Genetics and Rare Diseases Research

Fruit flies can model human genetic kidney disease

March 20, 2017

Zhe Han, Ph.D., has found that a majority of human genes known to be associated with nephrotic syndrome play conserved roles in renal function, from fruit flies to humans.

Drosophila melanogaster, the common fruit fly, has played a key role in genetic research for decades. Even though D. melanogaster and humans look vastly different, researchers estimate that about 75 percent of human disease-causing genes have a functional homolog in the fly.

A Children’s National Health System research team reported in a recent issue of Human Molecular Genetics that the majority of genes associated with nephrotic syndrome (NS) in humans also play pivotal roles in Drosophila renal function, a conservation of function across species that validates transgenic flies as ideal pre-clinical models to improve understanding of human disease.

NS is a cluster of symptoms that signal kidney damage, including excess protein in urine, low protein levels in blood, elevated cholesterol and swelling. Research teams have identified mutations in more than 40 genes that cause genetic kidney disease, but knowledge gaps remain in understanding the precise roles that specific genes play in kidney cell biology and renal disease. To address those research gaps, Zhe Han, Ph.D., a principal investigator and associate professor in the Center for Cancer & Immunology Research at Children’s National, and colleagues systematically studied NS-associated genes in the Drosophila model, including seven genes whose renal function had never been analyzed in a pre-clinical model.

“Eighty-five percent of these genes are required for nephrocyte function, suggesting that a majority of human genes known to be associated with NS play conserved roles in renal function from flies to humans,” says Han, the paper’s senior author. “To hone in on functional conservation, we focused on Cindr, the fly’s version of the human NS gene, CD2AP,” Han adds. “Silencing Cindr in nephrocytes led to dramatic impairments in nephrocyte function, shortened their life span, collapsed nephrocyte lacunar channels – the fly’s nutrient circulatory system – and effaced nephrocyte slit diaphragms, which diminished filtration function.”

And, to confirm that the phenotypes they were studying truly caused human disease, they reversed the damage by expressing a wild-type human CD2AP gene. A mutant allele derived from a patient with CD2AP-associated NS did not rescue the phenotypes.

Thus, the Drosophila nephrocyte can be used to explain the clinically relevant molecular mechanisms underlying the pathogenesis of most monogenic forms of NS, the research team concludes. “This is a landmark paper for using the fly to study genetic kidney diseases,” Han adds. “For the first time, we realized that the functions of essential kidney genes could be so similar from the flies to humans.”

A logical next step will be to generate personalized in vivo models of genetic renal diseases bearing patient-specific mutations, Han says. These in vivo models can be used for drug screens to identify treatments for kidney diseases that currently lack therapeutic options, such as most of the 40 genes studies in this paper as well as the APOL1 gene that is associated with the higher risk of kidney diseases among millions of African Americans.

Researchers tackle Zika’s unanswered questions

March 17, 2017

Youssef A. Kousa, D.O., Ph.D., M.S., is examining whether interplays between certain genes make some women more vulnerable to symptomatic Zika infections.

A Maryland woman traveled to the Dominican Republic early in her pregnancy, spending three weeks with family. She felt dizzy and tired and, at first, attributed the lethargy to jet lag. Then, she experienced a rash that lasted about four days. She never saw a bite or slapped a mosquito while in the Dominican Republic but, having heard about the Zika virus, asked to be tested.

Her blood tested positive for Zika.

Why was this pregnant woman infected by Zika while others who live year-round in Zika hot zones remain free of the infectious disease? And why was she among the slim minority of Zika-positive people to show symptoms?

Youssef A. Kousa, D.O., Ph.D., M.S., a pediatric resident in the child neurology track at Children’s National Health System, is working on a research study that will examine whether interplays between certain genes make some women more vulnerable to symptomatic Zika infections during pregnancy, leaving some fetuses at higher risk of developing microcephaly.

Dr. Kousa will present preliminary findings during Research and Education Week 2017 at Children’s National.

At sites in Puerto Rico, Colombia and Washington D.C., Dr. Kousa and his research collaborators are actively recruiting study participants and drawing blood from women whose Zika infections were confirmed in the first or second trimester of pregnancy. The blood is stored in test tubes with purple caps, a visual cue that the tube contains an additive that binds DNA, preventing it from being cut up. Additional research sites are currently being developed.

When the blood arrives at Children’s National, Dr. Kousa will use a centrifuge located in a sample preparation room to spin the samples at high speed for 11 minutes. The sample emerges from the centrifuge in three discrete layers, separated by weight. The rose-colored section that rises to the top is plasma. Plasma contains tell-tale signs of the immune system’s past battles with viruses and will be analyzed by Roberta L. DeBiasi, M.D., M.S., Chief of the Division of Pediatric Infectious Diseases at Children’s National, and Dr. Kousa’s mentor.

A slender line at the middle indicates white blood cells. The dark red layer is heavier red blood cells that sink to the bottom. This bottom half of the test tube, where the DNA resides, is where Dr. Kousa will perform his genetic research.

For years, Dr. Kousa has worked to identify genetic risk factors that influence which fetuses develop cleft lip and palate. In addition to genetic variances that drive disease, he looks at environmental overlays that can trigger genes to respond in ways that cause pediatric disease. When Zika infections raced across the globe, he says it was important to apply the same genetic analyses to the emerging disease. Genes make proteins that carry out instructions, but viral infection disrupts how genes interact, he says. Cells die. Other cells do not fully mature.

While certain poverty-stricken regions of Brazil have recorded the highest spikes in rates of microcephaly, more is at play than socioeconomics, he says. “It didn’t feel like all of the answers lie in the neighborhood. One woman with a Zika-affected child can live just down the street from a child who is more or less severely affected by Zika.”

As a father, Dr. Kousa is particularly concerned about how Zika stunts growth of the fetal brain at a time when it should expand exponentially. “I have three kids. You see them as they achieve milestones over time. It makes you happy and proud as a parent,” he says.

Sarah B. Mulkey, M.D., Ph.D., is studying whether infants exposed to Zika in utero achieve the same developmental milestones as uninfected infants.

While Dr. Kousa concentrates on Zika’s most devastating side effects, his colleague Sarah B. Mulkey, M.D., Ph.D., is exploring more subtle damage Zika can cause to fetuses exposed in utero. In the cohort of Colombian patients that Dr. Mulkey is researching, just 8 percent had abnormal fetal brain magnetic resonance images (MRIs). At first glance, the uncomplicated MRIs appear to be reassuring news for the vast majority of pregnant women.

Dr. Mulkey also will present preliminary findings during Research and Education Week 2017 at Children’s National.

In the fetus, the Zika virus makes a beeline to the developing brain where it replicates with ease and can linger after birth. “We need to be cautious about saying the fetal MRI is ‘normal’ and the infant is going to be ‘normal,’ ” Dr. Mulkey says. “We know with congenital cytomegalovirus that infected infants may not show symptoms at birth yet suffer long-term consequences, such as hearing deficits and vision loss.”

Among Zika-affected pregnancies in Colombia in which late-gestational age fetal MRIs were normal, Dr. Mulkey will use two different evaluation tools at 6 months and 1 year of age to gauge whether the babies accomplish the same milestones as peers. One evaluation tool is a questionnaire that has been validated in Spanish.

At 6 months and 1 year of age, the infants’ motor skills will be assessed, such as their ability to roll over in both directions, sit up, draw their feet toward their waist, stand, take steps independently and purposefully move their hands. Videotapes of the infants performing the motor skills will be scored by Dr. Mulkey and her mentor, Adre du Plessis, M.B.Ch.B., Chief of the Division of Fetal and Transitional Medicine at Children’s National. The Thrasher Research Fund is funding the project, “Neurologic outcomes of apparently normal newborns from Zika virus-positive pregnancies,” as part of its Early Career Award Program.

