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Children with asthma are at risk for low lung function extending into adulthood, but understanding of clinical predictors is incomplete.We sought to determine phenotypic factors associated with FEVLung function was measured at baseline and annually. Multivariate linear mixed-effects models were constructed to assess the effect of baseline and time-varying predictors of prebronchodilator FEVA total of 862 spirometry assessments were performed for 188 participants. Factors associated with FEVIn children with severe and nonsevere asthma, several clinically relevant factors predict FEV

Asthma is a heterogeneous disease, with multiple underlying inflammatory pathways and structural airway abnormalities that impact disease persistence and severity. Recent progress has been made in developing targeted asthma therapeutics, especially for subjects with eosinophilic asthma. However, there is an unmet need for new approaches to treat patients with severe and exacerbation-prone asthma, who contribute disproportionately to disease burden. Extensive deep phenotyping has revealed the heterogeneous nature of severe asthma and identified distinct disease subtypes. Acurrent challenge in the field is to translate new and emerging knowledge about different pathobiologic mechanisms in asthma into patient-specific therapies, with the ultimate goal of modifying the natural history of disease. Here, we describe the Precision Interventions for Severe and/or Exacerbation-Prone Asthma (PrecISE) Network, a groundbreaking collaborative effort of asthma researchers and biostatisticians from around the United States. The PrecISE Network was designed to conduct phase II/proof-of-concept clinical trials of precision interventions in the population with severe asthma, and is supported by the National Heart, Lung, and Blood Institute of the National Institutes of Health. Using an innovative adaptive platform trial design, the PrecISE Network will evaluate up to 6 interventions simultaneously in biomarker-defined subgroups of subjects. We review the development and organizational structure of the PrecISE Network, and choice of interventions being studied. We hope that the PrecISE Network will enhance our understanding of asthma subtypes and accelerate the development of therapeutics for severe asthma.

Background Despite advances in asthma care, disparities persist. Black patients are disproportionally affected by asthma and also have poorer outcomes compared with white patients. Objective We sought to determine associations between black and white patients and asthma-related health care use, accounting for complex relationships. Methods This study was completed as part of the National Heart, Lung, and Blood Institute's Severe Asthma Research Program, a prospective observational cohort. Between November 2012 and February 2015, it enrolled 579 participants 6 years and older with 1 year of observation time and complete data. Inverse probability of treatment weighting was used to balance racial groups with respect to community and family socioeconomic variables and environmental exposure variables. The primary outcome was emergency department (ED) use for asthma. Secondary outcomes included inhaled corticosteroid use, outpatient physician's office visits for asthma, and asthma–related hospitalization. Results Black patients had greater odds of ED use over 1 year (odds ratio, 2.19; 95% CI, 1.43-3.35) but also differed in the majority (>50%) of baseline variables measured. After statistical balancing of the racial groups, the difference between black and white patients with respect to ED use no longer reached the level of significance. Instead, in secondary analyses black patients were less likely to see an outpatient physician for asthma management (adjusted odds ratio, 0.57; 95% CI, 0.38-0.85). Conclusions The disparity in ED use was eliminated after consideration of multiple variables. Social and environmental policies and interventions tailored to black populations with a high burden of asthma are critical to reduction (or elimination) of these disparities.

Background: Severe asthma has multiple phenotypes for which biomarkers are still being defined. Plasma P-selectin reports endothelial and/or platelet activation. Objective: To determine if P-selectin is associated with features of asthma in a longitudinal study. Methods: Plasmas from 70 adult patients enrolled in the Severe Asthma Research Program (SARP) III at the University of Wisconsin-Madison were analyzed for concentration of P-selectin at several points over the course of 3 years, namely, at baseline (BPS), after intramuscular triamcinolone acetonide (TA) injection, and at 36 months after baseline. Thirty-four participants also came in during acute exacerbation and 6 weeks after exacerbation. Results: BPS correlated inversely with forced expiratory volume in 1 s (FEV1) and with residual volume/total lung capacity, an indicator of air trapping. BPS was inversely associated with FEV1 change after TA, by regression analysis. FEV1 did not change significantly after TA if BPS was above the median, whereas patients with BPS below the median had significantly increased FEV1 after TA. BPS was higher in and predicted assignment to SARP phenotype cluster 5 (“severe fixed-airflow asthma”). P-selectin was modestly but significantly increased at exacerbation but returned to baseline within 3 years. Conclusions: High BPS is associated with airway obstruction, air trapping, the “severe fixed-airflow” cluster, and lack of FEV1 improvement in response to TA injection. P-selectin concentration, which is a stable trait with only modest elevation during exacerbation, may be a useful biomarker for a severe asthma pheno- or endotype characterized by low pulmonary function and lack of corticosteroid responsiveness.

