People With This Rare Disease Can Barely Eat Protein. Biotechnology May Change That.
Imagine that the protein in bread, eggs, steak, even beans is not the foundation for a healthy diet, but a poison to your brain. That is the reality for people living with Phenylketonuria, or PKU. This cluster of rare genetic variations affects the ability to digest phenylalanine (Phe), one of the chemical building blocks of protein. The toxins can build up in the brain causing severe mental retardation.
Can a probiotic help digest the troublesome proteins before they can enter the bloodstream and travel to the brain? A Boston area biotech start up, Synlogic, believes it can. Their starting point is an E. coli bacterium that has been used as a probiotic for more than a century. The company then screened thousands of gene variants to identify ones that produced enzymes most efficient at slicing and dicing the target proteins and optimized them further through directed evolution. The results have been encouraging.
But Christine Brown knew none of this when the hospital called saying that standard newborn screening of her son Connor had come back positive for PKU. It was urgent that they visit a special metabolic clinic the next day, which was about a three-hour drive away.
“I was told not to go on the Internet,” Christine recalls, “So when somebody tells you not to go on the Internet, what do you do? Even back in 2005, right.” What she saw were the worst examples of retardation, which was a common outcome from PKU before newborn screening became routine. “We were just in complete shell shock, our whole world just kind of shattered and went into a tail spin.”
“I remember feeding him the night before our clinic visit and almost feeling like I was feeding him poison because I knew that breast milk must have protein in it,” she says.
“Some of my first memories are of asking, ‘Mommy, can I eat this? There were yes foods and no foods.'"
Over the next few days the dedicated staff of the metabolic clinic at the Waisman Center at the University of Wisconsin Madison began to walk she and husband Kevin back from that nightmare. They learned that a simple blood test to screen newborns had been developed in the early 1960s to detect PKU and that the condition could be managed with stringent food restrictions and vigilant monitoring of Phe levels.
Everything in Your Mouth Counts
PKU can be successfully managed with a severely restricted diet. That simple statement is factually true, but practically impossible to follow, as it requires slashing protein consumption by about 90 percent. To compensate for the missing protein, several times a day PKU patients take a medical formula – commonly referred to simply as formula – containing forms of proteins that are digestible to their bodies. Several manufacturers now add vitamins and minerals and offer a variety of formats and tastes to make it more consumer friendly, but that wasn't always the case.
“When I was a kid, it tasted horrible, was the consistency of house paint. I didn't think about it, I just drank it. I didn't like it but you get used to it after a while,” recalls Jeff Wolf, the twang of Appalachia still strong in his voice. Now age 50, he grew up in Ashland, Kentucky and was part of the first wave of persons with PKU who were identified at birth as newborn screening was rolled out across the US. He says the options of taste and consistency have improved tremendously over the years.
Some people with PKU are restricted to as little as 8 grams of protein a day from food. That's a handful of almonds or a single hard-boiled egg; a skimpy 4-ounce hamburger and slice of cheese adds up to half of their weekly protein ration. Anything above that daily allowance is more than the body can handle and toxic levels of Phe begin to accumulate in the brain.
“Some of my first memories are of asking, ‘Mommy, can I eat this? There were yes foods and no foods,’” recalls Les Clark. He has never eaten a hamburger, steak, or ribs, practically a sacrilege for someone raised in Stanton, a small town in northeastern Nebraska, a state where the number of cattle and hogs are several-fold those of people.
His grandmother learned how to make low protein bread, but it looked and tasted different. His mom struggled making birthday cakes. “I learned some bad words at a very young age” as mom struggled applying icing that would pull the cake apart or a slice would collapse into a heap of crumbs, Les recalls.
Les Clark with a birthday cake.
Courtesy Clark
Controlling the diet “is not so bad when you are a baby” because that's all you know, says Jerry Vockley, Director of the Center for Rare Disease Therapy at Children's Hospital of Pittsburgh. “But after a while, as you get older and you start tasting other things and you say, Well, gee, this stuff tastes way better than what you're giving me. What's the deal? It becomes harder to maintain the diet.”
First is the lure of forbidden foods as children venture into the community away from the watchful eyes of parents. The support system weakens further when they leave home for college or work. “Pizza was mighty tasty,” Wolf' says of his first slice.
