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illustration of lungs with virus

Segmenting viral bronchiolitis patients to better predict clinical outcomes

illustration of lungs with virus

By evaluating viral bronchiolitis patients at first presentation and categorizing them based on clinical phenotype, the researchers were able to better predict outcomes and disease progression patterns.

Researchers from Children’s National Hospital have recently published a pilot study of children with viral bronchiolitis. By evaluating viral bronchiolitis patients at first presentation and categorizing them based on clinical phenotype, the researchers were able to better predict outcomes and disease progression patterns. Nasal airway cytokine levels were also measured to assess the underlying airway immunobiology of different clinical phenotypes. The researchers believe this novel subdivision of viral bronchiolitis patients based on a robust combination of clinical and molecular assessment can help lead to more individualized care and better patient outcomes.

Viral bronchiolitis is broadly used to group together infants with first-time severe viral respiratory infection, which is the most common cause of early life sick visits and hospitalizations worldwide. However, viral respiratory infections can vary significantly in clinical manifestations, which has raised concern among experts that the use of viral bronchiolitis as a catchall term may be compromising patient care. Children’s National researchers hypothesized that a novel segmentation technique of viral bronchiolitis patients by phenotype at first episode could provide better outcome prediction. In addition, lung X-rays and nasal cytokine profiles could help illuminate the underlying airway disease processes that drive the phenotypical differences observed at bedside.

The study examined 50 children ≤ 2 years old, including 41 patients admitted at Children’s National with PCR-confirmed viral respiratory infection and 9 controls. Researchers examined clinical features at presentation by reviewing each patient’s electronic medical record. Key parameters served as the basis for patient segmentation into three phenotypical groups: hypoxemia, wheezing and mild phenotypes. Patients in the hypoxia group (n = 16) were characterized by their need for supplemental oxygen; patients in the wheezing phenotype (n = 16) were distinguished by wheezing or subcostal retractions and patients in the mild phenotype (n = 9) displayed persistent respiratory symptoms but not hypoxia, wheezing or subcostal retractions. Chest x-rays further revealed that patients in the hypoxia phenotype displayed significantly more lung opacities than the other phenotypes.

As hypothesized, the three phenotype groups displayed distinct clinically relevant outcomes. Patients in the hypoxia group had more severe clinical symptoms at presentation and were significantly more likely to require prolonged hospitalization and pediatric intensive care unit (PICU) settings for treatment. Patients in the wheezing phenotype had shorter hospital stays but were significantly more likely to make a respiratory sick visit after initial discharge, with 69% coming back to the hospital with the same symptoms. Patients in the mild phenotype had the shortest hospital stays and did not require transfer to the PICU.

Nasal cytokine profiles were also assessed for all study subjects. Controls had lower cytokine levels than patients, with no significant difference between phenotype groups. However, wheezing patients with ≥1 recurrent respiratory sick visit had higher nasal levels of type 2 cytokines IL-13 and IL-4, consistent with the pathobiology of allergic asthma. This result adds support for the potential of initial sub-setting in guiding timely intervention.

The researchers hope that the strong results of their pilot study will guide clinicians to revise current practices regarding viral bronchiolitis and personalize care of viral respiratory illnesses from first presentation in order to improve outcomes. Study author and Children’s National pulmonologist Maria Arroyo, M.D., says, “if we can prevent these patients from coming [back] to the hospital just by doing a clinical evaluation the first time that they present with [viral respiratory infection]…that would be very impactful.”

The associated article, “Phenotypical Sub-setting of the First Episode of Severe Viral Respiratory Infection Based on Clinical Assessment and Underlying Airway Disease: A Pilot Study,” was published April 2, 2020 in Frontiers in Pediatrics. Notable authors include Maria Arroyo, M.D., Kyle Salka, M.S., and Gustavo Nino, M.D., M.S.H.S., D.A.B.S.M.

preterm baby

Validating a better way to stratify BPD risk in vulnerable newborns

preterm baby

Factoring in the total number of days that extremely preterm infants require supplemental oxygen and tracking this metric for weeks longer than usual improves clinicians’ ability to predict respiratory outcomes according to bronchopulmonary dysplasia severity.

Factoring in the total number of days that extremely preterm infants require supplemental oxygen and tracking this metric for weeks longer than usual improves clinicians’ ability to predict respiratory outcomes according to bronchopulmonary dysplasia (BPD) severity, a research team led by Children’s National Hospital writes in Scientific Reports. What’s more, the researchers defined a brand-new category (level IV) for newborns who receive supplemental oxygen more than 120 days as a reliable way to predict which infants are at the highest risk of returning to the hospital due to respiratory distress after discharge.

