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.
Deaf Scientists Just Created Over 1000 New Signs to Dramatically Improve Ability to Communicate
For the deaf, talent and hard work may not be enough to succeed in the sciences. According to the National Science Foundation, deaf Americans are vastly underrepresented in the STEM fields, a discrepancy that has profound economic implications.
The problem with STEM careers for the deaf and hard-of-hearing is that there are not enough ASL signs available.
Deaf and hard-of-hearing professionals in the sciences earn 31 percent more than those employed in other careers, according to a 2010 study by the National Technical Institute for the Deaf (NTID) in Rochester, N.Y., the largest technical college for deaf and hard-of-hearing students. But at the same time, in 2017, U.S. students with hearing disabilities earned only 1.1 percent of the 39,435 doctoral degrees awarded in science and engineering.
One reason so few deaf students gravitate to science careers and may struggle to complete doctoral programs is the communication chasm between deaf and hard-of-hearing scientists and their hearing colleagues.
Lorne Farovitch is a doctoral candidate in biomedical science at the University of Rochester of New York. Born deaf and raised by two deaf parents, he communicated solely in American Sign Language (ASL) until reaching graduate school. There, he became frustrated at the large chunk of his workdays spent communicating with hearing lab mates and professors, time he would have preferred spending on his scientific work.
The problem with STEM careers for the deaf and hard-of-hearing is that there are not enough ASL signs available, says Farovitch. Names, words, or phrases that don't exist in ASL must be finger spelled — the signer must form a distinct hand shape to correspond with each letter of the English alphabet, a tedious and time-consuming process. For instance, it requires 12 hand motions to spell out the word M-I-T-O-C-H-O-N-D-R-I-A. Imagine repeating those motions countless times a day.
To bust through this linguistic quagmire, Farovitch, along with a team of deaf STEM professionals, linguists, and interpreters, have been cooking up signs for terms like Anaplasma phagocytophilum, the tick-borne bacterium Farovitch studies. The sign creators are then videotaped performing the new signs. Those videos are posted on two crowd-sourcing sites, ASLcore.org and ASL Clear.
The beauty of ASL is you can express an entire concept in a single sign, rather than by the name of a word.
"If others don't pick it up and use it, a sign goes extinct," says Farovitch. Thus far, more than 1,000 STEM terms have been developed on ASL Clear and 500 vetted and approved by the deaf STEM community, according to Jeanne Reis, project director of the ASL Clear Project, based at The Learning Center for the Deaf in Framingham, Mass.
The beauty of ASL is you can express an entire concept in a single sign, rather than by the name of a word. The signs are generally intuitive and wonderfully creative. To express "DNA" Farovitch uses two fingers of each hand touching the tips of the opposite hand; then he draws both the hands away to suggest the double helix form of the hereditary material present in most organisms.
"If you can show it, you can understand the concept better,'' says the Canadian-born scientist. "I feel I can explain science better now."
The hope is that as ASL science vocabulary expands more, deaf and hard-of-hearing students will be encouraged to pursue the STEM fields. "ASL is not just a tool; it's a language. It's a vital part of our lives," Farovitch explains through his interpreter.
The deaf community is diverse—within and beyond the sciences. Sarah Latchney, PhD, an environmental toxicologist, is among the approximately 90 percent of deaf people born to hearing parents. Hers made sure she learned ASL at an early age but they also sent Latchney to a speech therapist to learn to speak and read lips. Latchney is so adept at both that she can communicate one-on-one with a hearing person without an interpreter.
Like Favoritch, Latchney has developed "conceptually accurate" ASL signs but she has no plans to post them on the crowd-sourcing sites. "I don't want to fix [my signs]; it works for me," she explains.
Young scientists like Farovitch and Latchney stress the need for interpreters who are knowledgeable about science. "When I give a presentation I'm a nervous wreck that I'll have an interpreter who may not have a science background," Latchney explains. "Many times what I've [signed] has been misinterpreted; either my interpreter didn't understand the question or didn't frame it correctly."
To enlarge the pool of science-savvy interpreters, the University of Rochester will offer a new masters degree program: ASL Interpreting in Medicine and Science (AIMS), which will train interpreters who have a strong background in the biological sciences.
