DISCUSSION: ORGAN
TRANSPLANTS
Addressing the organ shortage:
presumed consent and xenotransplants
Vijay
Rajput
The transplantation of organs is a triumph of
modern medicine. Kidney transplantation provides a longer life expectancy and
better quality of life than maintenance with dialysis does. Successful liver and
heart transplantation are life saving. However, there is a wide gap between the
need for organs and their supply. In 1999, 6,448 people in the USA died while
waiting for an organ transplant; 3088 were for kidneys and 1,767 for livers
(1).
The organ shortage is due not to a lack of
potential donors, but rather to a failure to turn potential donors into actual
donors - 'a paradox of shortage in the face of plenty.'(2) Our system of organ
procurement is clearly inadequate.
Transplantation is physically possible because of
an intricate biological inherence, with varying degrees of compatibility,
between members of the human species, and given technical advances, between
humans and some non-human species. It becomes an ethical option on the basis of
conventions, using moral reasoning and grounded in altruism, reconciling the
claims of bodily integrity with those of others in need, in a non-exploitative
manner (3).
The ethics of transplantation can be expressed in
certain requirements. The first is medical integrity. Patients and the public
must be able to trust their doctors not to sacrifice the interest of one to that
of another. Individual may make that sacrifice, but not their doctors. The
second requirement is scientific validity: the basic biology and technology must
be sufficiently assured to offer a probability of beneficial outcome, case by
case. The third is consent, based upon information adequately presented,
weighted and understood, and unforced.
The collection and use of human body tissue - from
18th century practices of dissection to 20th century organ transplantation -
have evoked various concerns: about the use of body parts without consent; the
psychological, social and religious impact of breaking down bodily integrity;
and the potential exploitation of individuals who are the sources of organ and
tissues. Physicians and scientists have been accused of profiteering,
insensitivity to patients' or families' emotions, and secrecy about unseemly
practices as they sought cadavers and body parts (4).
Presumed
consent
The ethical basis of donation is consent. Consent
to donation may be explicit or presumed. If not given explicitly by the deceased
beforehand, it may be given by proxy under conditions set out by law, regulation
and professional practice. Proxy consent will not suffice for a live donation,
except - perhaps - bone marrow from a child. Proxy consent gives the relevant
organisations liberty to exact material unless the source has expressly refused
to donate, in prescribed form, in advance. Explicit consent may also permit
donation even if it is to our own detriment.
Over 30 years ago, Dukeminier and Sanders said,
"The legal rule should favor removal of cadaver organs and preservation of life;
the exception should permit objection and decay."(5) The suggestion was opposed
with the argument that presumed consent discards the principle of autonomy and
voluntary donation and thus would not supported by the public. Further, every
member of the public would have to be informed of the proposal andhave
opportunity to object. Still, today some countries have a system of presumed
consent to organ donation. All citizens agree to become organ donors unless they
have actively taken steps to indicate that in the relevant circumstances they
would not wish to do so. It is felt that this system results in a greater
availability of organs for transplantation.
Presumed consent can be criticised because those
who are unable, or too slow, to take the necessary steps to opt out may later
have their organs used in violation of their wishes. As a result of this
argument, a number of countries do not have presumed consent. Presumed consent
is based on the following argument. Doctors and families surely expect patients
to permit a transplant if it was in their best interest. Likewise, most persons
would accept an organ transplant if their condition required it. If we assume
this, why do we not accept - in the absence of positive evidence - that most
persons would be prepared to donate their organs on their death? The
justification for this asymmetry of inference seems to be that there is no
interdependent relation between donor and recipient: the recipient depends on
the donor, and not vice versa. However, before any particular person is
identified as either a donor or a recipient, all people are interdependent as
potential donors or recipients. An opting out system recognises this potential
interdependence while ensuring the right to individual exceptions.
(6)
However, if a person has not opted out of organ
donation, at the time of death, the system must also take into account the
wishes of the deceased's relatives who may refuse removal of the organs. Such
wishes are respected though they may seem weak against the claims of the person
in need of a transplant. On the other hand, in Singapore, the Human Organ
Transplant Act presumes consent to kidney donation in the absence of written
refusal, and family consent is not required. In such a system, when people
refuse consent to organ donation on religious grounds, they become free riders
in the system, predisposed to benefit without ever consenting to contribute. In
practice, 'free riders' needing organ transplant may be discriminated against in
the allocation of organs. Singapore has adopted a controversial set of
incentives and disincentives, with those who consent to donation getting
priority access to kidneys over those who refuse. This raises questions of
coercion and discrimination. The humanitarian and altruistic principles behind
organ donation may be undermined by a law which tends to foster spirit of
self-interest in some donors. (7)
It is difficult to overcome some ethical problems
associated with presumed consent. Conceivably, it is a violation of the
principle of consent to assume an altruistic motive to donate organs. The
response has been to pre-suppose self-interest, combined with the concept of
interdependence and obligation. Singapore held a public awareness campaign
before the law was passed, and ensures careful implementation, but has not been
able to respond to the charges that incentives and disincentives are
coercive.
