For over a century, physicians and scientists have dreamed of using animals to help humans whose kidneys, hearts, and other organs failed. In 2004, the year I learned that my kidneys would soon stop working, I began to share their vision.
My first kidney transplant gave out after ten years. Thesecond, obtained six years ago, functions well but won’t last forever. The insider maxim among some of us older transplant recipients is “may your organ outlive you” – otherwise, you may not survive the queue for a new one.
The recent breakthroughs in xenotransplantation—the implantation of animal tissues and organs across species – have thus been exhilarating.
Last September, when doctors at NYU Langone Medical Center attached a pig kidney to blood vessels in a dead woman’s leg (with family permission). It produced urine and cleared waste products during the observation period of 54 hours. (Two months later, they repeated the procedure.)
In late September, a team at the University of Alabama at Birmingham implanted the first-ever genetically-modified pig kidneys into the body of Jim Parsons, 57, of Huntsville, who had died in a motorcycle accident. The new kidneys turned “beautiful and pink,” the lead surgeon said, until the experiment ended 77 hours later.
Then, on January 7, surgeons at the University of Maryland transplanted a heart from a genetically modified pig into a 57-year-old David Bennett Sr. The patient, who doctors said had exhausted all other treatment options, is still alive.
We have come a long way from Baby Fae, the California infant who lived three weeks after receiving a baboon heart in 1984. True momentum was gained in the 1990s with advances in genetic modification of the donor animal to prevent organ rejection. The application of CRISPR-Cas9 gene editing, discovered in 2012, accelerated that progress by enabling researchers to snip out traces of pig virus that could be transmitted to human.
Sick and dying patients are waiting. Currently, over 90,000 people need a kidney, yet fewer than 25,000 of them received one and about 41,000 would-be recipients were added to the national waiting list. About a dozen people die each day for want of a kidney, not to mention those “in-activated” from the list because they fell too ill to tolerate transplant surgery even if an organ had come along.
Having your blood cleansed three times a week does give you more years of life – though not nearly as many as a transplant—but is often a psychological and physical ordeal. Here the numbers get very large: over half million have end-stage kidney disease and depend on dialysis, according to the National Institute of Diabetes and Digestive and Kidney Diseases. Meanwhile, a large fraction of those are medically eligible for a transplant are not even listed.
An enhanced supply of kidneys would help low-income and minority patients who are not only more prone to renal failure due to diabetes and hypertension, but also less likely to receive an organ than their white counterparts. Reasons range from difficulty finding a living donor ( relatives and friends may too suffer from diabetes and high blood pressure or they cannot get sick leave) to not being listed for a deceased donor by their doctors.
Finally, the costs of dialysis to Medicare’s End State Renal Disease program are imposing: $51.0B in 2019, the last year for which government has published data – a little over 6 percent of the total Medicare budget.
No doubt, I have been blessed. Two magnificent friends donated kidneys to me, but so many are far less fortunate. To help those languishing on dialysis, my colleagues and I have proposed a compensation system – currently exchanging anything of value for a human organ is illegal –by which the government or an approved charity offers non-cash benefits to healthy, fully informed people willing to give a kidney to a stranger.
Incentives could include a tax credit, a contribution to a retirement account, tuition voucher, or loan forgiveness,. A congressman introduced a bill that would allow pilot compensation trials, but it has not advanced much.
The thrust behind the xenotransplantation, however, heralds nothing less than a revolution. Under monitoring by the Food and Drug Administration, local institutional review boards, and institutional animal care and use committee, it is the future of the field. Surgeon Jayme Locke, head of the University of Alabama team, said she hopes to be able to offer pig kidney transplants to her patients within five years, as long as “we hit every milestone, and there are no setbacks.”
Godspeed to you, Dr. Locke, to your colleagues, and to the noble pig. Make the donor shortage – its heartbreak, unfairness, and its expense—a thing of the past.
Sally Satel is a senior fellow at the American Enterprise Institute and a visiting professor of psychiatry at Columbia University’s Vagelos College of Physicians and Surgeons