New Hope for Organ Transplantation: Life Without Anti-Rejection Drugs
Rob Waddell dreaded getting a kidney transplant. He suffers from a genetic condition called polycystic kidney disease that causes the uncontrolled growth of cysts that gradually choke off kidney function. The inherited defect has haunted his family for generations, killing his great grandmother, grandmother, and numerous cousins, aunts and uncles.
But he saw how difficult it was for his mother and sister, who also suffer from this condition, to live with the side effects of the drugs they needed to take to prevent organ rejection, which can cause diabetes, high blood pressure and cancer, and even kidney failure because of their toxicity. Many of his relatives followed the same course, says Waddell: "They were all on dialysis, then a transplant and ended up usually dying from cancers caused by the medications."
When the Louisville native and father of four hit 40, his kidneys barely functioned and the only alternative was either a transplant or the slow death of dialysis. But in 2009, when Waddell heard about an experimental procedure that could eliminate the need for taking antirejection drugs, he jumped at the chance to be their first patient. Devised by scientists at the University of Louisville and Northwestern University, the innovative approach entails mixing stem cells from the live kidney donor with that of the recipient to create a hybrid immune system, known as a chimera, that would trick the immune system and prevent it from attacking the implanted kidney.
The procedure itself was done at Northwestern Memorial Hospital in Chicago, using a live kidney donated by a neighbor of Waddell's, who camped out in Chicago during his recovery. Prior to surgery, Waddell underwent a conditioning treatment that consisted of low dose radiation and chemotherapy to weaken his own immune system and make room for the infusion of stem cells.
"The low intensity chemo and radiation conditioning regimen create just enough space for the donor stem cells to gain a foothold in the bone marrow and the donor's immune system takes over," says Dr. Joseph Levanthal, the transplant surgeon who performed the operation and director of kidney and pancreas transplantation at Northwestern University Feinberg School of Medicine. "That way the recipient develops an immune system that doesn't see the donor organ as foreign."
"As a surgeon, I saw what my patients had to go through—taking 25 pills a day, dying at an early age from heart disease, or having a 35% chance of dying every year on dialysis."
A week later, Waddell had the kidney transplant. The following day, he was infused with a complex cellular cocktail that included blood-forming stem cells derived from his donor's bone marrow mixed what are called tolerance inducing facilitator cells (FCs); these cells help the foreign stem cells get established in the recipient's bone marrow.
Over the course of the following year, he was slowly weaned off of antirejection medications—a precaution in case the procedure didn't work—and remarkably, hasn't needed them since. "I felt better than I had in decades because my kidneys [had been] degrading," recalls Waddell, now 54 and a CPA for a global beverage company. And what's even better is that this new approach offers hope for one of his sons who has also inherited the disorder.
Kidney transplants are the most frequent organ transplants in the world and more than 23,000 of these procedures were done in the United States in 2019, according to the United Network for Organ Sharing. Of this, about 7,000 operations are done annually using live organ donors; the remainder use organs from people who are deceased. Right now, this revolutionary new approach—as well as a similar strategy formulated by Stanford University scientists--is in the final phase of clinical trials. Ultimately, this research may pave the way towards realizing the holy grail of organ transplantation: preventing organ rejection by creating a tolerant state in which the recipient's immune system is compatible with the donor, which would eliminate the need for a lifetime of medications.
"As a surgeon, I saw what my patients had to go through—taking 25 pills a day, dying at an early age from heart disease, or having a 35% chance of dying every year on dialysis," says Dr. Suzanne Ildstad, a transplant surgeon and director of the Institute for Cellular Therapeutics at the University of Louisville, whose discovery of facilitator cells were the basis for this therapeutic platform. Ildstad, who has spent more than two decades searching for a better way, says, "This is something I have worked for my entire life."