Background There is an unmet need for an objective biomarker to predict asthma exacerbations. Objective Our aim was to assess the ventilation defect percent (VDP) on hyperpolarized helium-3 magnetic resonance imaging as a predictor of exacerbation frequency following imaging. Methods Subjects underwent hyperpolarized helium-3 and conventional clinical measurements, including pulmonary function tests, during a period of disease stability, and exacerbations were recorded prospectively over the following 2 years. We used a Poisson regression tree model to estimate an optimal VDP threshold for classifying subjects into high- versus low-exacerbation groups and then used statistical regression to compare this VDP threshold against conventional clinical measures as predictors of exacerbations. Results A total of 67 individuals with asthma (27 males and 40 females, 28 with mild-to-moderate asthma and 39 with severe asthma) had a median VDP of 3.75% (1.2% [first quartile]-7.9% [third quartile]). An optimal VDP threshold of 4.28% was selected on the basis of the maximum likelihood estimation of the regression tree model. Subjects with a VDP greater than 4.28% (n = 32) had a median of 1.5 exacerbations versus 0.0 for subjects with a VDP less than 4.28% (n = 35). In a stepwise multivariate regression model, a VDP greater than 4.28% was associated with an exacerbation incidence rate ratio of 2.5 (95% CI = 1.3-4.7) versus a VDP less than or equal to 4.28%. However, once individual medical history was included in the model, VDP was no longer significant. Nonetheless, VDP may provide an objective and complementary quantitative marker of individual exacerbation risk that is useful for monitoring individual change in disease status, selecting patients for therapy, and assessing treatment response. Conclusion VDP measured with magnetic resonance imaging shows promise as a biomarker of prospective asthma exacerbations.

RATIONALE: In practice, asthma control is assessed according to symptom burden and office spirometry. However spirometry poorly tests peripheral lung function, which may be abnormal in asthma. Impluse oscillometry (IOS) and multiple-breath washout (MBW) are novel methods which measure reactance (X5) and ventilation heterogeneity (VH) in the peripheral lung, but how well these tests reflect asthma control is poorly understood. OBJECTIVE: To compare the diagnostic accuracy of tests of large airways caliber (FEV¬1¬, FEV¬1-/FVC, R20), peripheral zone properties (X5, VH), and airways inflammation (FeNO) as predictors of poor control in asthmatic children (44 poorly-controlled/10 controlled). METHODS: 54 children enriched in severe asthma completed a symptom-based control scale (ACT/cACT) and lung function tests after overnight bronchodilator withhold. The accuracy of each variable to predict poor control was ranked by area under the receiver operating characteristic (ROC) curve, sensitivity, and specificity. RESULTS: Among measures of large airways caliber, the FEV¬1¬% had the highest ROC curve area, with low sensitivity but perfect specificity. Among measures of peripheral lung function, X5 and VH in the conducting zone had fair curve areas with higher sensitivity but lower specificity compared to the FEV¬1¬%. VH in the acinar zone and FeNO both had poor accuracy. CONCLUSION: Tests of large airway and peripheral zone lung function performed disparately as predictors of poor control in a sample of children enriched in severe asthma. Further studies in a larger sample with more diverse phenotypic features are necessary to validate this preliminary conclusion.

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.

Background The effect of age on asthma severity is poorly understood. Objectives The objective of this study was to compare the baseline features of severe and nonsevere asthma in the Severe Asthma Research Program (SARP) III cohort, and examine in cross section the effects of age on those features. Methods SARP III is a National Institutes of Health/National Heart Lung Blood Institute multisite 3-year cohort study conducted to investigate mechanisms of severe asthma. The sample included 188 children (111 severe, 77 nonsevere) and 526 adults (313 severe, 213 nonsevere) characterized for demographic features, symptoms, health care utilization, lung function, and inflammatory markers compared by age and severity. Results Compared with children with nonsevere asthma, children with severe asthma had more symptoms and more historical exacerbations, but no difference in body weight, post-bronchodilator lung function, or inflammatory markers. After childhood, and increasing with age, the cohort had a higher proportion of women, less allergen sensitization, and overall fewer blood eosinophils. Enrollment of participants with severe asthma was highest in middle-aged adults, who were older, more obese, with greater airflow limitation and higher blood eosinophils, but less allergen sensitization than adults with nonsevere asthma. Conclusions The phenotypic features of asthma differ by severity and with advancing age. With advancing age, patients with severe asthma are more obese, have greater airflow limitation, less allergen sensitization, and variable type 2 inflammation. Novel mechanisms besides type 2 inflammatory pathways may inform the severe asthma phenotype with advancing age.

