TORONTO, 13 August — A Canadian health report cautions against the transplant of animal organs into humans. The report by a Canadian health expert on infectious disease says experiments with xenotransplantation should not be allowed until special precautions and a national oversight body is put in place. Citing AIDS and the human version of mad cow disease, illnesses that originated in the animal world, the document notes there is a grave concern about introducing a dangerous new disease to people.
“Since xenotransplantation carries an as yet undefined risk to the public in the way of a new epidemic, the assessment and containment of this risk at the clinical trial level is essential,” says the report compiled by Dr. Marian Laderoute, of Health Canada.
The precautions it discusses implementing around xenotransplantation include:
• A national patient registry charting any problems after an animal transplant.
• A special lab to test the patients.
• A committee of experts to oversee the procedures.
• An emergency preparedness plan in the event of an outbreak traced to xenotransplants. Xenotransplantation — inter-species transplanting of organs and tissues — has become a major focus of the biotechnology sector recently. With human organs in short supply, using parts from pigs, judged particularly suitable to the human body, offers hope to many people who would die waiting for an organ.
Several companies around the world are working on xenotransplantation including the Scottish firm, PPL Therapeutics PLC, which produced Dolly the cloned sheep. Japan’s National Institute of Animal Industry last year cloned Xena, the first step toward using pigs to grow replacement hearts and other organs for humans in need of transplants.
No one in Canada has applied to conduct a clinical trial of xenotransplantation yet, but if anyone did the trial could proceed under the current regulations governing drugs and medical devices if the proponent provided sufficient supporting documentation. Health Canada has already prepared draft guidelines that incorporate some of the ideas proposed in Dr. Laderoute’s report, but a decision on whether to implement these or other guidelines has not been made yet.
The Laderoute report follows a discussion in Ottawa last year among experts from Canada, Britain, France, the United States and Germany. It notes the evidence is unclear whether disease is likely to be transmitted from pigs to humans. There is some date to suggest hepatitis E, which can be fatal to fetuses in some pregnant women, could cross the species barrier. There is also concern about transmission of PERVs, viruses embedded in the pig’s genetic material, that could theoretically produce silent infections that stay latent for many years and result in “incurable and devastating” disease. Although there is no data to prove PERVs could infect humans, scientists have yet to rule it out, the report says.