Xenotransplantation: Can an animal organ save your life?

 from http://www.rds-online.org.uk/pages/page.asp?i_ToolbarID=5&i_PageID=161

•Xenotransplantation is a form of organ transplantation that utilizes non-human species (pigs or primates, for example) as organ donors in order to create large stocks of viable organs for human use.

 •Virtually all xenotransplantation research is at an early experimental stage.

 •Currently, over 79,000 U.S. patients are waiting for an organ transplant. Nearly 3,000 new patients are added to the waiting list each month.

 •Because of the lack of available donors in this country, 2,025 kidney patients, 1,347 liver patients, 458 heart patients and 361 lung patients died in 2001 while waiting for life-saving organ transplants.

 •In theory, Xenotransplantation would allow the healthcare system to create vast stores of viable organs for donation.

 

Creating Xenotransplantation Donors

There are several methods to create viable organ donors. Currently, however, only one method is federally approved for use:

 

a) Animal egg cells are cultured in petri dishes and foreign DNA is added to their own DNA. This foreign DNA generally contains genes of interest, e.g., one that would prevent organ rejection in humans.

b) Successfully transfected cells are selected and allowed to develop.

c) Cells are transferred to pseudopregnant recipients (mothers who aren’t actually pregnant, but are hormonally-primed to have offspring).

d) After the donors have grown to maturity, any viable organs are harvested and transferred to approved recipients.

 

Benefits of Xenotransplantation

•Elimination of the demand for human organ donors--There is about a 1:7 ratio of organs to those in need of transplants.

•Ability to alter the genetics of the organ, which could make it stronger, more resilient, etc.--because xenotranplantation already involves the alteration of genes, other modifications could be made to the DNA of the animal donor.

•Ability to mass produce donor organs--since animal donors are generally slaughtered during the transplantation process.

 

heart transplant in progress (from http://www.stronghealth.com/services/cardiology/images/cardtrans.jpg)

 

Possible Risks

•Hyper-acute rejection--there is a high risk of rejection in cross species transplantation.

•Ethics--some critics of xenotransplantation feel the rights of the animals involved are violated. Others feel that animal organs do not belong in human beings.

•Low Profitability--As of now, the most popular technique for xenotransplantation (pronuclear microinjection) is extremely inefficient (1-5%). Furthermore, many people in need of organs can't afford such a costly operation.

•Cross-species infection--in addition to rejection, there is the possibility of viruses that originated in the animal donor crossing over into human beings

 

Further information

http://www.kidney.org/general/news/factsheet.cfm?id=30 --Facts about organ donation and transplantation from the National Kidney Foundation.

 

Milking the Genome for Profit http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=11017040

 

Uncertainty in xenotransplantation: individual benefit versus collective risk http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=9461178

 

Xenotransplantation and other means of organ replacement

http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=11905823