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Alternatives to Xenotransplantation
Proponents of xenotransplantation insist that using animals for spare
parts is the only solution to the perceived human organ and tissue shortage.
But there are safer, more cost-effective, and humane alternatives to xenotransplantation
that are not being adequately explored. Below are some of them.
- Prevention
Ironically, it is precisely because we eat too much bacon and pork chops,
and have unhealthy lifestyles, that pig organ transplants are being
considered. Top nutritional and health experts now agree that a diet
rich in saturated fat from animal products (meat, dairy, butter, etc.)
is one of the major causes of heart disease, cancer, stroke, noninsulin
dependent diabetes, and obesity.1
In 1997, researchers suggested that 100,000 first-time heart attacks
could be averted by the year 2005 if Americans simply reduced their
average saturated fat intake by one to three percentage points.2
Lifestyle changes have proven capable of reversing and controlling many
chronic diseases.3
Diabetes, for example, is the most common condition found in patients
who need kidney transplants. A 1999 study revealed that a strict vegetarian
diet and regular exercise can control type 2 diabetes.4
Several researchers, including Hans-Michael Dosch, an immunologist at
Toronto's Hospital for Sick Children, and Outi Vaarala of the National
Public Health Institute in Finland, have linked Type 1 diabetes with
early intake of cow's milk.5
Alcohol-related cirrhosis and alcoholic hepatitis are the most common
forms of fatal liver disease in the US, which could be prevented through
avoidance of alcohol. Similarly, about 5,000 intravenous drug users
develop a chronic and potentially fatal form of hepatitis C every year
which could be prevented through avoidance of drugs or needle sharing.6
If implemented on a grand scale, population based prevention programs
could drastically curtail chronic disease rates. Preventing disease
before it begins would shrink the number of people on transplant waiting
lists, reduce the demand for human organs (and surgical procedures of
all kinds), save money, and eliminate the prospect of dangerous cross-species
transplants.
- Improving Success Rates of Human-to-Human Transplants
Chronic rejection remains a major problem in human-to-human transplants.
Roughly 50% of transplanted human organs are rejected and fail within
five years.7 Before
embarking on dangerous and more complex cross-species transplantation
technologies, it would be wise to try to perfect existing allotransplantation
techniques.
- Improving Organ Delivery System
A General Accounting Office report on organ donation (April 1998) found
that the U.S. Health Care Finance Administration (HCFA), which sets
performance standards for organ procurement organizations, has not accurately
determined the number of usable organs in the U.S., and that number
may be much higher than previously thought.8
Improving the organization and performance of organ procurement agencies,
instituting nationally standardized hospital procedures to ensure that
all potential donors are identified, that every family is approached
about the possibility of organ donation, and that the request is properly
structured,9 and
launching public education campaigns to increase public awareness about
organ donation would help considerably. For example, Illinois spends
$1 million annually on organ donor TV ads, and has more residents on
its organ donor registry (4.5 million) than any other state.10
- Increasing Cadaveric Organ Donation
In 1998, Yong W. Cho, et al. reported in the New England Journal of
Medicine, that cadaveric organ donation using kidneys from newly
deceased people whose hearts have stopped beating (as opposed to organs
from brain-dead donors with beating hearts) could increase the
supply of kidneys two-to-five fold.11
- Kidney Transplantation From Living Donors
Kidney transplantation from living donors has been successfully performed
in the U.S., and is associated with an 85% increase in rate of organ
donations from living donors. In Norway, between 4550% of transplanted
kidneys come from living donors.12
Liver transplantation from living donors has also been performed successfully.
Livers can regenerate to almost their normal size in a matter of weeks.13
- Expanding Donor Criteria
Coleman-Musser, et al., found that kidneys and livers can be transplanted
from older donors with positive outcomes.14
- Split Organ Transplants
Split organ transplants of livers from cadaveric donors have been successfully
performed in Israel and elsewhere. These transplants could save two
lives instead of one and reduce the number of people on transplant waiting
lists.15
- Financial Incentives
Lloyd Cohen, Professor of law at George Mason University in Virginia,
claims that, the U.S. organ shortage could be alleviated by creating
financial incentives or rewards for donors and/or their beneficiaries.16
For example, Congressman James Greenwood of Pennsylvania has introduced
legislation to use federally-financed life insurance programs as an
incentive for people to donate their organs.17
Some estimate that such financial incentives could produce up to 80,000
organ donations each year.