Both research projects are extensions of a larger multinational study co-led by Drs. du Plessis and DeBiasi that explores the impact of prolonged Zika viremia in pregnant women, fetuses and infants; the feasibility of using fetal MRI to describe the continuum of neurological impacts in Zika-affected pregnancies; and long-term developmental issues experienced by Zika-affected infants.

FSH Society awards grant to Yi-Wen Chen

March 10, 2017

The FSH Society has awarded the FSH Society Grant FSHS-82016-4 to Children’s National researcher Yi-Wen Chen, D.M.V., Ph.D., to study facioscapulohumeral muscular dystrophy (FSHD).

Chen, Principal Investigator at the Center for Genetic Medicine Research at Children’s National and associate professor of pediatrics and integrative systems biology at George Washington University, will receive the research grant of $179,104 for two years for her project titled “Developing LNA-based therapy for facioscapulohumeral muscular dystrophy.”

FSHD is a complex genetic disorder caused by aberrantly expressed double homeobox protein 4 (DUX4) in patients’ cells that ultimately leads to the weakening of skeletal muscles often beginning in teenage years or early adulthood. Her research will focus on the next phases of developing LNA-based therapy for patients with FSHD through an in vivo study in a preclinical model.

“We have been designing compounds to inject into a preclinical model of FSHD in order to first reduce the DUX4 in the muscle and then identify the compounds that work best,” says Chen. Researchers will inject varying doses of the compound directly into the muscle for localized delivery and under the skin to reach the entire body for systemic delivery.

Currently there is no treatment for FSHD. After 15 years spent researching the disease, Chen hopes to test the efficacy of the compounds in order to identify a treatment.

Illuminating cardiometabolic risk in Down syndrome

February 24, 2017

A leading researcher at Children’s National says researchers should look closely at the increased risks of obesity and thyroid disease common in patients with Down Syndrome, and determine how these long term comorbidities relate to cardiovascular and metabolic (cardiometabolic) risk, body image, and quality of life.

Over the last several decades, physicians’ improved ability to treat the common comorbidities of Down syndrome, such as congenital heart disease, has dramatically prolonged survival. Today, more than 400,000 people across the country are living with Down syndrome, and life expectancy has increased to 60 years.

New strategies to manage care for patients with Down syndrome must include preventive, evidence-based approaches to address the unique needs of these patients, according to Sheela N. Magge, M.D., M.S.C.E., Director of Research in the Division of Endocrinology and Diabetes at Children’s. She says that these efforts should include looking more closely at the increased risks of obesity and thyroid disease common in this population, and determining how these long term comorbidities relate to cardiovascular and metabolic (cardiometabolic) risk, body image, and quality of life.

An NIH-funded study from Children’s National and the Children’s Hospital of Philadelphia (CHOP), led by Dr. Magge and her colleague from CHOP, Dr. Andrea Kelly, seeks to better understand how the body composition of patients with Down syndrome impacts their likelihood for developing diabetes and obesity-related cardiovascular risks long term.

“We know that individuals with Down syndrome are at increased risk for obesity, but what hasn’t been clear is whether or not they also have the same cardiometabolic risk associated with obesity that we know holds true for other populations,” says Dr. Magge. “In this previously under-studied population, the common assumption based on very limited studies from the 1970’s was that individuals with Down syndrome were protected from the diabetes and cardiovascular risks that can develop in other overweight people. However, more recent epidemiologic studies contradict those early findings.”

The study has enrolled 150 Down syndrome patients and almost 100 controls to date, and the team is currently beginning to analyze the data. Dr. Magge believes that the findings from this study will help to provide new, research-driven evidence to inform the long term clinical management of obesity and cardiometabolic risk in adolescents with Down syndrome.

She concludes, “The goal is for our research to provide the foundation that will advance prevention and treatment strategies for this understudied group, so that individuals with Down syndrome not only have a longer life expectancy, but also a healthier and better quality of life.”

T-cell therapy success for relapsing blood cancer

February 24, 2017

A unique immunotherapeutic approach that expands the pool of donor-derived lymphocytes (T-cells) that react and target three key tumor-associated antigens (TAA) is demonstrating success at reducing or eliminating acute leukemias and lymphomas when these cancers have relapsed following hematopoietic stem cell transplant (HSCT).

“There’s currently a less than 10 percent chance of survival for a child who relapses leukemia or lymphoma after a bone marrow transplant—in part because these patients are in a fragile medical condition and can’t tolerate additional intense therapy,” says Kirsten Williams, M.D., a blood and marrow transplant specialist in the Division of Hematology at Children’s National Health System, and principal investigator of the Research of Expanded multi-antigen Specifically Oriented Lymphocytes for the treatment of VEry High Risk Hematopoietic Malignancies (RESOLVE) clinical trial.

The unique manufactured donor-derived lymphocytes used in this multi-institutional Phase 1 dose-ranging study are receptive to multiple tumor-associated antigens within the cell, including WT1, PRAME, and Survivin, which have been found to be over-expressed in myelodysplastic syndromes (MDS), acute myeloid leukemia (AML), B-cell AML/MDS, B-cell acute lymphoblastic leukemia (ALL), and Hodgkins lymphoma. Modifying the lymphocytes for several antigens, rather than a single target, broadens the ability of the T-cells to accurately target and eradicate cancerous cells.

Preliminary results demonstrate a 78 percent response rate to treatment, and a 44 percent rate of total remission for participating patients. To date, nine evaluable patients with refractory and relapsed AML/MDS, B-cell ALL, or Hodgkins lymphoma have received 1-3 infusions of the expanded T-cells, and of those, seven have responded to the treatment, showing reduction in cancer cells after infusion with little or no toxicity. All of these patients had relapse of their cancer after hematopoietic cell transplantation. The study continues to recruit eligible patients, with the goal of publishing the full study results within the next 12 months.

“Our preliminary data also shows that this new approach has few if any side effects for the patient, in part because the infused T-cells target antigens that are found only in cancer cells and not found in healthy tissues,” Dr. Williams notes.

The approach used to expand existing donor-derived TAA-lymphocytes, rather than using unselected T cells or genetically modified T-cells as in other trials, also seems to reduce the incidence of post infusion graft versus host disease and other severe inflammatory side effects. Those side effects typically occur when the infused lymphocytes recognize healthy tissues as foreign and reject them or when the immune system reacts to the modified elements of the lymphocytes, she adds.

“These results are exciting because they may present a truly viable option for the 30 to 40 percent of children who will relapse post-transplant,” Dr. Williams concludes. “Many of the patients who participated were given two options: palliative care or this trial. To see significant success and fewer side effects gives us, and families with children facing relapsing leukemia, some hope for this new treatment.”

Dr. Williams discussed the early outcomes of the RESOLVE trial during an oral presentation at the American Society for Blood and Marrow Transplantation meeting on February 22, 2017.

“The early indicators are very promising for this patient population,” says Catherine Bollard, M.D., M.B.Ch.B., Chief of the Division of Allergy and Immunology, Director of the Program for Cell Enhancement and Technologies for Immunotherapy (CETI) at Children’s National, and senior author of the study. “If we can achieve this, and continue to see good responses with few side effects, it’s possible these methods could become a viable alternative to HSCT for patients with no donor match or who aren’t likely to tolerate transplant.”

This is one of the first immunotherapeutic approaches to successfully capitalize on the natural ability of human T-cells to kill cancer, though previous research has shown significant success for this approach in reducing the deadly impact of several viruses, including Epstein-Barr virus, adenovirus, and cytomegalovirus, post HSCT. These new findings have led to the development of additional clinical trials to investigate applications of this method of TAA-lymphocyte manufacture and infusion for pre-HSCT MDS/AML, B-cell ALL, Hodgkins Lymphoma, and even some solid tumors.

