Pork Futures

Xenotransplantation gets another shot.

MARK ROBERTS

Now that science can spot a disposition toward kidney disease or detect an undiagnosed lung cancer through signs in the blood, the medical community is sensing public pressure for a cure. Jeffrey Platt, director of transplantation biology at the Mayo Clinic, foresees that such pressure will bear heavily on an already scarce resource: organs.The queue for a kidney transplant in the United States is 55,000 people long, with an average wait time of three years. Another 17,000 Americans await a liver, and nearly 8,000 need a new heart or lung. Every year 6,500 people die while waiting for organ transplants. Worldwide, the pressure has already spawned an exploitative trade in kidneys from living donors in poor countries.

If organs aren’t to be found in other human beings, the next obvious source is animals. But efforts at restoring human health with transplanted animal parts have always been defeated by the body’s immunological rejection of alien tissue. In a highly controversial case in the United States in 1984, Leonard Bailey gave an under-developed newborn, “Baby Fae,” the heart of a baboon. The child was kept alive for 20 days thanks to the powerful immunosuppressant drug cyclosporine.

Genetic engineering seemed to offer a way around the problems of rejection, and interest in xenotransplantation flared up again in the mid-’90s. Money poured into startups that promised pig hearts in patients within 18 months. The promises proved wild, concerns surfaced about risky human experimentation and trans-species infection, and the money dried up. Today only two large firms remain involved in xenotransplantation, and one, Novartis, has announced that it will pull back by the end of the year. The other, Baxter Healthcare, handed intellectual property rights back to its collaborator, the Mayo Clinic, in March 2003.