Article

Xenotransplantation and organ donation

There is a worldwide shortage of deceased organ donors. In this theme, we explore ways of increasing the availability of cells, tissues and organs for transplants.

Enhanced image of a human heart.

Enhanced image of a human heart.

Cell, tissue and organ transplants

When a person suffers organ failure, their body needs assistance quickly. In some cases, this can be supplied by a machine, for example, dialysis is used to replace kidney function in patients whose kidneys are not working properly. However, organ transplants provide a much better long-term solution. Transplants can also be used to replace diseased or damaged cells or tissues with healthy, living alternatives.

Uses of transplants

  • Organ transplants – replacing diseased organs, such as hearts, lungs, livers, pancreases or kidneys.

  • Cell transplants – replacing damaged or dead cells in diseases such as diabetes, Alzheimer’s or Parkinson’s disease

  • Tissue transplants – replacing skin, corneas, blood, blood vessels or bone.

Diagram of which organ, cell and tissue are suitable transplants

Organ, cell and tissue transplants

Diseased, damaged and failing human organs, cells and tissues can be replaced with healthy alternatives. Transplants usually come from human donors (allotransplantation), but researchers are investigating whether animal donors can also be used (xenotransplantation).

Rights: The University of Waikato Te Whare Wānanga o Waikato

Worldwide demand for transplants

The worldwide demand for cells, tissues and organs for transplantation far exceeds supply. People are dying while on waiting lists for transplants. Several ways to provide more donor tissue and save lives are being investigated including changing donation systems and legislation, sourcing tissue from animals and stem cell therapies.

Organ donation systems and the donor shortfall

Each country has its own organ donation system, rules and regulations. Some systems may result in more donors than others, but ultimately, donation rates are strongly influenced by peoples’ cultural, spiritual and religious views. For example, New Zealand has a low rate of deceased organ donors by international standards. New Zealand uses an ‘opt in’ organ donation system where you choose if you would like to donate your organ, and this is noted on your driver’s licence. However, your organs will be only be donated if your family members agree to it. Use this article to generate a discussion on the ethics of organ donation.

Xenotransplantation and the donor shortfall

Transplanting living cells, tissues or organs from animals to humans could solve the donation shortfall. This is called xenotransplantation. Xenotransplantation was first attempted in the early 1900s but failed, as organs were rapidly rejected by the immune system. Since then, researchers have been developing new technologies to overcome xenotransplant rejection and reduce the risks of cross-species infection. Find out more about the History of xenotransplantation and in this timeline.

A group of piglets on hay.

Piglets

Pigs are the current preferred donor species for Xenotransplantation.

Rights: Glyn Lewis, licenced through 123RF Ltd.

New Zealand is leading the way with its world-class research into pig cell transplants. Auckland-based company Living Cell Technologies (LCT) is developing a pig cell product that may be used to treat type 1 diabetes. This product has been tested in human clinical trials since 2009 and could be available within the next decade.

Stem cell therapies and the donor shortfall

Stem cells may provide an alternative to xenotransplantation. A stem cell is a special type of cell that has the potential to become any type of body cell. Stem cells are found in brain, liver, bone marrow, embryonic tissue and cord blood. Any of these could be sources for stem cell transplants. In the future, new organs or tissues could be grown from an individual’s own stem cells. Find out more about stem cells.

Published: 9 December 2011,Updated: 9 December 2011