Puzzling symptoms lead to collaboration

February 24, 2017

Sarah B. Mulkey, explaining the research

Sarah B. Mulkey, M.D., Ph.D., is lead author of a study that describes a brand-new syndrome that stems from mutations to KCNQ2, a genetic discovery that began with one patient’s unusual symptoms.

Unraveling one of the greatest mysteries of Sarah B. Mulkey’s research career started with a single child.

At the time, Mulkey, M.D., Ph.D., a fetal-neonatal neurologist in the Division of Fetal and Transitional Medicine at Children’s National Health System, was working at the University of Arkansas for Medical Sciences. Rounding one morning at the neonatal intensive care unit (NICU), she met a new patient: A newborn girl with an unusual set of symptoms. The baby was difficult to wake and rarely opened her eyes. Results from her electroencephalogram (EEG), a test of brain waves, showed a pattern typical of a severe brain disorder. She had an extreme startle response, jumping and twitching any time she was disturbed or touched, that was not related to seizures. She also had trouble breathing and required respiratory support.

Dr. Mulkey did not know what to make of her new patient: She was unlike any baby she had ever cared for before. “She didn’t fit anything I knew,” Dr. Mulkey remembers, “so I had to get to the bottom of what made this one child so different.”

Suspecting that her young patient’s symptoms stemmed from a genetic abnormality, Dr. Mulkey ran a targeted gene panel, a blood test that looks for known genetic mutations that might cause seizures or abnormal movements. The test had a hit: One of the baby’s genes, called KCNQ2, had a glitch. But the finding deepened the mystery even further. Other babies with a mutation in this specific gene have a distinctly different set of symptoms, including characteristic seizures that many patients eventually outgrow.

Dr. Mulkey knew that she needed to dig deeper, but she also knew that she could not do it alone. So, she reached out first to Boston Children’s Hospital Neurologist Philip Pearl, M.D., an expert on rare neurometabolic diseases, who in turn put her in touch with Maria Roberto Cilio, M.D., Ph.D., of the University of California, San Francisco and Edward Cooper, M.D., Ph.D., of Baylor College of Medicine. Drs. Cilio, Cooper and Pearl study KCNQ2 gene variants, which are responsible for causing seizures in newborns.

Typically, mutations in this gene cause a “loss of function,” causing the potassium channel to remain too closed to do its essential job properly. But the exact mutation that affected KCNQ2 in Dr. Mulkey’s patient was distinct from others reported in the literature. It must be doing something different, the doctors reasoned.

Indeed, a research colleague of Drs. Cooper, Cilio and Pearl in Italy — Maurizio Taglialatela, M.D., Ph.D., of the University of Naples Federico II and the University of Molise — had recently discovered in cell-based work that this particular mutation appeared to cause a “gain of function,” leaving the potassium channel in the brain too open.

Wondering whether other patients with this same type of mutation had the same unusual constellation of symptoms as hers, Dr. Mulkey and colleagues took advantage of a database that Dr. Cooper had started years earlier in which doctors who cared for patients with KCNQ2 mutations could record information about symptoms, lab tests and other clinical findings. They selected only those patients with the rare genetic mutation shared by her patient and a second rare KCNQ2 mutation also found to cause gain of function — a total of 10 patients out of the hundreds entered into the database. The researchers began contacting the doctors who had cared for these patients and, in some cases, the patients’ parents. They were scattered across the world, including Europe, Australia and the Middle East.

Dr. Mulkey and colleagues sent the doctors and families surveys, asking whether these patients had similar symptoms to her patient when they were newborns: What were their EEG results? How was their respiratory function? Did they have the same unusual startle response?

She is lead author of the study, published online Jan. 31, 2017 in Epilepsia, that revealed a brand-new syndrome that stems from specific mutations to KCNQ2. Unlike the vast majority of others with mutations in this gene, Dr. Mulkey and her international collaborators say, these gain-of-function mutations cause a distinctly different set of problems for patients.

Dr. Mulkey notes that with a growing focus on precision medicine, scientists and doctors are becoming increasingly aware that knowing about the specific mutation matters as much as identifying the defective gene. With the ability to test for more and more mutations, she says, researchers likely will discover more cases like this one: Symptoms that differ from those that usually strike when a gene is mutated because the particular mutation differs from the norm.

Such cases offer important opportunities for researchers to come together to share their collective expertise, she adds. “With such a rare diagnosis,” Dr. Mulkey says, “it’s important for physicians to reach out to others with knowledge in these areas around the world. We can learn much more collectively than by ourselves.”

Lisa Guay-Woodford: minimizing kidney disease effects

February 16, 2017

Lisa M. Guay-Woodford, M.D., is internationally recognized for her examination of the mechanisms that make certain inherited renal disorders particularly lethal, a research focus inspired by her patients.

The artist chose tempera paint for her oeuvre. The flower’s petals are the color of Snow White’s buddy, the Bluebird of Happiness. Each petal is accentuated in stop light red, and the blossom’s leaves stretch up toward the sun. With its bold strokes and exuberant colors, the painting exudes life itself.

It’s the first thing Lisa M. Guay-Woodford, M.D., sees when she enters her office. It’s the last thing she sees as she leaves.

Dr. Guay-Woodford, a pediatric nephrologist, is internationally recognized for her research into the mechanisms that make certain inherited renal disorders, such as autosomal recessive polycystic kidney disease (ARPKD), particularly lethal. She also studies disparate health disorders that have a common link: Disruption to the cilia, slim hair-like structures that protrude from almost every cell in the human body and that play pivotal roles in human genetic disease.

Sarah, the artist who painted the bright blue flower more than 20 years ago when she was 8, was one of Dr. Guay-Woodford’s patients. And she’s part of the reason why Dr. Guay-Woodford has spent much of her career focused on the broader domain of disorders tied to just a single defective gene, such as ARPKD.

“It dates back to when I was a house officer and took care of kids with this disorder,” Dr. Guay-Woodford says. “Maybe 30 percent die in the newborn period. Others survive, but they have a whole range of complications.”

Two of her favorite patients died from ARPKD-related reasons in the same year. One died from uncontrolled high blood pressure. The other, Sarah, died from complications from a combined kidney and liver transplant.

“The picture she drew hangs in my office,” she says. “She was a wonderful kid who was really full of life, and what she chose really mirrored who she was as a person. We put up lots of those sorts of those things in my office. It’s a daily reminder of why we do the things we do and the end goal.”

ARPKD is characterized by the growth of cysts in the liver, the kidney – which can lead to kidney failure – and complications within other structures, such as blood vessels in the heart and brain, according to the National Institutes of Health. About 1 in 20,000 live births is complicated by the genetic disorder. The age at which symptoms arise varies.

“Given the way it plays out, starting in utero, this is not a disease we are likely to cure,” she says. “But there are children who have very minimal complications. The near-term goal is to use targeted therapies to convert the children destined to have a more severe disease course to one that is less complicated so that no child suffers the full effects of the disease.”

That’s why it is essential to attain detailed knowledge about the defective gene responsible for ARPKD. To that end, Dr. Guay-Woodford participated in an international collaboration – one of three separate groups that 14 years ago identified PKHD1 as the defective gene that underlies ARPKD.

“The progress has been slow, partly because the gene and its protein products are very complex,” she says. “The good news is the gene has been identified. The daunting news is the identification did not leap us forward. It is just sort of an important step in what is going to be a fits-and-starts kind of journey.”

The field is trying to emulate the clinical successes that have occurred for patients with cystic fibrosis, which now can be treated by a drug that targets the defective gene, attacking disease at a fundamental level. Patient outcomes also have improved due to codifying care.