BACKGROUND: Comparisons of the technical acceptability of spirometry and impulse oscillometry (IOS) and clinical correlations of the measurements have not been well studied in young children. There are no large studies focused on African American and Hispanic children. OBJECTIVES: We sought to (1) compare the acceptability of spirometry and IOS in 3–5 year old children and (2) examine the relationship of maternal smoking during pregnancy to later lung function. METHODS: Spirometry and IOS were attempted at 4 sites from the URECA birth cohort at ages 3, 4 and 5 years (472, 471 and 479 children respectively). We measured forced expiratory flow in 0.5 sec (FEV(0.5)) with spirometry and area of reactance (A(X)), resistance and reactance at 5 Hz (R5 and X5 respectively) using IOS. RESULTS: Children were more likely to achieve acceptable maneuvers with spirometry than with IOS at age 3 (60% vs 46%, p< 0.001) and 5 years (89% vs 84%, p=0.02). Performance was consistent among the 4 study sites. In children without recurrent wheeze, there were strong trends for higher FEV(0.5) and lower R5 and A(X) over time. Maternal smoking during pregnancy was associated with higher A(X)at ages 4 and 5 years (p

Background Sex influences the risk of wheezing illnesses and the prevalence of asthma throughout childhood. Objective To better understand the mechanisms of these effects, we analyzed longitudinal relationships between sex, lung physiology, and asthma in the Childhood Origins of ASThma birth cohort study. Methods Childhood Origins of ASThma birth cohort study children were followed prospectively from birth and assessed annually. Results of spirometry, fractional exhaled nitric oxide (Feno), mannitol provocation testing, and 3 He gas magnetic resonance imaging were assessed by sex using multivariate models including age, asthma diagnosis, and wheezing histories. Results Girls had higher prebronchodilator forced expiratory volume in 0.5 seconds/forced vital capacity values than did boys (mean difference, 0.017; 95% CI, 0.000-0.034; P = .05) of equivalent age. Postbronchodilator findings were more pronounced, with boys demonstrating reduced forced expiratory volume in 0.5 seconds/forced vital capacity values than did girls of equivalent age (mean difference, 0.032; 95% CI, 0.014-0.049; P = .0005). Conversely, girls were noted to have higher ventilation defects on 3 He magnetic resonance imaging than did boys ( P = .01). No differences were noted in the rate of positive responses to mannitol provocation or Feno measurements. Conclusions Lower airflow values are present by spirometry for prepubertal boys than for age-matched girls; however, greater 3 He ventilation defects were noted in girls. This could represent a greater degree of subclinical air trapping in prepubertal girls because residual volumes are not detected on standard spirometric readings. No differences were noted between the 2 sexes with airway hyperresponsiveness (mannitol provocation testing) or inflammation (Feno). Prospective peripubertal follow-up will determine whether these differences persist or change with the de novo expression and remission of asthma based on sex and age.

BACKGROUND: Small airways instability, resulting in premature airway closure, has been recognized as a risk for asthma severity and poor control. Although spirometry has limited sensitivity for detecting small airway dysfunction, a focus on the air-trapping component of obstruction may identify a risk factor for asthma instability. OBJECTIVE: To use spirometric measurements to identify patterns of airway obstruction in children, and define obstruction phenotypes that relate to asthma instability. METHODS: Pre- and post-bronchodilation spirometry data were obtained from 560 children in the Asthma Phenotypes in the Inner City study. An air-trapping obstruction phenotype (A Trpg) was defined as forced vital capacity (FVC) Z-score < −1.64, or an increase of FVC ≥ 10% predicted with bronchodilation. The airflow limitation phenotype (A Limit) had forced expiratory volume in 1 s (FEV(1))/FVC Z-score < −1.64, but not A Trpg. The None phenotype had neither A Trpg nor A Limit. The 3 obstruction phenotypes were assessed as predictors of number of exacerbations, asthma severity, and airway lability. RESULTS: The A Trpg phenotype (14% of the cohort) had more exacerbations during the 12-month study, compared with the A Limit (P

Ventilation defect percent (VDP) measured in asthmatics with hyperpolarized helium-3 MRI was more strongly associated with ED visits and hospitalizations due to asthma exacerbation than were conventional biomarkers of lung function and inflammation.

