Impact of Lung Function on Asthma Exacerbation Rates in Children Treated with Dupilumab: The VOYAGE Study

Background

Severe, uncontrolled asthma and asthma exacerbations in children are associated with abnormal lung function and airway development, and increased risk of chronic obstructive lung disease in adulthood. The rationale for this post hoc analysis was to explore the relationship between changes in asthma exacerbation rates and lung function in children treated with dupilumab.

Methods

This post hoc analysis included children aged 6 to 11 years with uncontrolled, moderate-to-severe type 2 asthma (blood eosinophils ≥150 cells/μL or fractional exhaled nitric oxide ≥20 ppb) who received dupilumab or placebo in the phase 3 LIBERTY ASTHMA VOYAGE study (NCT02948959). Endpoints were the proportion of patients achieving clinically meaningful improvements (≥5% or ≥10%) in pre-bronchodilator percent-predicted forced expiratory volume in 1 second (ppFEV1) by Week 12, annualized severe asthma exacerbation rates from Week 12-52, and mean change from baseline in ppFEV1 to Week 12.

Results

At Week 12 of VOYAGE, 141/236 (60%) of children treated with dupilumab and 57/114 (50%) of children receiving placebo showed improvements of ≥5% in ppFEV1; 106/236 (45%) children receiving dupilumab and 36/114 (32%) receiving placebo achieved improvements in ppFEV1 ≥10%. During the Week 12-52 treatment period, dupilumab vs placebo significantly reduced severe exacerbation rates in all subgroups by 52-60% (all P<0.05). Dupilumab treatment resulted in rapid and sustained improvements in ppFEV1 (Week 12 least squares mean difference [95% CI] vs placebo: 3.54 [0.30, 6.78] percentage points; P=0.03) in children who achieved improvements of ≥5%.

Conclusion

Dupilumab vs placebo significantly improved pre-bronchodilator ppFEV1, with a higher proportion of patients achieving a clinically meaningful response at Week 12. Dupilumab also significantly reduced severe exacerbation rates, independent of pre-bronchodilator ppFEV1 response at Week 12.

Trial Registration

NCT02948959.

How Schools Can Help Address Social Determinants of Health in Asthma Management

Schools are in a unique position to address social determinants of health (SDOHs) in pediatric asthma management because of their potential to provide resources and facilitate collaboration with health care providers and services for children at risk within their community. SDOHs include economic factors, educational attainment and health literacy, neighborhood factors and the built environment, social and community aspects including discrimination and racism, and health care access and quality. These factors have a significant impact on asthma health in children, and certain populations such as minoritzed populations and those living in high-poverty environments have been shown to be at greater risk for adverse effects of SDOHs on asthma outcomes. School-based asthma programs address several SDOHs including health literacy, the built environment, and health care quality and access and have been shown to improve asthma outcomes. Key components include connection between the school and the health care team, self-management education, and directly observed therapy. School nurses play a key role in directing and managing effective programs because they can evaluate and support a student's health while considering the effect of SDOHs at interpersonal, institutional, community, and policy levels.

Airway transcriptome networks identify susceptibility to frequent asthma exacerbations in children

BACKGROUND

Frequent asthma exacerbators, defined as those experiencing more than 1 hospitalization in a year for an asthma exacerbation, represent an important subgroup of individuals with asthma. However, this group remains poorly defined and understudied in children.

OBJECTIVE

Our aim was to determine the molecular mechanisms underlying asthma pathogenesis and exacerbation frequency.

METHODS

We performed RNA sequencing of upper airway cells from both frequent and nonfrequent exacerbators enrolled in the Ohio Pediatric Asthma Repository.

RESULTS

Through molecular network analysis, we found that nonfrequent exacerbators display an increase in modules enriched for immune system processes, including type 2 inflammation and response to infection. In contrast, frequent exacerbators showed expression of modules enriched for nervous system processes, such as synaptic formation and axonal outgrowth.

CONCLUSION

These data suggest that the upper airway of frequent exacerbators undergoes peripheral nervous system remodeling, representing a novel mechanism underlying pediatric asthma exacerbation.

Comparison of Caregiver- and Child-Reported Quality of Life in Children With Sleep-Disordered Breathing

OBJECTIVE

Caregivers frequently report poor quality of life (QOL) in children with sleep-disordered breathing (SDB). Our objective is to assess the correlation between caregiver- and child-reported QOL in children with mild SDB and identify factors associated with differences between caregiver and child report.

STUDY DESIGN

Analysis of baseline data from a multi-institutional randomized trial SETTING: Pediatric Adenotonsillectomy Trial for Snoring, where children with mild SDB (obstructive apnea-hypopnea index <3) were randomized to observation or adenotonsillectomy.

METHODS

The Pediatric Quality of Life Inventory (PedsQL) assessed baseline global QOL in participating children 5 to 12 years old and their caregivers. Caregiver and child scores were compared. Multivariable regression assessed whether clinical factors were associated with differences between caregiver and child report.

RESULTS

PedsQL scores were available for 309 families (mean child age, 7.0 years). The mean caregiver-reported PedsQL score was higher at 75.2 (indicating better QOL) than the mean child-reported score of 67.9 (P < .001). The agreement between caregiver and child total PedsQL scores was poor, with intraclass correlation coefficients of 0.03 (95% CI, -0.09 to 0.15) for children 5 to 7 years old and 0.21 (95% CI, 0.03-0.38) for children 8 to 12 years old. Higher child age and health literacy were associated with closer agreement between caregiver and child report.