When she was a resident in the 1980s, children with cystic fibrosis died in their teens. “Now, they’re living well into their 40s because of careful efforts by really astute clinicians to deliver a standardized approach to care, an approach now enhanced by a terrific new drug. We measure quality care in terms of patient outcomes. That has allowed us to really understand how to effectively use antibiotics, physical therapy and how to think about nutrition – which makes a hugely important contribution that previously had been underappreciated.”

Standardizing clinical approaches dramatically improved and extended patients’ lives. “For renal cystic disease, we are beginning to do that better and better,” she adds.

There’s no targeted medicine yet for ARPKD. But thanks to an international conference that Dr. Guay-Woodford convened in Washington in 2013, such consensus expert recommendations have been published to guide diagnosis, surveillance and management of pediatric patients with ARPKD.

“There is an awful lot we can do in the way we systematically look at the clinical disease in these patients and improve our management. And, if you can overlay on top of that specific insights about why one person goes one way in disease progression versus another way, I think we can boost the baseline by developing good standards of care,” she says.

“Science does march on. There are a number of related research studies that are expanding our understanding of ARPKD. Within the next decade, we probably will be able to capitalize on not just the work in ARPKD but work in related diseases to learn the entry points for targeting therapies. That way, we can build a portfolio of markers of disease progression and test how effective these potential therapies are in slowing the course of the disease.”

Muscular Dystrophy Association awards grants to two Children’s National scientists

February 8, 2017

Marshall Hogarth, Ph.D

James Novak, Ph.D.

Two Children’s National Health System research scientists, Marshall Hogarth, Ph.D. and James Novak, Ph.D., have received Post-Doctoral Development Grants from the Muscular Dystrophy Association (MDA) as part of funding awarded to young, rising researchers who are poised to become independent investigators.

Over the next three years, Hogarth and Novak will be allotted $180,000 each to underwrite their individual research projects.

Hogarth’s research is focused on limb-girdle muscular dystrophy (LGMD), a disease which presents as muscle weakness when patients are in their late teens before rapidly progressing to severe debilitation. The MDA grant will allow Hogarth to continue his research investigating the replacement of muscle with fatty tissue and the role this plays in the late onset and subsequent progression of LGMD in patients.

Novak focuses mainly on researching Duchenne Muscular Dystrophy (DMD), a severely debilitating form of MD, that leads to progressive muscle weakness and respiratory and cardiac failure. Currently, the only Food and Drug Administration (FDA) approved treatment for DMD is exon-skipping. The MDA grant will support Novak’s study of the mechanisms that regulate the delivery of exon-skipping drugs in muscle, in order to identify new therapeutic targets and improve drug efficacy for patients with DMD.

While Hogarth and Novak focus on different aspects of neuromuscular disease, both look forward to making significant contributions that lead to overall improvements in the treatment of patients impacted by muscular dystrophy.

Eric Vilain to lead genetic medicine research

February 6, 2017

Eric Vilain, M.D., Ph.D., emphasizes the idea of health and disease as a compound process that will transform children’s health and impact a patient throughout life.

Eric Vilain, M.D., Ph.D., an internationally renowned geneticist well known for groundbreaking studies of gender based biology, will soon lead the Center for Genetic Medicine Research at Children’s National Health System.

Dr. Vilain joins Children’s National from the University of California, Los Angeles (UCLA) where he serves as Professor of Human Genetics, Pediatrics and Urology, Chief of Medical Genetics, and attending physician in the Department of Pediatrics.

As the Director of the Center for Genetic Medicine Research, Dr. Vilain will emphasize the idea of health and disease as a compound process, which he believes “can transform children’s health and help the treatment and prevention of illness, not only in childhood, but throughout a patient’s life.”

The Center for Genetic Medicine Research currently houses a highly interdisciplinary faculty of over 50 scientists and physician investigators and brings together a variety of clinical and scientific disciplines to coordinate scientific and clinical investigations simultaneously from multiple angles. The Center also provides access to the leading edge innovative technologies in genomics, microscopy, proteomics, bioinformatics, pre-clinical drug trials, and multi-site clinical trial networks for faculty within the Children’s Research Institute, the academic arm of Children’s National.

Dr. Vilain’s current laboratory focuses on the genetics of sexual development and sex differences – specifically the molecular mechanisms of gonad development and the genetic variants of brain sexual differentiation. His research also explores the biological bases of sex variations in predisposition to disease. His work crosses several disciplines (genetics, neuroscience, psychology) leading to findings with major societal implications. In addition to scientific investigation, Dr. Vilain created a clinic devoted to caring for patients with a wide array of genetic and endocrine issues, particularly those with variations of sexual development.

He brings nearly 30 years of expertise with him to Children’s National. He has authored seminal articles regarding the field of sexual development, and his research program has continuously been funded by the National Institutes of Health (NIH). Dr. Vilain is a Fellow of the American College of Medical Genetics and a member of numerous professional committees. The recipient of numerous awards, he has been recognized by organizations ranging from the NIH to the Doris Duke Charitable Foundation, March of Dimes, and the Society for Pediatric Research. He has served as an advisor to the International Olympic Committee Medical Commission since 2011 and has been a member of the Board of Scientific Counselors of the National Institute of Child Health and Human Development since 2015.

Mark Batshaw, M.D., Executive Vice President, Physician-in-Chief, and Chief Academic Officer at Children’s National says, “Dr. Vilain’s vision and expertise in the study and use of precision medicine approaches, and the development of novel treatments for diseases of childhood, will lead to drastically different and improved outcomes for some of the most devastating diseases, such as cancer.”

“I am honored to join the world-renowned team at Children’s National, and look forward to continuing to find new, innovative ways to research, diagnose and treat rare and common disorders,” Dr. Vilain adds.

Children’s National creates first-of-its-kind Rare Disease Institute

February 1, 2017

Children’s National Health System has announced the creation of the Children’s National Rare Disease Institute (CNRDI), a first-of-its-kind clinical research center focused exclusively on the care and treatment of children and adults with rare genetic disorders. Designated by the National Organization for Rare Disorders (NORD) as the first Center of Excellence for Clinical Care for Rare Diseases, the CNRDI will focus on developing care standards for patients, advancing research and developing new therapies to better treat rare diseases. The institute will be led by Marshall Summar, M.D., Chief of Genetics and Metabolism at Children’s National, and will collaborate with the NORD natural history/registry program, which was developed with input from the U.S. Food and Drug Administration and the National Institutes of Health to advance monitoring databases for patient outcomes and disease.

Vittorio Gallo named Chief Research Officer

January 12, 2017

As chief research officer, Vittorio Gallo, Ph.D., will be instrumental in developing and realizing Children’s Research Institute’s long-term strategic vision.

Children’s National Health System has appointed the longtime director of its Center for Neuroscience Research, Vittorio Gallo, Ph.D., as Chief Research Officer. Gallo’s appointment comes at a pivotal time for the institution’s research strategic plan, as significant growth and expansion will occur in the next few years. Gallo is a neuroscientist who studies white matter disorders, with particular focus on white matter growth and repair. He is also the Wolf-Pack Chair in Neuroscience at Children’s Research Institute, the academic arm of Children’s National.

As Chief Research Officer, Gallo will be instrumental in developing and realizing Children’s Research Institute’s long-term strategic vision, which includes building out the nearly 12-acre property once occupied by Walter Reed National Military Medical Center to serve as a regional innovation hub and to support Children’s scientists conducting world-class pediatric research in neuroscience, genetics, clinical and translational science, cancer and immunology. He succeeds Mendel Tuchman, M.D., who has had a long and distinguished career as Children’s Chief Research Officer for the past 12 years and who will remain for one year in an emeritus role, continuing federally funded research projects and mentoring junior researchers.