Viral infections are closely linked to wheezing in infancy, and those children with recurrent virus-induced wheezing episodes are at great risk for chronic childhood asthma. Infancy is a time of increased susceptibility to viral infections, and this stage is also characterized by pulmonary alveolar multiplication and extensive remodeling of the airways to accommodate growth. This coincidence, together with the observation that children with asthma can have structural lung changes and functional deficits at an early age, suggests that viral infections could adversely affect lung development. Inflammatory mediators induced by viral infection are known to have effects on the remodeling process, suggesting a plausible mechanism to support this theory. Furthermore, animal models of viral infection during lung growth and development suggest that developmental factors are important in determining the consequences of infection on long-term lung function. Greater understanding of the effects of viral infections on lung development and growth in early childhood might lead to the discovery of additional strategies for the prevention of recurrent wheezing and chronic asthma.

Studies with isolated cells are important to the understanding of mechanisms by which eosinophils participate in allergic inflammation. Due to species variability, isolation techniques and cell biology need to be defined for each source. We developed methods to obtain rat eosinophils with purity and viability exceeding 90%, characterized the superoxide anion production of these cells in response to standard activators, and compared these results with those previously obtained in our laboratories with the use of human eosinophils. Rat eosinophils responded vigorously to phorbol myristate acetate and poorly to platelet-activating factor and to N-formyl-methionyl-leucyl-phenylalanine, parallel to the responses of human eosinophils. In contrast, rat eosinophils responded unlike human eosinophils to other activators, having a larger response to calcium ionophore A23187, a smaller response to serum-treated or serum-opsonized zymosan, and a negative rather than positive modulatory effect of cytochalasin B. We conclude that rat eosinophils can be obtained in high purity and with intact responsiveness to a number of different activators.

Background Coagulation Factor XIII (FXIII) plays an important role in wound healing by stabilizing fibrin clots and cross-linking extracellular matrix proteins. FXIII is expressed in cells of the monocyte/macrophage and dendritic cell lineages in response to type 2 cytokines. Objective We sought to determine the association between FXIII and asthma pathobiology. Methods We analyzed the expression of FXIII mRNA and protein levels in bronchoalveolar lavage samples obtained before and after segmental allergen challenge from patients with mild asthma and in induced sputum samples collected from patients with mild-to-moderate and severe asthma. Results FXIII mRNA and protein levels were highly upregulated in bronchoalveolar cells and fluid after allergen challenge and mRNA levels correlated with protein levels. In sputum of asthmatic patients, FXIII expression was positively correlated with type 2 immune response and dendritic cell markers (CD209 and CD207). FXIII expression was also associated with increased airflow limitation (FEV 1 /forced vital capacity and residual volume/total lung capacity ratios) and greater reversibility to β-agonists. Conclusions FXIII expression was upregulated in the airways of asthmatic patients after allergen exposure. Expression in the sputum of asthmatic patients correlated with the type 2 immune response and airflow limitation. Excessive activity of FXIII could contribute to the pathophysiology of airway obstruction in asthmatic patients.

Background Outcomes of pulmonary physiology have a central place in asthma clinical research. Objective At the request of National Institutes of Health (NIH) institutes and other federal agencies, an expert group was convened to provide recommendations on the use of pulmonary function measures as asthma outcomes that should be assessed in a standardized fashion in future asthma clinical trials and studies to allow for cross-study comparisons. Methods Our subcommittee conducted a comprehensive search of PubMed to identify studies that focused on the validation of various airway response tests used in asthma clinical research. The subcommittee classified the instruments as core (to be required in future studies), supplemental (to be used according to study aims and in a standardized fashion), or emerging (requiring validation and standardization). This work was discussed at an NIH-organized workshop in March 2010 and finalized in September 2011. Results A list of pulmonary physiology outcomes that applies to both adults and children older than 6 years was created. These outcomes were then categorized into core, supplemental, and emerging. Spirometric outcomes (FEV 1 , forced vital capacity, and FEV 1 /forced vital capacity ratio) are proposed as core outcomes for study population characterization, for observational studies, and for prospective clinical trials. Bronchodilator reversibility and prebronchodilator and postbronchodilator FEV 1 also are core outcomes for study population characterization and observational studies. Conclusions The subcommittee considers pulmonary physiology outcomes of central importance in asthma and proposes spirometric outcomes as core outcomes for all future NIH-initiated asthma clinical research.

