SAFEGUARDS to ensure that proposed transplants of "humanised" animal organs into patients do not put the public at risk of new diseases were announced by the Government yesterday.
The use of "humanised" animal organs is being pursued to meet a serious shortage of donor organs. Globally, only one person in three will receive the organ they need this year.
Using genetic engineering, pigs have been changed to overcome the rejection problems that would otherwise destroy a transplanted porcine organ within minutes. But there are concerns about the risk of infection.
Yesterday's announcement detailed further steps to regulate companies planning to test this kind of procedure - xenotransplantation - in clinical trials.
Frank Dobson, the Health Secretary, said that he would explore giving the regulation of xenotransplantation statutory backing.
His announcement followed consultation with the UK Xenotransplantation Interim Regulatory Authority, chaired by Lord Habgood, formerly the Archbishop of York, who is a pharmacologist by training.
Mr Dobson wants all hospitals to comply with procedures set by the authority. It will scrutinise applications before advice is put to ministers for a final decision.
Animal welfare would be included in the authority's terms of reference and a code of practice was being developed, he said.
There would also be surveillance of patients who receive animal tissue, and the Advisory Committee on Dangerous Pathogens is to study infection risks.
Mr Dobson said that human trials would take place only "if and when we are fully satisfied that the risks associated with such procedures are acceptable, taking account of all the available evidence at the time".
The consultation underlined the need for more human organs. "We are committed to promoting and supporting human organ donation and will be launching a new publicity campaign later this year," said Mr Dobson.
Lord Habgood said that he was satisfied with the new steps. "It is a question of balancing the needs, which are real because there are never going to be enough human transplants, against the possible dangers of using animals."
The main concerns focused on whether a xenotransplant would work, how long it would work, and the risks that a pig infection could take hold in humans, particularly given that the recipient's immune system could be damped down by drugs to reduce the risk of long-term rejection.
"We are concerned with the dangers of new viruses which might then spread to the population as a whole," Lord Habgood said. "This is the main field in which more experiment needs to take place."
The Cambridge company Imutran has developed "humanised" pigs and, in preparation for the first trials, is studying 160 patients worldwide who have received living pig tissue for the presence of porcine viruses.
The first clinical trials will probably involve the use of a "humanised" pig liver outside the body as temporary support for a patient awaiting a human organ, a procedure that has been carried out in several centres in the United States.
"The whole approach is to take things step by step," said Lord Habgood. "Any major transplant programme [in the UK], if it ever happens, is several years away."
Dr Jonathan Fryer and colleagues at Northwestern University Medical School and Northwestern Memorial Hospital in Evanston, Illinois, are about to use genetically altered pig livers to help patients dying of end-stage liver failure.
A spokesman said that the Food and Drug Administration had placed a temporary stay on the team's work because of concern about disease but had "relaxed the hold" since then.