- Presumed Consent
Many nations, including Austria, Spain, Belgium, and Singapore, have
seen organ donation rates soar after the passage of "presumed consent"
laws which assume that citizens will donate their organs after death
unless they "opt out."18
Dr. Phil Berry, an organ transplant recipient and past President of
the Texas Medical Association, the British Medical Association, and
Ronald Davis, the North American editor of the British Medical Journal,
have published views in favor of "presumed consent." Very
little research has been done to determine the feasibility of such legislation
in the U.S. "Mandated choice" laws require citizens to declare
whether they want to donate their organs or not. Such laws produced
600,000 new donors in Sweden and 150,000 in Denmark.19
One U.S. survey suggested that 90% of Americans would support a "mandated
choice law" and over 60% would support a "presumed consent"
law.20 Public debate
is needed to discuss the merits of these laws in the U.S.
- Innovative Research
- Because human embryonic stem (ES) cells have the capacity to develop
into any type of tissue in the body, including internal organs,
researchers and bioethicists say that the cells could be cultured
to grow unlimited supplies of human tissue for transplant and, eventually,
whole human organs.21
The cells can be obtained from cadavers and in vitro fertilization
clinics which destroy huge numbers of fertilized embryos each year.22
- Scientists at the Medical College of Virginia in Richmond froze
liver cells from donated organs that were unsuitable for transplantation,
and infused them into patients with liver damage. Seven out of 12
patients survived long enough to have a whole organ transplant and
one patient made a full recovery with the cells alone.23
- A consortium of seven Seattle-area research centers have formed
the Seattle Human Islet Transplantation Project, to transplant human
(as opposed to porcine) pancreatic islet cells into human diabetics
in an attempt to treat the disease.24
- Dr. Jayanta Roy Chowdhury and colleagues at the Albert Einstein
College of Medicine in New York say that an injection of liver cells
may preclude the need for whole organ transplantation.25
- Reuters reported that about 75% of heart disease patients who
undergo a procedure called ventricular remodeling in which
a section of heart muscle is removed and reshaped can be
taken off the transplant waiting list.26
- Cloning Human Organs
Some have suggested that, cloning human tissues and organs from a patient's
own cells, would eliminate the prospect of cross-species transplants,
as well as the problem of hyperacute rejection, theoretically doing
away with toxic immunosuppressive medications.27
Dr. Jonathan Hughes, professor of political thought at the University
of Manchester, U.K., writes that, "a moratorium should be imposed
upon xenotransplantation procedures at least until possible avenues for
increasing the supply of human organs have been exhausted and until a
more reassuring judgement can be reached on the prospects for preventing
and containing transmitted infections."28
References
1 R.J. Deckelbaum, et al.,
"Summary of a Scientific Conference on Preventive Nutrition . . .,"
Circulation: The Journal of the American Heart Association, Vol. 100 (July
27, 1999): 450-6; Wayne R. Bidlack, "Interrelationships of Food,
Nutrition, Diet and Health . . .," Journal of the American College
of Nutrition, Vol. 15, No. 5 (1996): 422-33.
2 Gerry Oster, David Thompson,
"Estimated Effects of Reducing Dietary Saturated Fat Intake . . .,"
Journal of the American Dietetic Association, Vol. 96, No. 2 (February 1996):
127-31.
3 See Dean Ornish, et al., "Intensive Lifestyle
Changes for Reversal of Coronary Heart Disease," Journal of the American
Medical Association, Vol. 280, No. 23 (December 16, 1998: 2001-7.
4 A. Nicholson, et al., "Toward Improved
Management of NIDDM . . .," Preventive Medicine, Vol. 29, No. 2 (August
1999): 87-91.
5 See O. Vaarala, et al., Diabetes, Vol. 48,
No. 7 (July 1999): 1389-94.
