Comparison of paired human nasal and bronchial airway epithelial cell responses to rhinovirus infection and IL-13 treatment

BACKGROUND

Because of its advantage as a minimally invasive procedure, nasal brushings have been increasingly used and proposed as a valuable approach to study lower airway diseases in lieu of bronchial epithelial cells. However, there is limited or conflicting evidence pertaining to whether nasal samples can be surrogates to bronchial samples. The goal of the present study is to test whether nasal epithelial cells have similar antiviral and inflammatory responses to IL-13 treatment and rhinovirus infection, a condition mimicking virally induced asthma exacerbation. Nasal and bronchial airway epithelial cells taken from the same patient were cultured under submerged and air-liquid interface (ALI) culture in the absence or presence of rhinovirus and IL-13 treatment. Inflammatory cytokines IP-10 and eotaxin-3, antiviral gene Mx1 and viral levels were measured.

RESULTS

In the absence of IL-13 treatment, nasal and bronchial cells showed a similar IP-10 response in both ALI and submerged cultures. Under the ALI culture, short term (e.g., 3 days) IL-13 treatment had a minimal effect on viral and Mx1 levels in both cell types. However, prolonged (e.g., 14 days) IL-13 treatments in both cell types decreased viral load and Mx1 expression. Under the submerged culture, IL-13 treatment in both cell types has minimal effects on viral load, IP-10 and Mx1. IL-13-induced eotaxin-3 production was similar in both types of cells under either submerged or ALI culture, which was not affected by viral infection.

CONCLUSIONS

Our data suggest that nasal epithelial cells could serve as a surrogate to bronchial epithelial cells in future studies aimed at defining the role of type 2 cytokine IL-13 in regulating pro-inflammatory and antiviral responses.

Mono-, di-, and trichlorinated biphenyls (PCB 1-PCB 39) in the indoor air of office rooms and their relevance on human blood burden

Exposure to polychlorinated biphenyls (PCBs) from indoor air can lead to a significant increase in lower chlorinated congeners in human blood. Lower chlorinated congeners with short biological half-lives can exhibit an indirect genotoxic potential via their highly reactive metabolites. However, little is known about their occurrence in indoor air and, therefore, about the effects of possible exposure to these congeners. We analyzed all mono-, di-, and trichlorinated biphenyls in the indoor air of 35 contaminated offices, as well as in the blood of the 35 individuals worked in these offices for a minimum of 2 years. The median concentration of total PCB in the indoor air was 479 ng/m³ . The most prevalent PCBs in the indoor air samples were the trichlorinated congeners PCB 31, PCB 18, and PCB 28, with median levels of 39, 31, and 26 ng/m³ , respectively. PCB 8 was the most prevalent dichlorinated congener (median: 9.1 ng/m³ ). Monochlorinated biphenyls were not detected in relevant concentrations. In the blood samples, the most abundant congener was PCB 28; nearly 90% of all mono-, di-, and trichlorinated congeners were attributed to this congener (median: 12 ng/g blood lipid).

Effect of the S-nitrosoglutathione reductase inhibitor N6022 on bronchial hyperreactivity in asthma

RATIONALE

Patients with asthma demonstrate depletion of the endogenous bronchodilator GSNO and upregulation of GSNOR.

OBJECTIVES

An exploratory proof of concept clinical study of N6022 in mild asthma to determine the potential bronchoprotective effects of GSNOR inhibition. Mechanistic studies aimed to provide translational evidence of effect.

METHODS

Fourteen mild asthma patients were treated with intravenous N6022 (5 mg) or placebo and observed for 7 days, with repeated assessments of the provocative dose of methacholine causing a 20% fall in FEV1 (methacholine PC₂₀ FEV1), followed by a washout period and crossover treatment and observation. In vitro studies in isolated eosinophils investigated the effect of GSNO and N6022 on apoptosis.