After viral bronchiolitis at an early age, a chronic asthma-like syndrome develops in BN, but not F344, rats. We hypothesized that the BN strain is less effective at clearing virus from the involved tissues. Weanling BN and F344 rats were inoculated with Sendai virus, and lung and peribronchial lymph nodes were harvested from each strain at 5 to 84 days after infection; control tissues were obtained from noninfected rats. Lung viral titers were similar for the 2 strains, with no infectious virus detectable by day 10. However, viral RNA was detected consistently by means of RT-PCR analyses in lungs and lymph nodes of both strains from days 10 to 27 and was still present at day 84 in some of the tissues from each strain. In contrast, there were strain-related differences in immune responses because IL-13 levels remained increased in the lung secretions of BN rats at 4 weeks after inoculation. Thus although Sendai virus could persist for at least 3 months after an acute infection in rats, this did not differ with strain. The persistent increase in IL-13 suggests instead that the strain-related variability in virus-associated airway pathology might be determined by the host response to infection rather than by the intensity or duration of infection. (J Allergy Clin Immunol 2002;110:607-9.)

To evaluate the association of various leukocytes with pulmonary resistance and methacholine responsiveness, we induced pulmonary eosinophil-rich inflammation in IgE-sensitized (ovalbumin) Sprague Dawley rats. Sensitized rats were challenged with either relevant (OA) or irrelevant antigen by tracheal insufflation a) with no other treatment, b) in conjunction with intravenous Sephadex beads pretreatment, or c) with antigen coupled covalently to Sepharose beads. About 24 h after antigen challenge, respiratory system resistance (Rrs), response to aerosolized methacholine, and pulmonary histopathology were evaluated. Challenge with OA, insufflation with Sepharose, and treatment with i.v. Sephadex all independently increased inflammatory cell infiltrates, but the combination of OA with the other agents did not significantly enhance the inflammatory response over OA alone. Interactive stepwise regression techniques were utilized to identify correlates for Rrs and methacholine responsiveness. Mononuclear cell score was a significant predictor (p < .01) for Rrs, and insufflation of Sepharose had a significant independent effect on Rrs (p = .01) above that predicted by mononuclear cell infiltrates. Conversely, eosinophil score and neutrophil score were not significant predictors for Rrs, and challenges with antigen or Sephadex had no significant independent effect on Rrs beyond that predicted from mononuclear cell infiltrates. Eosinophil score was the only significant histological predictor for methacholine responsiveness (p < .0001). Challenges with Sephadex, antigen and Sepharose did not significantly change methacholine responsiveness independently of the changes associated with eosinophil infiltrates. These findings suggest that mononuclear cells and eosinophils contribute to increases in airway resistance and responsiveness, respectively, following the induction of pulmonary inflammation by both allergic and non-allergic stimuli.

In this cross-sectional evaluation of 77 severe and 71 non-severe asthmatics ages 6–17, boys, unlike girls with severe asthma, exhibited adult-like patterns of air-trapping and post-bronchodilator airflow limitation, apparently coincident with the onset of the severe asthma phenotype.

Background Rhinovirus infections are frequent causes of asthma exacerbations. Objective This study was conducted to test whether subjects with and without allergic asthma have different responses to infection and to identify baseline patient risk factors that predict cold outcomes. Methods Twenty subjects with mild persistent allergic asthma and 18 healthy subjects were experimentally inoculated with rhinovirus-16. Subjects were evaluated at baseline, during the acute infection, and during recovery for asthma and cold symptoms by using a validated questionnaire. Sputum and nasal lavage fluid were evaluated for viral shedding, cytokines, and cellular inflammation. Results There were no group-specific significant differences in peak cold symptom scores (10.0 ± 5.8 vs 11.1 ± 6.2, asthmatic vs healthy subjects), peak nasal viral titers (log 10 4.3 ± 0.8 vs 3.7 ± 1.4 50% tissue culture infective dose/mL, respectively), or changes in peak flow during the study (10% ± 10% vs 8% ± 6%, respectively). Rhinovirus-16 infection increased peak asthma index values in the asthmatic group (median, 6 → 13; P = .003) but only marginally in the healthy group (median, 4 → 7; P = .09). More asthmatic subjects had detectable eosinophils in nasal lavage and sputum samples at baseline and during infection, but otherwise, cellular and cytokine responses were similar. Baseline sputum eosinophilia and CXCL8 (IL-8) levels were positively associated with cold symptoms, whereas CCL2 (monocyte chemotactic protein 1) levels were inversely associated with nasal viral shedding. Conclusions These findings suggest that subjects with mild allergic asthma and healthy subjects have similar cold symptoms and inflammatory and antiviral responses. In addition, eosinophilia and other selective baseline measures of airway inflammation in subjects with or without asthma might predict respiratory outcomes with rhinovirus infection.