“I am tremendously pleased that Vittorio has agreed to become Chief Research Officer as of July 1, 2017, at such a pivotal time in Children’s history,” says Mark L. Batshaw, M.D., Physician-in-Chief and Chief Academic Officer at Children’s National. “Since Mendel announced plans to retire last summer, I spent a great deal of time talking to Children’s Research Institute investigators and leaders and also asking colleagues around the nation about the type of person and unique skill sets needed to serve as Mendel’s successor. With each conversation, it became increasingly clear that the most outstanding candidate for the Chief Research Officer position already works within Children’s walls,” Dr. Batshaw adds.

“I am deeply honored by being selected as Children’s next Chief Research Officer and am excited about being able to play a leadership role in defining the major areas of research that will be based at the Walter Reed space. The project represents an incredible opportunity to maintain the core nucleus of our research strengths – genetics, immunology, neurodevelopmental disorders and disabilities – and to expand into new, exciting areas of research. What’s more, we have an unprecedented opportunity to form new partnerships with peers in academia and private industry, and forge new community partnerships,” Gallo says. “I am already referring to this as Walter Reed ‘Now,’ so that we are not waiting for construction to begin to establish these important partnerships.”

Gallo’s research focus has been on white matter development and injury, myelin and glial cells – which are involved in the brain’s response to injury. His past and current focus is also on neural stem cells. His work in developmental neuroscience has been seminal in deepening understanding of cerebral palsy and multiple sclerosis. He came to Children’s National from the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) intramural program. His intimate knowledge of the workings of the National Institutes of Health (NIH) has helped him to establish meaningful collaborations between both institutions. During his tenure, he has transformed the Center for Neuroscience Research into one of the nation’s premier programs. The Center is home to the prestigious NIH/NICHD-funded District of Columbia Intellectual and Developmental Disabilities Research Center, which Gallo directs.

Children’s research scientists working under the auspices of Children’s Research Institute conduct and promote highly collaborative and multidisciplinary research within the hospital that aims to better understand, treat and, ultimately, prevent pediatric disease. As Chief Research Officer, Gallo will continue to establish and enhance collaborations between research and clinical programs. Such cross-cutting projects will be essential in defining new mechanisms that underlie pediatric disease. “We know, for instance, that various mechanisms contribute to many genetic and neurological pediatric diseases, and that co-morbidities add another layer of complexity. Tapping expertise across disciplines has the potential to unravel current mysteries, as well as to better characterize unknown and rare diseases,” he says.

“Children’s National is among the nation’s top seven pediatric hospitals in NIH research funding, and the extraordinary innovations that have been produced by our clinicians and scientists have been put into practice here and in hospitals around the world,” Dr. Batshaw adds. “Children’s leadership aspires to nudge the organization higher, to rank among the nation’s top five pediatric hospitals in NIH research funding.”

Gallo says the opportunity for Children’s research to expand beyond the existing buildings and the concurrent expansion into new areas of research will trigger more hiring. “We plan to grow our research enterprise through strategic hires and by attracting even more visiting investigators from around the world. By expanding our community of investigators, we aim to strengthen our status as one of the nation’s leading pediatric hospitals,” he says.

Drug dosing guidelines poor fit for obese patients

January 6, 2017

Children’s National researchers are among the top teams examining how obesity alters pharmacokinetics and the effect of body mass index on drug dosing and treatment outcomes specifically for pediatric and adolescent patients.

Obesity affects about 12.7 million U.S. children and adolescents – or about 1 in 6 kids across the nation, according to the Centers for Disease Control and Prevention. Despite this, there is a significant dearth of dosing guidelines for practitioners, for example pediatric anesthesiologists, to follow when administering potent anesthetics to pediatric patients who are obese.

Janelle D. Vaughns, M.D., director of bariatric anesthesia within the Division of Anesthesiology, Pain and Perioperative Medicine, says Children’s National Health System sees pediatric and adolescent patients of extreme weight (as much as 450 pounds) presenting for weight-loss surgery. In order to ensure that patients remain anesthetized during their surgical procedures, anesthesiologists use various classes of drugs, including hypnotics, muscle relaxants and pain medications. Dr. Vaughns says providers across the nation face similar challenges when determining accurate and precise dosing of drugs for obese pediatric patients.

“Medical guidelines calibrated for a 13-year-old of typical weight cannot be applied to a 13-year-old who weighs 400 pounds. Because morbid obesity in kids is a relatively new phenomenon in our country and globally, there are no formal guidelines to aid with dosing. In this scenario, most doctors extrapolate from guidelines written for lean patients. Because anesthetic drugs are so strong, it is essential to use the correct dose in all patients,” she says.

A recent brief report that Dr. Vaughns co-authored examines this issue. Researchers at Children’s National and the Washington Hospital Center conducted a retrospective review for 440 adult patients who received rapid sequence endotracheal intubation (RSI) in an urban, tertiary care academic Emergency Department. The patients received succinylcholine (a muscle relaxant) and etomidate (a short-acting anesthetic), whose doses are ideally calculated in milligrams per kilogram of total body weight.

The work, published in the December 2016 issue of American Journal of Emergency Medicine, reinforced the importance of data-driven guidelines for all patients. The research team found that the 129 obese patients included in the study were more likely to receive too little of the studied drugs while the 311 non-obese patients studied were more likely to receive too much medicine.

“Our single-center study demonstrates that obesity is a significant risk factor for underdosing RSI medications, whereas non-obesity is a risk factor for overdosing of these medications,” the research team concludes. This study also was reviewed and featured by the New England Journal of Medicine “Journal Watch” in October 2016.

Broadly, the issue of dosing potent medicines for pediatric obese patients is a national public health concern, Dr. Vaughns says. Research teams across the nation have made a concerted effort to publish papers on topics such as how obesity alters pharmacokinetics – how the body takes up, distributes and disposes of powerful medicines – and the deleterious effect of unhealthy body mass index on treatment outcomes for children with diseases such as acute myeloid leukemia.

Dr. Vaughns is among the clinician researchers working with the Pediatric Trials Network (PTN), sponsored by the Eunice Kennedy Shriver National Institute of Child Health and Human Development, to fill this research gap. Working as a team, she, Evan Nadler, M.D., a bariatric surgeon, and Johannes N. van den Anker, M.D., Ph.D., division chief of Clinical Pharmacology, enroll pediatric patients in ongoing trials with a special focus on surgical patients who are obese.

The network is currently conducting pediatric studies at a number of locations, including Children’s National, leveraging blood samples and other specimens drawn during regular care to better understand how medicines routinely used in pediatric patients actually work in kids and to determine appropriate dosing.

Ultimately, the information PTN researchers discover from their multi-year studies will help the Food and Drug Administration update medicine labels to reflect safer, more accurate and more effective dosing for all pediatric patients.

Down syndrome indicators in diverse populations

December 21, 2016

According to a large international study published in the American Journal of Medical Genetics, physical features vary in patients with Down syndrome across diverse populations. The study, led by the National Human Genome Research Institute (NHGRI), part of the National Institutes of Health, used an objective digital facial analysis technology developed by the Sheikh Zayed Institute for Pediatric Surgical Innovation at Children’s National Health System to identify the most relevant facial features characteristic in Down syndrome in diverse populations from 12 countries. This study is the first to compare and contrast Down syndrome across diverse populations. It is the first in a series of studies to be used in the NIH’s Atlas of Human Malformation Syndromes in Diverse Populations, a free resource to help clinicians around the world diagnose birth defects and genetic diseases in people of diverse ancestry, and is the first in a series focused on different genetic syndromes.

Harnessing progenitor cells in neonatal white matter repair

December 21, 2016

The sirtuin protein Sirt1 plays a crucial role in the proliferation and regeneration of glial cells from an existing pool of progenitor cells — a process that rebuilds vital white matter following neonatal hypoxic brain injury. Although scientists do not fully understand Sirt1’s role in controlling cellular proliferation, this pre-clinical model of neonatal brain injury outlines for the first time how Sirt1 contributes to development of additional progenitor cells and maturation of fully functional oligodendrocytes.