MEASUREMENTS AND MAIN RESULTS

This was a negative trial as it failed to reach its primary endpoint, which was change from baseline in methacholine PC₂₀ FEV1 at 24 h. However, our exploratory analysis demonstrated significantly more two dose-doubling increases in PC₂₀ FEV1 for N6022 compared with placebo (21% vs 6%, P < 0.05) over the 7-day observation period. Furthermore, a significant treatment effect was observed in the change in PC₂₀ FEV1 from baseline averaged over the 7-day observation period (mean change: +0.82 mg/ml [N6022] from 1.34 mg/ml [baseline] vs -0.18 mg/ml [placebo] from 1.16 mg/ml [baseline], P = 0.023). N6022 was well tolerated in mild asthmatics. In vitro studies demonstrated enhanced eosinophilic apoptosis with N6022.

CONCLUSIONS

In this early phase exploratory proof of concept trial in asthma, N6022 did not significantly alter methacholine PC₂₀ FEV1 at 24 h, but did have a treatment effect at 7 days compared to baseline. Further investigation of the efficacy of S-nitrosoglutathione reductase inhibition in a patient population with eosinophilic asthma is warranted.

Management of Severe Asthma before Referral to the Severe Asthma Specialist

Severe asthma is associated with significant morbidity and can be challenging to assess and control, due to heterogeneity of disease, complexity of diagnosis, and impact of comorbidities. A structured approach to the assessment and management of severe asthma may be helpful to the practicing clinician. First, it is important to confirm a diagnosis of asthma. In patients who are either not responding to treatment, or who require high doses of medication to control symptoms, it is highly possible that disease mimickers or comorbidities are present and can inhibit therapeutic responsiveness. The assessment and management of common comorbidities of asthma may dramatically impact disease control and thus medication requirement. Determining medication adherence and optimizing drug dose and delivery may separate out truly severe asthmatics from those not using medications regularly or properly. Next, although true personalized medicine for severe asthma is not yet realized, for those individuals with severe asthma, phenotypic characteristics of each patient may guide which therapeutic options may be most effective for that patient. Finally, evaluation and management of severe asthma at a referral center can add additional phenotyping, therapeutic, and diagnostic strategies.

Toll-Interacting Protein, Tollip, Inhibits IL-13-Mediated Pulmonary Eosinophilic Inflammation in Mice

Toll-interacting protein (Tollip) is a key negative regulator of innate immunity by preventing excessive proinflammatory responses. Tollip genetic variation has been associated with airflow limitation in asthma subjects and Tollip expression. Whether Tollip regulates lung inflammation in a type 2 cytokine milieu (e.g., IL-13) is unclear. Our goal was to determine the in vivo role of Tollip in IL-13-mediated lung eosinophilic inflammation and the underlying mechanisms. Tollip-knockout (KO) and wild-type (WT) mice were inoculated intranasally with recombinant mouse IL-13 protein to examine lung inflammation. To determine how Tollip regulates inflammation, alveolar macrophages and bone marrow-derived macrophages from Tollip KO and WT mice were cultured with or without IL-13 and/or IL-33. IL-13-treated Tollip KO mice significantly increased lung eosinophilic inflammation and eotaxin-2 (CCL24) levels compared with the WT mice. IL-13- treated Tollip KO (vs. WT) macrophages, in the absence and particularly in the presence of IL-33, increased expression of the IL-33 receptor ST2L and CCL24, which was in part dependent on enhanced activation of interleukin (IL)-1 receptor-associated kinase 1 (IRAK1) and signal transducer and activator of transcription 6 (STAT6). Our results suggest that Tollip downregulates IL-13-mediated pulmonary eosinophilia in part through inhibiting the activity of the ST2L/IL-33/IRAK1 axis and STAT6.

Targeted HAS2 Expression Lessens Airway Responsiveness in Chronic Murine Allergic Airway Disease