Background Infiltration, accumulation, and degranulation of eosinophils in the lung are hallmarks of active allergic asthma. The pulmonary response to inhaled allergen triggers the secretion of eosinophil chemoattractants and antiapoptotic cytokines, including GM-CSF, IL-3, IL-4, IL-5, and eotaxin, among others. We recently showed that in vitro Pin1 regulated eosinophil production of and response to GM-CSF. Objective We sought to determine the effect of Pin1 inhibition on pulmonary eosinophilia after allergen challenge. Methods The Pin1 inhibitor juglone (5-hydroxy-1,4-naphthoquinone) was administered to allergen-sensitized and allergen-challenged Brown Norway rats. Bronchoalveolar lavage fluid and lungs were assessed for inflammation, cytokine expression, and Pin1 activity. Results Juglone-treated rats showed a dramatic reduction (approximately 75%) in bronchoalveolar lavage fluid and pulmonary eosinophilia but no change in lymphocyte, monocyte/macrophage, or neutrophil numbers. GM-CSF and IL-5 expression were also significantly reduced, whereas Pin1-independent cytokines, such as eotaxin or IL-4, as well as housekeeping mRNAs and proteins, including actin, were unaffected by juglone. The eosinophils present in the lung in juglone-treated rats showed significantly greater apoptosis. Conclusion These data suggest that in vivo Pin1 blockade attenuates GM-CSF and IL-5 production and can selectively reduce eosinophilic allergic inflammation. Clinical implications Eosinophils can be selectively reduced by Pin1 blockade, despite allergen challenge.

Background Obstructive sleep apnea (OSA) may worsen asthma, but large studies are lacking and the underlying mechanisms are unknown. Objective The objective of this study was to determine the prevalence of OSA risk among patients with asthma of different severity compared with normal controls (NC), and among asthmatics, to test the relationship of OSA risk with asthma burden and airway inflammation. Methods Subjects with severe (SA, n = 94) and nonsevere asthma (NSA, n = 161), and NC (n = 146) were recruited in an add-on substudy, to the observational Severe Asthma Research Program (SARP) II; subjects completed sleep quality, sleepiness and OSA risk (Sleep Apnea scale of the Sleep Disorders Questionnaire [SA-SDQ]) questionnaires, and clinical assessments. Sputum was induced in a subset of asthmatics. Results Relative to NC, despite similar sleep duration, the subjects with SA and NSA had worse sleep quality, were sleepier, and had higher SA-SDQ scores. Among asthmatics, higher SA-SDQ was associated with increased asthma symptoms, β-agonist use, health care utilization, and worse asthma quality of life. A significant association of SA-SDQ with sputum polymorphonuclear cells% was noted: each increase in SA-SDQ by its standard deviation (6.85 units) was associated with a rise in % sputum neutrophils of 7.78 (95% CI 2.33-13.22, P = .0006), independent of obesity and other confounders. Conclusions OSA symptoms are more prevalent among asthmatics, in whom they are associated with higher disease burden. OSA risk is associated with a neutrophilic airway inflammation in asthma, which suggests that OSA may be an important contributor to the neutrophilic asthma. Further studies are necessary to confirm these findings and better understand the mechanistic underpinnings of this relationship.

