Stem Cell Position Statement

Stem cells have recently come to the forefront of biomedical research based on their enormous therapeutic potential for treating and even curing many diseases. Questions regarding the source of stem cells and their use are frequently asked, and often passionately debated. Knowledge regarding the appropriate use of this exciting technology is crucial to decisions that will ultimately determine how this technology will impact the future of medicine.

Stem cells have several properties that separate them from other cells in the human body. First, they can divide and renew themselves for long periods of time. Second, they are uncommitted cells, and therefore not a specific cell or tissue type. Third, they can give rise to specialized cells through the process of differentiation. The triggers that lead to differentiation of stem cells are the subject of ongoing research, but likely result from a combination of genetic signals from within the cell, and chemical signals from other cells in the stem cell’s microenvironment.

Stem cells can be isolated from three main sources. Embryonic stem cells are derived from a three to five-day-old embryo called a blastocyst. Large numbers of stem cells can be taken from blastocysts and grown for research studies in a laboratory. Embryos created by in vitro fertilization and donated for research are the major source of stem cells. Stem cells can also be generated from umbilical cord blood. After the birth of a child, the umbilical cord is usually discarded. Blood from the umbilical cord is a good source of undifferentiated blood stem cells. Adult or somatic stem cells are another source of stem cells found within specific tissues such as the bone marrow or skin. These adult stem cells are much fewer in number and can only differentiate into the specialized cells and tissues from which they came. They are not grown as easily as embryonic stem cells.

The American Society of Transplantation (AST) recognizes the potential of stem cells to expand the options for cell and organ transplantation, tissue engineering, and regenerative medicine. A remarkable number of major medical problems faced by all Americans are natural targets for successful therapies derived from stem cells. For example, diabetes mellitus, liver disease, cardiovascular disease, and Parkinson’s disease have the potential to be improved or even cured by stem cell research. In addition, metabolic and genetic diseases in children could be treated by the transplantation of genetically healthy cells.

While the tremendous potential of stem cells to treat many serious diseases is quite evident, much research needs to be done to determine strategies for the safe and effective implementation of stem cell therapy. It is therefore of great importance that support for research in this critical area be advanced and continued. The AST supports and encourages investigator-initiated, peer-reviewed, and ethical research efforts, with adult, umbilical cord blood, and embryonic stem cells in existing and future stem cell lines. While the AST recognizes the value of existing stem cell lines, the development of new stem cell lines will be necessary to support future research. For these reasons, the AST will work to encourage funding for all related aspects of stem cell research by the National Institutes of Health (NIH) and other funding groups in the federal and private sectors.

In conclusion, the American Society of Transplantation recognizes the tremendous potential of stem cell research to contribute to the health of patients and the future of American medicine. We also recognize the considerable ethical, policy, and regulatory challenges in this area. Thus, the AST supports the following principles for stem cell research:

• Continued and strong support of basic research on embryonic, umbilical cord blood, and adult stem cells,
• Equally strong support for complementary and alternative approaches in cell transplantation, tissue engineering, and gene therapy to facilitate stem cell therapies or provide safe alternatives,
• Basic research and clinical trials that include the necessary ethical, scientific, and regulatory controls,
• Continued emphasis through education at all levels to insure the public’s understanding and expectations for stem cell research and its alternatives are realistic as defined by the science and medicine in this rapidly evolving field,
• Discussion on a national level concerning regulatory oversight of the development, generation, and use of embryonic stems cells.

Approved by the Executive Committee on July 27, 2005
Revised and approved by the AST Board of Directors on April 13, 2009
Revised and approved by the AST Board of Directors on September 6, 2011