Hyaluronan (HA), a major component of the extracellular matrix, is secreted by airway structural cells. Airway fibroblasts in allergic asthma secrete elevated levels of HA in association with increased HA synthase 2 (HAS2) expression. Thus, we hypothesized that HA accumulation in the airway wall may contribute to airway remodeling and hyperresponsiveness in allergic airways disease. To examine this hypothesis, transgenic mice in which the α-smooth muscle actin (α-SMA) promoter drives HAS2 expression were generated. Mixed male and female α-SMA-HAS2 mice (HAS2+ mice, n = 16; HAS2- mice, n = 13) were sensitized via intraperitoneal injection and then chronically challenged with aerosolized ovalbumin (OVA) for 6 weeks. To test airway responsiveness, increasing doses of methacholine were delivered intravenously and airway resistance was measured using the forced oscillation technique. HA, cytokines, and cell types were analyzed in bronchoalveolar lavage fluid, serum, and whole lung homogenates. Lung sections were stained using antibodies specific for HA-binding protein (HABP) and α-SMA, as well as Masson's trichrome stain. Staining of lung tissue demonstrated significantly increased peribronchial HA, α-SMA, and collagen deposition in OVA-challenged α-SMA-HAS2+ mice compared with α-SMA-HAS2- mice. Unexpectedly, OVA-challenged α-SMA-HAS2+ mice displayed significantly reduced airway responsiveness to methacholine compared with similarly treated α-SMA-HAS2- mice. The total numbers of inflammatory cell types in the bronchoalveolar lavage fluid did not differ significantly between OVA-challenged α-SMA-HAS2+ mice and α-SMA-HAS2- mice. We conclude that allergen-challenged mice that overexpress HAS2 in myofibroblasts and smooth muscle cells develop increased airway fibrosis, which lessens airway hyperresponsiveness to bronchoconstrictors.

Factors associated with reporting results for pulmonary clinical trials in ClinicalTrials.gov

Background/aims The Food and Drug Administration Amendments Act mandates that applicable clinical trials report basic summary results to the ClinicalTrials.gov database within 1 year of trial completion or termination. We aimed to determine the proportion of pulmonary trials reporting basic summary results to ClinicalTrials.gov and assess factors associated with reporting. Methods We identified pulmonary clinical trials subject to the Food and Drug Administration Amendments Act (called highly likely applicable clinical trials) that were completed or terminated between 2008 and 2012 and reported results by September 2013. We estimated the cumulative percentage of applicable clinical trials reporting results by pulmonary disease category. Multivariable Cox regression modeling identified characteristics independently associated with results reporting. Results Of 1450 pulmonary highly likely applicable clinical trials, 380 (26%) examined respiratory neoplasms, 238 (16%) asthma, 175 (12%) chronic obstructive pulmonary disease, and 657 (45%) other respiratory diseases. Most (75%) were pharmaceutical highly likely applicable clinical trials and 71% were industry-funded. Approximately 15% of highly likely applicable clinical trials reported results within 1 year of trial completion, while 55% reported results over the 5-year study period. Earlier phase highly likely applicable clinical trials were less likely to report results compared to phase 4 highly likely applicable clinical trials (phases 1/2 and 2 (adjusted hazard ratio 0.41 (95% confidence interval: 0.31-0.54)), phases 2/3 and 3 (adjusted hazard ratio 0.55 (95% confidence interval: 0.42-0.72)) and phase not applicable (adjusted hazard ratio 0.43 (95% confidence interval: 0.29-0.63)). Pulmonary highly likely applicable clinical trials without Food and Drug Administration oversight were less likely to report results compared with those with oversight (adjusted hazard ratio 0.65 (95% confidence interval: 0.51-0.83)). Conclusion A total of 15% of pulmonary clinical highly likely applicable clinical trials report basic summary results to ClinicalTrials.gov within 1 year of trial completion. Strategies to improve reporting are needed within the pulmonary community.

American Thoracic Society/National Heart, Lung, and Blood Institute Asthma-Chronic Obstructive Pulmonary Disease Overlap Workshop Report

Asthma and chronic obstructive pulmonary disease (COPD) are highly prevalent chronic obstructive lung diseases with an associated high burden of disease. Asthma, which is often allergic in origin, frequently begins in infancy or childhood with variable airflow obstruction and intermittent wheezing, cough, and dyspnea. Patients with COPD, in contrast, are usually current or former smokers who present after the age of 40 years with symptoms (often persistent) including dyspnea and a productive cough. On the basis of age and smoking history, it is often easy to distinguish between asthma and COPD. However, some patients have features compatible with both diseases. Because clinical studies typically exclude these patients, their underlying disease mechanisms and appropriate treatment remain largely uncertain. To explore the status of and opportunities for research in this area, the NHLBI, in partnership with the American Thoracic Society, convened a workshop of investigators in San Francisco, California on May 14, 2016. At the workshop, current understanding of asthma-COPD overlap was discussed among clinicians, pathologists, radiologists, epidemiologists, and investigators with expertise in asthma and COPD. They considered knowledge gaps in our understanding of asthma-COPD overlap and identified strategies and research priorities that will advance its understanding. This report summarizes those discussions.