CONCLUSION

Caregiver- and child-reported global QOL in children with SDB was weakly correlated, more so for young children. In pediatric SDB, child-perceived QOL may be poorer than that reported by caregivers. Further research is needed to assess whether similar trends exist for disease-specific QOL metrics.

Improving Surveillance and Epidemic Response in Ohio Childcare Settings

At the start of the Coronavirus Disease of 2019 (COVID-19) pandemic, the risk of cases in childcare programs was unknown. Thus, a rapid-response research approach was launched in Ohio childcare settings. Passive surveillance data from a state-operated incident reporting system were evaluated to estimate the number of COVID-19 cases from 15 August 2020 to 1 January 2021. Additionally, active surveillance with self-administered reverse transcriptase-polymerase chain reaction (RT-PCR) tests were conducted among staff at 46 childcare programs. Finally, six zoom-based focus groups with program administrators were used to gain feedback. Staff and children in childcare settings contributed 0.38% and 0.15% of the COVID-19 cases in Ohio during this timeframe, respectively. RT-PCR testing identified 3 unrecognized cases (0.88% of tests), and all occurred when the statewide positivity rate was >5%. Focus groups revealed that access to affordable cleaning supplies, masks, and reliable staffing were critical. Perhaps most importantly, we conclude that expanding the incident reporting system to include a childcare census would allow for the tracking of future health problems with highly valuable incidence rate estimations.

Neurobehavioral morbidity of pediatric mild sleep-disordered breathing and obstructive sleep apnea

STUDY OBJECTIVES

Obstructive sleep apnea is associated with neurobehavioral dysfunction, but the relationship between disease severity as measured by the apnea-hypopnea index and neurobehavioral morbidity is unclear. The objective of our study is to compare the neurobehavioral morbidity of mild sleep-disordered breathing versus obstructive sleep apnea.

METHODS

Children 3-12 years old recruited for mild sleep-disordered breathing (snoring with obstructive apnea-hypopnea index < 3) into the Pediatric Adenotonsillectomy Trial for Snoring were compared to children 5-9 years old recruited for obstructive sleep apnea (obstructive apnea-hypopnea 2-30) into the Childhood Adenotonsillectomy Trial. Baseline demographic, polysomnographic, and neurobehavioral outcomes were compared using univariable and multivariable analysis.

RESULTS

The sample included 453 participants with obstructive sleep apnea (median obstructive apnea-hypopnea index 5.7) and 459 participants with mild sleep-disordered breathing (median obstructive apnea-hypopnea index 0.5). By polysomnography, participants with obstructive sleep apnea had poorer sleep efficiency and more arousals. Children with mild sleep-disordered breathing had more abnormal executive function scores (adjusted odds ratio 1.96, 95% CI 1.30-2.94) compared to children with obstructive sleep apnea. There were also elevated Conners scores for inattention (adjusted odds ratio 3.16, CI 1.98-5.02) and hyperactivity (adjusted odds ratio 2.82, CI 1.83-4.34) in children recruited for mild sleep-disordered breathing.

CONCLUSIONS

Abnormal executive function, inattention, and hyperactivity were more common in symptomatic children recruited into a trial for mild sleep-disordered breathing compared to children recruited into a trial for obstructive sleep apnea. Young, snoring children with only minimally elevated apnea-hypopnea levels may still be at risk for deficits in executive function and attention.

TRIAL REGISTRATION

Pediatric Adenotonsillectomy for Snoring (PATS), NCT02562040; Childhood Adenotonsillectomy Trial (CHAT), NCT00560859.

Use of Fractional Exhaled Nitric Oxide to Guide the Treatment of Asthma: An Official American Thoracic Society Clinical Practice Guideline

Background: The fractional exhaled nitric oxide (FE_NO) test is a point-of-care test that is used in the assessment of asthma.

Objective: To provide evidence-based clinical guidance on whether FE_NO testing is indicated to optimize asthma treatment in patients with asthma in whom treatment is being considered.

Methods: An international, multidisciplinary panel of experts was convened to form a consensus document regarding a single question relevant to the use of FE_NO. The question was selected from three potential questions based on the greatest perceived impact on clinical practice and the unmet need for evidence-based answers related to this question. The panel performed systematic reviews of published randomized controlled trials between 2004 and 2019 and followed the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) evidence-to-decision framework to develop recommendations. All panel members evaluated and approved the recommendations.

Main Results: After considering the overall low quality of the evidence, the panel made a conditional recommendation for FE_NO-based care. In patients with asthma in whom treatment is being considered, we suggest that FE_NO is beneficial and should be used in addition to usual care. This judgment is based on a balance of effects that probably favors the intervention; the moderate costs and availability of resources, which probably favors the intervention; and the perceived acceptability and feasibility of the intervention in daily practice.

Conclusions: Clinicians should consider this recommendation to measure FE_NO in patients with asthma in whom treatment is being considered based on current best available evidence.

Burden of prematurity-associated recurrent wheezing: caregiver missed work in the D-Wheeze trial

OBJECTIVE

This study describes the burden of prematurity-associated wheezing in black infants with respect to caregiver missed work.