The Louisville group uses a combination of chemo and radiation to replace the recipient's immune and blood forming cells with that of the donor. In contrast, the Stanford protocol involves harvesting the donor's blood stem cells and T-cells, which are the foot soldiers of the immune system that fight off infections and would normally orchestrate the rejection of the transplanted organ. Their transplant recipients undergo a milder form of "conditioning" that only radiates discrete parts of the body and selectively targets the recipient's T-cells, creating room for both sets of T-cells, a strategy these researchers believe has a better safety profile and less of a chance of rejection.
"We try to achieve immune tolerance by a true chimerism," says Dr. Samuel Strober, a professor of medicine for immunology and rheumatology at Stanford University and a leader of this research team. "The recipients immune system cells are maintained but mixed in the blood with that of the donor."
Studies suggest both approaches work. In a 2018 clinical trial conducted by Talaris Therapeutics, a Louisville-based biotech founded by Ildstad, 26 of 37 (70%) of the live donor kidney transplant recipients no longer need immunosuppressants. Last fall, Talaris began the final phase of clinical tests that will eventually encompass more than 120 such patients.
The Stanford group's cell-based immunotherapy, which is called MDR-101 and is sponsored by the South San Francisco biotech, Medeor Therapeutics, has had similar results in patients who received organs from live donors who were either well matched, such as one from siblings, meaning they were immunologically identical, or partially matched; Talaris uses unrelated donors where there is only a partial match.
In their 2020 clinical trial of 51 patients, 29 were fully matched and 22 were a partial match; 22 of the fully matched recipients didn't need antirejection drugs and ten of the partial matches were able to stop taking some of these medications without rejection. "With our fully matched, roughly 80% have been completely off drugs up to 14 years later," says Strober, "and reducing the number of drugs from three to one [in the partial matches] means you have far fewer side effects. The goal is to get them off of all drugs."
But these protocols are limited to a small number of patients—living donor kidney recipients. As a consequence, both teams are experimenting with ways to broaden their approach so they can use cadaver organs from deceased donors, with human tests planned in the coming year. Here's how that would work: after the other organs are removed from a deceased donor, stem cells are harvested from the donor's vertebrae in the spinal column and then frozen for storage.
"We do the transplant and give the patient a chance to recover and maintain them on drugs," says Ildstad. "Then we do the tolerance conditioning at a later stage."
If this strategy is successful, it would be a genuine game changer, and open the door to using these protocols for transplanting other cadaver organs, including the heart, lungs and liver. While the overall procedure is complex and costly, in the long run it's less expensive than repeated transplant surgeries, the cost of medications and hospitalizations for complications caused by the drugs, or thrice weekly dialysis treatments, says Ildstad.
And she adds, you can't put a price tag on the vast improvement in quality of life.
Friday Five: These boots were made for walking, even for people who can't
The Friday Five covers important stories in health and science research that you may have missed - usually over the previous week but, today, we're doing a lookback on breakthrough research over the month of October. There are plenty of controversies and troubling ethical issues in science – and we get into many of them in our online magazine – but this news roundup focuses on scientific creativity and progress to give you a therapeutic dose of inspiration headed into the weekend.
Listen on Apple | Listen on Spotify | Listen on Stitcher | Listen on Amazon | Listen on Google
This Friday Five episode covers the following studies published and announced over the past month:
- New boots could have you moving like Iron Man
- The problem with bedtime munching
- The perfect recipe for tiny brains
- The best sports for kids to avoid lifelong health risks
- Can virtual reality reduce pain?
Should egg and sperm donors reveal their identities? The debate pivots on genetics and medical history.
Until age 35, Cassandra Adams assumed her mother and father were her biological parents. Then she took saliva tests through two genealogy databases—23andMe and AncestryDNA—and discovered a discrepancy in her heritage. In bringing up the matter with her parents, she learned that fertility issues had led the couple to use a sperm donor.
“Most people my age were not told,” said Adams, now 40 and a stay-at-home mom in Jersey City, New Jersey, who is involved with donor-conception advocacy. “Even now, there’s still a lot of secrecy in the industry. There are still many parents who aren’t truthful or planning not to be truthful with their children.”