Background Metered-dose inhalers (MDIs) are convenient, simple, inexpensive, and reproducible devices for administering aerosolized drugs through the pulmonary route, but methods have not been available for use of these devices in small animals. Objective We sought to test the efficacy of delivery of fluticasone through an MDI to rats with a rodent-adapted spacer chamber and to compare this treatment with systemic dexamethasone for the acute pulmonary allergic inflammatory response. Methods Changes in body and thymus weights were used as indicators for systemic steroid effects. Rats were sensitized to ragweed pollen extract 2 weeks before the experiment, and pulmonary allergic responses were evaluated 48 hours after a single aerosolized antigen challenge on the basis of bronchoalveolar leukocytes, lung tissue sections, total lung capacity, and forced expiratory volumes. Results Inhaled fluticasone caused dose-related systemic effects, indicating successful pulmonary drug delivery. Inhaled fluticasone was more effective than placebo but less effective than systemic dexamethasone in attenuating the increase in lung eosinophils and inflammatory infiltrates and the decrease in total lung capacity associated with the allergic inflammatory response. Inhaled fluticasone prevented airway obstruction and proximal inflammation, as did dexamethasone, but it appeared to have less effect in areas of lung served by the most distal airways. Conclusion This is an effective method for use of MDIs to deliver inhaled drugs to small laboratory animals, and it should be valuable for investigations of treatment effects, as well as for in vivo testing of delivery devices.

Background Magnetic resonance imaging (MRI) with 3 He does not require ionizing radiation and has been shown to detect regional abnormalities in lung ventilation and structure in adults with asthma, but the method has not been extended to children with asthma. Measurements of regional lung ventilation and microstructure in subjects with childhood asthma could advance our understanding of disease mechanisms. Objective We sought to determine whether 3 He MRI in children can identify abnormalities related to the diagnosis of asthma or prior history of respiratory illness. Methods Forty-four children aged 9 to 10 years were recruited from a birth cohort at increased risk of asthma and allergic diseases. For each subject, a time-resolved 3-dimensional image series and a 3-dimensional diffusion-weighted image were acquired in separate breathing maneuvers. The numbers and sizes of ventilation defects were scored, and regional maps and statistics of average 3 He diffusion lengths were calculated. Results Children with mild-to-moderate asthma had lower average root-mean-square diffusion length ( X r m s ¯ ) values ( P = .004), increased regional SD of diffusion length values ( P = .03), and higher defect scores ( P = .03) than those without asthma. Children with histories of wheezing illness with rhinovirus infection before the third birthday had lower X r m s ¯ values ( P = .01) and higher defect scores ( P = .05). Conclusion MRI with 3 He detected more and larger regions of ventilation defect and a greater degree of restricted gas diffusion in children with asthma compared with those seen in children without asthma. These measures are consistent with regional obstruction and smaller and more regionally variable dimensions of the peripheral airways and alveolar spaces.

and Viral Inflammatory Stimuli in Rats With the Chronic Postbronchiolitis Asthma-Like Phenotype R. L. SORKNESS1, L. A. ROSENTHAL2, T. PIER2, S. P. AMINEVA2, R. J. SZAKALY2, R. F. LEMANSKE, Jr.3; 1Sch of pharmacy, UNIVERSITY OF WISCONSIN, Madison, WI, 2Medicine, UNIVERSITY OF WISCONSIN, Madison, WI, 3Pediatrics, UNIVERSITY OF WISCONSIN, Madison, WI. RATIONALE: Airway inflammation in asthma may be due to enhanced vulnerability of airways to common inflammatory stimuli. We hypothesized that rats with chronic airway dysfunction would differ from normals in their acute pulmonary inflammatory responses. METHODS: Normal BN rats were compared with asthma-like BN rats that were >10wks post early age bronchiolitis. Acute allergic inflammation was induced by a single exposure to aerosolized ragweed pollen extract 2wks after sensitization, and evaluated at 1 or 7 days; viral inflammation was induced with a tracheal insufflation of attenuated mengovirus, and evaluated in 3 days. Airspace infiltrates were quantified with bronchoalveolar lavage (BAL), and airway wall eosinophils (eos) with staining of major basic protein (MBP) in lung sections. RESULTS: Unchallenged normal and asthma-like rats did not differ significantly with regard to BAL eos or airway MBP. However, the asthmalike rats had significantly greater airway wall MBP (p=0.001) and fewer BAL eos (p=0.02) 1 day after allergen challenge, and fewer BAL eos (p=0.04) with similar airway MBP 7 days after allergen. During viral infection a similar pattern occurred, the asthma-like rats having few eos and neutrophils in BAL (p

