Will religious people reject organ transplants from pigs?
The first successful recipient of a human heart transplant lived 18 days. The first artificial heart recipient lived just over 100.
Their brief post-transplant lives paved the way toward vastly greater successes. Former Vice President Dick Cheney relied on an artificial heart for nearly two years before receiving a human heart transplant. It still beats in his chest more than a decade later.
Organ transplantation recently reached its next phase with David Bennett. He survived for two months after becoming the first recipient of a pig’s heart genetically modified to function in a human body in February. Known as a xenotransplant, the procedure could pave the way for greatly expanding the use of transplanted vital organs to extend human lives.
Clinical trials would have to be held in the U.S. before xenotransplants become widespread; Bennett’s surgery was authorized under a special Food and Drug Administration program that addresses patients with life-threatening medical conditions.
German researchers plan to perform eight pig-to-human heart transplants as part of a clinical trial beginning in 2024. According to an email sent to Leaps.org by three scholars working on the German project, these procedures will focus on one of the reasons David Bennett did not survive longer: A porcine infection from his new heart.
The transplant team will conduct more sensitive testing of the donor organs, “which in all likelihood will be able to detect even low levels of virus in the xenograft,” note the scientists, Katharina Ebner, Jochen Ostheimer and Jochen Sautermeister. They are confident that the risk of infection with a porcine virus in the future will be significantly lower.
Moreover, hearts are not the only genetically modified organs that are being xenotransplanted. A team of surgeons at the University of Alabama at Birmingham successfully transplanted genetically modified pig kidneys into a brain-dead human recipient in September. The kidneys functioned normally for more than three days before the experiment ended. The UAB team is now moving forward with clinical trials focusing on transplanting pig kidneys into human patients.
Some experts believe the momentum for xenotransplantation is building, particularly given the recent successes. “I think there is a strong likelihood this will go mainstream,” says Brendan Parent of NYU Langone Health.
Douglas Anderson, a surgeon who is part of that kidney xenotransplant team, observes that, “organ shortages have been the major issue facing transplantation since its inception” and that xenotransplantation is a potential solution to that quandary. “It can’t be understated the number of people waiting for a kidney on dialysis, which has a significant mortality rate,” he says. According to the advocacy group Donate Life America, more than 100,000 people in the U.S. alone are waiting for a donated organ, and 85 percent of them need a kidney.
Other experts believe the momentum for xenotransplantation is building, particularly given the recent successes. “I think there is a strong likelihood this will go mainstream,” says Brendan Parent, director of transplant ethics and policy at NYU Langone Health, a New York City-based hospital system. Like the UAB team, surgeons at NYU Langone have had success coaxing modified pig kidneys to work in deceased humans.
“There is a genuinely good chance that within a generation, (xenotransplantation) might become very common in reasonably wealthy countries,” says Michael Reiss, professor of science education at University College in London. In addition to his academic position, Reiss sits on the Nuffield Council on Bioethics, a nonprofit that is one of Britain’s most prominent watchdogs regarding medical and scientific issues. Reiss is also an Anglican priest and has studied xenotransplantation from both a scientific and religious point of view.
Moreover, genetic modifications could one day lead to organs being specifically optimized for their recipients. That could ensure issues like donor rejection and the calculated risk of artificially suppressing recipient immune systems become concerns of the past.
Major bioethical, religious concerns
Despite the promise of xenotransplantation, numerous bioethical issues swirl around the procedure. They could be magnified if xenotransplantation evolves from one-off experiments to a routine medical procedure.
One of the biggest is the millennia-long prohibitions Islam and Judaism have had regarding the consumption of pork. Will followers of these religions assume such rules extend to those taboo materials being inserted into a human body?
“Initially, one’s instinctual reaction is that, oh, crumbs! – how are Jews and Muslims going to react to that?” Reiss says. But in a world where science and secularism are accepted on an everyday basis, he notes it is not a significant issue. Reiss points out that valves from pig hearts have been used in human patients for decades without any issues. He adds that both Islam and Judaism waive religious dietary restrictions if a human life is at risk.
“While nobody's saying an individual patient is to be forced to have these, the very high proportion of people who identify as Jews or Muslims when given this option are content with it,” he says.
Concurring with Reiss is Michael Gusamano, professor of health policy at Lehigh University and director of its Center for Ethics. He is currently performing research on the ethics of xenotransplantation for the National Institutes of Health.
“Leaders from all major religions have commented on this and have indicated that this is not inconsistent with religious doctrine,” Gusamano says in written remarks to Leaps.org. “Having said that, it is plausible to believe that some people will assume that this is inconsistent with the teaching of their religion and may object to…receiving a xenotransplant as part of routine medical care.”
A history of clashes
Despite those assurances, science has long clashed with theology. Although Galileo proved the planets revolved around the sun, the Catholic Church found him guilty of heresy and rewarded his discovery with house arrest for the last decade of his life. A revolt occurred in mid-19th century India after native-born soldiers believed the ammunition supplied by their British occupiers had been lubricated with pork and beef tallow. Given they had to use their mouths to tear open ammunition pouches, this violated both the tenets of Islam and Hinduism. And one of the conspiracy theories hatched as a result of COVID-19 was that the vaccines developed to fight the disease were the “mark of the beast” – a sign of impending Armageddon under evangelical Christian theology.
