Umbilical cord blood stem cells as alternative to embryonic stem cells

Scientists have been aware of the existence of these stem cells for many years but have only recently realized the potential medical applications of the cells. More than a decade ago, scientists discovered that if the normal connections between the early cellular progeny of the fertilized egg were disrupted, the cells would fall apart into a single cell progeny that could be maintained in a culture. These dissociated cells, otherwise known as embryonic stem cell lines, continue to divide in culture, producing large numbers of cells at a fast pace. However, these early embryonic cells would lose the coordinated activity.

Scientists quickly discovered that these cells retain the ability to generate a great number of mature cell types in culture if they are provided with appropriate molecular signals (Reaves, 2001). Scientists have made significant progress in discovering these signals and are still working on it. While it is a difficult task, scientists are pursuing it with great excitement because it is widely believed that cultured embryonic stem calls can be induced to generate all the mature cell types in the body. These cells could possibly be used to replace damaged or sick cells in patients with injuries or degenerative diseases.

In the most controversial method, scientists can take the stem cells from aborted fetuses, first asking for signed consent from a patient who had previously decided to terminate her pregnancy. This is the procedure most often highlighted by pro-life activists who oppose supporting stem cell research.

However, there are other less-controversial methods in which stem cells can be utilized, such as umbilical cord blood stem cell use. Umbilical cord blood stem cells are the youngest safely available stem cells and are the product of live birth. Freezing these cells basically stops the clock and prevents aging and damage that may occur to the cells later in life. Another category of stem cells is adult stem cells, such as those found in bone marrow. Adult stem cells serve very specialized roles in children and adults and are not as proliferative as those found in cord blood. These types of stem cells are far less controversial than embryonic stem cells, and will be the focus of this paper.

Umbilical cord blood, in particular, offers great hope for the future of stem cell research and use. It has been approved for use by the FDA and other authorities since the late 1980's. The first umbilical cord blood transfusion cured a blood cancer in 1988. Over 1,000 cord blood transfusions, frequently used for children with leukemia, have been successfully performed in the United States with little side effects. Recent research has shown that umbilical cord blood stem cells have similar powers and health promoting benefits as do embryonic stem cells.

Advances are being made each day in providing greater safety to the patient. New methods of separating the stem cells from all other blood components have resulted in a product that consists of only stem cells. Since these umbilical cord stem cells have not developed ABO and HLA antigens on their surfaces, they do not induce graft vs. host reactions nor other problems that may occur with embryonic and adult bone marrow stem cells. Since the umbilical cord stem cells do not contain mature blood or tissue cells, foreign protein reactions are minimized. This paper will examine the potential of these types of stem cells, in an effort to demonstrate how stem cells from umbilical cord blood may help scientists solve the ethical debate and enhance humanity.

Background on Stem Cells

Stem cells are cells in the body that have the unique ability to regenerate and change shape (How Stuff Works, 2003). Unlike other types of cells, stem cells can change into other types of cells. Stem cells are at the center of an innovative field of science known as regenerative medicine. Because stem cells can become bone, muscle, cartilage and other specialized types of cells, scientists believe that they have the potential to treat a variety of diseases, including Parkinson's, Alzheimer's, diabetes and cancer. Eventually, stem cells may also be used to regenerate organs, eliminating the need for organ transplants and other surgeries.

Stem cells are like little kids who, when they grow up, can enter a variety of professions," says Dr. Marc Hedrick of the UCLA School of Medicine (How Studd Works, 2003). "A child might become a fireman, a doctor or a plumber, depending on the influences in their life -- or environment. In the same way, these stem cells can become many tissues by making certain changes in their environment."

Stem cells can be broken down into four basic types (How Stuff Works, 2003):

Embryonic stem cells - Stem cells found in human embryos

Fetal stem cells- Stem cells found in aborted fetal tissue

Umbilical stem cells - Stem cells found in umbilical cords

About Umbilical Cord Stem Cells

Umbilical cord stem cells, which are taken from newborn babies, are the same hematopoietic, or blood-forming, cells found in bone marrow and in the circulation, although their quantities in the blood are relatively scarce (Barker, 2002). Stem cells can regenerate the body's ability to produce the erythrocytes, platelets, and leukocytes it needs.

