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.
Your Privacy vs. the Public's Health: High-Tech Tracking to Fight COVID-19 Evokes Orwell
The COVID-19 pandemic has placed public health and personal privacy on a collision course, as smartphone technology has completely rewritten the book on contact tracing.
It's not surprising that an autocratic regime like China would adopt such measures, but democracies such as Israel have taken a similar path.
The gold standard – patient interviews and detective work – had been in place for more than a century. It's been all but replaced by GPS data in smartphones, which allows contact tracing to occur not only virtually in real time, but with vastly more precision.
China has gone the furthest in using such tech to monitor and prevent the spread of the coronavirus. It developed an app called Health Code to determine which of its citizens are infected or at risk of becoming infected. It has assigned each individual a color code – red, yellow or green – and restricts their movement depending on their assignment. It has also leveraged its millions of public video cameras in conjunction with facial recognition tech to identify people in public who are not wearing masks.
It's not surprising that an autocratic regime like China would adopt such measures, but democracies such as Israel have taken a similar path. The national security agency Shin Bet this week began analyzing all personal cellphone data under emergency measures approved by the government. It texts individuals when it's determined they had been in contact with someone who had the coronavirus. In Spain and China, police have sent drones aloft searching for people violating stay-at-home orders. Commands to disperse can be issued through audio systems built into the aircraft. In the U.S., efforts are underway to lift federal restrictions on drones so that police can use them to prevent people from gathering.
The chief executive of a drone manufacturer in the U.S. aptly summed up the situation in an interview with the Financial Times: "It seems a little Orwellian, but this could save lives."
Epidemics and how they're surveilled often pose thorny dilemmas, according to Craig Klugman, a bioethicist and professor of health sciences at DePaul University in Chicago. "There's always a moral issue to contact tracing," he said, adding that the issue doesn't change by nation, only in the way it's resolved.
"Once certain privacy barriers have been breached, it can be difficult to roll them back again."
In China, there's little to no expectation for privacy, so their decision to take the most extreme measures makes sense to Klugman. "In China, the community comes first. In the U.S., individual rights come first," he said.
As the U.S. has scrambled to develop testing kits and manufacture ventilators to identify potential patients and treat them, individual rights have mostly not received any scrutiny. However, that could change in the coming weeks.
The American approach is also leaning toward using smartphone apps, but in a way that may preserve the privacy of users. Researchers at MIT have released a prototype known as Private Kit: Safe Paths. Patients diagnosed with the coronavirus can use the app to disclose their location trail for the prior 28 days to other users without releasing their specific identity. They also have the option of sharing the data with public health officials. But such an app would only be effective if there is a significant number of users.
Singapore is offering a similar app to its citizens known as TraceTogether, which uses both GPS and Bluetooth pings among users to trace potential encounters. It's being offered on a voluntary basis.
The Electronic Frontier Foundation, the leading nonprofit organization defending civil liberties in the digital world, said it is monitoring how these apps are developed and deployed. "Governments around the world are demanding new dragnet location surveillance powers to contain the COVID-19 outbreak," it said in a statement. "But before the public allows their governments to implement such systems, governments must explain to the public how these systems would be effective in stopping the spread of COVID-19. There's no questioning the need for far-reaching public health measures to meet this urgent challenge, but those measures must be scientifically rigorous, and based on the expertise of public health professionals."
Andrew Geronimo, director of the intellectual property venture clinic at the Case Western University School of Law, said that the U.S. government is currently in talks with Facebook, Google and other tech companies about using deidentified location data from smartphones to better monitor the progress of the outbreak. He was hesitant to endorse such a step.
"These companies may say that all of this data is anonymized," he said, "but studies have shown that it is difficult to fully anonymize data sets that contain so much information about us."
Beyond the technical issues, social attitudes may mount another challenge. Epic events such as 9/11 tend to loosen vigilance toward protecting privacy, according to Klugman and Geronimo. And as more people are sickened and hospitalized in the U.S. with COVID-19, Klugman believes more Americans will be willing to allow themselves to be tracked. "If that happens, there needs to be a time limitation," he said.
However, even if time limits are put in place, Geronimo believes it would lead to an even greater rollback of privacy during the next crisis.
"Once certain privacy barriers have been breached, it can be difficult to roll them back again," he warned. "And the prior incidents could always be used as a precedent – or as proof of concept."
Stem Cell Therapy for COVID-19 Is Gaining Steam in China, But Some Skeptical Scientists Urge Caution
Over the past two months, China's frantic search for an effective COVID-19 treatment has seen doctors trying everything from influenza drugs to traditional herbal remedies and even acupuncture, in a bid to help patients suffering from coronavirus-induced pneumonia.
"This treatment is particularly aimed at older patients who are seriously ill. These kinds of patients are in the danger zone."
Since mid February, one approach that has gained increasing traction is stem cell therapies, treatments that have often been viewed as a potential panacea by desperate patients suffering from degenerative incurable conditions ranging from Parkinson's to ALS. In many of these diseases, reality has yet to match the hype.