Vockley estimates that about 90 percent of adults with PKU are off of treatment. Moving might mean finding a new metabolic clinic that treats PKU. A lapse in insurance coverage can be a factor. Finally there is plain fatigue from multiple daily dosing of barely tolerable formula, monitoring protein intake, and simply being different in terms of food restrictions. Most people want to fit in and not be defined by their medical condition.
Jeff Wolf was one of those who dropped out in his twenties and thirties. He stopped going to clinic, monitoring his Phe levels, and counting protein. But the earlier experience of living with PKU never completely left the back of his mind; he listened to his body whenever eating too much protein left him with the “fuzzy brain" of a protein hangover. About a decade ago he reconnected with a metabolic clinic, began taking formula and watching his protein intake. He still may go over his allotment for a single day but he tries to compensate on subsequent days so that his Phe levels come back into balance.
Jeff Wolf on a boat.
Courtesy Wolf
One of the trickiest parts of trying to manage phenylalanine intake is the artificial sweetener aspartame. The chemical is ubiquitous in diet and lite foods and drinks. Gum too, you don't even have to swallow to receive a toxic dose of Phe. Most PKUers say it is easier to simply avoid these products entirely rather than try to count their Phe content.
Treatments
Most rare diseases have no treatment. There are two drugs for PKU that provide some benefit to some portion of patients but those drugs often have their own burdens.
KUVAN® (sapropterin dihydrochloride) is a pill or powder that helps correct a protein folding error so that food proteins can be digested. It is approved for most types of PKU in adults and children one month and older, and often is used along with a protein-restricted diet.
“The problem is that it doesn't work for every [patient's genetic] mutation, and there are hundreds of mutations that have been identified with PKU. Two to three percent of patients will have a very dramatic response and if you're one of those small number of patients, it's great,” says Vockley. “If you have one of the other mutation, chances are pretty good you still are going to end up on a restricted diet.”
PALYNZIQ® (pegvaliase-pqpz) “has the potential to lower the Phe to normal levels, it's a real breakthrough in the field,” says Vockley. “But is a very hard drug to use. Most folks have to take either one or two 2ml injections a day of something that is basically a gel, and some individuals have to take three.”
Many PKUers have reactions at the site of the injection and some develop anaphylaxis, a severe potentially life-threatening allergic reaction that can happen within seconds and can occur at any time, even after long term use. Many patients using Palynziq carry an EpiPen, a self-injection devise containing a form of adrenaline that can reverse some of the symptoms of anaphylaxis.
Then there is the cost. With the Kuvan dosing for an adult, “you're talking between $100,000 and $200,000 a year. And Palynziq is three times that,” says Vockley. Insurance coverage through a private plan or a state program is essential. Some state programs provide generous coverage while others are skimpy. Most large insurance company plans cover the drugs, sometimes with significant copays, but companies that are self-insured are under no legal obligation to provide coverage.
Les Clark found that out the hard way when the company he worked for was sold. The new owner was self-insured and declined to continue covering his drugs. Almost immediately he was out of pocket an additional $1500 a month for formula, and that was with a substantial discount through the manufacturer's patient support program. He says, “If you don't have an insurance policy that will cover the formula, it's completely unaffordable.” He quickly began to look for a new job.
Hope
It's easy to see why PKUers are eager for advances that will make managing their condition more effect, easier, and perhaps more affordable. Synlogic's efforts have drawn their attention and raised hopes.
Just before Thanksgiving Jerry Vockley presented the latest data to a metabolism conference meeting in Australia. There were only 8 patients in this group of a phase 2 trial using the original version of the company's lead E. coli product, SYNB1618, but they were intensely studied. Each was given the probiotic and then a challenge meal. Vockley saw a 40% reduction in Phe absorption and later a 20% reduction in mean fasting Phe levels in the blood. The product was easy to use and tolerate.
The company also presented early results for SYNB1934, a follow on version that further genetically tweaked the E. coli to roughly double the capacity to chop up the target proteins. Synlogic is recruiting patients for studies to determine the best dosing, which they are planning for next year.
“It's an exciting approach,” says Lex Cowsert, Director of Research Development at the National PKU Alliance, a nonprofit that supports the patient, family, and research communities involved with PKU. “Every patient is different, every patient has a different tolerance for the type of therapy that they are willing to pursue,” and if it pans out, it will be a welcome addition, either alone or in combination with other approaches, to living with PKU.
Author's Note: Reporting this story was made possible by generous support from the National Press Foundation and the Fondation Ipsen. Thanks to the people who so generously shared their time and stories in speaking with me.