The findings, published December 19 in Nature Communications, suggest that modulation of this protein could enhance progenitor cell regeneration, spurring additional white matter growth and repair following neonatal brain injury.

“It is not a cure. But, in order to regenerate the white matter that is lost or damaged, the first steps are to identify endogenous cells capable of regenerating lost cells and then to expand their pool. The glial progenitor cells represent 4 to 5 percent of total brain cells,” says Vittorio Gallo, Ph.D., Director of the Center for Neuroscience Research at Children’s National, and senior author of the study. “It’s a sizable pool, considering that the brain is made up of billions of cells. The advantage is that these progenitor cells are already there, with no requirement to slip them through the blood-brain barrier. Eventually they will differentiate into oligodendrocyte cells in white matter, mature glia, and that’s exactly what we want them to do.”

The study team identified Sirt1 as a novel, major regulator of basal oligodendrocyte progenitor cell (OPC) proliferation and regeneration in response to hypoxia in neonatal white matter, Gallo and co-authors write. “We demonstrate that Sirt1 deacetylates and activates Cdk2, a kinase which controls OPC expansion. We also elucidate the mechanism by which Sirt1 targets other individual members of the Cdk2 signaling pathway, by regulating their deacetylation, complex formation and E2F1 release, molecular events which drive Cdk2-mediated OPC proliferation,” says Li-Jin Chew, Ph.D., research associate professor at Children’s Center for Neuroscience Research and a study co-author.

Hypoxia-induced brain injury in neonates initiates spontaneous amplification of progenitor cells but also causes a deficiency of mature oligodendrocytes. Inhibiting Sirt1 expression in vitro and in vivo showed that loss of its deacetylase activity prevents OPC proliferation in hypoxia while promoting oligodendrocyte maturation – which underscores the importance of Sirt1 activity in maintaining the delicate balance between these two processes.

The tantalizing findings – the result of four years of research work in mouse models of neonatal hypoxia – hint at the prospect of lessening the severity of developmental delays experienced by the majority of preemies, Gallo adds. About 1 in 10 infants born in the United States are delivered preterm, prior to the 37^th gestational week of pregnancy, according to the Centers for Disease Control and Prevention. Brain injury associated with preterm birth – including white matter injury – can have long-term cognitive and behavioral consequences, with more than 50 percent of infants who survive prematurity needing special education, behavioral intervention and pharmacological treatment, Gallo says.

Time is of the essence, since Sirt1 plays a beneficial role at a certain place (white matter) and at a specific time (while the immature brain continues to develop). “We see maximal Sirt1 expression and activity within the first week after neonatal brain injury. There is a very narrow window in which to harness the stimulus that amplifies the progenitor cell population and target this particular molecule for repair,” he says.

Sirt1, a nicotinamide adenine dinucleotide-dependent class III histone deacetylase, is known to be involved in normal cell development, aging, inflammatory responses, energy metabolism and calorie restriction, the study team reports. Its activity can be modulated by sirtinol, an off-the-shelf drug that inhibits sirtuin proteins. The finding points to the potential for therapeutic interventions for diffuse white matter injury in neonates.

Next, the research team aims to study these processes in a large animal model whose brains are structurally, anatomically and metabolically similar to the human brain.

“Ideally, we want to be able to promote the timely regeneration of cells that are lost by designing strategies for interventions that synchronize these cellular events to a common and successful end,” Gallo says.

Cleft lip and palate: caught in the web of genetic interactions

December 15, 2016

Children’s National research scientists are working to unravel the complicated web of genetic interactions that lead children to develop cleft lip and palate.

On June 26, 2000, scientists around the world hailed the first draft of the human genetic code as a scientific milestone that eventually would revolutionize the practice of medicine. By knowing the approximately 20,000 protein-coding genes for humans, many speculated that researchers and doctors eventually might elucidate the unique factors that influence thousands of diseases—and, someday, make it easier to find custom ways to treat these conditions.

“It is humbling for me and awe inspiring to realize that we have caught the first glimpse of our own instruction book, previously known only to God,” said Francis S. Collins, M.D., Ph.D., who directed the international effort to sequence the human genome and who now directs the National Institutes of Health.

Nearly two decades later, actually using this wealth of information has proven exceedingly more complicated than many envisioned. While some genetic diseases like Huntington’s disease or sickle cell anemia follow a simple pattern in which variations in a single gene lead to deleterious effects, the vast majority of other genetic health problems result from the interaction of multiple genes, from a handful to hundreds.

One condition that has proven especially tricky to understand on the genetic level is cleft lip and palate (CLP), says Youssef A. Kousa, D.O., Ph.D., a pediatric neurology resident at Children’s National Health System who has made human development a central focus of his research program. CLP, which affects about 1 in 1,000 babies born worldwide, can be devastating, Kousa explains. At some point between 6 and 12 weeks gestation, the palate and lip fail to close in some fetuses. Those children are born with a fissure that can significantly impair eating and speaking and that can complicate social interactions.

While researchers have linked some genes to CLP, Kousa says it has become increasingly clear that these genes do not exert their influence in isolation. In a review paper published recently in Developmental Dynamics, he and Brian C. Schutte, Ph.D., of Michigan State University, detail the story of three of those genes. The trio plays a role in CLP but also is implicated in another devastating congenital problem, neural tube defects.

One of these genes is IRF6, which scientists tagged as the gene responsible for inherited forms of CLP called van der Woude syndrome and popliteal pterygium syndrome more than a decade ago. In the interim, research has shown IRF6 also appears to be important in orofacial clefting that occurs independently of these syndromes. Estimates suggest that mutations in IRF6 increase the risk for CLP by 12 percent to 18 percent.

That means at least 80 percent of the risk for clefting is caused by different genes. Kousa and Schutte write that one of these is GRHL3, which also can cause van der Woude syndrome if it is mutated. GRHL3 is regulated by IRF6, Kousa explains. So, if IRF6 does not work properly, neither does GRHL3.

But what regulates IRF6? Upstream of this important gene is another called TFAP2A. The healthy operation of TFAP2A is key for IRF6 and orofacial clefting. Complicating the scenario further, several studies also have shown that TFAP2A is essential for normal development of the palate and neural tube, the embryo’s precursor to the central nervous system that eventually develops into the brain and spinal cord.

To shed light on the interplay of the full array of genes involved CLP, Kousa and colleagues recently published a paper in Birth Defects Research in which they use computer programs to analyze datasets on all genes identified thus far that are involved in orofacial and neural tube development and which molecules these genes produce and target. Their analyses showed that many of these genes are linked in associated pathways that influence vast realms of development, risk of cancer and folate metabolism. (Women who take folic acid supplements before getting pregnant and during pregnancy can reduce birth defect risks.)

By better understanding how these genes are connected into networks, Kousa says, researchers may be able to reduce the risk of both CLP and neural tube defects with a single intervention. However, like the study of genetic diseases itself, finding the right intervention might not be so simple. A drug or supplement that can alleviate one condition might exacerbate others, based on the complicated web of genetic interactions, he says.

“That’s why work from our lab and others is so important,” Kousa says. “It adds layers and layers of knowledge that, eventually, we’ll be able to put together to help prevent these devastating problems.”

Key to genetic influence of APOL1 on chronic kidney disease

November 23, 2016

Drosophila melanogaster nephrocytes share structural and functional similarities with human renal cells, making the fruit fly an ideal pre-clinical model for studying how the APOL1 gene contributes to renal disease in humans.

Using the Drosophila melanogaster pre-clinical model, a Children’s National Health System research team identified a key mechanism by which the APOL1 gene contributes to chronic kidney disease in people of African descent. The model exploits the structural and functional similarities between the fruit fly’s nephrocytes and renal cells in humans to give scientists an unprecedented ability to study gene-to-cell interactions, identify other proteins that interact with APOL1 in renal disease, and target novel therapies, according to a paper published November 18 in the Journal of the American Society of Nephrology.