STUDY DESIGN

We analyzed data from the D-Wheeze trial (ClinicalTrials.gov identifier NCT01601847). Black infants between 28-0/7 to 36-6/7 weeks' gestational age at birth receiving <28 days of supplemental oxygen were enrolled. The primary outcome was missed work to care for the infant in the first year.

RESULTS

147/277 (53.1%) infants had caregivers who reported time off. In an adjusted model, vitamin D supplementation (OR 0.52 [95% CI 0.30-0.89]; P = 0.018), recurrent wheeze (OR 2.26 [95% CI, 1.15-4.44]; P = 0.018), and other children in the household <5 years old (OR 0.45 [95% CI 0.26-0.78]; P = 0.004) were significantly associated with caregiver missed work.

CONCLUSIONS

Black premature infants had a significant burden of caregiver missed work, emphasizing the impact of prematurity-associated wheezing.

Evidence for Exacerbation-Prone Asthma and Predictive Biomarkers of Exacerbation Frequency

Rationale: Cross-sectional studies suggest an exacerbation-prone asthma (EPA) phenotype and the utility of blood eosinophils and plasma IL-6 as predictive biomarkers.Objectives: To prospectively test for EPA phenotype and utility of baseline blood measures of eosinophils and IL-6 as predictive biomarkers.Methods: Three-year asthma exacerbation data were analyzed in 406 adults in the Severe Asthma Research Program-3. Transition models were used to assess uninformed and informed probabilities of exacerbation in year 3. Binomial regression models were used to assess eosinophils and IL-6 as predictive biomarkers.Measurements and Main Results: Eighty-three participants (21%) had ≥1 exacerbation in each year (EPA) and 168 participants (41%) had no exacerbation in any year (exacerbation-resistant asthma). The uninformed probability of an exacerbation in Year 3 was 40%, but the informed probability increased to 63% with an exacerbation in Year 2 and 82% with an exacerbation in Years 1 and 2. The probability of a Year 3 exacerbation with no Year 1 or 2 exacerbations was 13%. Compared with exacerbation-resistant asthma, EPA was characterized by lower FEV₁ and a higher prevalence of obesity, hypertension, and diabetes. High-plasma IL-6 occurred in EPA, and the incident rate ratio for exacerbation increased 10% for each 1-pg/μl increase in baseline IL-6 level. Although high blood eosinophils did not occur in EPA, the incident rate ratio for exacerbations increased 9% for each 100-cell/μl increase in baseline eosinophil number.Conclusions: Longitudinal analysis confirms an EPA phenotype characterized by features of metabolic dysfunction. Blood measures of IL-6, but not eosinophils, were significantly associated with EPA, and IL-6 and eosinophils predicted exacerbations in the sample as a whole.

Correlations between oxygen and positive pressure exposure in the neonatal intensive care unit and wheezing in preterm infants without bronchopulmonary dysplasia

BACKGROUND

Oxygen exposure has been associated with increased wheezing and respiratory morbidity after discharge in extremely preterm infants and those with bronchopulmonary dysplasia. More mature preterm infants with less severe disease are also at risk for pulmonary complications, including rehospitalization for respiratory illnesses and wheezing disorders. Our aim was to evaluate associations between respiratory support and morbidity in preterm infants without bronchopulmonary dysplasia.

METHODS

A secondary analysis was performed on 300 infants born at 28-34 weeks gestation without bronchopulmonary dysplasia. Exposure included oxygen or positive pressure, (continuous positive airway pressure or mechanical ventilation). The primary outcome was recurrent wheezing. Secondary outcomes were respiratory medications, emergency room visits, and hospitalizations.

RESULTS

50% of infants who received oxygen experienced recurrent wheezing compared to 42.4% of infants who did not (OR 1.15 CI 0.72-1.85 adjusted OR 1.15 CI 0.67-1.98). 51.1% of infants who received positive pressure experienced recurrent wheezing compared to 38.1% who did not (OR 1.57 CI 0.97-2.53 adjusted OR 1.58 CI 0.90-2.77). There were no significant associations between oxygen and positive pressure exposure and any primary or secondary outcomes in the adjusted analyses.

CONCLUSIONS

After adjustment for known risk factors the analyses showed no significant associations between oxygen and positive pressure with respiratory morbidity in this population. Further study of infants with mild disease is needed.

Severe asthma during childhood and adolescence: A longitudinal study

BACKGROUND

Morbidity and mortality associated with childhood asthma are driven disproportionately by children with severe asthma. However, it is not known from longitudinal studies whether children outgrow severe asthma.

OBJECTIVE

We sought to study prospectively whether well-characterized children with severe asthma outgrow their asthma during adolescence.

METHODS

Children with asthma were assessed at baseline with detailed questionnaires, allergy tests, and lung function tests and were reassessed annually for 3 years. The population was enriched for children with severe asthma, as assessed by the American Thoracic Society/European Respiratory Society guidelines, and subject classification was reassessed annually.

RESULTS

At baseline, 111 (59%) children had severe asthma. Year to year, there was a decrease in the proportion meeting the criteria for severe asthma. After 3 years, only 30% of subjects met the criteria for severe asthma (P < .001 compared with enrollment). Subjects experienced improvements in most indices of severity, including symptom scores, exacerbations, and controller medication requirements, but not lung function. Surprisingly, boys and girls were equally likely to has resolved asthma (33% vs 29%). The odds ratio in favor of resolution of severe asthma was 2.75 (95% CI, 1.02-7.43) for those with a peripheral eosinophil count of greater than 436 cells/μL.