Race is associated with differences in airway inflammation in patients with asthma

BACKGROUND

African American subjects have a greater burden from asthma compared with white subjects. Whether the pattern of airway inflammation differs between African American and white subjects is unclear.

OBJECTIVE

We sought to compare sputum airway inflammatory phenotypes of African American and white subjects treated or not with inhaled corticosteroids (ICSs; ICS+ and ICS-, respectively).

METHODS

We performed a secondary analysis of self-identified African American and white subjects with asthma enrolled in clinical trials conducted by the National Heart, Lung, and Blood Institute-sponsored Asthma Clinical Research Network and AsthmaNet. Demographics, clinical characteristics, and sputum cytology after sputum induction were examined. We used a sputum eosinophil 2% cut point to define subjects with either an eosinophilic (≥2%) or noneosinophilic (<2%) inflammatory phenotype.

RESULTS

Among 1018 participants, African American subjects (n = 264) had a lower FEV1 percent predicted (80% vs 85%, P < .01), greater total IgE levels (197 vs 120 IU/mL, P < .01), and a greater proportion with uncontrolled asthma (43% vs 28%, P < .01) compared with white subjects (n = 754). There were 922 subjects in the ICS+ group (248 African American and 674 white subjects) and 298 subjects in the ICS- group (49 African American and 249 white subjects). Eosinophilic airway inflammation was not significantly different between African American and white subjects in either group (percentage with eosinophilic phenotype: ICS+ group: 19% vs 16%, P = .28; ICS- group: 39% vs 35%, P = .65; respectively). However, when adjusted for confounding factors, African American subjects were more likely to exhibit eosinophilic airway inflammation than white subjects in the ICS+ group (odds ratio, 1.58; 95% CI, 1.01-2.48; P = .046) but not in the ICS- group (P = .984).

CONCLUSION

African American subjects exhibit greater eosinophilic airway inflammation, which might explain the greater asthma burden in this population.

Obese asthmatic patients have decreased surfactant protein A levels: Mechanisms and implications

BACKGROUND

Eosinophils are prominent in some patients with asthma and are increased in the submucosa in a subgroup of obese patients with asthma (OAs). Surfactant protein A (SP-A) modulates host responses to infectious and environmental insults.

OBJECTIVE

We sought to determine whether SP-A levels are altered in OAs compared with a control group and to determine the implications of these alterations in SP-A levels in asthmatic patients.

METHODS

Bronchoalveolar lavage fluid from 23 lean, 12 overweight, and 20 obese subjects were examined for SP-A. Mouse tracheal epithelial cells grown at an air-liquid interface were used for mechanistic studies. SP-A^-/- mice were challenged in allergen models, and exogenous SP-A therapy was given after the last challenge. Eosinophils were visualized and quantitated in lung parenchyma by means of immunostaining.

RESULTS

Significantly less SP-A (P = .002) was detected in samples from OAs compared with those from control subjects. A univariable regression model found SP-A levels were significantly negatively correlated with body mass index (r = -0.33, P = .014), whereas multivariable modeling demonstrated that the correlation depended both on asthma status (P = .017) and the interaction of asthma and body mass index (P = .008). Addition of exogenous TNF-α to mouse tracheal epithelial cells was sufficient to attenuate SP-A and eotaxin secretion. Allergen-challenged SP-A^-/- mice that received SP-A therapy had significantly less tissue eosinophilia compared with mice receiving vehicle.

CONCLUSIONS

SP-A functions as an important mediator in resolving tissue and lavage fluid eosinophilia in allergic mouse models. Decreased levels of SP-A in OAs, which could be due to increased local TNF-α levels, might lead to impaired eosinophil resolution and could contribute to the eosinophilic asthma phenotype.