The German xenotransplant research team has encountered such potential concerns when the procedure is regarded through a religious lens. “The pastors in our research suspected that many recipients might feel disgust and revulsion,” they write. “Even beyond these special religious reservations, cultural scripts about pigs as inferior living beings are also generally widespread and effective in the western world, so that here too possible disgust reactions cannot be ruled out.”
The German researchers add that “Jewish and Muslim hospital pastoral workers believe possible considerable problems in this respect, which must be dealt with psychosocially, religiously, and pastorally prior to a possible transplantation in order to strengthen the acceptance of the received organ by the patients and their relatives.”
Parent, the director at NYU Langone, shares a concern that xenotransplantation could move “too fast,” although much of his worry is focused on zoonotic disease transmission – pig viruses jumping into humans as a result of such procedures.
Another ethical issue
Moreover, the way pigs and other animals are raised for transplants could pose future ethical dilemmas.
Reiss notes that pigs raised for medical procedures have to be grown and kept in what are known as a designated pathogen-free facility, or DPF. Such facilities are kept painstakingly antiseptic so as to minimize the risk of zoonotic transmissions. But given pigs are fond of outdoor activities such as wallowing in mud and sleeping on hay, they lead “stunningly boring lives” that they probably do not enjoy, Reiss observes.
Ethical concerns with using pigs may push transplantation medicine into its next logical phase: Growing functional organs for transplant in a laboratory setting.
“There’s no doubt that these research pigs have gotten much better veterinary care, et cetera, (compared to farmed pigs). But it’s not a great life,” Reiss says. “And although it hasn’t so far dominated the discussion, I think as the years go by, rather as we’ve seen with the use of apes and now monkeys in medical research, more and more theologians will get uncomfortable about us just assuming we can do this with…pigs.”
The German research team raises the same concerns, but has taken a fairly sanguine view on the topic. “The impairments of the species-typical behavior will certainly provoke criticism and perhaps also public protest. But the number of animals affected is very small in relation to slaughter cattle,” the German researchers note. “Moreover, the conditions there and also in several animal experiments are far worse.”
Observers say that may push transplantation medicine into its next logical phase: Growing functional organs for transplant in a laboratory setting. Anderson, the UAB transplant surgeon, believes such an accomplishment remains decades away.
But other experts believe there is a moral imperative that xenotransplantation remain a temporary solution. “I think we have a duty to go in that direction,” Parent says. “We have to go that way, with the xenotransplantation process (as) a steppingstone and research path that will be useful for bioengineered organs.”
Stronger psychedelics that rewire the brain, with Doug Drysdale
A promising development in science in recent years has been the use technology to optimize something natural. One-upping nature's wisdom isn't easy. In many cases, we haven't - and maybe we can't - figure it out. But today's episode features a fascinating example: using tech to optimize psychedelic mushrooms.
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These mushrooms have been used for religious, spiritual and medicinal purposes for thousands of years, but only in the past several decades have scientists brought psychedelics into the lab to enhance them and maximize their therapeutic value.
Today’s podcast guest, Doug Drysdale, is doing important work to lead this effort. Drysdale is the CEO of a company called Cybin that has figured out how to make psilocybin more potent, so it can be administered in smaller doses without side effects.
The natural form of psilocybin has been studied increasingly in the realm of mental health. Taking doses of these mushrooms appears to help people with anxiety and depression by spurring the development of connections in the brain, an example of neuroplasticity. The process basically shifts the adult brain from being fairly rigid like dried clay into a malleable substance like warm wax - the state of change that's constantly underway in the developing brains of children.
Neuroplasticity in adults seems to unlock some of our default ways of of thinking, the habitual thought patterns that’ve been associated with various mental health problems. Some promising research suggests that psilocybin causes a reset of sorts. It makes way for new, healthier thought patterns.
So what is Drysdale’s secret weapon to bring even more therapeutic value to psilocybin? It’s a process called deuteration. It focuses on the hydrogen atoms in psilocybin. These atoms are very light and don’t stick very well to carbon, which is another atom in psilocybin. As a result, our bodies can easily breaks down the bonds between the hydrogen and carbon atoms. For many people, that means psilocybin gets cleared from the body too quickly, before it can have a therapeutic benefit.
In deuteration, scientists do something simple but ingenious: they replace the hydrogen atoms with a molecule called deuterium. It’s twice as heavy as hydrogen and forms tighter bonds with the carbon. Because these pairs are so rock-steady, they slow down the rate at which psilocybin is metabolized, so it has more sustained effects on our brains.
Cybin isn’t Drysdale’s first go around at this - far from it. He has over 30 years of experience in the healthcare sector. During this time he’s raised around $4 billion of both public and private capital, and has been named Ernst and Young Entrepreneur of the Year. Before Cybin, he was the founding CEO of a pharmaceutical company called Alvogen, leading it from inception to around $500 million in revenues, across 35 countries. Drysdale has also been the head of mergers and acquisitions at Actavis Group, leading 15 corporate acquisitions across three continents.