CONCLUSIONS

In longitudinal analysis of this well-characterized cohort, half of the children with severe asthma no longer had severe asthma after 3 years; there was a stepwise decrease in the proportion meeting severe asthma criteria. Surprisingly, asthma severity decreased equally in male and female subjects. Peripheral eosinophilia predicted resolution. These data will be important for planning clinical trials in this population.

Development and initial validation of the Asthma Severity Scoring System (ASSESS)

BACKGROUND

Tools for quantification of asthma severity are limited.

OBJECTIVE

We sought to develop a continuous measure of asthma severity, the Asthma Severity Scoring System (ASSESS), for adolescents and adults, incorporating domains of asthma control, lung function, medications, and exacerbations.

METHODS

Baseline and 36-month longitudinal data from participants in phase 3 of the Severe Asthma Research Program (NCT01606826) were used. Scale properties, responsiveness, and a minimally important difference were determined. External replication was performed in participants enrolled in the Severe Asthma Research Program phase 1/2. The utility of ASSESS for detecting treatment response was explored in participants undergoing corticosteroid responsiveness testing with intramuscular triamcinolone and participants receiving biologics.

RESULTS

ASSESS scores ranged from 0 to 20 (8.78 ± 3.9; greater scores reflect worse severity) and differed among 5 phenotypic groups. Measurement properties were acceptable. ASSESS was responsive to changes in quality of life with a minimally important difference of 2, with good specificity for outcomes of asthma improvement and worsening but poor sensitivity. Replication analyses yielded similar results, with a 2-point decrease (improvement) associated with improvements in quality of life. Participants with a 2-point or greater decrease (improvement) in ASSESS scores also had greater improvement in lung function and asthma control after triamcinolone, but these differences were limited to phenotypic clusters 3, 4, and 5. Participants treated with biologics also had a 2-point or greater decrease (improvement) in ASSESS scores overall.

CONCLUSIONS

The ASSESS tool is an objective measure that might be useful in epidemiologic and clinical research studies for quantification of treatment response in individual patients and phenotypic groups. However, validation studies are warranted.

Weighing in on asthma: Insights on BMI, magnesium, and hospitalizations from the Ohio Pediatric Asthma Repository

Objective: Little is known about weight status and its effects on clinical course during hospitalization for asthma exacerbation. We sought to evaluate associations between weight status, specifically body mass index (BMI), with inpatient clinical course and clinical history.Methods: We retrospectively analyzed data from 2012 to 2013 on children hospitalized for asthma exacerbation in a state-wide longitudinal cohort, the Ohio Pediatric Asthma Repository. We examined BMI continuously (z scores) and categorically, comparing overweight and obese (Ov/Ob) to non-overweight and non-obese (nOv/nOb) children. We used linear mixed models controlling for site effects to determine if BMI was related to length of stay, as determined by physiologic readiness for discharge (PRD), defined as time to albuterol spaced every 4 h, need for nonstandard care or clinical history.Results: Across six hospitals, 874 children were included in analyses. BMI was positively associated with PRD (p=.008) but this increase was unlikely to be clinically significant. Ov/Ob children were more likely than nOv/nOb to require nonstandard care with repeat magnesium dosing in intensive care after dosing in the emergency department (OR = 3.23, 95%CI 1.39-7.78). Hospitalization in the year prior to enrollment was positively associated with BMI percentile (73.3 vs. 66.0, p=.028). Sleep disordered breathing was also associated with higher BMI percentile (78.2 vs. 65.9; p=.0013).Conclusions: Ov/Ob children had similar PRD to nOv/nOb children and were prone to repeat magnesium dosing. Previous hospitalization for exacerbation was positively associated with increasing BMI percentile. Additional research should investigate differential magnesium use by weight status, quantifying risks and benefits.

Prenatal particulate air pollution exposure and sleep disruption in preschoolers: Windows of susceptibility

BACKGROUND

The programming of sleep architecture begins in pregnancy and depends upon optimal in utero formation and maturation of the neural connectivity of the brain. Particulate air pollution exposure can disrupt fetal brain development but associations between fine particulate matter (PM_2.5) exposure during pregnancy and child sleep outcomes have not been previously explored.

METHODS

Analyses included 397 mother-child pairs enrolled in a pregnancy cohort in Mexico City. Daily ambient prenatal PM_2.5 exposure was estimated using a validated satellite-based spatio-temporally resolved prediction model. Child sleep periods were estimated objectively using wrist-worn, continuous actigraphy over a 1-week period at age 4-5 years. Data-driven advanced statistical methods (distributed lag models (DLMs)) were employed to identify sensitive windows whereby PM_2.5 exposure during gestation was significantly associated with changes in sleep duration or efficiency. Models were adjusted for maternal education, season, child's age, sex, and BMI z-score.

RESULTS

Mother's average age was 27.7 years, with 59% having at least a high school education. Children slept an average of 7.7 h at night, with mean 80.1% efficiency. The adjusted DLM identified windows of PM_2.5 exposure between 31 and 35 weeks gestation that were significantly associated with decreased sleep duration in children. In addition, increased PM_2.5 during weeks 1-8 was associated with decreased sleep efficiency. In other exposure windows (weeks 39-40), PM_2.5 was associated with increased sleep duration.

CONCLUSION

Prenatal PM_2.5 exposure is associated with altered sleep in preschool-aged children in Mexico City. Pollutant exposure during sensitive windows of pregnancy may have critical influence upon sleep programming.

