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.
How Smallpox Was Wiped Off the Planet By a Vaccine and Global Cooperation
For 3000 years, civilizations all over the world were brutalized by smallpox, an infectious and deadly virus characterized by fever and a rash of painful, oozing sores.
Doctors had to contend with wars, floods, and language barriers to make their campaign a success.
Smallpox was merciless, killing one third of people it infected and leaving many survivors permanently pockmarked and blind. Although smallpox was more common during the 18th and 19th centuries, it was still a leading cause of death even up until the early 1950s, killing an estimated 50 million people annually.
A Primitive Cure
Sometime during the 10th century, Chinese physicians figured out that exposing people to a tiny bit of smallpox would sometimes result in a milder infection and immunity to the disease afterward (if the person survived). Desperate for a cure, people would huff powders made of smallpox scabs or insert smallpox pus into their skin, all in the hopes of getting immunity without having to get too sick. However, this method – called inoculation – didn't always work. People could still catch the full-blown disease, spread it to others, or even catch another infectious disease like syphilis in the process.
A Breakthrough Treatment
For centuries, inoculation – however imperfect – was the only protection the world had against smallpox. But in the late 18th century, an English physician named Edward Jenner created a more effective method. Jenner discovered that inoculating a person with cowpox – a much milder relative of the smallpox virus – would make that person immune to smallpox as well, but this time without the possibility of actually catching or transmitting smallpox. His breakthrough became the world's first vaccine against a contagious disease. Other researchers, like Louis Pasteur, would use these same principles to make vaccines for global killers like anthrax and rabies. Vaccination was considered a miracle, conferring all of the rewards of having gotten sick (immunity) without the risk of death or blindness.
Scaling the Cure
As vaccination became more widespread, the number of global smallpox deaths began to drop, particularly in Europe and the United States. But even as late as 1967, smallpox was still killing anywhere from 10 to 15 million people in poorer parts of the globe. The World Health Assembly (a decision-making body of the World Health Organization) decided that year to launch the first coordinated effort to eradicate smallpox from the planet completely, aiming for 80 percent vaccine coverage in every country in which the disease was endemic – a total of 33 countries.
But officials knew that eradicating smallpox would be easier said than done. Doctors had to contend with wars, floods, and language barriers to make their campaign a success. The vaccination initiative in Bangladesh proved the most challenging, due to its population density and the prevalence of the disease, writes journalist Laurie Garrett in her book, The Coming Plague.
In one instance, French physician Daniel Tarantola on assignment in Bangladesh confronted a murderous gang that was thought to be spreading smallpox throughout the countryside during their crime sprees. Without police protection, Tarantola confronted the gang and "faced down guns" in order to immunize them, protecting the villagers from repeated outbreaks.
Because not enough vaccines existed to vaccinate everyone in a given country, doctors utilized a strategy called "ring vaccination," which meant locating individual outbreaks and vaccinating all known and possible contacts to stop an outbreak at its source. Fewer than 50 percent of the population in Nigeria received a vaccine, for example, but thanks to ring vaccination, it was eradicated in that country nonetheless. Doctors worked tirelessly for the next eleven years to immunize as many people as possible.
The World Health Organization declared smallpox officially eradicated on May 8, 1980.
A Resounding Success
In November 1975, officials discovered a case of variola major — the more virulent strain of the smallpox virus — in a three-year-old Bangladeshi girl named Rahima Banu. Banu was forcibly quarantined in her family's home with armed guards until the risk of transmission had passed, while officials went door-to-door vaccinating everyone within a five-mile radius. Two years later, the last case of variola major in human history was reported in Somalia. When no new community-acquired cases appeared after that, the World Health Organization declared smallpox officially eradicated on May 8, 1980.
Because of smallpox, we now know it's possible to completely eliminate a disease. But is it likely to happen again with other diseases, like COVID-19? Some scientists aren't so sure. As dangerous as smallpox was, it had a few characteristics that made eradication possibly easier than for other diseases. Smallpox, for instance, has no animal reservoir, meaning that it could not circulate in animals and resurge in a human population at a later date. Additionally, a person who had smallpox once was guaranteed immunity from the disease thereafter — which is not the case for COVID-19.
