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BY B.E.N

3. transplantation

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Page 1: 3. transplantation

BY B.E.N

Page 2: 3. transplantation

COURSE OUTLINE1. Introduction2. Types of transplants3. Major organs and tissues transplanted4. Types of donors5. Reasons for donation6. Ethical concerns

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Organ transplantation is the moving of an organ from one body to another or from a donor site on the patient's own body, for the purpose of replacing the recipient's damaged or absent organ

The emerging field of regenerative medicine is allowing scientists and engineers to create organs to be re-grown from the patient's own cells (stem cells, or cells extracted from the failing organs)

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i/ Autograft and autotransplantationTransplant of tissue to the same person.

Sometimes this is done with surplus tissue, or tissue that can regenerate, or tissues more desperately needed elsewhere (examples include skin grafts)

Sometimes an autograft is done to remove the tissue and then treat it or the person, before returning it (examples include stem cell autograft and storing blood in advance of surgery)

2.TYPES OF TRANSPLANTS

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ii/ Allograft and allotransplantation

An allograft is a transplant of an organ or tissue between two genetically non-identical members of the same species.

Most human tissue and organ transplants are allografts. Due to the genetic difference between the organ and the recipient, the recipient's immune system will identify the organ as foreign and attempt to destroy it, causing transplant rejection.

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iii/ IsograftA subset of allografts in which organs or

tissues are transplanted from a donor to a genetically identical recipient (such as an identical twin).

Isografts are differentiated from other types of transplants because while they are anatomically identical to allografts, they do not trigger an immune response.

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iv/ Xenograft and xenotransplantationA transplant of organs or tissue from one

species to another. Eg. 1). Porcine heart valve transplant, which is

quite common and successful. 2). Attempted piscine-primate (fish to non-

human primate) transplant of islet (i.e. pancreatic ) tissue.

The latter research study was intended to pave the way for potential human use, if successful.

However, xenotransplantion is often an extremely dangerous type of transplant because of the increased risk of non-compatibility, rejection, and disease carried in the tissue.

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v/ Split transplants

Sometimes a deceased-donor organ, usually a liver, may be divided between two recipients.

This is not usually a preferred option because the transplantation of a whole organ is more successful.

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vi/ Domino transplantsThis is the series of transplantation in which the

first recepient become the donor for another recipient

Eg. 1. In patients with cystic fibrosis, where both lungs need to be replaced, it is technically easier operation with a higher rate of success to replace both the heart and lungs of the recipient with those of the donor. As the recipient's original heart is usually healthy, it can then be transplanted into a second recipient in need of a heart transplant

2. Familial amyloidotic polyneuropathy

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3.MAJOR ORGANS AND TISSUES TRANSPLANTEDThoracic organsHeart (Deceased-donor only)Lung (Deceased-donor and living-related

lung transplantation)Heart/Lung (Deceased-donor and Domino

transplant)

Abdominal organsKidney (Deceased-donor and Living-Donor)Liver (Deceased-donor and Living-Donor)Pancreas (Deceased-donor only)Intestine (Deceased-donor and Living-Donor)Stomach (Deceased-donor only)Testis

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Tissues, cells, fluidsHand (Deceased-donor only)Cornea (Deceased-donor only)Skin including Face replant (autograft) and

Face transplant (extremely rare)Islets of Langerhans (Pancreas Islet Cells)

(Deceased-donor and Living-Donor)Bone marrow/Adult stem cell (Living-Donor and

Autograft)Blood transfusion/Blood Parts Transfusion

(Living-Donor and Autograft)Blood vessels (Autograft and Deceased-Donor)Heart valve (Deceased-Donor, Living-Donor and

Xenograft [Porcine/bovine])Bone (Deceased-Donor and Living-Donor)

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4. TYPES OF DONORS1) Living donor

In "living donors", the donor remains alive and donates a renewable tissue, cell, or fluid (e.g. blood, skin), or donates an organ or part of an organ in which the remaining organ can regenerate or take on the workload of the rest of the organ

Eg.(primarily single kidney donation, partial donation of liver, small bowel).