While some of those offspring may never know a significant part of their medical history, Adams is grateful that she does. Surprisingly, the DNA test revealed Jewish ancestry.
“There are a lot more genetic conditions that run in Jewish families, so it was really important that I get my medical history, because it’s very different from my dad who raised me,” said Adams, who has met her biological father and two of three known half-siblings. As a result of this experience, she converted to Judaism. “It has been a big journey,” she said.
In an era of advancing assisted reproduction technologies, genetics and medical history have become front and center of the debate as to whether or not egg and sperm donations should be anonymous – and whether secrecy is even possible in many cases.
Obstacles to staying anonymous
People looking to become parents can choose what’s called an “identity-release donor,” meaning their child can receive information about the donor when he or she turns 18. There’s no way to ensure that the donor will consent to a relationship at that time. Instead, if a relationship between the donor and child is a priority, parents may decide to use a known donor.
The majority of donors want to remain anonymous, said reproductive endocrinologist Robert Kiltz, founder and director of CNY Fertility in Syracuse, New York. “In general, egg and sperm donation is mostly anonymous, meaning the recipient doesn’t know the donor and the donor doesn’t know the recipient.”
Even if the donor isn’t disclosed, though, the mystery may become unraveled when a donor-conceived person undergoes direct-to-consumer genetic testing through ancestry databases, which are growing in number and popularity. These services offer DNA testing and links to relatives with identifiable information.
In the future, another obstacle to anonymity could be laws that prohibit anonymous sperm and egg donations, if they catch on. In June, Colorado became the first state in the nation to ban anonymous sperm and egg donations. The law, which takes effect in 2025, will give donor-conceived adults the legal authority to obtain their donor’s identity and medical history. It also requires banks that provide sperm and egg collection to keep current medical records and contact information for all donors. Meanwhile, it prohibits donations from those who won’t consent to identity disclosures.
“The tradition of anonymous sperm or egg donation has created a vast array of problems, most significantly that the people thus created want to know who their mommy and daddy are,” said Kenneth W. Goodman, professor and director of the Institute for Bioethics and Health Policy at the University of Miami Miller School of Medicine.
“There are counter arguments on both sides. But the current situation has led to great uncertainty and, in many cases, grief,” Goodman said.
Donors should bear some moral responsibility for their role in reproduction by allowing their identity to be disclosed to donor-conceived individuals when they turn 18, Goodman added, noting that “there are counter arguments on both sides. But the current situation has led to great uncertainty and, in many cases, grief.”
Adams, the Jersey City woman who learned she was Jewish, has channeled these feelings into several works of art and performances on stage at venues such as the Jersey City Theater Center. During these performances, she describes the trauma of “not knowing where we come from [or] who we look like.”
In the last five years, Kathleen “Casey” DiPaola, a lawyer in Albany, New York, who focuses her practice on adoption, assisted reproduction and surrogacy, has observed a big shift toward would-be parents looking to use known sperm donors. On the other hand, with egg donation, “I’m not seeing a whole lot of change,” she said. Compared to sperm donation, more medical screening is involved with egg donation, so donors are primarily found through fertility clinics and egg donor agencies that prefer anonymity. This leads to fewer options for prospective parents seeking an egg donor with disclosed identity, DiPaola said.
Some donors want to keep in touch
Rachel Lemmons, 32, who lives in Denver, grew interested in becoming an egg donor when, as a graduate student in environmental sciences, she saw an online advertisement. “It seemed like a good way to help pay off my student loan debt,” said Lemmons, who is married and has a daughter who will turn 2-years-old in December. She didn’t end up donating until many years later, after she’d paid off the debt. “The primary motivation at that point wasn’t financial,” she said. “Instead, it felt like a really wonderful way to help someone else have a family in a few weeks’ time.”
Lemmons originally donated anonymously because she didn’t know open donations existed. She was content with that until she became aware of donor-conceived individuals’ struggles. “It concerned me that I could potentially be contributing to this,” she said, adding that the egg donor and surrogacy agency and fertility clinic wouldn’t allow her to disclose her identity retroactively.
