Besides organ rejection, one of the most common transplant complications is infection. Physicians must strike a balance when prescribing immunosuppressants. Too low a dose may cause rejection, and too high a dose may make the patient more susceptible to infection. Immunosuppressants are powerful drugs that can cause a variety of side effects, including fatigue, nausea, and vomiting.
Despite the deaths of two people who received pig hearts, Riera remains optimistic about Suleiman's transplant. First, he says Suleiman was relatively healthy when he underwent the surgery. He was qualified to harvest human kidneys, but because of his rare blood type, it would likely take six to seven years to harvest a kidney. The two recipients of pig heart transplants had severe symptoms and were not eligible to receive human organs.
In addition to close monitoring and traditional immunosuppressants, Suleiman's medical team is treating him with an experimental drug called tegopulvert, developed by Eledon Pharmaceuticals in Irvine, California. Tegopulvert is given to her IV every three weeks to block the crosstalk between her two important immune cells in the body, T cells and B cells, suppressing the immune response to the donor organ. The drug is being used in monkeys that have been transplanted with gene-edited pig organs.
“It's pretty miraculous that this man was able to get out of the hospital a few weeks after receiving a pig kidney transplant,” said Stephen Perrin, Eledon's president and chief scientific officer. “I didn't think you'd be here so soon.”
Riera also hopes that the 69 genetic modifications made to the donor pig will help keep Suleiman's kidneys functioning. Pig organs are not naturally compatible with the human body. eGenesis, the company that supplied the pigs, used Crispr to add certain human genes and remove some pig genes to eliminate latent viruses in the pig genomes that are hypothesized to infect human recipients. Inactivated. Pigs are produced using cloning technology. Scientists make edits to a single pig's cells and use them to form embryos. The embryos are cloned and implanted into the sow's uterus, and her offspring are eventually edited.
“We hope that this combination will be the secret sauce to making this kidney graft survive longer,” Riera says.
Scientists debate how long pig organs need to be preserved in humans. For the pig heart transplants, the researchers used donor animals with 10 edits developed by Rivivicol, a subsidiary of United Therapeutics.
There is another big difference between this surgery and heart surgery. Riera said that even if Suleiman's kidneys stopped working, he could resume dialysis. Pig heart recipients had no backup options. Even if pig organs aren't a long-term alternative, they could provide a bridge to transplants for patients like Suleiman, who suffer for years on dialysis, he says.
“We received so many letters, emails, and messages from people who volunteered to become xenotransplant candidates despite all the unknowns,” Riera says. “Many of them are suffering so much from dialysis that they are looking for alternatives.”
Mass General's team plans to begin formal clinical trials to transplant the edited pig kidneys into more patients. They received special approval from the U.S. Food and Drug Administration for just her one procedure. But for now, their main focus is to keep Suleiman healthy.