Xenotransplantation Each new announcement of
medical progress calls forth a sense of hope, even urgency. What sickness might
soon be cured? Whose lives might be saved? What critical knowledge might be
gained? The seduction of medical progress can tip the balance of careful public
policy consideration.
Xenotransplantation, or the transplant of organs
from animals to humans, raises a host of complex issues, challenging division
between individual and public health, human and animal identity and welfare and
scientific progress and public concern about risk.
Despite the immunological hurdles, animal organs
appear to offer the best solution to an inadequate supply of donor organs. The
pig has been identified as a potential donor, its advantage being its
availability in large numbers, ease of breeding and maintenance under
gnotobiotic or pathogen-free conditions, and its more likely public acceptance,
as it is already an accepted food source (8).
The crucial distinction between pigs and primates
is made to rest on the presumption of the latter's greater capacity of
suffering. The conclusion is that the harm to pigs is not so unjustifiable as to
make their use unacceptable in principle. The ethical acceptability of the use
of the pig then becomes a matter of balancing the potential benefits to the
human against the harm involved to the pig (9).
The overlapping capacities of humans and other
animals is often advanced as an argument against the use of animals in, for
example, research. Other have argued that in fact this aspect makes
experimentation on animals too valuable to do without. RG Frey goes so far as to
suggest the use of severely mentally impaired humans as experimental subjects
(10). In the area of transplants, this could mean mentally impaired humans
should be used for their organs.
The infectious disease risk of xenotransplants
poses a problem for recipients of organ transplants and the public at
large if they create an epidemic of a new infectious disease in humans. Two
years ago the risk of disease spread by pig to human transplants was so
worrisome that the US FDA placed a hold on ongoing clinical trials. Developments
since then suggest that there is no appreciable current evidence of porcine
endogenous retroviral infection in human recipients of xenotransplants
(11).
The main ethical issue raised by these risks is
that of consent. The US Department of Health's reports recommend that early
xenograft be offered only to competent adults who make an informed choice to
accept such transplants. The reports recommend that patients who refuse
xenografts should remain eligible for human organs on the same basis as before
(12).
The issue of reallocating resources is not specific
to xenotransplants, but raises the same problem as the introduction of any other
new and experimental treatment: predicting future costs and benefits and
ensuring effective and equitable use of resources. The question here is whether
xenotransplant would be a better or worse use of resources than the available
alternatives. Xenotransplants as bridges to allotransplants might improve some
patients' survival chances and quality of life. They could also serve as
definitive treatment for some groups of patients who are excluded from
allotransplant waiting lists.
Conclusion From a moral standpoint, the social
context in which any law - or medical practice - is to operate must be
considered when determining policy. A law on presumed consent can follow
informed public debate and a demonstration that it would be morally acceptable
to most people. Most objection to change would be mitigated by public education.
Presumed consent must be explored before resorting to xenotransplantation. It
would avoid, or at least postpone, the risk of transmitting infectious disease
from animals to the human population. However, it is not known if such measures
would be sufficient to close the organ gap.
References:
1. United
Network for Organ Sharing: unpublished data, May 6, 2000
2. Bart KJ, Macon
EJ, Whittier FC, et al. cadaveric kidneys for transplantation: a paradox of
shortage in the face of plenty. Transplantation 1981;31:379-82
3. Dunstan,
GR. The ethics of organ donation. British Medical Bulletin 1997; 53 (4):
921-939
4. Andrews L, Nelkin D. Whose body is it anyway? Dispute over body
tissue in a biotechnology age, Lancet 1998; 351:53-57
5. Dukeminier J Jr.,
Sander D. Organ transplantation: a proposal for routine salvaging of cadaver
organs. N Eng J Med. 1968; 279: 413-9
6. Eaton S, The subtle politics of
organ donation: a proposal. Journal of Medical Ethics, 1998; 24: 166-170
7.
Bernard Teo. Organ for Transplantation: The Singapore Experience. Hastings
Center Report, 1991; Nov-Dec: 10-13
8. Cooper DKC, Ye Y, Rolf LL, et al: In
Cooper DKC, et al (eds.): Xenotansplantation. Heidelberg, Springer, 1991, p481
9. B. Brophy. 'In the pursuit of a fantasy' in S. Godlovitch and J. Harris
(Eds.), Animals, Men and Morals (Victor Gallancz) 124-45
10. Frey RG.
Medicine, animals experimentation, and the moral problem of unfortunate humans.
Social Philosophy and Policy. 1996; 13.2: 181-211
11. Patience C. et al. No
evidence of pig DNA or retroviral infection in patient with short-term
extracorporeal connection to pig kidneys. Lancet 1998;352:699-701
12.
Advisory group on the ethics of xenotransplantation. Animals tissue into humans;
a report by the advisory group on the ethics of xenotransplantation. London:
stationery office, 1997.
Dr Vijay Rajput,Assistant Professor of medicine, UMDNJ-Robert Wood Johnson Medical School, 401
Haddon Avenue, E&R Bldg., Room 242, Camden, NJ, 08103, USA. Email:rajputvk1@home.com
