WASHINGTON _ Officials from the FDA and Centersfor Disease Control and Prevention (CDC) have asked themedical community and patients to be aware of the publichealth risks posed by xenotransplantation.

The agencies' request and words of caution werepublished Thursday in an article in the New EnglandJournal of Medicine.

"We are throwing down the gauntlet," said Phil Noguchi,a co-author and director of the division of cellular andgene therapy with FDA's Center for Biologics Evaluationand Research.

"There is a risk here. We don't know what it is. Even themost aggressive transplant surgeon does not want tocause the next pandemic after AIDS. This is a wake upcall," Noguchi told BioWorld Today.

"This is notification to the medical community in generalto do its homework," said Michael Egan, senior vicepresident, of Diacrin Inc., in Charlestown, Mass.

Egan, who worked with Noguchi to obtain approval of itsprotocol to harvest porcine cells, remarked, "There arethose who think they do not have to go through the FDA.This article puts them on notice that the agency expectsthem to obtain approval."

While the FDA wants to maintain a proactive role inanticipating many of the regulatory and public healthissues, physicians and patients and the rest of the medicalcommunity have to play an active role, said Noguchi."We cannot oversee every Institutional Review Board[IRB]. Local IRBs and surgeons have to step up to theirresponsibilities," he told BioWorld Today.

His division plans to issue before the end of the month adraft discussion paper which lays out the collaborativeapproach between the FDA and the newly emerging fieldof xenotransplantation.

Noguchi stressed the collaborative approach. "We don'twant the FDA and the medical community to be buttingheads like goats. We want to be able to put the bestinterests of the patient first. We want the FDA, drugcompanies and physicians to look at the patient as thecenter of therapy."

The article, written by Noguchi and Louisa Chapman, anepidemiologist with the CDC in Atlanta, was anoutgrowth of a presentation they made before variousmembers of the transplant community and an FDAadvisory committee meeting. (See BioWorld Today, July17, 1995, p. 1.)

Noguchi said that while most of the popular images ofviruses portray highly contagious ones such as Ebola, hewas more concerned about "silent insidious viruses suchas AIDS." Accordingly, the planned baboon bone marrowtransplant at the University of California at San Franciscohospital has beefed up its isolation and screening method,he said. (See BioWorld Today, Aug. 2, 1995, p. 1.)

Noguchi and Chapman recommended in the article thatbefore proceeding further with xenotransplantation, thereshould be a "multi-disciplinary consensus to facilitate thedevelopment of measures designed to protect the safety ofall, to indicate directions for future research, and toadvance well-designed clinical trials as the use ofxenogeneic issues makes the transition from animalmodels to medical practice."

"Clinicians and policy makers alike must recognize thatalthough xenotransplantation promises benefits forspecific patients, that promise is accompanied byundeniable potential for harm to the wider community."

It is a "matter of public concern, not merely a privatematter for individual scientists, physicians and patients todecide" if "this field constitutes an acceptable risk in thebalance between caution and progress," according to thearticle.

Ideally, transmission of unknown pathogens from the hostto transplant recipient would be mitigated by "controllingthe quality and source of animals, screening andquarantining those animals and procuring tissues withaseptic techniques."

"However, in patients with xenotransplants the diagnosisand management of familiar zoonoses may becomplicated by immunologic manipulations that alter theclinical presentation of illness, the reliability of antibodytesting, and the response to therapy," the article stated."Infusion of bone marrow from the animal and other newstrategies proposed for manipulating the immuneresponse of the host undergoing xenotransplantation mayalso raise the risk of infectious disease." n

-- Michele L. Robinson Washington Editor

(c) 1997 American Health Consultants. All rights reserved.