Obesity's effect on asthma extends to diagnostic criteria

BACKGROUND

The use of inflammatory biomarkers to delineate the type of lung inflammation present in asthmatic subjects is increasingly common. However, the effect of obesity on these markers is unknown.

OBJECTIVES

We aimed to determine the effect of obesity on conventional markers of inflammation in asthmatic subjects.

METHODS

We performed secondary analysis of data from 652 subjects previously enrolled in 2 Asthma Clinical Research Network trials. We performed linear correlations between biomarkers and logistic regression analysis to determine the predictive value of IgE levels, blood eosinophil counts, and fraction of exhaled nitric oxide values in relationship to sputum eosinophil counts (>2%), as well as to determine whether cut points existed that would maximize the sensitivity and specificity for predicting sputum eosinophilia in the 3 weight groups.

RESULTS

Overall, statistically significant but relatively weak correlations were observed among all 4 markers of inflammation. Within obese subjects, the only significant correlation found was between IgE levels and blood eosinophil counts (r = 0.33, P < .001); furthermore, all other correlations between inflammatory markers were approximately 0, including correlations with sputum eosinophil counts. In addition, the predictive value of each biomarker alone or in combination was poor in obese subjects. In fact, in obese subjects none of the biomarkers of inflammation significantly predicted the presence of high sputum eosinophil counts. Obese asthmatic subjects have lower cut points for IgE levels (268 IU), fraction of exhaled nitric oxide values (14.5 ppb), and blood eosinophil counts (96 cells/μL) than all other groups.

CONCLUSIONS

In obese asthmatic subjects conventional biomarkers of inflammation are poorly predictive of eosinophilic airway inflammation. As such, biomarkers currently used to delineate eosinophilic inflammation in asthmatic subjects should be approached with caution in these subjects.

Assessing upper-extremity motion: An innovative method to quantify functional capacity in patients with chronic obstructive pulmonary disease

BACKGROUND

Assessment of functional capacity is important in directing chronic obstructive pulmonary disease (COPD) care (e.g., rehabilitation and discharge readiness), and in predicting outcomes (e.g., exacerbation, hospitalization, and mortality). The 6-minute walk distance (6MWD) test for functional capacity assessment, may be time-consuming and burdensome.

OBJECTIVE

The purpose of the current study was to evaluate an upper-extremity function (UEF) test for assessing functional capacity in older adults with COPD.

METHODS

In this cross-sectional study, 49 older adults (≥55 years) with diagnosed COPD were recruited, and pulmonary function measures and 6MWD were obtained. Participants wore wireless sensors on forearm and upper-arm and performed rapid elbow flexion for 20 seconds (the UEF test). Slowness was assessed by measuring elbow speed, and acceleration and weakness (muscle strength) were assessed by measuring power of movement and elbow moment.

RESULTS

Speed, power, and moment UEF parameters were independently associated with 6MWD, when controlling for age, gender, and body mass index (BMI) (r = 0.78, p < .001). Elbow moment showed significant Pearson correlations with all pulmonary function measures and maximal inspiratory/expiratory pressure measures (r = 0.35-0.69, p<0.02).

CONCLUSIONS

Results show promise of a quick upper-extremity measure of functional capacity in patients with COPD, and as an outcome measure in clinical COPD trials.

Changing Paradigms in the Treatment of Severe Asthma: The Role of Biologic Therapies

Cytokine antagonists are monoclonal antibodies that offer new treatment options for refractory asthma but will also increase complexity because they are effective only for patients with certain asthma subtypes that remain to be more clearly defined. The clinical and inflammatory heterogeneity within refractory asthma makes it difficult to manage the disease and to determine which, if any, biologic therapy is suitable for a specific patient. The purpose of this article is to provide a data-driven discussion to clarify the use of biologic therapies in patients with refractory asthma. We first discuss the epidemiology and pathophysiology of refractory asthma. We then interpret current evidence for biomarkers of eosinophilic or type 2-high asthma so that clinicians can determine potential treatments for patients based on knowledge of their effectiveness in specific asthma phenotypes. We then assess clinical data on the efficacy, safety, and mechanisms of action of approved and pipeline biologic therapies. We conclude by discussing the potential of phenotyping or endotyping refractory asthma and how biologic therapies can play a role in treating patients with refractory asthma.

