All cells that have specialized functions within the body are generated from cells called stem cells. Because they have a unique ability to differentiate into other specific types of cells, they can be utilized in modern day medicine to help treat many conditions. Generally, stem cell therapy is used to stimulate the repair and regeneration of dead, injured, or dysfunctional tissues. The body uses its own stem cells in its natural repair mechanism, however, sometimes this process cannot be initiated on its own and the stem cells cannot be easily summoned for certain types of tissues. In other diseases, sometimes this repair mechanism simply works too slow to treat certain conditions that cause the deterioration of certain organs and their functions. In addition, stem cells can be used to conduct valuable research to help understand what happens within cells when they are affected by certain diseases.
Stem cells are the only cells in the body that have the natural capability to differentiate into new cell types. When stem cells undergo the cell cycle and divide, they can become two new stem cells called self-renewal, or stem cells can differentiate themselves for a certain function in the body. There are four main classifications of stem cells. Embryonic stem cells are cells from human embryos that are between three and five days old. These stem cells have the ability to divide into more stem cells or can differentiate to any cell type.
Adult stem cells are cells that can be located in adult tissues like fatty tissue and bone marrow. Adult stem cells in their natural form only have the ability to make stem cells that are in the same localized region and organ system in the body. Induced pluripotent stem cells are adult stem cells that have been genetically reprogrammed by scientists to act similar to how embryonic stem cells work. Perinatal stem cells are stem cells that can be located in the umbilical cord blood and amniotic fluid. Like embryonic stem cells, perinatal stem cells can differentiate into specialized types of cells.
The most commonly utilized stem cell therapy used today is bone marrow transplantation. Bone marrow is the spongy and soft tissues that are in the center of bones. Bone marrow contains stem cells that can differentiate into numerous other cell types. These cells have the ability to turn into any type of blood cell or they can produce more bone marrow cells. When a bone marrow transplant is done, cells are taken from the bone marrow, filtered, and then given to another person or back to the donor. Stem cells have been successfully used to treat lymphomas, disorders of the immune system, leukemia, aplastic anemia, and solid tumor cancers.
Leukemia is a blood cell cancer that affects the white blood cells in the body. Very high numbers of abnormally functioning white blood cells are produced by a genetic mutation that crowds out the other platelets and red blood cells that are imperative for the body to function. Healthy bone marrow stem cells are used to treat leukemia by taking the place of non-functioning and diseased bone marrow cells. The stem cells also help the body generate a new immune system capable of helping to fight against residual or existing leukemia cells that were not eradicated with other treatments.
Aplastic anemia is a disorder of the blood where the bone marrow and stem cells are damaged to the point where they do not produce a sufficient number of new blood cells. A healthy bone marrow transplant provides healthy and functioning bone marrow to replace the diseased marrow that results in this form of anemia. The new bone marrow can produce normal numbers of new blood cells instead of abnormally low numbers.
Sickle cell anemia is a disorder of the red blood cells that involves the hemoglobin in red blood cells causing them to develop into a concave or crescent shape instead of a disc shape. These cells have a lifetime that is only a quarter of the normal red blood cell lifetime, and the body struggles to replace them with healthy red blood cells. Healthy bone marrow stem cells are used to stimulate the growth of normal red blood cells in order to replace the cells that develop abnormally.
Primary immunodeficiency disorders are rare disorders that are genetic and severely impair the body's immune system. Without an immune system, the body is extremely susceptible to contracting an infinite number of infections, most of which can be fatal. The body is unable to fight off germs when they are encountered, and almost always falls ill as a result. Bone marrow stem cell transplants make it possible to help the body create a correctly functioning immune system for an individual with primary immunodeficiency.
Any type of cancer that require the use of high doses of chemotherapy and or radiation may cause the individual to incur permanent damage to their bone marrow. Bone marrow stem cell transplants can be utilized to replace the damaged marrow cells after the cancer cells have been eradicated.