About 1 in 10 U.S. infants is born preterm, before 37 weeks gestation, according to the Centers for Disease Control and Prevention. That includes extremely preterm infants who weigh about 1 lb. at birth. These very low birthweight newborns have paper thin skin, frail hearts and lungs that are not yet mature enough to deliver oxygen throughout the body as needed. Thanks to advances in neocritical care, an increasing number of them survive prematurity, and many develop BPD, a chronic lung disease characterized by abnormal development of the lungs and pulmonary vasculature.

“About half of the babies born prematurely will come back to the hospital within the first year of life with a respiratory infection. The key is identifying them and, potentially, preventing complications in this high-risk population,” says Gustavo Nino, M.D., a Children’s National pulmonologist and the study’s lead author.

For decades, the most common way to stratify BPD risk in these vulnerable newborns has been to see if they require supplemental oxygen at 36 weeks corrected gestational age.

“The problem with this classification is it doesn’t take into account the very premature babies who are on oxygen for much longer than other babies. So, we asked the question: Can we continue risk stratification beyond 36 weeks in order to identify a subset of babies who are at much higher risk of complications,” Dr. Nino says.

The longitudinal cohort study enrolled 188 infants born extremely preterm who were admitted to the neonatal intensive care unit (NICU) at Children’s National and tracked their data for at least 12 months after discharge. The team used a multidimensional approach that tracked duration of supplemental oxygen during the newborns’ NICU stay as well as scoring lung imaging as an independent marker of BPD severity. To validate the findings, these U.S.-born newborns were matched with 130 infants who were born preterm and hospitalized at two NICUs located in Bogotá, Colombia.

“Babies who are born very preterm and require oxygen beyond 120 days should have expanded ventilation of the lungs and cardiovascular pulmonary system before going home,” he notes. “We need to identify these newborns and optimize their management before they are discharged.”

And, the babies with level IV BPD risk need a different type of evaluation because the complications they experience – including pulmonary hypertension – place them at the highest risk of developing sleep apnea and severe respiratory infection, especially during the first year of life.

“The earlier we identify them, the better their outcome is likely to be,” Dr. Nino says. “We really need to change the risk stratification so we don’t call them all ‘severe’ and treat them the same when there is a subset of newborns who clearly are at a much higher risk for experiencing respiratory complications after hospital discharge.”

In addition to Dr. Nino, Children’s National study co-authors include Awais Mansoor, Ph.D., staff scientist at the Sheikh Zayed Institute for Pediatric Surgical Innovation (SZI); Geovanny F. Perez, M.D., pediatric pulmonologist; Maria Arroyo, M.D., pulmonologist; Xilei Xu Chen, M.D., postdoctoral fellow; Jered Weinstock, pediatric pulmonary fellow; Kyle Salka, MS, research technician; Mariam Said, M.D., neonatologist, and Marius George Linguraru, DPhil, MA, MSc, SZI principal investigator and senior author. Additional co-authors include Ranniery Acuña-Cordero, Universidad Militar Nueva Granada, Bogotá, Colombia; and Monica P. Sossa-Briceño and Carlos E. Rodríguez-Martínez, both of Universidad Nacional de Colombia.

Funding for research described in this post was provided by the National Institutes of Health (NIH) under award Nos. HL145669, AI130502 and HL141237. In addition, the NIH has awarded Dr. Nino an RO1 grant to continue this research.

Gustavo Nino

Gustavo Nino, M.D., honored with national award from American Thoracic Society

Gustavo Nino

Gustavo Nino, M.D., a pulmonologist who directs the Sleep Medicine program at Children’s National, was honored by the American Thoracic Society with The Robert B. Mellins, M.D. Outstanding Achievement Award in recognition of his contributions to pediatric pulmonology and sleep medicine.

“I am humbled and pleased to be recognized with this distinction,” says Dr. Nino. “This national award is particularly special because it honors both academic achievements as well as research that I have published to advance the fields of pediatric pulmonology and sleep medicine.”

After completing a mentored career development award (K Award) from the National Institutes of Health (NIH), Dr. Nino established an independent research program at Children’s National funded by three different NIH R-level grants, an R01 research project grant; an R21 award for new, exploratory research; and an R4 small business/technology transfer award to stimulate research innovation.

The research team Dr. Nino leads has made important contributions to developing novel models to study the molecular mechanisms of airway epithelial immunity in newborns and infants. He also has pioneered the use of computer-based lung imaging tools and physiological biomarkers to predict early-life respiratory disease in newborns and infants.