Since then, she has donated as an open donor, and kept in touch with the recipients through email and video calls. Knowing that they were finally able to have children is “incredibly rewarding,” Lemmons said.
When to tell the kids
Stanton Honig, professor of urology and division chief of sexual and reproductive medicine at Yale School of Medicine, said for years his team has recommended that couples using donor sperm inform children about the role of the donor and their identity. “Honesty is always the best policy, and it is likely that when they become of age, they might or will be able to find out about their biological sperm donor,” he said. “Hiding it creates more of a complicated situation for children in the long run.”
Amy Jones, a 45-year-old resident of Syracuse, N.Y., has three children, including twins, who know they were conceived with anonymous donor eggs from the same individual, so they share the same genetics. Jones, who is a registered nurse and asked for her real name not to be published, told them around age seven.
“The thought of using a known donor brought more concerns—what if she wanted my babies after they were born, or how would I feel if she treated them as her own every time I saw her?” said Jones.
“I did a lot of reading, and all psychologists said that it is best to start the conversation early,” she recalled. “They understood very little of what I was telling them, but through the years, I have brought it up in discussion and encouraged them to ask questions. To this day, they don't seem to be all that interested, but I expect that later on in life they may have more questions.”
Jones and her husband opted to use a donor because premature ovarian failure at age 27 had rendered her infertile. “The decision to use an egg donor was hard enough,” she said. “The thought of using a known donor brought more concerns—what if she wanted my babies after they were born, or how would I feel if she treated them as her own every time I saw her?”
Susan C. Klock, a clinical psychologist in the section of fertility and reproductive medicine at Northwestern University Feinberg School of Medicine, said, “Anonymity is virtually impossible in the age of direct-to-consumer genetic testing.” In addition, “selecting an identity-release donor is typically not the first thing parents are looking at when they select a donor. First and foremost, they are looking for a donor with a healthy medical background. Then they may consider donor characteristics that resemble the parents.”
The donor’s medical history can be critical
Donor agencies rely on the self-reported medical history of egg and sperm donors, which can lead to gaps in learning important information. Knowing a donor’s medical history may have led some families to make different or more well-informed choices.
After Steven Gunner, a donor-conceived adult, suffered from schizophrenia and died of a drug overdose at age 27 in 2020, his parents, who live in New York, learned of a potential genetic link to his mental illness. A website, Donor Sibling Registry, revealed that the sperm donor the couple had used, a college student at the time of donation, had been hospitalized during childhood for schizophrenia and died of a drug overdose at age 46. Gunner’s story inspired Steven’s Law, a bill that was introduced in Congress in July. If passed, it would mandate sperm banks to collect information on donors’ medical conditions, and donors would have to disclose medical information the banks weren’t able to find.
With limited exceptions, the U.S. Food and Drug Administration requires donors to be screened and tested for relevant communicable disease agents and diseases such as HIV, hepatitis viruses B and C, the Zika virus and several STDs. With current technology, it is also impossible to screen for thousands of rare genetic diseases. “If a couple is using IVF (in vitro fertilization) to conceive with the donor gamete, some may opt for pre-implantation genetic testing to assess for chromosomal abnormalities,” Klock said.
Even these precautions wouldn't cover every disease, and some would-be parents don't get the genetic screening. In a situation where one donor has a large number of offspring, it is concerning that he or she can spread a rare disease to multiple people, said Nick Isel, 37, of Yorkville, Illinois, who was conceived with donor sperm due to his parents’ fertility issues. They told him the truth when he was a teenager, and he found his biological father with a journalist’s help.
Since 2016, Isel, who owns a roofing company, has been petitioning the FDA to extend the retention of medical records, requiring the fertility establishment to maintain information on sperm and egg donors for 50 years instead of the current 10-year mandate.
“The lack of family health information,” he said, “is an ongoing, slow-motion public health crisis since donor conception began being regulated by the FDA as a practice.”