In this episode, Drysdale walks us through the promising research of his current company, Cybin, and the different therapies he’s developing for anxiety and depression based not just on psilocybin but another psychedelic compound found in plants called DMT. He explains how they seem to have such powerful effects on the brain, as well as the potential for psychedelics to eventually support other use cases, including helping us strive toward higher levels of well-being. He goes on to discuss his views on mindfulness and lifestyle factors - such as optimal nutrition - that could help bring out hte best in psychedelics.
Show links:
Doug Drysdale full bio
Doug Drysdale twitter
Cybin website
Cybin development pipeline
Cybin's promising phase 2 research on depression
Johns Hopkins psychedelics research and psilocybin research
Mets owner Steve Cohen invests in psychedelic therapies
Doug Drysdale, CEO of Cybin
How the body's immune resilience affects our health and lifespan
Story by Big Think
It is a mystery why humans manifest vast differences in lifespan, health, and susceptibility to infectious diseases. However, a team of international scientists has revealed that the capacity to resist or recover from infections and inflammation (a trait they call “immune resilience”) is one of the major contributors to these differences.
Immune resilience involves controlling inflammation and preserving or rapidly restoring immune activity at any age, explained Weijing He, a study co-author. He and his colleagues discovered that people with the highest level of immune resilience were more likely to live longer, resist infection and recurrence of skin cancer, and survive COVID and sepsis.
Measuring immune resilience
The researchers measured immune resilience in two ways. The first is based on the relative quantities of two types of immune cells, CD4+ T cells and CD8+ T cells. CD4+ T cells coordinate the immune system’s response to pathogens and are often used to measure immune health (with higher levels typically suggesting a stronger immune system). However, in 2021, the researchers found that a low level of CD8+ T cells (which are responsible for killing damaged or infected cells) is also an important indicator of immune health. In fact, patients with high levels of CD4+ T cells and low levels of CD8+ T cells during SARS-CoV-2 and HIV infection were the least likely to develop severe COVID and AIDS.
Individuals with optimal levels of immune resilience were more likely to live longer.
In the same 2021 study, the researchers identified a second measure of immune resilience that involves two gene expression signatures correlated with an infected person’s risk of death. One of the signatures was linked to a higher risk of death; it includes genes related to inflammation — an essential process for jumpstarting the immune system but one that can cause considerable damage if left unbridled. The other signature was linked to a greater chance of survival; it includes genes related to keeping inflammation in check. These genes help the immune system mount a balanced immune response during infection and taper down the response after the threat is gone. The researchers found that participants who expressed the optimal combination of genes lived longer.
Immune resilience and longevity
The researchers assessed levels of immune resilience in nearly 50,000 participants of different ages and with various types of challenges to their immune systems, including acute infections, chronic diseases, and cancers. Their evaluation demonstrated that individuals with optimal levels of immune resilience were more likely to live longer, resist HIV and influenza infections, resist recurrence of skin cancer after kidney transplant, survive COVID infection, and survive sepsis.
However, a person’s immune resilience fluctuates all the time. Study participants who had optimal immune resilience before common symptomatic viral infections like a cold or the flu experienced a shift in their gene expression to poor immune resilience within 48 hours of symptom onset. As these people recovered from their infection, many gradually returned to the more favorable gene expression levels they had before. However, nearly 30% who once had optimal immune resilience did not fully regain that survival-associated profile by the end of the cold and flu season, even though they had recovered from their illness.
Intriguingly, some people who are 90+ years old still have optimal immune resilience, suggesting that these individuals’ immune systems have an exceptional capacity to control inflammation and rapidly restore proper immune balance.
This could suggest that the recovery phase varies among people and diseases. For example, young female sex workers who had many clients and did not use condoms — and thus were repeatedly exposed to sexually transmitted pathogens — had very low immune resilience. However, most of the sex workers who began reducing their exposure to sexually transmitted pathogens by using condoms and decreasing their number of sex partners experienced an improvement in immune resilience over the next 10 years.
Immune resilience and aging
The researchers found that the proportion of people with optimal immune resilience tended to be highest among the young and lowest among the elderly. The researchers suggest that, as people age, they are exposed to increasingly more health conditions (acute infections, chronic diseases, cancers, etc.) which challenge their immune systems to undergo a “respond-and-recover” cycle. During the response phase, CD8+ T cells and inflammatory gene expression increase, and during the recovery phase, they go back down.
However, over a lifetime of repeated challenges, the immune system is slower to recover, altering a person’s immune resilience. Intriguingly, some people who are 90+ years old still have optimal immune resilience, suggesting that these individuals’ immune systems have an exceptional capacity to control inflammation and rapidly restore proper immune balance despite the many respond-and-recover cycles that their immune systems have faced.
Public health ramifications could be significant. Immune cell and gene expression profile assessments are relatively simple to conduct, and being able to determine a person’s immune resilience can help identify whether someone is at greater risk for developing diseases, how they will respond to treatment, and whether, as well as to what extent, they will recover.