Transplanted pig kidney patient leaves hospital to go home

The first patient to receive a kidney transplant from a genetically modified pig recovered so well that he was released from hospital on Wednesday, just two weeks after the groundbreaking surgery.

The transplant and its encouraging results represent a remarkable moment in medicine, scientists say, perhaps heralding an era of cross-species organ transplants.

Two previous organ transplants from genetically modified pigs have failed. Both patients received hearts and both died a few weeks later. In one patient there were signs that the immune system had rejected the organ, a constant risk.

But the kidney transplanted to Richard Slayman, 62, produces urine, removes waste products from the blood, balances body fluids and performs other key functions, according to his doctors at Massachusetts General Hospital.

“This moment – ​​leaving the hospital today with one of the cleanest health bills I have had in a long time – is one I have wished would come for many years,” he said in a statement released by the hospital. “Now it's a reality.”

He said he had received “exceptional care” and thanked his doctors and nurses, as well as supporters who reached out to him, including kidney patients who were waiting for an organ.

“Today marks a new beginning not only for me, but for them as well,” Mr. Slayman said.

The procedure brings the prospect of xenotransplantation, or animal-to-human organ transplantation, significantly closer to reality, said Dr. David Klassen, medical director of the United Network for Organ Sharing, which runs the nation's organ transplant system.

“Although much work remains to be done, I think the potential of this approach to benefit large numbers of patients will be realized, and that has been a question mark hovering over the field,” Dr. Klassen said.

It is not yet known whether Mr. Slayman's body will ultimately reject the transplanted organ, Dr. Klassen noted. And there are other hurdles: A successful operation would have to be replicated in numerous patients and studied in clinical trials before xenografts become widely available.

If these transplants are to be scaled up and integrated into the health system, there are “daunting” logistical challenges, he said, starting with ensuring an adequate supply of organs from genetically modified animals.

Cost, of course, could become a substantial obstacle. “Is this something we can really realistically attempt as a health system?” Dr. Klassen said. “We have to think about it.”

Treating kidney disease already represents a huge expense. According to the National Kidney Foundation, end-stage renal disease, the point at which organs are failing, affects 1% of Medicare beneficiaries but accounts for 7% of Medicare spending.

Yet the medical potential of pig-to-human transplantation is enormous.

Mr. Slayman opted for the experimental procedure because he had few options left. He had difficulty with dialysis due to blood vessel problems and faced a long wait to donate a kidney.

The kidney transplanted into Mr Slayman came from a pig genetically modified by the biotechnology company eGenesis. The company's scientists removed three genes that could trigger organ rejection, inserted seven human genes to improve compatibility and took steps to inactivate retroviruses carried by pigs that could infect humans.

More than 550,000 Americans suffer from kidney failure and require dialysis, and more than 100,000 are on the waiting list to receive a kidney transplant from a human donor.

Additionally, tens of millions of Americans suffer from chronic kidney disease, which can lead to organ failure. Black Americans, Hispanic Americans, and Native Americans have the highest rates of end-stage renal disease. Black patients generally fare worse than white patients and have less access to a donated kidney.

Although dialysis keeps people alive, the treatment of choice for many patients is a kidney transplant, which greatly improves quality of life. But only 25,000 kidney transplants are performed each year, and thousands of patients die each year waiting for a human organ due to a lack of donors.

Xenotransplantation has been discussed as a potential solution for decades.

The challenge in any organ transplant is that the human immune system is primed to attack foreign tissue, causing life-threatening complications for recipients. Patients who receive transplanted organs generally must take drugs intended to suppress the immune system's response and preserve the organ.

Mr. Slayman showed signs of rejection on the eighth day after surgery, according to Dr. Leonardo V. Riella, medical director for kidney transplants at Mass General. (The hospital's parent organization, Mass General Brigham, developed the transplant program.)

The rejection was a type called cellular rejection, which is the most common form of acute transplant rejection. It can happen at any time, but especially within the first year after an organ transplant. Up to 25% of organ recipients experience cellular rejection within the first three months.

The rejection was not unexpected, although Mr. Slayman experienced it more quickly than usual, Dr. Riella said. Doctors were able to reverse the rejection with steroids and other drugs used to curb the immune reaction.

“The first week was a roller coaster,” Dr. Riella said. Reassuringly, he added, Mr. Slayman responded to treatment like patients who receive organs from human donors.

Mr. Slayman is taking several immunosuppressant medications and will continue to be closely monitored with blood and urine tests three times a week, as well as doctor visits twice a week.

His doctors do not want Mr. Slayman to return to work, at the state Department of Transportation, for at least six weeks, and he must take precautions to avoid infection because of the drugs that suppress his immune system.

“Ultimately, we want patients to get back to doing the things they love to do, to improve their quality of life,” Dr. Riella said. “We want to avoid restrictions.”

By Wednesday, Mr. Slayman was clearly ready to go home, Dr. Riella said.

“When we arrived, he had a lot of apprehension and anxiety about what was going to happen,” Dr. Riella said. “But when we reached her at 7 o'clock this morning, you could see a big smile on her face and she was making plans.”

Leave a Reply

Your email address will not be published. Required fields are marked *