In The Coming Plague, Japanese physician Isao Arita, who led the WHO's Smallpox Eradication Unit, admitted to routinely defying orders from the WHO, mobilizing to parts of the world without official approval and sometimes even vaccinating people against their will. "If we hadn't broken every single WHO rule many times over, we would have never defeated smallpox," Arita said. "Never."
Still, thanks to the life-saving technology of vaccines – and the tireless efforts of doctors and scientists across the globe – a once-lethal disease is now a thing of the past.
Over 1 Million Seeds Are Buried Near the North Pole to Back Up the World’s Crops
The impressive structure protrudes from the side of a snowy mountain on the Svalbard Archipelago, a cluster of islands about halfway between Norway and the North Pole.
"Before, we trusted the permafrost. We do not trust the permafrost anymore."
Art installations on the building's rooftop and front façade glimmer like diamonds in the polar night, but it is what lies buried deep inside the frozen rock, 475 feet from the building's entrance, that is most precious. Here, in the Svalbard Global Seed Vault, are backup copies of more than a million of the world's agricultural seeds.
Inside the vault, seed boxes from many gene banks and many countries. "The seeds don't know national boundaries," says Kent Nnadozie, the UN's Secretary of the International Treaty on Plant Genetic Resources for Food and Agriculture.
(Photo credit: Svalbard Global Seed Vault/Riccardo Gangale)
The Svalbard vault -- which has been called the Doomsday Vault, or a Noah's Ark for seeds -- preserves the genetic materials of more than 6000 crop species and their wild relatives, including many of the varieties within those species. Svalbard's collection represents all the traits that will enable the plants that feed the world to adapt – with the help of farmers and plant breeders – to rapidly changing climactic conditions, including rising temperatures, more intense drought, and increasing soil salinity. "We save these seeds because we want to ensure food security for future generations," says Grethe Helene Evjen, Senior Advisor at the Norwegian Ministry of Agriculture and Food .
A recent study in the journal Nature predicted that global warming could cause catastrophic losses of biodiversity in regions across the globe throughout this century. Yet global warming also threatens the permafrost that surrounds the seed vault, the very thing that was once considered a failsafe means of keeping these seeds frozen and safeguarding the diversity of our crops. In fact, record temperatures in Svalbard a few years ago – and a significant breach of water into the access tunnel to the vault -- prompted the Norwegian government to invest $20 million euros on improvements at the facility to further secure the genetic resources locked inside. The hope: that technology can work in concert with nature's freezer to keep the world's seeds viable.
"Before, we trusted the permafrost," says Hege Njaa Aschim, a spokesperson for Statsbygg, the government agency that recently completed the upgrades at the seed vault. "We do not trust the permafrost anymore."
The Apex of the Global Conservation System
More than 1700 genebanks around the globe preserve the diverse seed varieties from their regions. They range from small community seed banks in developing countries, where small farmers save and trade their seeds with growers in nearby villages, to specialized university collections, to national and international genetic resource repositories. But many of these facilities are vulnerable to war, natural disasters, or even lack of funding.
"If anything should happen to the resources in a regular genebank, Svalbard is the backup – it's essentially the apex of the global conservation system," says Kent Nnadozie, Secretary of the International Treaty on Plant Genetic Resources for Food and Agriculture at the United Nations, who likens the Global Vault to the Central Reserve Bank. "You have regular banks that do active trading, but the Central Bank is the final reserve where the banks store their gold deposits."
Similarly, farmers deposit their seeds in regional genebanks, and also look to these banks for new varieties to help their crops adapt to, say, increasing temperatures, or resist intrusive pests. Regional banks, in turn, store duplicates from their collections at Svalbard. These seeds remain the sovereign property of the country or institution depositing them; only they can "make a withdrawal."
The Global Vault has already proven invaluable: The International Centre for Agricultural Research in the Dry Areas (ICARDA), formerly located outside of Aleppo, Syria, held more than 140,000 seed samples, including plants that were extinct in their natural habitats, before the Syrian Crisis in 2012. Fortunately, they had managed to back up most of their seed samples at Svalbard before they were forced to relocate to Lebanon and Morocco. In 2017, ICARDA became the first – and only – organization to withdraw their stored seeds. They have now regenerated almost all of the samples at their new locations and recently redeposited new seeds for safekeeping at Svalbard.