In COVID-19, there are hopes it might, though some experts are warning not to count on it. At Beijing's YouAn Hospital, doctors have been treating patients at various stages of the illness with intravenous infusions of so-called mesenchymal stem cells taken from umbilical cord tissue, as part of an ongoing clinical trial since January 21. The outcomes of the initial seven patients – published last month – appeared promising and the trial has since been expanded to 31 patients according to Dr. Kunlin Jin, a researcher at University of North Texas Health Science Center who is collaborating with the doctors in Beijing.
"Sixteen of these patients had mild symptoms, eight are severe, and seven are critically severe," Jin told leapsmag. "But all patients have shown improvements in lung function following the treatment, based on CT scans -- most of them in the first three days and seven have now been completely discharged from hospital. This treatment is particularly aimed at older patients who are seriously ill. These kinds of patients are in the danger zone; it's essential that they receive treatment, but right now we have nothing for most of them. No drugs or anything."
The apparent success of the very small Beijing trial has since led to a nationwide initiative to fast-track stem cell therapies for COVID-19. Across China, there are currently 36 clinical trials intending to use mesenchymal stem cells to treat COVID-19 patients that are either in the planning or recruiting phases. The Chinese Medical Association has now issued guidelines to standardize stem cell treatment for COVID-19, while Zhang Xinmin, an official in China's Ministry of Science and Technology, revealed in a press conference last week that a stem cell-based drug has been approved for clinical trials.
The thinking behind why stem cells could be a fast-acting and effective treatment is due to the nature of COVID-19. The thousands of fatalities worldwide are not from the virus directly, but from a dysfunctional immune response to the infection. Patients die because their respiratory systems become overwhelmed by a storm of inflammatory molecules called cytokines, causing lung damage and failure. However, studies in mice have long shown that stem cells have anti-inflammatory properties with the ability to switch off such cytokine storms, reducing such virus-induced lung injuries.
"There has been an enormous amount of hype about these cells, and there is scant scientific evidence that they have any therapeutic effect in any situation. "
"The therapy can inhibit the overactivation of the immune system and promote repair by improving the pulmonary microenvironment and improve lung function," explained Wei Hou, one of the doctors conducting the trial at YouAn Hospital.
However not everyone is convinced, citing the small number of patients treated to date, and potential risks from such therapy. "We just don't know enough to believe that stem cells might be helpful with COVID-19," said Paul Knoepfler, professor of cell biology at UC Davis. "The new stem cell studies are too small and lack controls, making it impossible to come to any solid conclusions. The chance of benefit is low based on the little we know so far and there are going to be risks that are hard to pin down. For instance, what if a stem cell infusion impairs some kind of needed immune response?"
Other scientists are even more skeptical. "I am concerned about all treatments that use mesenchymal stem cells," warned Jeanne Loring, the Director of the Center for Regenerative Medicine at Scripps Research in La Jolla, Calif. "There has been an enormous amount of hype about these cells, and there is scant scientific evidence that they have any therapeutic effect in any situation. Typically, these treatments are offered to people who have diseases without cures. I'm certain that there will be evidence-based treatments for COVID19, but I understand that they are not yet available, people are desperate, and they will try anything. I hope the sick are not taken advantage of because of their desperation."
Despite such concerns, the steadily rising death toll from COVID-19 means other nations are preparing to proceed with their own clinical trials of mesenchymal stem cells. Jin said he has been contacted by researchers and clinicians around the world seeking information on how to conduct their own trials, with the University of Cambridge's Stem Cell Institute in the U.K. reportedly looking to initiate a trial.
The scale of the global emergency has seen governments repeatedly calling on the corporate world to invest in the search for a cure, and the Australian company Mesoblast – a global leader in cell-based therapies for a range of diseases – are expecting to receive the green light to initiate clinical trials of their own stem cell based product against COVID-19.
"We're talking to at least three major governments," said Silviu Itescu, CEO and Managing Director of Mesoblast. "We are working with groups in Australia, the U.S. and the U.K., and I expect there'll be trials starting imminently in all those jurisdictions."
Itescu is bullish that the therapy has a good chance of proving effective, as it recently successfully completed Phase III trials for severe steroid-refractory acute graft versus host disease (GVHD) – a condition which leads to a very similar disease profile to COVID-19.
"The exact same cytokine profile is occurring in the lungs of COVID-19 infected patients as in GVHD which is destructive to the local lung environment," he said. "If our cells are able to target that in GVHD, they ought to be able to switch off the cytokine response in COVID lung disease as well."
"What we should be focusing on now is not the possible boost to the stem cell field, but rather doing rigorous science to test whether stem cells can help COVID-19 patients."
Jin is hopeful that if the imminent trials yield successful results, the U.S. FDA could fast-track mesenchymal stem cells as an approved emergency therapy for COVID-19. However, Knoepfler cautions that there is a need for far more concrete and widespread proof of the benefit before regulatory bodies start ushering through the green light.
"What we should be focusing on now is not the possible boost to the stem cell field, but rather doing rigorous science to test whether stem cells can help COVID-19 patients," he said. "During a pandemic, it's reasonable to do some testing of unproven interventions like stem cells in small studies, but results from them should be discussed in a sober, conservative manner until there is more evidence."