Time to visit your TikTok doc? The good and bad of doctors on social media
Rakhi Patel has carved a hobby out of reviewing pizza — her favorite food — on Instagram. In a nod to her preferred topping, she calls herself thepepperoniqueen. Photos and videos show her savoring slices from scores of pizzerias. In some of them, she’s wearing scrubs — her attire as an inpatient neurology physician associate at Tufts Medical Center in Boston.
“Depending on how you dress your pizza, it can be more nutritious,” said Patel, who suggests a thin crust, sugarless tomato sauce and vegetables galore as healthier alternatives. “There are no boundaries for a health care professional to enjoy pizza.”
Beyond that, “pizza fuels my mental health and makes me happy, especially when loaded with pepperoni,” she said. “If I’m going to be a pizza connoisseur, then I also need to take care of my physical health by ensuring that I get at least three days of exercise per week and eat nutritiously when I’m not eating pizza.”
She’s among an increasing number of health care professionals, including doctors and nurses, who maintain an active persona on social media, according to bioethics researchers. They share their hobbies and interests with people inside and outside the world of medicine, helping patients and the public become acquainted with the humans behind the scrubs or white coats. Other health care experts limit their posts to medical topics, while some opt for a combination of personal and professional commentaries. Depending on the posts, ethical issues may come into play.
“Health care professionals are quite prevalent on social media,” said Mercer Gary, a postdoctoral researcher at The Hastings Center, an independent bioethics research institute in Garrison, New York. “They’ve been posting on #medTwitter for many years, mainly to communicate with one another, but, of course, anyone can see the threads. Most recently, doctors and nurses have become a presence on TikTok.”
On social media, many health care providers perceive themselves to be “humanizing” their profession by coming across as more approachable — “reminding patients that providers are people and workers, as well as repositories of medical expertise,” Gary said. As a result, she noted that patients who are often intimidated by clinicians may feel comfortable enough to overcome barriers to scheduling health care appointments. The use of TikTok in particular may help doctors and nurses connect with younger followers.
When health care providers post on social media, they must bear in mind that they have legal and ethical duties to their patients, profession and society, said Elizabeth Levy, founder and director of Physicians for Justice.
While enduring three years of pandemic conditions, many health care professionals have struggled with burnout, exhaustion and moral distress. “Much health care provider content on social media seeks to expose the difficulties of the work,” Gary added. “TikTok and Instagram reels have shown health care providers crying after losing a patient or exhausted after a night shift in the emergency department.”
A study conducted in Beijing, China and published last year found that TikTok is the world’s most rapidly growing video application, amassing 1.6 billion users in 2021. “More and more patients are searching for information on genitourinary cancers via TikTok,” the study’s authors wrote in Frontiers in Oncology, referring to cancers of the urinary tracts and male reproductive organs. Among the 61 sample videos examined by the researchers, health care practitioners contributed the content in 29, or 47 percent, of them. Yet, 22 posts, 36 percent, were misinformative, mostly due to outdated information.
More than half of the videos offered good content on disease symptoms and examinations. The authors concluded that “most videos on genitourinary cancers on TikTok are of poor to medium quality and reliability. However, videos posted by media agencies enjoyed great public attention and interaction. Medical practitioners could improve the video quality by cooperating with media agencies and avoiding unexplained terminologies.”
When health care providers post on social media, they must bear in mind that they have legal and ethical duties to their patients, profession and society, said Elizabeth Levy, founder and director of Physicians for Justice in Irvine, Calif., a nonprofit network of volunteer physicians partnering with public interest lawyers to address the social determinants of health.
“Providers are also responsible for understanding the mechanics of their posts,” such as who can see these messages and how long they stay up, Levy said. As a starting point for figuring what’s acceptable, providers could look at social media guidelines put out by their professional associations. Even beyond that, though, they must exercise prudent judgment. “As social media continues to evolve, providers will also need to stay updated with the changing risks and benefits of participation.”
Patients often research their providers online, so finding them on social media can help inform about values and approaches to care, said M. Sara Rosenthal, a professor and founding director of the program for bioethics and chair of the hospital ethics committee at the University of Kentucky College of Medicine.
Health care providers’ posts on social media also could promote patient education. They can advance informed consent and help patients navigate the risks and benefits of various treatments or preventive options. However, providers could violate ethical principles if they espouse “harmful, risky or questionable therapies or medical advice that is contrary to clinical practice guidelines or accepted standards of care,” Rosenthal said.