“This is one of the hottest research topics in the kidney field. We are the first group to generate this result in fruit flies,” says Zhe Han, Ph.D., a senior Drosophila specialist and associate professor in the Center for Cancer & Immunology Research at Children’s National. Han, senior author of the paper, presented the study results this month during Kidney Week 2016, the American Society of Nephrology’s annual gathering in Chicago that was expected to draw more than 13,000 kidney professionals from around the world.

The advantages of Drosophila for biomedical research include its rapid generation time and an unparalleled wealth of sophisticated genetic tools to probe deeply into fundamental biological processes underlying human diseases. People of African descent frequently inherit a mutant version of the APOL1 gene that affords protection from African sleeping sickness, but is associated with a 17- to 30-fold greater chance of developing certain types of kidney disease. That risk is even higher for individuals infected with the human immunodeficiency virus (HIV). Drosophila renal cells, called nephrocytes, accurately mimic pathological features of human kidney cells during APOL1-associated renal disease.

“Nephrocytes share striking structural and functional similarities with mammalian podocytes and renal proximal tubule cells, and therefore provide us a simple model system for kidney diseases,” says Han, who has studied the fruit fly for 20 years and established the fly nephrocyte as a glomerular kidney disease model in 2013 with two research papers in the Journal of the American Society of Nephrology.

In this most recent study, Han’s team cloned a mutated APOL1 gene from podocyte cells cultured from a patient with HIV-associated nephropathy. They created transgenic flies making human APOL1 in nephrocytes and observed that initially the transgene caused increased cellular functional activity. As flies aged, however, APOL1 led to reduced cellular function, increased cell size, abnormal vesicle acidification, and accelerated cell death.

“The main functions of nephrocytes are to filter proteins and remove toxins from the fly’s blood, to reabsorb protein components, and to sequester harmful toxins. It was surprising to see that these cells first became more active and temporarily functioned at higher levels,” says Han. “The cells got bigger and stronger but, ultimately, could not sustain that enhancement. After swelling to almost twice their normal size, the cells died. Hypertrophy is the way that the human heart responds to stress overload. We think kidney cells may use the same coping mechanism.”

The Children’s research team is a multidisciplinary group with members from the Center for Cancer & Immunology Research, the Center for Genetic Medicine Research, and the Division of Nephrology. The team also characterized fly phenotypes associated with APOL1 expression that will facilitate the design and execution of powerful Drosophila genetic screening approaches to identify proteins that interact with APOL1 and contribute to disease mechanisms. Such proteins represent potential therapeutic targets. Currently, transplantation is the only option for patients with kidney disease linked to APOL1.

“This is only the beginning,” Han says. “Now, we have an ideal pre-clinical model. We plan to start testing off-the-shelf therapeutic compounds, for example different kinase inhibitors, to determine whether they block any of the steps leading to renal cell disease.”

‘Trojan horse’ macrophage TNF-alpha opens door for HIV-1 to enter kidney epithelial cells, causing nephropathy

November 18, 2016

Like a Trojan horse, the macrophage sits atop the epithelial cell with HIV hidden inside, opening a doorway into the kidney cell for high levels of HIV-1 to enter.

When nephrologist Patricio Ray, M.D., began investigating human immunodeficiency virus (HIV) as a renal fellow, children infected with the virus had a life expectancy of no more than seven years, and kids of African descent curiously were developing a type of HIV-related kidney disease.

HIV-associated nephropathy (HIVAN) is a progressive kidney disease seen in people who are both HIV-positive and of African ancestry. Kids who carry a modified protein that protects them against sleeping sickness are 80 times more likely to develop this type of kidney disease. Due to the kidney damage, they can have abnormal amounts of protein in their urine, focal segmental glomerulosclerosis, and microcystic tubular dilation, which can lead to enlarged kidneys and chronic kidney failure.

“No one understood how HIV could affect kidney cells that lack the receptors expressed in T cells and white cells,” recalls Dr. Ray, Robert Parrott Professor of Pediatrics at Children’s National Health System. Virologists said kidney epithelial cells that lacked CD4, a major receptor where HIV attaches, could not be infected with the virus. Nephrologists, meanwhile, were seeing that HIV infection was damaging these cells.

It’s taken two decades to unravel the medical mystery, aided by urine samples he coaxed kids to donate by offering them the latest music from New Kids on the Block in exchange for each urine bottle. Many of the kids died years ago, but their immortalized cells were essential in determining, through a process of elimination, which renal cell types were capable of being infected by HIV-1.

The paper represents the capstone of Dr. Ray’s career.

“This is how difficult it is to get an important contribution in science,” he says. “It’s 20 years of work involving the excellent contributions of many people, but that’s why research is called research. In the end, it’s all a learning process. But, it’s amazing how the puzzle pieces begin to fit. When the puzzle fits, it’s good.”

Dr. Ray, in collaboration with lead author Jinliang Li, Ph.D., and four additional Children’s National co-authors, published a paper November 3 in the Journal of the American Society of Nephrology that establishes a new role for transmembrane TNF-alpha, that of a facilitator that makes it easier for the HIV virus to enter certain cell types and replicate there. Like a Trojan horse, the macrophage sits atop the epithelial cell with HIV hidden inside, opening a doorway into the kidney cell for high levels of HIV-1 to enter.

As a starting point, the research team cultured podocytes from the urine of kids with HIVAN. Through a number of steps, they isolated the unique contributions of the HIV envelope, heparan sulfate proteoglycans as attachment receptors – the glue that binds HIV to podocytes – and the essential role played by TNF-a, a 212-amino acid long type 2 transmembrane protein, in regulating at least two processes, including viral entry and fusion. They used a fluorescent marker to tag HIV-1 viruses, so it lit up bright green. Thus primed with transmembrane TNF-a, the podocytes were susceptible to HIV-1 infection when exposed to high viral loads.

Additional research is needed, such as in vitro work to help understand how HIV traffics within the cell, Dr. Ray says. Those insights could winnow the list of existing therapies that could block key steps, such as attachment to the viral envelope, which could help all people of African descent carrying the genetic mutation, including underserved kids in sub-Saharan Africa.

Another open research question is that certain cells located in the placenta and cervix express TNF-a, and may be more likely to be infected by HIV. Blocking that process could help prevent pregnant HIV-positive mothers from transmitting illness to their offspring.

Minimally invasive surgery brings lasting relief to pediatric achalasia patients

October 27, 2016

Achalasia affects only a small number of people around the world, estimated at 1.6 per 100,000, and children make up fewer than 5 percent of that total. In most cases, the causes are unknown, but it is attributed to a combination of heredity and autoimmune or nerve cell disorders. For adults, treatment might include oral medication to prevent narrowing, balloon dilation, or botulinum toxin injections to relax the muscle at the end of the esophagus. For a growing child, who faces not just months but a lifetime of injections and potential repeat procedures, these methods aren’t viable. Instead, surgical correction is the standard of care. In the past 10 years, the surgical option evolved from a traditional open procedure with weeks of recovery and pain to less-invasive approaches.

“The total number of children with achalasia is small,” says Timothy D. Kane, M.D., Division Chief of General and Thoracic Surgery at Children’s National Health System. “But Children’s National treats more of these cases than most other children’s hospitals around the world, and that gives us the ability to look at a larger population and see what works.”

Dr. Kane is senior author of a study recently published in the Journal of Pediatric Surgery that analyzed the outcomes from nearly a decade’s worth of these cases to gauge the effectiveness of two different minimally invasive surgical approaches for children with achalasia.