Life Cycle of Childhood Asthma: Prenatal, Infancy and Preschool, Childhood, and Adolescence

Asthma is a heterogeneous developmental disorder influenced by complex interactions between genetic susceptibility and exposures. Wheezing in infancy and early childhood is highly prevalent, with a substantial minority of children progressing to established asthma by school age, most of whom are atopic. Adolescence is a time of remission of symptoms with persistent lung function deficits. The transition to asthma in adulthood is not well understood.

Ohio Pediatric Asthma Repository: Opportunities to Revise Care Practices to Decrease Time to Physiologic Readiness for Discharge

BACKGROUND

Large-scale, multisite studies in which researchers evaluate patient- and systems-level factors associated with pediatric asthma exacerbation outcomes are lacking. We sought to investigate patient-level risks and system-level practices related to physiologic readiness for discharge (PRD) in the prospective Ohio Pediatric Asthma Repository.

METHODS

Participants were children ages 2 to 17 years admitted to an Ohio Pediatric Asthma Repository hospital for asthma exacerbation. Demographics, disease characteristics, and individual hospital practices were collected. The primary outcome was PRD timing (hours from admission or emergency department [ED] presentation until the first 4-hour albuterol spacing).

RESULTS

Data for 1005 participants were available (865 ED presentations). Several nonstandard care practices were associated with time to PRD (P < .001). Continuous pulse oximetry was associated with increased time to PRD (P = .004). ED dexamethasone administration was associated with decreased time to PRD (P < .001) and less ICU admittance and intravenous steroid use (P < .0001). Earlier receipt of chest radiograph, antibiotics, and intravenous steroids was associated with shorter time to PRD (P < .05). Care practices associated with shorter time to PRD varied markedly by hospital.

CONCLUSIONS

Substantial variation in care practices for inpatient asthma treatment exists among children's hospital systems in Ohio. We found several modifiable, system-level factors and therapies that contribute to PRD that warrant further investigation to identify the best and safest care practices. We also found that there was no standardized measure of exacerbation severity used across the hospitals. The development of such a tool is a critical gap in current practice and is needed to enable definitive comparative effectiveness studies of the management of acute asthma exacerbation.

Effects of endogenous sex hormones on lung function and symptom control in adolescents with asthma

BACKGROUND

Although pre-puberty asthma is more prevalent in males, after puberty through middle-age, asthma is more prevalent in females. The surge of sex hormones with puberty might explain this gender switch.

METHODS

To examine the effects of sex hormones on lung function and symptoms with puberty, Tanner stage was assessed in 187 children 6-18 years of age (59% severe) enrolled in the NIH/NHLBI Severe Asthma Research Program (SARP). The effects of circulating sex hormones (n = 68; testosterone, dehydroepiandrosterone sulfate (DHEA-S), estrogen, and progesterone) on lung function and 4 week symptom control (ACQ6) in cross-section were tested by linear regression.

RESULTS

From pre-/early to late puberty, lung function did not change significantly but ACQ6 scores improved in males with severe asthma. By contrast females had lower post-BD FEV₁% and FVC% and worse ACQ6 scores with late puberty assessed by breast development. In males log DHEA-S levels, which increased by Tanner stage, associated positively with pre- and post-BD FEV₁%, pre-BD FVC %, and negatively (improved) with ACQ6. Patients treated with high-dose inhaled corticosteroids had similar levels of circulating DHEA-S. In females, estradiol levels increased by Tanner stage, and associated negatively with pre-BD FEV₁% and FVC %.

CONCLUSIONS

These results support beneficial effects of androgens on lung function and symptom control and weak deleterious effects of estradiol on lung function in children with asthma. Longitudinal data are necessary to confirm these cross-sectional findings and to further elucidate hormonal mechanisms informing sex differences in asthma features with puberty.

TRIAL REGISTRATION

ClinicalTrials.gov registration number: NCT01748175 .

Adjunctive Pharmacotherapies in Children With Asthma Exacerbations Requiring Continuous Albuterol Therapy: Findings From The Ohio Pediatric Asthma Repository

OBJECTIVES

To identify associations between use of ipratropium and/or intravenous magnesium and outcomes of children hospitalized with acute asthma exacerbations and treated with continuous albuterol.

METHODS

Secondary analysis of data from children prospectively enrolled in the multicenter Ohio Pediatric Asthma Repository restricted to only children who were treated with continuous albuterol in their initial inpatient location. Children were treated with adjunctive therapies per the clinical team.

RESULTS

Among 242 children who received continuous albuterol, 94 (39%) received ipratropium only, 13 (5%) received magnesium alone, 42 (17%) received both, and 93 (38%) received neither. The median duration of continuous albuterol was 7.0 (interquartile range [IQR]: 2.8-12.0) hours. Ipratropium use was associated with a shorter duration of continuous albuterol (4.9 [IQR: 2.0-10.0] hours) compared with dual therapy (11.0 [IQR: 5.6-28.6] hours; P = .001), but magnesium use was not (7.5 [IQR: 2.5-16.0] hours; P = .542). In Cox proportional models (adjusted for hospital, demographics, treatment location, and respiratory failure), magnesium was associated with longer durations of continuous albuterol (hazard ratio, 0.54 [95% confidence interval: 0.37-0.77]; P < .001) and hospitalization (hazard ratio, 0.41 [95% confidence interval: 0.28-0.60]; P < .001), but ipratropium was not.