Dr. Nino has published roughly 60 peer-review manuscripts including in the “Journal of Allergy and Clinical Immunology,” the “European Respiratory Journal,” and the “American Journal of Respiratory and Critical Care Medicine,” the three top journals in the field of respiratory medicine. He has been invited to chair sessions about sleep medicine during meetings held by the Pediatric Academic Societies, American College of Chest Physicians and the American Thoracic Society (ATS).

Dr. Nino also has served as NIH scientific grant reviewer of the Lung Cellular and Molecular Immunology Section; The Infectious, Reproductive, Asthma and Pulmonary Conditions Section; and The Impact of Initial Influenza Exposure on Immunity in Infants NIH/National Institute of Allergy and Infectious Diseases Special Emphasis Panel.

In addition to his research and academic contributions, over the past five years Dr. Nino has led important clinical and educational activities at Children’s National and currently directs the hospital’s Sleep Medicine program, which has grown to become one of the region’s largest programs conducting more than 1,700 sleep studies annually.

He has developed several clinical multidisciplinary programs including a pediatric narcolepsy clinic and the Advanced Sleep Apnea Program in collaboration with the Division of Ear, Nose and Throat at Children’s National. In addition, Dr. Nino started a fellowship program in Pediatric Sleep Medicine accredited by the Accreditation Council for Graduate Medical Education in collaboration with The George Washington University and has served as clinical and research mentor of several medical students, pediatric residents and fellows.

Asthma is associated with severe obstructive sleep apnea in children

Pulmonologists have often observed a link between asthma and the need for continuous positive airway pressure treatment (CPAP) among children with severe obstructive sleep apnea syndrome (OSAS).

Now, research published in the March 2019 issue of the journal Pediatric Pulmonology confirms the correlation.

Four-hundred eligible children with severe OSAS were included in a randomized, controlled study that took place at Children’s National Health System between September 2015 and June 2017. The mean age among study participants, ages 0 to 20, was 7.

Out of the 400 severe OSAS study participants, 113 children, about one-third, had asthma. Those with asthma were 29% more likely to require CPAP, compared to 14% of study participants without asthma. This association was independent of demographics, OSAS severity, obesity and a history of adenotonsillectomy, an operation to remove the tonsils.

“This is the first randomized, controlled study to test the association between asthma and CPAP among children with severe sleep apnea,” says Gustavo Nino, M.D., a corresponding study author, a pediatric pulmonologist and the director of sleep medicine at Children’s National Health System. “We’ve seen similar patterns in adults, but we needed to confirm the link in children to provide preventive screenings and personalized treatment.”

Dr. Nino mentions the goal now is to detect symptoms earlier, whether this occurs at an annual wellness exam with a pediatrician or at the first visit with a sleep medicine specialist.

“The next step for our research team, or for others interested in this topic, is to explore how these factors influence each other,” adds Dr. Nino. “Asthma itself is worse when you sleep. This leads us to wonder if obstructive sleep apnea exacerbates symptoms of asthma. Or could controlling asthma decrease the risk for CPAP therapy among children with severe obstructive sleep apnea?”

Until these questions have answers, Dr. Nino encourages pediatricians and specialists to keep the association in mind, especially since 7 million children nationwide have asthma, including 13,981 children in the District.

Parents should know that children who have severe obstructive sleep apnea and asthma are more likely to need extensive treatment, like CPAP, to maintain a positive flow of air to the nasal passages to keep the airway open.

Managing symptoms of asthma is also something parents can do at home, especially with the onset of spring asthma triggers, such as pollen, dust, dander, mold and smoke.

For help creating an asthma action plan, visit the Centers for Disease Control and Prevention.

Gustavo Nino

New method may facilitate childhood respiratory research

Gustavo Nino

“The use of CRC is a potentially powerful translational approach to shed light on the molecular mechanisms that control airway epithelial immune responses in infants and young children. This novel approach enables us to study the origins of respiratory disease and its chronic progression through childhood and beyond,” observes Gustavo Nino, M.D., a Children’s pulmonologist and study senior author.

A new method perfected by a team at Children’s National Health System may help expand research into pulmonary conditions experienced by infants and children, an understudied but clinically important age group. The study describing the new technique was published in the December 2017 print edition of Pediatric Allergy and Immunology.

Using conditionally reprogrammed cells (CRCs), a technique that enables indefinite proliferation of cells in the lab, the team was able to produce cell cultures that have a number of advantages over standard cultures and that may make it easier and more efficient to conduct research into pediatric respiratory immune responses.

The epithelial cells that line human airways are crucial in controlling immune responses to viruses, allergens and other environmental factors. The function and dysfunction of these airway epithelial cells (AECs) play a key role in asthma, cystic fibrosis and other pulmonary conditions, many of which begin in early life.