Regenerative medicine is promising, one day may allow for laboratory-grown organs, using patient's own cells via stem cells, or healthy cells extracted from the failing organs.

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2) Deceased donor (formerly cadaveric) Deceased are donors who have been declared

brain-dead and whose organs are kept viable by ventilators or other mechanical mechanisms until they can be excised for transplantation.

Brain-dead donors, have formed the majority of deceased donors for the last twenty years, but nower days are not enough donors as the demand for transplants continues to grow.

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5. REASONS FOR DONATION

(i) Living related donorsLiving related donors donate to family members

or friends in whom they have an emotional investment.

The risk of surgery is offset by the psychological benefit of not losing someone related to them, or not seeing them suffer the ill effects of waiting on a list.

(ii) Paired exchangeA "paired-exchange" is a technique of matching

willing living donors to compatible recipients using serotyping

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Eg. A spouse may be willing to donate a kidney to his /her partner, but cannot since there is no biological match.

The willing spouse's kidney is donated to a matching recipient who also has an incompatible but willing spouse. The second donor must match the first recipient to complete the pair exchange.

Typically the surgeries are scheduled simultaneously in case one of the donors decides to back out and the couples are kept anonymous from each other until after the transplant.

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(iii) Good SamaritanGood Samaritan or "altruistic" donation is

giving a donation to someone not well-known to the donor.

Some people choose to do this out of a need to donate. Some donate to the next person on the list; others use some method of choosing a recipient based on criteria important to them.

Websites are being developed that facilitate such donation. It has been featured in recent television journalism that over half of the members of the Jesus Christians, an Australian religious group, have donated kidneys in such a fashion

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(iv) Compensated donation(Sometimes referred to Organ sale or Organ trade)

In compensated donation, donors get money or other compensation in exchange for their organs.

This practice is common in some parts of the world, whether legal or not, and is one of the many factors driving medical tourism.

In the United States, The National Organ Transplant Act of 1984 made organ sales illegal. In the United Kingdom, the Human Organ Transplants Act 1989 first made organ sales illegal, and has been superseded by the Human Tissue Act 2004. What about in Africa???

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(v) Forced donation Harvesting organs from executed/ condemned

people (who seem to be the undesirable/ unwanted) without their consent.

There have been various accusations that certain authorities are harvesting organs from those the authorities deem undesirable, such as prison populations.

The World Medical Association stated that individuals in detention are not in the position to give free consent to donate their organs .

Illegal dissection of corpses is a form of body-snatching and may have taken place to obtain allografts

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Comparative costsOne of the driving forces for illegal organ

trafficking and for “transplantation tourism” is the price differences for organs and transplant surgeries in different areas of the world.

According to the New England Journal of Medicine, a human kidney can be purchased for $1000–$2000, but in urban Latin America a kidney may cost more than $10,000. Kidneys in South Africa have been sold for as high as $20,000.

Price disparity based on donor race are a driving force of attractive organ sales in South Africa, as well as in other parts of the world.

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In China, a kidney transplant operation runs for around $70,000, liver for $160,000, and heart for $120,000.

Although these prices are still unattainable to the poor, compared to the fees of the United States, where a kidney transplant may demand $100,000, a liver $250,000, and a heart $860,000, Chinese prices have made China a major provider of organs and transplantation surgeries to other countries.

In India, a kidney transplant operation runs for around as low as $5000 thus make it a place to go for developing countries, Tanzania inclusive.

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6. ETHICAL CONCERNSThe existence and distribution of organ

transplantation procedures in developing countries, while almost always beneficial to those receiving them, raise many ethical concerns.

Both the source and method of obtaining the organ to transplant are major ethical issues to consider, as well as the notion of distributive justice.

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“transplantation tourism” has the potential to violate human rights or exploit the poor, to have unintended health consequences and to provide unequal access to services, all of which ultimately may cause harm.

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ARE WE GOING TO REACH???

THE END