CONCLUSIONS

Ipratropium and magnesium were both often used in children with severe asthma hospitalizations that required continuous albuterol therapy. Magnesium use was associated with unfavorable outcomes, possibly reflecting preferential treatment to patients with more severe cases and differing practices between centers. Given the high prevalence of asthma, wide variations in practice, and the potential to improve outcomes and costs, prospective trials of these adjunctive therapies are needed.

Pediatric Positive Airway Pressure Adherence in Obstructive Sleep Apnea Enhanced by Family Member Positive Airway Pressure Usage

STUDY OBJECTIVES

Adherence to positive airway pressure (PAP) therapy for obstructive sleep apnea (OSA) remains a challenge in children. We hypothesized that the presence of another family member on PAP therapy (parent, sibling, other family member) would be associated with better adherence in the child.

METHODS

We conducted a retrospective chart review to identify children < 18 years of age who had a new diagnosis of OSA between Jan 2011 and May 2013. Outcomes were objective PAP adherence at 1 week, 1 month, and 3 months. Potential predictors included family member on PAP therapy, patient demographics, and clinical characteristics. Group differences between children with and without a family member on PAP therapy were determined using χ(2) test and Wilcoxon two-sample test. PAP adherence measures at each time point and patterns of change across time between the two groups were examined using mixed-effects models.

RESULTS

The final analytic sample included 56 children: age 13.2 ± 3.7 years, 60% male, 67% African American, 65% obese, and 32% with developmental disabilities. The mean obstructive apnea-hypopnea index was 25.2 ± 28.7, and 19 (33%) had a family member on PAP therapy. Overall PAP adherence was 2.8 ± 2.4 h/night at 3 months. At month 3, the group with a family member on PAP therapy had significantly greater average nightly PAP use on all nights (3.6 ± 0.6 vs. 2.3 ± 0.39) and on nights used (4.8 ± 0.6 vs. 3.8 ± 0.40); (p value = 0.04).

CONCLUSIONS

Overall PAP adherence was low, but having a family member on PAP therapy as a "role model" was associated with better adherence.

COMMENTARY

A commentary on this article appears in this issue on page 941.

Heterogeneity in asthma care in a statewide collaborative: the Ohio Pediatric Asthma Repository

BACKGROUND AND OBJECTIVE

Asthma heterogeneity causes difficulty in studying and treating the disease. We built a comprehensive statewide repository linking questionnaire and medical record data with health outcomes to characterize the variability of clinical practices at Ohio children's hospitals for the treatment of hospitalized asthma.

METHODS

Children hospitalized at 6 participating Ohio children's hospitals for asthma exacerbation or reactive airway disease aged 2 to 17 were eligible. Medical, social, and environmental histories and past asthma admissions were collected from questionnaires and the medical record.

RESULTS

From December 2012 to September 2013, 1012 children were enrolled. There were significant differences in the population served, emergency department and inpatient practices, intensive care unit usage, discharge criteria, and length of stay across the sites (all P < .0001, total n = 1012). Public insurance was highest in Cleveland and Cincinnati (72 and 65%). In the emergency department, Cincinnati and Akron had the highest intravenous magnesium sulfate use (37% and 33%); Columbus administered the most intramuscular epinephrine (15%). Cleveland and Columbus had the highest intensive care unit admittance (44% and 41%) and proportion of long-stay patients (95% and 85%). Moderate/severe asthma severity classification was associated with discharge prescription for inhaled corticosteroids (odds ratio = 2.7; 95% confidence interval: 1.6-4.5; P = .004) but not stay length.

CONCLUSIONS

These data highlight the need for standardization of treatment practices for inpatient asthma care. There is considerable opportunity for personalized care plans that incorporate a patient's asthma impairment, risk, and treatment response history into hospital practices for asthma exacerbation treatment. The Ohio Pediatric Asthma Repository is a unique statewide resource in which to conduct observational, comparative effectiveness, and ultimately intervention studies for pediatric asthma.

Sleep and respiratory physiology in children

Maturational changes of breathing during sleep contribute to the unique features of childhood sleep disorders. The clinician's ability to evaluate common disorders related to sleep in children relies on an understanding of normal patterns of breathing during sleep across the ages. This article reviews respiratory physiology during sleep throughout childhood. Specific topics include an overview of respiration during sleep, normal parameters through childhood including respiratory rate, oxygen saturation, and measures of carbon dioxide, normal patterns of apneas throughout childhood, and features of breathing during sleep seen in term and preterm infants.

Assessing the relationship between obesity and asthma in adolescent patients: a review

The parallel rise in the prevalence of obesity and asthma over the last several decades has led to an extensive line of investigation into the relationship between these two conditions. This review will discuss evidence from laboratory-based studies, observational clinical studies, and clinical trials that suggests that obesity adversely influences asthma through multiple mechanisms. The effect of obesity on asthma during adolescence, including asthma incidence, the severity and control of existing asthma, lung function, and exacerbations, will be reviewed.

Sleep-disordered breathing is associated with asthma severity in children

OBJECTIVE

To examine the relationships among obesity, sleep-disordered breathing (SDB, defined as intermittent nocturnal hypoxia and habitual snoring), and asthma severity in children. We hypothesized that obesity and SDB are associated with severe asthma at a 1- year follow-up.