Umbilical cord blood stem cells are referable to those found in bone marrow for the following reasons:

Higher chance of match: Cord blood can be successfully used even when a perfect match does not exist. Siblings have up to a 50% chance to find a cord blood match, compared to bone marrow.

Immediate availability: Families who bank cord blood can be assured that the stem cells are available if needed in the future. It is commonly known that trying to find a bone marrow match can be a much more time consuming process, even between family members. Early treatment can minimize disease progression.

Less GVHD: Patients who receive cord blood transplants from their families have significantly fewer problems with Graft vs. Host Disease, a fatal complication associated with transplants.

Various stem cells are obtained differently according to their source (Wolf, 2002). From bone marrow, stem cells are obtained in the hospital under anesthesia: the donor stores units of blood in advance to be infused during and after the procedure, and has insertions of a large bore needle into the hip bones for removal of marrow. Stem cells are obtained from peripheral blood by a process called apheresis or leukapheresis. Blood is drawn from peripheral blood through an IV and flows into a leukapheresis machine. The stem cells are collected by centrifugation and removed, and the blood is returned to the patient in one continuous process. The harvest of umbilical cord blood involves syringes or small infusion bags to remove blood from the cord after it is clamped and cut. Ideally, the process is initiated shortly after the birth while waiting for the placenta to be delivered, though it can be delayed for up to 10 minutes so that the blood can be collected after expulsion of the placenta.

Cord blood stem cells have been used as successfully as bone marrow to treat many conditions, including leukemia, anemia, and lymphoma, and may also be useful in gene therapy (Wolf, 2002). Cord blood stem cells have an advantage because they are less likely to cause problems with similarly matched specimens than bone marrow. The immune cells present in cord blood seem to have immunologic immaturity. In addition, fewer viruses are present in umbilical cord blood stem cells than in bone marrow. Umbilical cord blood also seems to require less stringent matching for unrelated donors.

In addition, the cord blood is a perfect match for the infant from whom it is collected. Siblings have up to a 50% chance of being a suitable match for future transplantation in another sibling in need. Parents may be matches as well. Some adoptive parents have worked with their social service agency to obtain the birth mother's permission to collect the umbilical cord blood so they will have a source of genetic material available for their adopted baby.

Since the first cord blood stem cell transplant in 1988, more than 2000 transplants have been performed (Wolf, 2002). Research is being conducted at medical centers worldwide and the National Institutes of Health has a number of working groups and conferences revolving around stem cell research. While much debate revolves around the use of embryonic stem cell lines for research, the collection of cord blood stem cells is simply a matter of recycling medical waste.

According to research, more than 125,000 units of cord blood have been stored worldwide (Wolf, 2002). In the past few years alone, research has demonstrated that cord blood stem cells can differentiate into other types of cells in the body. The regenerative qualities of stem cells have been brought to the forefront in the field of cellular repair. Stem cells have been labeled an important biological resource and researchers are conducting more and more studies to unlock the potential of umbilical cord blood stem cells in future applications for diseases like Alzheimer's, diabetes, heart and liver disease, muscular dystrophy, Parkinson's disease, spinal cord injury, and stroke.

The ability to store cord blood stem cells for a family's potential need may be particularly significant for those with a family history of leukemia or cancer. Long waits for a bone marrow donor search often means that the patient becomes more ill. If an extensive system of cord blood is available, the waiting time for a search could be greatly reduced, because cord blood requires less stringent matching. In time, greater amounts of cord blood will be saved, as the list of potential benefits increases.

Still, while this type of research is not as controversial as embryonic stem cell research, the collection and storage of cord blood are not without controversy (Wolf, 2002). Placentas and umbilical cords were once casually discarded. Now that their biologic potential has been confirmed, many companies are marketing cord blood's potential benefits to expectant parents. The odds of needing a given sample of cord blood by the family saving it are unknown, though for some families, the expense of saving it is worth it.

Estimations regarding the need for a given cord blood sample vary. One estimate of a child needing his or her own cord blood stem cells is 1:10,000 (Wolf, 2002). Another places the odds at 1:1000 to 1:2000. The probability of use varies depending on individual circumstances. Disturbing statistics reveal that every year there are about 8,000 new cases of cancer in children under the age of 15. These children could potentially benefit from the use of cord blood stem cells, so perhaps expectant parents should make the effort to donate their newborn's cord blood or store it for their own family's potential use.

