2) Stem cell therapy
Quackery Sicca cell treatment
Segen's Medical Dictionary. © 2012 Farlex, Inc. All rights reserved.