Cell Therapies
Therapeutic applications of cells
Two sources of cells
Two major cell categories have been defined: autologous cells derived from an individual for treatment of that person AND allogenic cells which are derived from a human source other than the patient.
Existing cell therapies
Bone marrow repair has been possible for over 50 years with stem cells derived from bone marrow or blood. Treatment can occur following diseases which destroy bone marrow and following destructive therapies required for the treatment of cancer within the bone marrow. Both allogenic and autologous cells can be used. For a comprehensive list of bone marrow disorders treatable by stem cell transplant see British Medical Journal 2000; 321:433-437 & other sources.
Umbilical cord blood stem cells (both autologous and allogenic) have been used in over 2500 patients to repair bone marrow. Their effectiveness is considered to be as good as or better than cells derived from adult blood or bone marrow (the alternative sources) as these cells are young and have a great potential to multiply. Stem cells and other repair cells derived from various sources are being used in trials to determine their effectiveness in repair of damage to other organs.
Future cell therapies
- Bone marrow repair with stem cells is starting to be used in the treatment of auto-immune diseases. This use is expected to increase dramatically in the future with a major effect on diseases such as multiple sclerosis, lupus (SLE), glomerulonephritis (kidney disease), scleroderma, ulcerative colitis and other auto-immune diseases. We will soon see other advances in clinically applicable cell therapy. This will be a result of treatments developed with both autologous and allogenic cells. Stored umbilical cord blood stem cells are expected to be the most effective active ingredients in some therapies.
- Repair of acute tissue damage (recent tissue damage) will involve the use of stem cells or other repair cells delivered to the site of tissue damage soon after the injury. Repair cells will rebuild the damaged tissue under the influence of the body’s own chemical messengers with or without some added medication. These cells may or may not have undergone some manipulation. This form of treatment is the basis of all bone marrow repair presently available but will be extended to the repair of damaged skin, heart muscle, brain, lung and liver tissue (e.g. after a stroke or heart attack).
- Repair of chronic tissue damage (longstanding tissue damage) will require cells to be manipulated in the laboratory (in vitro) and later transplanted into patients. This is the field of “tissue engineering”. It will play a role in the correction of some brain, heart and skin disorders. In some instances the cells will be grown onto an artificial framework to create small functional tissue units (e.g. heart valves and bladders).
- Stem cells might also play a role in gene therapy. Some disorders caused by the poor functioning of a small piece of genetic material can probably be cured by a healthy gene. Autologous stem cells (e.g. cord blood stem cells) may be the most useful cells for this form of therapy.