To generate enough of these cells for research, scientists culture AECs from primary nasal and bronchial cell samples. Cells derived from adults have fueled research leading to new therapies and the discovery of key biomarkers. But little comparable research has been conducted in infants. Airway sampling in premature infants has not been reported, likely to due to airway size limitations and underlying comorbidities. Similarly, sampling in infants is limited by the need for bronchoscopy and sedation.

“A major barrier has been the lack of a good system to culture epithelial cells, since airway sampling in infants and children is a challenge,” says co-lead author, Geovanny F. Perez, M.D., co-director of Children’s Severe Bronchopulmonary Dysplasia Program. “We needed a better way to culture cells in this age group.”

While primary AECs do not survive long in the lab, that hurdle was recently overcome by a process that generates CRCs from the primary AECs of adults, making it possible to quickly generate cell cultures from specimens.

In this study, the Children’s team adapted that approach, producing CRCs from primary AECs of neonates and infants. The CRC induction successfully enabled AEC cultures from infants born prematurely and from bronchial specimens of young children.

Geovanny Perez

“A major barrier has been the lack of a good system to culture epithelial cells, since airway sampling in infants and children is a challenge,” says co-lead author, Geovanny F. Perez, M.D., co-director of Children’s Severe Bronchopulmonary Dysplasia Program. “We needed a better way to culture cells in this age group.”

“We found that the CRCs have longer cell life and greater proliferation ability than standard cultures of epithelial cells. They preserved their original characteristics even after multiple experiments. And, they presented an innate immune response similar to that seen in primary human epithelial cells during viral respiratory responses in children,” says Dr. Perez.

“The use of CRC is a potentially powerful translational approach to shed light on the molecular mechanisms that control airway epithelial immune responses in infants and young children. This novel approach enables us to study the origins of respiratory disease and its chronic progression through childhood and beyond,” observes Gustavo Nino, M.D., a Children’s pulmonologist and study senior author.

The authors note that further studies are needed to define more precisely the differences and similarities in the immune responses of CRC and non-CRC derived from primary AEC. However, they conclude that CRC represents a new, effective method to study AEC innate immune responses in infants.

In addition to Drs. Perez and Nino, Children’s Center for Genetic Medicine Research co-authors include Co-Lead Author S. Wolf; Lana Mukharesh; Natalia Isaza Brando, M.D.; Diego Preciado, M.D., Ph.D.; Robert J. Freishtat, M.D., M.P.H.; Dinesh Pillai, M.D.; and M. C. Rose.

Financial support for this research was provided by the National Institute of Allergy and Infectious Diseases under grant number R21AI130502; Eunice Kennedy Shriver National Institute of Child Health and Human Development under grant number HD001399; National Heart, Lung and Blood Institute under grant number HL090020; and National Center for Advancing Translational Sciences under grant number UL1TR000075.

chromosome

X-linked genes help explain why boys of all ages face higher respiratory risk

chromosome

A multi-institution research team that includes Children’s National Health System attempted to characterize gender-based epigenomic signatures in the human airway early in children’s lives with a special attention to defining DNA methylation patterns of the X chromosome.

Human airways already demonstrate gender-based differences in DNA methylation signatures at birth, providing an early hint of which infants may be predisposed to develop respiratory disorders like asthma later in life, a research team reports in a paper published online April 3, 2018, in Scientific Reports.

It’s clear that boys and young men are more likely to develop neonatal respiratory distress syndrome, bronchopulmonary dysplasia, viral bronchiolitis, pneumonia, croup and childhood asthma. Unlike boys, girls have an additional copy of the X chromosome, which is enriched with immune-related genes, some of which play key roles in the development of respiratory conditions. Methylation prevents excessive gene activity in X-linked genes, however much remains unknown about how this process influences infants’ risk of developing airway diseases.

A multi-institution research team that includes Children’s National Health System attempted to characterize gender-based epigenomic signatures in the human airway early in children’s lives with a special attention to defining DNA methylation patterns of the X chromosome.

“It’s clear as we round in the neonatal intensive care unit that baby boys remain hospitalized longer than girls and that respiratory ailments are quite common. Our work provides new insights about gender differences in airway disease risk that are pre-determined by genetics,” says Gustavo Nino, M.D., a Children’s pulmonologist and the study’s senior author.

“Characterizing early airway methylation signatures holds the promise of clarifying the nature of gender-based disparities in respiratory disorders and could usher in more personalized diagnostic and therapeutic approaches.”