Rapid Global Warming Threatens Permafrost
The Global Vault, a joint venture between the Norwegian government, the Crop Trust and the Nordic Genetic Resource Centre (NordGen) that started operating in 2008, was sited in Svalbard in part because of its remote yet accessible location: Svalbard is the northernmost inhabited spot on Earth with an airport. But experts also thought it a failsafe choice for long-term seed storage because its permafrost would offer natural freezing – even if cooling systems were to fail. No one imagined that the permafrost could fail.
"We've had record temperatures in the region recently, and there are a lot of signs that global warming is happening faster at the extreme latitudes," says Geoff Hawtin, a world-renowned authority in plant conservation, who is the founding director of -- and now advisor to -- the Crop Trust. "Svalbard is still arguably one of the safest places for the seeds from a temperature point of view, but it's actually not going to be as cold as we thought 20 years ago."
A recent report by the Norwegian Centre for Climate Services predicted that Svalbard could become 50 degrees Fahrenheit warmer by the year 2100. And data from the Norwegian government's environmental monitoring system in Svalbard shows that the permafrost is already thawing: The "active layer," that is, the layer of surface soil that seasonally thaws, has become 25-30 cm thicker since 1998.
Among the 35 depositors were several bringing their seeds to Svalbard for the first time, including the Cherokee Nation, which deposited nine heirloom seed varieties that predate European colonization.
Though the permafrost surrounding the seed vault chambers, which are situated well below the active layer, is still intact, the permafrost around the access tunnel never re-established as expected after construction of the Global Vault twelve years ago. As a result, when Svalbard saw record high temperatures and unprecedented rainfall in 2016, about 164 feet of rainwater and snowmelt leaked into the tunnel, turning it into a skating rink and spurring authorities to take what they called a "better safe than sorry approach." They invested in major upgrades to the facility. "The seeds in the vault were never threatened," says Aschim, "but technology has become more important at Svalbard."
Technology Gives Nature a Boost
For now, the permafrost deep inside the mountain still keeps the temperature in the vault down to about -25°F. The cooling systems then give nature a mechanical boost to keep the seed vault chilled even further, to about -64°F, the optimal temperature for conserving seeds. In addition to upgrading to a more effective and sustainable cooling system that runs on CO2, the Norwegian government added backup generators, removed heat-generating electrical equipment from inside the facility to an outside building, installed a thick, watertight door to the vault, and replaced the corrugated steel access tunnel with a cement tunnel that uses the same waterproofing technology as the North Sea oil platforms.
To re-establish the permafrost around the tunnel, they layered cooling pipes with frozen soil around the concrete tunnel, covered the frozen soil with a cooling mat, and topped the cooling mat with the original permafrost soil. They also added drainage ditches on the mountainside to divert meltwater away from the tunnel as the climate gets warmer and wetter.
New Deposits to the Global Vault
The day before COVID-19 arrived in Norway, on February 25th, Prime Minister Erna Solberg hosted the biggest seed-depositing event in the vault's history in honor of the new and improved vault. As snow fell on Svalbard, depositors from almost every continent traveled the windy road from Longyearbyen up Platåfjellet Mountain and braved frigid -8°F weather to celebrate the massive technical upgrades to the facility – and to hand over their seeds.
Among the 35 depositors were several bringing their seeds to Svalbard for the first time, including the Cherokee Nation, which deposited nine heirloom seed varieties that predate European colonization, and Israel's University of Haifa, whose deposit included multiple genotypes of wild emmer wheat, an ancient relative of the modern domesticated crop. The storage boxes carried ceremoniously over the threshold that day contained more than 65,000 new seed samples, bringing the total to more than a million, and almost filling the first of three seed chambers in the vault. (The Global Vault can store up to 4.5 million seed samples.)
"Svalbard's samples contain all the possibilities, all the options for the future of our agricultural crops – it's how crops are going to adapt," says Cary Fowler, former executive director of the Crop Trust, who was instrumental in establishing the Global Vault. "If our crops don't adapt to climate change, then neither will we." Dr. Fowler says he is confident that with the recent improvements in the vault, the seeds are going to remain viable for a very long time.
"It's sometimes tempting to get distracted by the romanticism of a seed vault inside a mountain near the North Pole – it's a little bit James Bondish," muses Dr. Fowler. "But the reality is we've essentially put an end to the extinction of more than a million samples of biodiversity forever."