According to Cryo-Care, a provider for the safe storage of stem cells taken from the umbilical cord blood, there are many steps that doctors must follow when collecting and storing these cells. In a sterile environment, preferably the delivery table, and immediately following the delivery, doctors collect the umbilical cord blood by following these steps:

1. Placing two clamps on the umbilical cord as close as possible to the baby's abdomen.

2. Cutting the umbilical cord between the two clamps and removing the baby from the sterile environment.

3. Taking the sterile blood bag out of its packaging and placing it nearby in preparation for the cord blood collection.

4. Disinfecting the umbilical cord where the needle will be inserted by means of the alcohol tissues or the supplied disinfectant kit.

5. Pricking the umbilical cord in the disinfected area with the needle attached to the blood collection bag.

6. Holding the bag below the level of the cord to allow the blood to drain freely.

7. Filling the bag to capacity if possible (it can contain 250ml, or approximately - 300gr). A minimum of 60ml of blood must be collected in the bag.

8. When as much blood as possible has been taken, gently squeezing any remaining blood from the tube into the bag.

9. At least two security knots should be tied in the collection tube to prevent leakage during transportation.

10. Cutting the needle from the bag and disposing of it appropriately in accordance with the hospital's waste disposal regulations.

11. Turning the bag over slowly several times, to mix the cord blood with the CPD anticoagulant.

12. The collected cord blood must be kept at room temperature; it should not be placed in a refrigerator or freezer.

Once the blood is collected by the cord blood bank, the red blood cells are removed from the cord blood, which is frozen in long-term cryogenic storage. Reputable banks remove the red blood cells so that the risk of blood type (ABO) compatibility is minimized. This means that if the stem cells are later needed for a family member other than the newborn, there is a greater chance of a match.

The Great Stem Cell Debate

Stem cell research is a hot topic for media headlines and has become one of the most controversial subjects in America today. For pro-life advocates, the moral costs of stem cell research far outweigh any potential benefits. For scientists, the possibilities of research are incredible and bewildering (Reaves, 2001). Neither party denies the moral dilemma of the stem cell debate. However, researchers say, to turn back now would be like turning our backs on a bright, sustaining light because we are terrified of the shadows it creates.

Scientists have revealed that stem cells could possibly hold the key to discovering a cure for several mysterious diseases, including Parkinson's and Alzheimer's. However, moral issues concern the public, despite the obvious positive consequences. The core of the stem cell debate is a battle over abortion, as stem cells come from embryos.

As far as public opinion is concerned, pro-life advocates compare the use of stem cells for research to experiments performed by Nazi doctors during World War II (Condic, 2002). According to pro-stem life research advocates, they are focusing in on a narrow subject and ignoring the possibilities of stem cells in scientific research. These cells could truly benefit millions of ailing patients and their families. In addition, they argue, these cells would otherwise be useless and unceremoniously discarded.

The issue of stem cell research first arrived on the scientific scene in 1998 when researchers first reported the isolation of human embryonic stem cells (Reese, 2001). The discovery, which was made by Dr. James Thomson, a biologist at the University of Wisconsin, offered great promise for new ways of treating various diseases. Stem cells, it was found, which are derived from embryos, can theoretically differentiate into virtually any type of human cell, from blood cells to skin cells.

Stem cells are basically any type of cell that is able to divide and generate two progeny (daughter cells). Of the progeny, one is destined to become something new and the other replaces the original stem cell. At different stages of development, there are many stem cell populations. For instance, the brain's cells arise from a neural stem cell population in which each cell produces one brain cell and another copy of itself every time it divides. The earliest stem cells are the embryonic stem cells and they give rise to all tissues in the body. This means that they are capable of generating all things.

Embryonic stem cells are considered the most useful in research because they can become any type of cell, while adult stem cells are more limited. There is no controversy revolving around the use of human adult stem cells in research, since they can be retrieved from the individual requiring the therapy. Since ES cells derive from the inner cell mass of the early embryo, they are capable of forming all the tissues of the body. But there is much controversy over the use of embryonic stem cells.