Rationale After Sendai virus-induced bronchiolitis as weanlings, BN, unlike F344, rats develop a postbronchiolitis asthma-like phenotype, which is prevented by IFN-γ therapy. Innate mechanisms of Sendai virus-induced IFN-γ production, which are dependent on NK cells and the production of IFN-γ-inducing cytokines (IL-12 and IL-18), are markedly attenuated in BN, compared with F344, weanlings. GM-CSF and Flt-3 ligand may enhance innate immunity by augmenting dendritic cell or dendritic and NK cell development, respectively. We hypothesized that treatment with GM-CSF and Flt-3 ligand would counteract the reduced capacity of BN weanlings to secrete IFN-γ and IFN-γ-inducing cytokines in response to virus. Methods Splenocytes from uninfected weanlings were preincubated for 16 h with or without GM-CSF or Flt-3 ligand and then for 24 h with or without Sendai virus. IFN-γ, IL-12, and IL-18 were measured in supernates by ELISA. Results GM-CSF and Flt-3 ligand triggered 12- and 8-fold increases, respectively, in virus-induced IFN-γ production by BN splenocytes ( p Conclusions GM-CSF-mediated enhancement of virus-induced IFN-γ production from BN splenocytes appeared to result from increases in IL-12 secretion, suggesting that GM-CSF augmented deficient dendritic cell activity. Flt-3 ligand-mediated, IL-12-independent increases in virus-induced IFN-γ production may arise from enhancement of deficient NK cell responses. These results suggest a basis for attenuated innate anti-viral responses in BN weanlings.

Rationale Animal studies involving administration of aerosolized drugs are complicated by the difficulties of generating and delivering the aerosol to the lungs effectively and reproducibly. A method utilizing a metered dose inhaler (MDI) would allow simplification and standardization of aerosol dosing. Methods 18 adult BN rats were sensitized to ragweed. A spacer chamber was modified with a latex face mask that allowed insertion of an awake rat's nose and mouth into the chamber opposite the MDI. After MDI actuation, rats breathed either placebo or fluticasone 220 aerosol from the chamber for 60s, once daily X7d prior to and 1d after aerosolized ragweed challenge. Others were treated with s.c. dexamethasone X3d for comparison. Body and thymus weights were indicators of systemic steroid effect, and lung volumes, forced expiratory maneuvers and BAL cells were indicators of pulmonary allergic responses at 48h after allergen challenge. Results Fluticasone MDI treatment caused body weight loss and thymus weight loss compared with placebo treatment, indicating sufficient pulmonary delivery to obtain systemic effects. Body weight loss was greater with systemic dexamethasone treatment. Fluticasone also protected the rats from pulmonary allergic responses, with preservation of total lung capacity, FEV 0.2 and FVC, and reduced BAL inflammatory cells, compared with placebo treatment (p 0.2 and BAL eosinophils, and both the fluticasone and dexamethasone groups showed small within-group variability. Conclusion This method of administering MDI aerosols to rats is simple, effective, and reproducible.

Rationale Allergens with intrinsic protease activity have been shown to enable Th2 priming, and allow the establishment of airway inflammation and airway hyperresponsiveness in Th1-skewed mice. We attempted to induce Th2 responses in the lung of Fisher (F344) rats, a Th1-skewed animal model, using a protease-containing crude Alternaria extract. Methods Four groups of F344 rats were evaluated over a six-week period. Group 1 was sensitized to crude Alternaria in AlOH 3 and nebulized with crude Alternaria biweekly. Group 2 was sensitized to crude Alternaria in AlOH 3 and exposed to crude Alternaria biweekly via direct intranasal inoculation. Group 3 was not sensitized and nebulized with crude Alternaria biweekly. Group 4 was not sensitized and nebulized with saline biweekly. At the end of six weeks, airway hyperresponsiveness was determined by methacholine challenge. Right-sided bronchoalveolar lavage was performed, and cell counts with differentials were obtained from the bronchoalveolar fluid (BALF). Protease levels in the crude Alternaria extract were confirmed using a protease assay kit. Results No differences in airway hyperresponsiveness or BALF cell counts with differentials were observed between the four groups (p>0.05). A correlation between the absolute eosinophil count in the BALF and PC20 was observed (r s =-0.57). The protease level in the crude Alternaria extract was 130ng/mg protein. Conclusion We were unable to induce airway hyperresponsiveness or evidence of Th2 responses in the BALF of F344 rats, despite the concentration of protease activity present in the crude Alternaria extract. Threshold doses of protease activity required to induce Th2 airway responses in rat models are currently unknown.