Xeno's paradox

Abstract

There has always been a serious shortage of transplant organs for use in patients with critical organ failure as the result of accident or disease. As such, the idea of transplanting animal organs into humans is almost a century old, having first been advanced in 1906 by the French surgeon Mathieu Jaboulay (1860–1913), who implanted a pig's kidney into one woman and a goat's liver into another, neither of whom survived. However, although xenotransplantation has promised to improve the provision of organs and tissues for sufferers from various otherwise terminal conditions, it has yet to find its way into clinical use. In fact, the 1990s seemed to sound a death knell for xenotransplantation, as growing fears that xenografts could be a source of potentially lethal zoonoses resulted in the mass withdrawal of the pharmaceutical industry from the research; a blow that came on top of the already seemingly intractable problem of immunological rejection of organ grafts. Against all odds, however, xenotransplantation research lived on in several countries, ultimately allowing the development of new techniques to address many of the problems, as well as fostering the conviction that the zoonosis threat might have been overstated. In any case, the chronic shortage of human organ donors continues, which means that, on average, about 60% of patients waiting for a transplant die before an organ becomes available. More recently, it has also become clear that it is going to take some time before artificial organs can be developed for use in the clinic. “Animal organs are, in my view, much further along than human‐made equivalents in being able to replace end‐stage failed organs,” commented Megan Sykes, Associate Director of the Transplantation Biology Research Centre at Massachusetts General Hospital (Boston, MA, USA). “The total artificial heart is farthest along, but is still far from …