A look at the two surgical options

The most common surgical intervention is laparoscopic Heller myotomy, performed through small incisions in the belly. Additionally, Dr. Kane and the Children’s surgical team are one of only two teams in the country who perform a different procedure called peroral endoscopic myotomy (POEM) on children. The POEM procedure is completed entirely through the mouth using an endoscope, with no additional incision needed. The procedure is commonly used for adult achalasia cases, but is not widely available for children elsewhere as it requires specialized training and practice to perform.

“Heller myotomy works very well for most kids — that’s why it’s the standard of care,” Dr. Kane says. “Our study found that patients who underwent the POEM procedure experienced the same successful outcomes as Heller patients, and we already knew from adult data that POEM patients reported less pain following surgery — a win-win for children.”

The retrospective study included all children who had undergone surgical treatment for achalasia at Children’s from 2006 to 2015. Since achalasia cases are few and far between, with most children’s hospitals seeing maybe one to five cases over 10 years, collecting reliable data on outcomes is challenging. This study provides a large enough sample to allow doctors to use the findings as a guide to find the interventions that are the best fit for each patient.

“Now we’re very comfortable presenting families with two really good options and letting them choose the one that works best for them,” he concludes.

Imagine the feeling of food stuck in your throat. For children with esophageal achalasia, that feeling is a constant truth: The muscles in the esophagus fail to function properly and the lower valve, or sphincter, of the esophagus controlling the flow of food into the stomach doesn’t relax enough to allow in food — causing a backup, heartburn, chest pain, and many other painful symptoms. For children, surgery is the best hope for permanent relief.

At AAP: hands-on simulation training with life-saving technology

October 24, 2016

Recent medical breakthroughs have enabled very premature infants and children with rare genetic and neurological diseases to survive what had once been considered to be fatal conditions. This has resulted in a growing number of children with medically complex conditions whose very survival depends on ongoing use of technology to help their brains function, their lungs take in oxygen, and their bodies remain nourished.

“Many pediatricians care for technology-dependent children with special health needs,” says Neha Shah, M.D., M.P.H., an associate professor of pediatrics in the Division of Hospitalist Medicine at Children’s National Health System. “These kids have unique risks – some of which may be associated with that life-saving device malfunctioning.” Because there is no standard residency training for these devices, many clinicians may feel ill-equipped to address their patients’ device-related issues. To bridge that training gap, Dr. Shah and co-presenters, Priti Bhansali, M.D., M.Ed., and Anjna Melwani, M.D., will lead hands-on simulation training during the American Academy of Pediatrics 2016 National Conference.

“Inevitably, these things happen at 3 in the morning,” Dr. Shah adds. “Individual clinicians’ skill level and comfort with the devices varies. We should all have the same core competency.”

How the training works

During the simulation, the audience is given a specific case. They have eight minutes to troubleshoot and resolve the issue, using mannequins specially fitted with devices, such as trach tubes and feeding tubes, in need of urgent attention. Depending on their actions, the mannequin may decompensate with worsened breathing and racing heartbeats. The high-stakes, hands-on demo is followed by a 12-minute debrief, a safe environment to review lessons learned. Once they complete one simulation, attendees move to the next in the series of four real-life scenarios.

“We’ve done this a few times and my heart rate still goes up,” Dr. Shah admits. After giving similar training sessions at other academic meetings, participants said that having a chance to touch and feel the devices and become familiar with them in a calm environment is a benefit.

Dr. Shah came up with the concept for the hands-on training by speaking with a small group of peers, asking about how comfortable they felt managing kids with medical complex cases. The vast majority favored additional education about common devices, such as gastronomy tubes, tracheostomy tubes, and ventriculoperitoneal shunts. In addition to the in-person training, the team has created a web-based curriculum discussing dysautonomia, spasticity, gastroesophageal reflux disease, enteric feeding tubes, venous thromboembolism, and palliative care, which they described in an article published in the Fall 2015 edition of the Journal of Continuing Education in the Health Professions.

“Most times, clinicians know what they need to do and the steps they need to follow. They just haven’t done it themselves,” Dr. Bhansali adds. “The simulation forces people to put their hands on these devices and use them.”

AAP 2016 presentations:
Saturday, October 22, 2016

W1059- “Emergencies in the Technology-Dependent Child: What Every Pediatrician Should Know” 8:30 a.m. to 10 a.m. (SOLD OUT)

W1131- “Emergencies in the Technology-Dependent Child: What Every Pediatrician Should Know” (Encore) 2 p.m. to 3:30PM

Biomarkers sensitive to daily corticosteroid use

September 14, 2016

Using a mass spectrometer, Yetrib Hathout, Ph.D., is able to quantify 3,000 to 4,000 proteins from a tissue sample to identify proteins associated with cancer.

Using a Somascan proteomics assay – which simultaneously analyzes 1,129 proteins in a small volume of serum – a team led by Children’s National Health System researchers identified 21 biomarkers that respond to corticosteroids taken daily by children with Duchenne muscular dystrophy (DMD) and inflammatory bowel disease.

Corticosteroids are commonly prescribed to treat inflammatory conditions. High daily doses of corticosteroids are considered the standard of care for DMD, a type of muscular dystrophy characterized by worsening muscle weakness that affects 1 in 3,600 male infants. However, depending on the age of the child and drug dosage, chronic use is associated with such side effects as changes in bone remodeling that can lead to stunted growth, weight gain, facial puffiness caused by fat buildup, mood changes, sleep disturbances, and immune suppression. The research team sought to identify blood biomarkers that could be leveraged to create a fast, reliable way to gauge the safety and efficacy of corticosteroid use by children. The biomarkers also could guide development of a replacement therapy with fewer side effects.

“Ten pro-inflammatory proteins were elevated in untreated patients and suppressed by corticosteroids (MMP12, IL22RA2, CCL22, IGFBP2, FCER2, LY9, ITGa1/b1, LTa1/b2, ANGPT2 and FGG),” Yetrib Hathout, Ph.D., Proteomic Core Director at Children’s National, and colleagues write in the journal Scientific Reports. “These are candidate biomarkers for anti-inflammatory efficacy of corticosteroids.”

The blood biomarkers sensitive to corticosteroids fit into three broad groups, according to the authors. The children taking corticosteroids were matched with children of the same age who had never taken the medicine. Five biomarkers significantly increased in this corticosteroid-naïve group and decreased in kids prescribed corticosteroids. The biomarkers generally were inflammatory proteins and included chemokine, insulin-like growth factor binding protein 2, and integrin alpha-I/beta-1 complex.

The second group of biomarkers included nine proteins associated with macrophage and T-lymphocytes that were significantly reduced in concentration in kids taking corticosteroids. According to the study, this finding hints at corticosteroids blunting the ability of the immune system’s most able fighters to respond to infection.

In the third group were five proteins that were significantly increased by corticosteroid treatment in DMD and included matrix metalloproteinase 3, carnosine dipeptidase 1, angiotensinogen, growth hormone binding protein, insulin, and leptin, a hormone linked to appetite.

What researchers learned with this study will help them more accurately design the next phase of the work, Hathout says.

“We are the first team to report a number of novel discoveries, including that growth hormone binding protein (GHBP) levels increase with corticosteroid use. This represents a candidate biomarker for stunted growth. In order to use that new information effectively in drug development, the next studies must corroborate the role of serum GHBP levels as predictors of diminished stature,” he adds. “The study finding that four adrenal steroid hormones are depressed in kids taking corticosteroids raises additional questions about the broader impact of adrenal insufficiency, including its role in the delay of the onset of puberty.”

This work was supported by National Institutes of Health grants (R01AR062380, R01AR061875, P50AR060836, U54HD071601, K99HL130035, and R44NS095423) and Department of Defense CDMRP program grant W81XWH-15-1-0265. Additional support was provided by AFM-Telethon (18259) and the Muscular Dystrophy Association USA (MDA353094).