Since the Americans with Disabilities Act was enacted in 1990, opportunities in higher education for deaf and hard-of-hearing students have opened up in the form of federally funded financial aid and the creation of student disability services on many college campuses. Still, only 18 percent of deaf adults have graduated from college, compared to 33 percent of the general population, according to a survey by the U.S. Census Bureau in 2015.
The University of Rochester and the Rochester Institute of Technology, home to NTID, have jointly created two programs to increase the representation of deaf and hard-of-hearing professionals in the sciences. The Rochester Bridges to the Doctorate Program, which Farovitch is enrolled in, prepares deaf scholars for biomedical PhD programs. The Rochester Postdoctoral Partnership readies deaf postdoctoral scientists to successfully attain academic research and teaching careers. Both programs are funded by the National Institutes of Science. In the last five years, the University of Rochester has gone from zero deaf postdoctoral and graduate students to nine.
"Deafness is not a problem, it's just a difference."
It makes sense for these two private universities to support strong programs for the deaf: Rochester has the highest per capita population of deaf or hard-of-hearing adults younger than 65 in the nation, according to the U.S. Census. According to the U.S. Department of Education, there are about 136,000 post-secondary level students who are deaf or hard of hearing.
"Deafness is not a problem, it's just a difference," says Farovitch. "We just need a different way to communicate. It doesn't mean we require more work."
Pregnant and Breastfeeding Women Might Have a New Reason to Ditch Artificial Sweeteners
Women considering pregnancy might have another reason to drop artificial sweeteners from their diet, if a new study of mice proves to apply to humans as well. It highlights "yet another potential health impact of zero-calorie sweeteners," according to lead author Stephanie Olivier-Van Stichelen.
The discovery was serendipitous, not part of the original study.
It found that commonly used artificial sweeteners consumed by female mice transfer to pups in the womb and later through milk, harming their development. The sweeteners affected the composition of bacteria in the gut of the pups, making them more vulnerable to developing diabetes, and greatly reduced the liver's capacity to neutralize toxins.
The discovery was serendipitous, not part of the original study, says John Hanover, the senior author and a cell biologist at the NIH National Institute of Diabetes and Digestive and Kidney Diseases. The main study looked at how a high sugar diet in the mother turns genes on and off in the developing offspring.
It compared them with mothers fed a low sugar diet, replacing sugar with a mix of sucralose and acesulfame-K (AK), two non-nutrient artificial sugars that are already used extensively in our food products and thought to be safe.
While the artificial sweeteners had little effect on the mothers, the trace amounts that were transferred through the placenta and milk had a profound effect on the pups. Hanover believes the molecules are changing gene expression during a crucial, short period of development.
"Somewhat to our surprise, we saw in the pups a really dramatic change in the microbiome" of those whose mothers were fed the artificial sweeteners, Hanover told leapsmag. "It looked like the neonates were much, much more sensitive than their mothers to the sucralose and AK." The unexpected discovery led them to publish a separate paper.
"The protective microbe Akkermansia was largely missing, and we saw a pretty dramatic shift in the ratio of two bacteria that are normally associated with metabolic disease," a precursor to diabetes, he explains. Akkermansia is a bacteria that feeds on mucus in the gut and helps remodel the tissue to an adult state over the first several months of life in a mouse. A similar process takes several years in humans, as the infant is weaned off of breast milk as the primary food source.
The good news is the body seems to remove these artificial sweeteners fairly quickly, probably within a week.
Another problem the researchers saw in the animals was "a particularly striking change in the metabolism of the detoxification systems" in the liver, says Hanover. A healthy liver is dark red, but a high dose of the artificial sweeteners turned it white, "which is a sign of massive problems."
The study was conducted in mice and Hanover cautions the findings may not apply to humans. "But in general, the microbiome changes that one sees in the rodent model mimics what we see in humans...[and] the genes that are turned on in the mouse and the human are very similar."
Hanover acknowledges the quantity of artificial sweeteners used in the study is on the high end of human consumption, roughly the equivalent of 20 cans of diet soda a day. But the sweeteners are so ubiquitous in consumer products, from foods to lipstick, and often not even mentioned on the label, that it is difficult to measure just how much a person consumes every day.
The good news is the body seems to remove these artificial sweeteners fairly quickly, probably within a week. Until further studies provide a clearer picture, women who want to err on the side of caution can choose to reduce if not eliminate their exposure to artificial sweeteners during pregnancy and breastfeeding.