6 A. Fano, et al., Of Pigs, Primates and Plagues:
A Layperson's Guide to the Problems With Animal-to-Human Organ Transplants,
(Medical Research Modernization Committee, 1997).
7 David Stipp, "Replaceable You,"
Fortune, November 25, 1996, pp.131-138.
8 General Accounting Office, Organ Donation:
Assessing Performance of Organ Procurement Organizations, (GAO, Washington,
DC, April 8, 1998).
9 W. DeLong, "Options for Increasing Organ
Donation: the Potential Role of Financial Incentives, Standardized Hospital
Procedures, and Public Education to Promote Family Discussion," Milbank
Q, Vol. 73, No. 3 (1995): 463-79.
10 Jim Ritter, "What Will Make You Be An
Organ Donor?" Chicago Sun Times, November 5, 1999, p.6.
11 Y.W. Cho, et al., "Transplantation of
kidneys from donors whose hearts have stopped beating," New England
Journal of Medicine, Vol. 338, No. 4 (January 22, 1998):221-5; Associated
Press, "Study Supports Expanding Supply of Kidney Transplants from
Cadavers," January 21, 1998.
12 Anon, "Renal Transplantation From Living
Donors," British Medical Journal, (3 February 1999): 409-10; Anon,
"Drive to Increase Live Kidney Donors," BBC News Online, January
27, 2000.
13 Richard Saltus, "2 Donors Give Part
of Their Livers," The Boston Globe, December 12, 1998, p.B1.
14 Coleman-Musser, et al., "Discard Rates
and Transplant Outcomes in Organs Recovered From Older Donors," J.
Transpl. Coord, Vol. 7, No. 4 (December 1997): 190-4; M.L. Jordan, et al.,
"High-Risk Donors: Expanding Donor Criteria," Transplantation
Proceedings, Vol. 31 (1999): 1401-3.
15 Iris Krauz, "Donated Liver Split for
Two Patients," The Ha-aretz, Israel, April 22, 1999.
16 See Lloyd Cohen, Increasing the Supply of
Transplant Organs: The Virtues of an Options Market (Texas: R. G. Landes,
1995.
17 Patricia M. La Hay, "Organ-Donation
Bill Would Pay for Life Insurance," The Philadelphia Inquirer, November
22, 1999, p.B1.
18 Ian Kennedy, et al., "The Case for Presumed
Consent in Organ Donation," The Lancet, Vol. 351, (May 30 1998): 1650-2.
19 Moussa Awounda, "Swedish Organ-Donation
Drive Set for Success," The Lancet, Vol. 347 (May 18, 1996): 1401.
20 A. Spital, "Mandated Choice: The Preferred
Solution to the Organ Shortage," Archives of Internal Medicine, Vol.
152, No. 12 (December 1992): 2421-4.
21 J. Gearhart, "New Potential for Human
Embryonic Stem Cells," Science, Vol. 282 (6 November 1998): 1061-2;
Anon, "Alternative Ways of Meeting Demand," Nature, Vol. 391 (22
January 1998): 325; Anon, "The Politics of Embryos," The Washington
Post, Op-Ed, February 21, 2000; National Bioethics Advisory Commission,
Ethical Issues in Human Stem Cell Research, (NBAC, Rockville, Maryland,
September 1999).
22 Anon, "[Phoenix] Clinic Plans to Destroy
Unclaimed Embryos," The New York Times, July 13, 1999, p.D10.
23 Anon, "The Frozen Cells That Heal Sick
Livers," New Scientist, December 9, 1999, p.5.
24 Carol Smith, "A New Way to Attack Diabetes,"
Seattle Post-Intelligencer, August 16, 1999, p.A1.
25 Anon, "Cell Injection May Help Some
Liver Diseases," Reuters, May 14, 1998.
26 Anon, "Surgery Staves Off Heart Transplant,"
Reuters, March 17, 1997.
27 See www.humancloning.org and Anon, "Yes
to Cloned Tissue," New Scientist, December 12, 1998: 5.
28 Jonathan Hughes, "Xenografting: Ethical
Issues," Journal of Medical Ethics, Vol. 24 (1998): 18-24.
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