STUDY DESIGN

Children aged 4-18 years were recruited sequentially from a specialty asthma clinic and underwent physiological, anthropometric, and biochemical assessment at enrollment. Asthma severity was determined after 1 year of follow-up and guideline-based treatment, using a composite measure of level of controller medication, symptom burden, and health care utilization. Multivariate logistic regression was used to examine adjusted associations of SDB and obesity with asthma severity at 12-month follow-up.

RESULTS

Among 108 subjects (mean age, 9.1±3.4 years; 45.4% African-American; 67.6% male), obesity and SDB were common, affecting 42.6% and 29.6% of subjects, respectively. After adjusting for obesity, race, and sex, children with SDB had a 3.62-fold increased odds of having severe asthma at follow-up (95% CI, 1.26-10.40). Obesity was not associated with asthma severity.

CONCLUSION

SDB is a modifiable risk factor for severe asthma after 1 year of specialty asthma care. Further studies are needed to determine whether treating SDB improves asthma morbidity.

Obesity and obesity related co-morbidities in a referral population of children with asthma

OBJECTIVE

Although there is mounting evidence that childhood obesity is a risk factor for incident asthma, it remains unclear if there is a distinct "asthma-obesity" phenotype. This study characterized body composition, obesity related co-morbidities, and traditional risk factors for asthma in a cohort of children referred for asthma management in a pulmonary clinic. We hypothesized that children with asthma and obesity would have distinct risk factors and co-morbidities, particularly with respect to metabolic and sleep abnormalities.

PARTICIPANTS AND METHODS

One hundred sixteen asthmatic children ages 4-18 years underwent comprehensive measurements of common asthma risk factors as well as measurements of obesity-related morbidities, including lung function tests, atopy, and assessments of sleep (overnight oximetry and actigraphy), physical activity (accelerometry), and metabolism. Characteristics of children who were obese (BMI > or =95th percentile) were compared to those who were not obese (BMI <95th percentile).

RESULTS

Obesity was present in 44% of participants. Obese participants had similar rates of atopy and family history of atopy, lung function, and asthma control at enrolment as their non-obese peers. A significantly higher proportion of obese participants had metabolic syndrome (23% vs. 0%) and habitual snoring (60% vs. 33%) compared to non-obese participants; insufficient sleep and nocturnal desaturations tended to be more prevalent among obese subjects.

CONCLUSIONS

Obesity and obesity related co-morbidities were common in a referral population of children with asthma. The specific influence of metabolic abnormalities on asthma morbidity and management is still uncertain and likely will need to be addressed in prospective studies.

The role of inhaled corticosteroids in the management of cystic fibrosis

The lung disease of cystic fibrosis (CF) is characterized by a vicious cycle of airway obstruction, chronic bacterial infection, and vigorous inflammation, which ultimately results in bronchiectasis. Recognition that excessive and persistent inflammation is a key factor in lung destruction has prompted investigation into anti-inflammatory therapies. Although effective, the use of systemic corticosteroids has been limited by the unacceptable adverse effect profile. Inhaled corticosteroids (ICS) are a widely prescribed anti-inflammatory agent in CF, likely as a result of clinicians' familiarity with these agents and their excellent safety profile at low doses in asthmatic patients. However, while multiple studies are limited by small sample size and short duration, they consistently failed to demonstrate statistically or clinically significant benefits of ICS use in CF. This review provides an overview of the inflammatory response in CF, the mechanisms of action of corticosteroids, the safety of ICS, and the literature relevant to the use of ICS in CF.

SMAD3 expression is regulated by mitogen-activated protein kinase kinase-1 in epithelial and smooth muscle cells

SMAD3 is a transcription factor that mediates TGF-beta1 signaling and is known to be important in many of the cellular processes that regulate fibrosis and inflammation. Although several studies have examined SMAD3 activation, little is known about the control of SMAD3 expression. It is well established that the mitogen-activated protein kinase (MAPK) pathway is responsive to TGF-beta1 stimulation and coordinates with SMAD signaling in many cases; therefore, the hypothesis of this study is that the MAPK pathway will be involved in the regulation of SMAD3 expression. Using a SMAD3 promoter construct, we demonstrate that inhibition of either c-Jun-N-terminal kinase (JNK) or p38 activity has little effect on SMAD3 promoter function. Inhibition of mitogen-activated protein kinase kinase-1 (MEK1) with either PD98059 or UO126, however, results in a substantial dose-dependent inhibition of SMAD3 promoter activity. Further studies confirm that promoter activity correlates with protein expression by demonstrating reduced SMAD3 protein expression in A549 cells and airway smooth muscle cells after treatment with MEK1 inhibitors. Positive regulation of SMAD3 expression is also demonstrated by expression of a constitutively active (ca)-MEK1 construct, where the presence of ca-MEK1 resulted in increased SMAD3 protein expression. These data lead to the conclusion that MEK1 is an important regulator of SMAD3 expression.