In 2001, President Bush announced that he would allow federal financial support of research that uses embryonic stem cells being cultured in laboratories around the world, but would prohibit funding for the development of new lines that involve the creation and destruction of additional embryos.

This decision was likely the result of pressure from the media. Focus on the Family bioethics analyst Carrie Gordon Earll commented that the media has bombarded the headlines in 2001 with propaganda that supported the use of federal funds to conduct research using stem cells. For example, actress Mary Tyler Moore told Congress that it should support embryonic stem cell research, which said was "truly life affirming" in light of its promise for finding a cure for diabetes (AFA, 2001).

It is the true pinnacle of charity to give life to another," Tyler Morre told the Senate Permanent Subcommittee on Investigations (AFA, 2001). "Federal support for stem cell research is an extension of this affirmation of life and is the best way to ensure it is undertaken with the highest of ethical standards."

As a result, Bush's decision provided federal funding. But proponents of stem cell research say that this is not enough. Restricting federal funding to a limited number of cell lines will hamper the progress of the research. Proponents will continue to pressure the United States government to expand these limits and are hopeful that science will benefit from this pressure soon.

Opponents of the research, like Dr. Richard Dorflinger of the United States Conference of Catholic Bishops, argued that the idea of the federal government funding such research "is illegal, immoral and unnecessary (Wildmoon, 2001)." Dorflinger, who opposes embryonic research of any kind, argued that enough private funding was available to support such studies without "forcing U.S. taxpayers to pay for the deliberate destruction of embryos (to obtain stem cells)."

The lack of federal funding leaves the scientific research at the hands of privately funded projects. Dr. Mary Hendrix of the Federation of American Societies for Experimental Biology, argues that this research is far too important and too fresh to be left to private researchers, noting that researchers are required to share data when their work is federally funded (Wildmoon, 2001). The media supports the opinion that all stakeholders, including scientists, researchers, ethicists, and investors should be kept up-to-date on federally funded projects.

Amy Jo Thomas, a reporter for ABC News, made a valid point by using human cases instead of just facts. She told the story of Jennifer Estess, a 38-year-old woman who is dying of Amyotropic Lateral Sclerosis, better known as Lou Gehrig's disease.

Standing with Mary Tyler-Moore, Gina Gershon and Michael J. Fox, she spoke at a Senate subcommittee meeting, expressing the urgency of the situation and the importance of stem cell research to her and so many others who are dying every day from ALS, a degenerative disease. When you look at the living, breathing people who could truly benefit from a used fetus, it is obvious that morality can bend in the direction of those who need help.

Generally speaking, in the eyes of the general public, women who are having abortions are obviously pro-choice, and most likely believe that human personhood begins much later in pregnancy. They probably see the killing of surplus embryos to be acceptable morally, especially if it offers so many potential benefits to the advancement of mankind. What would happen to these stem cells if they were not donated to research? The answer is nothing. The abortion already happened. The stem cells are ready for use but if not donated, they would go to waste.

Conclusion

It is important to note, when looking at the debate over stem cells, that embryonic stem cells are not the same as umbilical cord blood stem cells. Cord blood stem cells require a new life. Embryonic stem cells come from aborted fetuses and leftover, donated embryos. For this reason, there is a great deal of controversy over using federal money for stem cell research.

Umbilical cord blood stem cells do not present the same ethical or moral issues as embryonic stem cells and most agree that these stem cells are the closest to embryonic stem cells that are safely available for research and treating diseases. In addition, in comparison to stem cells taken from bone marrow, cord blood stem cells are considered more immature and therefore more tolerant. Studies have shown cord blood stem cells are more resistant to infection and more effective in the treatment of disease than bone marrow. For these reasons, umbilical cord blood stem cells are at a more advantageous position than other types of stem cells.

Umbilical cord blood stem cell usage is an emerging technology that gives new hope for sufferers of an ever-increasing variety of conditions. Thousands of births taking place in the United States every day provide readily accessible sources of umbilical cord blood stem cells with the potential for all ethnic groups to contribute to and benefit from public cord blood banking or family banking. Therefore, in today's society, healthcare professionals should provide up-to-date information about umbilical cord blood banking so they can support the expectant couple in making the decision that's right for them.