Before the advent of successful anti-retroviral therapy (ART) for HIV infection in the late 1990s, HIV positivity was considered an absolute contraindication to transplantation. In addition, a law was in place in the United States that made transplantation of organs from HIV positive donors illegal. All of this has changed because of the surprising success of transplanting HIV positive individuals and, more recently, the demonstration that organs from HIV donors can be used to successfully transplant patients with HIV.
In the era of effective long term control of HIV infection using combinations of ART medicines, HIV positive individuals are living long, essentially normal lives and, in fact, starting to suffer from chronic health problems seen in the general population such as chronic kidney disease and end stage liver disease. In a series of ground-breaking clinical trials that began in the early 2000s, by Dr.Peter Stock and his colleagues at the University of California San Francisco demonstrated that patients with well controlled HIV infection on ART (defined by a robust CD4+ T cell count of greater than 200 and the absence of detectable HIV RNA in the blood) could undergo kidney or liver transplants with nearly equivalent results as the general population.
AdvertisementMost medical professionals and scientists were astonished to learn that pharmacologic immunosuppression with antirejection drugs after transplant did not cause HIV reactivation in these patients and that the overall outcomes were very favourable.
In another set of bold clinical experiments, Dr. Elmi Muller, a transplant surgeon in South Africa, began transplanting HIV positive recipients with kidneys from HIV positive donors. This situation came about because HIV positive people with kidney failure were not allowed to undergo dialysis in South Africa and the high prevalence of HIV in the general population. Preliminary results were very encouraging and a longer term study published in January 2015 in the New England Journal of Medicine also showed reasonable outcomes at 3 and 5 years after transplant. These results inspired many transplant physicians in the United States to lobby for reversing the law prohibiting HIV positive organ donors. The United States Congress passed the HIV Organ Policy Equity (HOPE) Act in November 2013, legalizing organ donation from one HIV positive person to another in the setting of a research protocol.
In a recent study published in the American Journal of Transplantation, lead investigator Dr. Emily Blumberg estimated that close to 400 additional donor organs could be available nationally if all appropriate HIV positive donors were utilized. This would result in a small but significant increase in the number of transplants performed each year. Additionally, HIV- patients on the transplant waitlist would benefit from HIV positive recipients being removed from the waitlist after receiving HIV positive donor organs. Note that strict measures are in place to avoid transplanting HIV positive donor organs to HIV negative recipients and these practices will continue.
HIV positive to HIV positive transplants will initially only be conducted in the context of controlled research trials, so such transplants would not be widely practiced until several years worth of data can be analyzed.
The accumulated experience will be of interest to transplant physicians and HIV specialists alike, as many questions about the natural history of HIV infection and specific viral molecular mechanisms can be addressed. Thousands of HIV infected individuals worldwide also stand to benefit from life-saving and life prolonging transplants.