Isoprenoid-mediated control of SMAD3 expression in a cultured model of cystic fibrosis epithelial cells

Several cellular signaling alterations have been identified in cystic fibrosis (CF) epithelium. One of these alterations is reduced SMAD3 protein expression and a corresponding reduction in SMAD3-mediated transforming growth factor-beta1 (TGF-beta1) signaling in CF epithelial cells compared with wild-type (wt) controls. The goal of this study was to identify a mechanism leading to reduced SMAD3 protein expression in CF epithelium. Based on previous work demonstrating isoprenoid-mediated regulation of CF-related alterations in signal transducer and activator of transcription-1 (Stat1) and inducible nitric oxide synthase (NOS2) expression, the hypothesis of this study is that inhibition of isoprenoid-dependent signaling will restore SMAD3 expression and signaling in a model of CF epithelium. Presented data will demonstrate that inhibition of both farnesyl and geranylgeranyl transferase activities partially restores SMAD3-mediated TGF-beta1 signaling and normalizes SMAD3 protein expression in one cultured model of CF cells. Analysis of the human SMAD3 promoter demonstrates that isoprenoid regulation of SMAD3 expression is dependent on Sp1/Sp3 activity, although farnesyl-mediated pathways may be acting through a secondary mechanism as well. Isoprenoid-mediated regulation of SMAD3 expression, coupled with previous data demonstrating isoprenoid control of Stat1 and NOS2 expression, suggest that the isoprenoid/cholesterol synthesis pathway is a critical intermediate in influencing CF-related cell signaling changes.

Glioma cell motility is associated with reduced transcription of proapoptotic and proliferation genes: a cDNA microarray analysis

Microarray analysis of complementary DNA (cDNA) allows large-scale, comparative, gene expression profiling of two different cell populations. This approach has the potential for elucidating the primary transcription events and genetic cascades responsible for increased glioma cell motility in vitro and invasion in vivo. These genetic determinants could become therapeutic targets. We compared cDNA populations of a glioma cell line (G112) exposed or not to a motility-inducing substrate of cell-derived extracellular matrix (ECM) proteins using two sets of cDNA microarrays of 5,700 and 7,000 gene sequences. The data were analyzed considering the level and consistency of differential expression (outliers) and whether genes involved in pathways of motility, apoptosis, and proliferation were differentially expressed when the motility behavior was engaged. Validation of differential expression of selected genes was performed on additional cell lines and human glioblastoma tissue using quantitative RT-PCR. Some genes involved in cell motility, like tenascin C, neuropilin 2, GAP43, PARG1 (an inhibitor of Rho), PLCy, and CD44, were over expressed; other genes, like adducin 3y and integrins, were down regulated in migrating cells. Many key cell cycle components, like cyclin A and B, and proliferation markers, like PCNA, were strongly down regulated on ECM. Interestingly, genes involved in apoptotic cascades, like Bcl-2 and effector caspases, were differentially expressed, suggesting the global down regulation of proapoptotic components in cells exposed to cell-derived ECM. Overall, our findings indicate a reduced proliferative and apoptotic activity of migrating cells. cDNA microarray analysis has the potential for uncovering genes linking the phenotypic aspects of motility, proliferation, and apoptosis.

Low-friction arthroplasty with Boneloc bone-cement: outcome at 2 to 4 years

We report the clinical and radiologic outcome of 109 Chamley low-friction arthroplasties implanted with Boneloc bone-cement (Biomet, Bridgend, South Wales, UK) into 104 patients. The mean follow-up was 30 months (range, 2-48 months). There were 72 women (mean age, 71 years) and 32 men (mean age, 72). Cartridge-packed cement was used in 37 cases and vacuum-packed cement in 72 cases. Survivorship analysis based on revision for aseptic loosening showed 79% survival at 4 years. Seventeen (15.5%) hips have been revised for aseptic loosening to date, in which all stems and 4 cups were loose. Extensive femoral osteolysis was always present and resulted in 4 cases of femoral cortical perforation at revision. Survivorship analysis based on revision and radiologic failure showed only 55% survival over the same period. When radiologic loosenings were included as failures, the vacuum-packed cement performed significantly worse than the cartridge-packed cement it replaced. These poor results were consistent with the withdrawal of Boneloc from clinical use in 1995, and we recommend indefinite follow-up for surviving prostheses.

Effects on plasma glucose concentration of light-for-date infants and infants of diabetic mothers of feeds supplemented with a glucose polymer

Serial plasma glucose estimations were performed in 44 light-for-date infants and 17 infants of diabetic mothers fed 2, 3 or 4-hourly with feeds containing 10% additional carbohydrate in the form of a glucose polymer (Caloreen). In the infants fed 2 and 3-hourly, plasma glucose was higher following the high carbohydrate feeds, particularly immediately before the next feed was due. Given 4-hourly, the high carbohydrate feed had little effect in most light-for-date infants, and in one light-for-date infant and two infants of diabetic mothers the plasma glucose was lower at the end of 4 hours than following normal formula. It is concluded that the addition of glucose polymer to feeds given 2 and 3 hourly has a potentially useful effect in neonates at risk of developing hypoglycaemia, but it cannot be used to increase the feed interval to 4 hours.

The effect of posture on ventilation and lung mechanics in preterm and light-for-date infants

The effect of right lateral, supine, and prone postures on ventilation and lung mechanics was studied in 23 healthy newborn infants, ten preterm and 13 term, "light-for-date," In the preterm group, tidal volume, minute volume, elastic work, inspiratory viscous work, total viscous work, and the total work of breathing were significantly greater in the prone position than in the supine position. Results obtained in the lateral position did not differ significantly from those in the prone or supine positions. Posture did not significantly affect tidal volume or lung mechanics in the light-for-date infants. The prone position is suggested to be the optimum nursing posture for healthy preterm infants.