Inappropriate self-disclosure also can affect a provider’s reputation, said Kelly Michelson, a professor of pediatrics and director of the Center for Bioethics and Medical Humanities at Northwestern University’s Feinberg School of Medicine. A clinician’s obligations to professionalism extend beyond those moments when they are directly taking care of their patients, she said. “Many experts recommend against clinicians ‘friending’ patients or the families on social media because it blurs the patient-clinician boundary.”
Meanwhile, clinicians need to adhere closely to confidentiality. In sharing a patient’s case online for educational purposes, safeguarding identity becomes paramount. Removing names and changing minor details is insufficient, Michelson said.
“The patient-clinician relationship is sacred, and it can only be effective if patients have 100 percent confidence that all that happens with their clinician is kept in the strictest of confidence,” she said, adding that health care providers also should avoid obtaining information about their patients from social media because it can lead to bias and risk jeopardizing objectivity.
Academic clinicians can use social media as a recruitment tool to expand the pool of research participants for their studies, Michelson said. Because the majority of clinical research is conducted at academic medical centers, large segments of the population are excluded. “This affects the quality of the data and knowledge we gain from research,” she said.
Don S. Dizon, a professor of medicine and surgery at the Warren Alpert Medical School of Brown University in Providence, Rhode Island, uses LinkedIn and Doximity, as well as Twitter, Instagram, TikTok, Facebook, and most recently, YouTube and Post. He’s on Twitter nearly every day, where he interacts with the oncology community and his medical colleagues.
Also, he said, “I really like Instagram. It’s where you will see a hybrid of who I am professionally and personally. I’ve become comfortable sharing both up to a limit, but where else can I combine my appreciation of clothes with my professional life?” On that site, he’s seen sporting shirts with polka dots or stripes and an occasional bow-tie. He also posts photos of his cats.
Don S. Dizon, a professor of medicine and surgery at Brown, started using TikTok several years ago, telling medical stories in short-form videos.
Don S. Dizon
Dizon started using TikTok several years ago, telling medical stories in short-form videos. He may talk about an inspirational patient, his views on end-of-life care and death, or memories of people who have passed. But he is careful not to divulge any details that would identify anyone.
Recently, some people have become his patients after viewing his content on social media or on the Internet in general, which he clearly states isn’t a forum for medical advice. “In both situations, they are so much more relaxed when we meet, because it’s as if they have a sense of who I am as a person,” Dizon said. “I think that has helped so much in talking through a cancer diagnosis and a treatment plan, and yes, even discussions about prognosis.”
He also posts about equity and diversity. “I have found myself more likely to repost or react to issues that are inherently political, including racism, homophobia, transphobia and lack-of-access issues, because medicine is not isolated from society, and I truly believe that medicine is a social justice issue,” said Dizon, who is vice chair of diversity, equity, inclusion and professional integrity at the SWOG Cancer Research Network.
Through it all, Dizon likes “to break through the notion of doctor as infallible and all-knowing, the doctor as deity,” he said. “Humanizing what I do, especially in oncology, is something that challenges me on social media, and I appreciate the opportunities to do it on TikTok.”
Could this habit related to eating slow down rates of aging?
Last Thursday, scientists at Columbia University published a new study finding that cutting down on calories could lead to longer, healthier lives. In the phase 2 trial, 220 healthy people without obesity dropped their calories significantly and, at least according to one test, their rate of biological aging slowed by 2 to 3 percent in over a couple of years. Small though that may seem, the researchers estimate that it would translate into a decline of about 10 percent in the risk of death as people get older. That's basically the same as quitting smoking.
Previous research has shown that restricting calories results in longer lives for mice, worms and flies. This research is unique because it applies those findings to people. It was published in Nature Aging.
But what did the researchers actually show? Why did two other tests indicate that the biological age of the research participants didn't budge? Does the new paper point to anything people should be doing for more years of healthy living? Spoiler alert: Maybe, but don't try anything before talking with a medical expert about it. I had the chance to chat with someone with inside knowledge of the research -- Dr. Evan Hadley, director of the National Institute of Aging's Division of Geriatrics and Clinical Gerontology, which funded the study. Dr. Hadley describes how the research participants went about reducing their calories, as well as the risks and benefits involved. He also explains the "aging clock" used to measure the benefits.
Evan Hadley, Director of the Division of Geriatrics and Clinical Gerontology at the National Institute of Aging
NIA