Designer animals for individual transplants - no rejection from patients

Main Category: Transplants / Organ Donations
Article Date: 18 Dec 2003 - 0:00 PDT


We will, one day, be able to grow an animal designed to provide replacement organs, organs designed for individual patients.

By injecting bone marrow into sheep foetus a 'chimaera', a blend of human and sheep cells is produced.

Researchers say that human liver cells, for example, could be harvested later in order to help a failing organ.

There would also be less chance of rejection if whole organs were taken from these animals.

The article in the New Scientist says that there is an urgent need for new organs. Researchers see animals as the source that will fill this widening gap (between demand and supply).

To date, this option is not possible due to the risk of animal viruses passing to humans. Patients also have to take powerful drugs to stop their bodies rejecting the new organ (with the present system).

The researchers (Nevada University, Reno, USA) say that they may be able to reduce this rejection problem. They say that by taking stem cells (found in the marrow of the human patient) and injecting it into the animal foetus growing inside the womb, these cells would be incorporated into the growing foetus. They would form part of virtually every tissue. Once the animal was fully grown these cells would be present in greater numbers.

As these would be human cells there would not be any problem of rejection.

Dr. Esmail Zanjani (team leader) said that they produced sheep human chimaeras. Some organs had a high proportion of human cells in them (7-8% of cells in sheep's livers were human).

They say that they could extract clusters of human cells and use them in liver transplantation operations.

Their animals also had high numbers of human heart cells in them.

According to the researchers, the sheep look like sheep and behave like normal sheep. Experts believe we could be ten to fifteen years away from creating our own-type sheep.

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