Tollip SNP rs5743899 modulates human airway epithelial responses to rhinovirus infection

BACKGROUND

Rhinovirus (RV) infection in asthma induces varying degrees of airway inflammation (e.g. neutrophils), but the underlying mechanisms remain unclear.

OBJECTIVE

The major goal was to determine the role of genetic variation [e.g. single nucleotide polymorphisms (SNPs)] of Toll-interacting protein (Tollip) in airway epithelial responses to RV in a type 2 cytokine milieu.

METHODS

DNA from blood of asthmatic and normal subjects was genotyped for Tollip SNP rs5743899 AA, AG and GG genotypes. Human tracheobronchial epithelial (HTBE) cells from donors without lung disease were cultured to determine pro-inflammatory and antiviral responses to IL-13 and RV16. Tollip knockout and wild-type mice were challenged with house dust mite (HDM) and infected with RV1B to determine lung inflammation and antiviral response.

RESULTS

Asthmatic subjects carrying the AG or GG genotype (AG/GG) compared with the AA genotype demonstrated greater airflow limitation. HTBE cells with AG/GG expressed less Tollip. Upon IL-13 and RV16 treatment, cells with AG/GG (vs. AA) produced more IL-8 and expressed less antiviral genes, which was coupled with increased NF-κB activity and decreased expression of LC3, a hallmark of the autophagic pathway. Tollip co-localized and interacted with LC3. Inhibition of autophagy decreased antiviral genes in IL-13- and RV16-treated cells. Upon HDM and RV1B, Tollip knockout (vs. wild-type) mice demonstrated higher levels of lung neutrophilic inflammation and viral load, but lower levels of antiviral gene expression.

CONCLUSIONS AND CLINICAL RELEVANCE

Our data suggest that Tollip SNP rs5743899 may predict varying airway response to RV infection in asthma.

Familial Hemiplegic Migraine—A Reappraisal and a Long-Term Follow-Up Study

Six patients (two females and four males in one family) with hemiplegic migraine are described. The age of onset was between six and eighteen years. Hemiplegic attacks were usually accompanied by transient neurological disturbances referable to the territory of the vertebrobasilar arterial tree. Brain-stem involvement and vertebrobasilar dysfunction in the reported family was supported by angiography in one case, revealing a marked and prolonged spasm of the basilar artery. Despite its dramatic character and occasionally prolonged deficits the course was essentially benign. Hemiplegic attacks disappeared during adolescence in five of the six patients. No permanent neurological residual phenomena were encountered during a mean follow-up of 14 years. The possibility is raised of a genetically determined susceptibility to periodic vasoconstriction in a particular vascular area as the basis of the syndrome.

Role of Matrix Metalloproteinases-1 and -2 in Interleukin-13-Suppressed Elastin in Airway Fibroblasts in Asthma

Elastin synthesis and degradation in the airway and lung parenchyma contribute to airway mechanics, including airway patency and elastic recoil. IL-13 mediates many features of asthma pathobiology, including airway remodeling, but the effects of IL-13 on elastin architecture in the airway wall are not known. We hypothesized that IL-13 modulates elastin expression in airway fibroblasts from subjects with allergic asthma. Twenty-five subjects with mild asthma (FEV1, 89 ± 3% predicted) and 30 normal control subjects (FEV1, 102 ± 2% predicted) underwent bronchoscopy with endobronchial biopsy. Elastic fibers were visualized in airway biopsy specimens using Weigert's resorcin-fuchsin elastic stain. Airway fibroblasts were exposed to IL-13; a pan-matrix metalloproteinase (MMP) inhibitor (GM6001); specific inhibitors to MMP-1, -2, -3, and -8; and combinations of IL-13 with MMP inhibitors in separate conditions in serum-free media for 48 hours. Elastin (ELN) expression as well as MMP secretion and activity were quantified. Results of this study show that elastic fiber staining of airway biopsy tissue was significantly associated with methacholine PC20 (i.e., the provocative concentration of methacholine resulting in a 20% fall in FEV1 levels) in patients with asthma. IL-13 significantly suppressed ELN expression in asthmatic airway fibroblasts as compared with normal control fibroblasts. The effect of IL-13 on ELN expression was significantly correlated with postbronchodilator FEV1/FVC in patients with asthma. MMP inhibition significantly stimulated ELN expression in patients with asthma as compared with normal control subjects. Specific inhibition of MMP-1 and MMP-2, but not MMP-3 or MMP-8, reversed the IL-13-induced suppression of ELN expression. In asthma, MMP-1 and MMP-2 mediate IL-13-induced suppression of ELN expression in airway fibroblasts.