The research team enrolled 12 newborns and infants in the study and obtained their nasal wash samples. Six of the infants were born preterm, and six were born full term. The researchers developed a robust gender classification algorithm to generate DNA methylation signals. The machine learning algorithm identified X-linked genes with significant differences in methylation patterns in boys, compared with girls.

As a comparison group, they retrieved pediatric nasal airway epithelial cultures from a study that looked at genomic DNA methylation patterns and gene expression in 36 children with persistent atopic asthma compared with 36 heathy children.

The team went on to classify X-linked genes that had significant gender-based X methylation and those genes whose X methylation was variable.

“These results confirm that the X chromosome contains crucial information about gender-related genetic differences in different airway tissues,” Dr. Nino says. “More detailed knowledge of the genetic basis for gender differences in the respiratory system may help to predict, prevent and treat respiratory disorders that can affect patients over their entire lifetimes.”

In addition to Dr. Nino, study co-authors include Lead Author Cesar L. Nino, bioinformatics scientist, Pontificia Universidad Javeriana; Geovanny F. Perez, M.D., co-director of Children’s Severe Bronchopulmonary Dysplasia Program; Natalia Isaza Brando, M.D., Children’s neonatology attending; Maria J. Gutierrez, Johns Hopkins University School of Medicine; and Jose L. Gomez, Yale University School of Medicine.

Financial support for this research was provided by the National Institutes of Health under award numbers
AI130502-01A1, HL090020, HL125474-03, HD001399, UL1TR000075 and KL2TR000076.

child sleeping

Losing sleep: Severe obstructive sleep apnea

child sleeping

Researchers at Children’s National collected information on 250 children with severe obstructive sleep apnea – defined as at least 10 pauses in breathing in an hour during sleep – who were seen at Children’s National’s Pediatric Sleep Laboratory.

Obstructive sleep apnea (OSA) often starts with a snore that sounds harmless enough. But over time, explains Sasikumar Kilaikode, M.D., a pediatric pulmonary fellow in the Division of Pulmonary Care at Children’s National Health System, this condition can lead to serious health consequences. OSA, caused when the airway becomes periodically blocked during sleep, has a bevy of associated and often serious complications that can affect children, including heart problems and neurocognitive issues, such as learning disabilities.

“Many of the consequences of obstructive sleep apnea are preventable if patients get timely diagnosis and treatment,” Dr. Kilaikode says. “But we haven’t been sure how timely these interventions happen for some of our patients.”

Researchers have reported that conditions such as asthma and probably OSA tend to disproportionally affect children from disadvantaged backgrounds and that the severity of this condition tends to be greater in minority groups. However, Dr. Kilaikode explains, there have been insufficient data about how the most severe form of this condition affects inner city residents, a population that tends to have relatively higher numbers of disadvantaged, minority children – particularly the timeliness of diagnosis and treatment for this group.

To investigate, Dr. Kilaikode, his mentor Gustavo Nino Barrera, M.D., and colleagues collected information on 250 children with severe OSA – defined as at least 10 pauses in breathing in an hour during sleep – who were seen at Children’s National’s Pediatric Sleep Laboratory. This facility performs sleep studies on children during which their oxygen levels, breathing patterns, movements and brain activity are monitored while they snooze in a hospital bed overnight.

Besides their sleep study data, the researchers also collected information about:

  • Risk factors for OSA (such as enlarged tonsils or adenoids, craniofacial abnormalities, asthma, prematurity or obesity)
  • Demographics
  • Duration of symptoms before diagnosis by the overnight sleep study

The vast majority of the 250 children enrolled in the study were African American, reflective of the demographics of the hospital’s service area. The team was surprised to learn that the time to diagnosis for African American study participants was much longer than the time to diagnosis for the non-Latino white study participants.

The team presented these results at the American Thoracic Society 2017 International Conference in Washington, D.C.

“The longer patients take to get diagnosed and treated,” Dr. Kilaikode notes, “the more likely the serious consequences of OSA become permanent.”

He adds that it’s unclear why it took so long for some patients to be diagnosed – the team’s current research efforts are focused on this question. Some of their theories are that families and schools might be unaware of this condition and its symptoms; some families might have limited access to the health care system; probable lack of screening by primary care providers; or problems with health insurance might preclude timely or adequate care.

In the future, he and other members of the Children’s pulmonary team would like to focus OSA education and outreach efforts on people that this study suggests have the greatest need: Minority and low-income families. The first step, Dr. Kilaikode says, is helping families recognize symptoms early.

Symptoms of obstructive sleep apnea include:

  • Snoring
  • Choking, gasping or prolonged pauses in breaths during sleep
  • Daytime fatigue and/or sleepiness
  • Learning problems or difficulty concentrating at school