Flow Cytometric Analysis of Myeloid Cells in Human Blood, Bronchoalveolar Lavage, and Lung Tissues

Clear identification of specific cell populations by flow cytometry is important to understand functional roles. A well-defined flow cytometry panel for myeloid cells in human bronchoalveolar lavage (BAL) and lung tissue is currently lacking. The objective of this study was to develop a flow cytometry-based panel for human BAL and lung tissue. We obtained and performed flow cytometry/sorting on human BAL cells and lung tissue. Confocal images were obtained from lung tissue using antibodies for cluster of differentiation (CD)206, CD169, and E cadherin. We defined a multicolor flow panel for human BAL and lung tissue that identifies major leukocyte populations. These include macrophage (CD206(+)) subsets and other CD206(-) leukocytes. The CD206(-) cells include: (1) three monocyte (CD14(+)) subsets, (2) CD11c(+) dendritic cells (CD14(-), CD11c(+), HLA-DR(+)), (3) plasmacytoid dendritic cells (CD14(-), CD11c(-), HLA-DR(+), CD123(+)), and (4) other granulocytes (neutrophils, mast cells, eosinophils, and basophils). Using this panel on human lung tissue, we defined two populations of pulmonary macrophages: CD169(+) and CD169(-) macrophages. In lung tissue, CD169(-) macrophages were a prominent cell type. Using confocal microscopy, CD169(+) macrophages were located in the alveolar space/airway, defining them as alveolar macrophages. In contrast, CD169(-) macrophages were associated with airway/alveolar epithelium, consistent with interstitial-associated macrophages. We defined a flow cytometry panel in human BAL and lung tissue that allows identification of multiple immune cell types and delineates alveolar from interstitial-associated macrophages. This study has important implications for defining myeloid cells in human lung samples.

LTRA inhibition of exercise-induced bronchoconstriction

Exercise-induced bronchoconstriction (EIB) affects between 70% and 80% of asthmatic patients. Shortly after strenuous exercise, several inflammatory mediators, including the cysteinyl leukotrienes, induce bronchoconstriction. Evidence of this phenomenon includes the increase in urinary leukotriene E4 excretion after exercise and the inhibition of EIB by the leukotriene synthesis inhibitor zileuton. Similarly, the leukotriene receptor antagonists (LTRAs) montelukast and zafirlukast have significantly reduced the decrease in pulmonary function after exercise and shortened the time to recovery. Because exercise is generally a less predictable event in children, EIB can be more difficult to manage in pediatric than in adult asthmatic patients. However, LTRA use may temper this problem. Montelukast administered once daily at bedtime protected pediatric patients against EIB throughout the entire day. Zafirlukast attenuated EIB within 4 hours of dosing in 6- to 17-year-old patients who had mild to moderate asthma. Currently, inhaled ss2-agonists are widely prescribed for EIB, but when used long term, their efficacy may wane because of tolerance. In contrast, one of the advantages offered by LTRA therapy is the absence of tolerance.

Vitamin D Supplementation and the Risk of Colds in Patients with Asthma

RATIONALE

Restoration of vitamin D sufficiency may reduce asthma exacerbations, events that are often associated with respiratory tract infections and cold symptoms.

OBJECTIVES

To determine whether vitamin D supplementation reduces cold symptom occurrence and severity in adults with mild to moderate asthma and vitamin D insufficiency.

METHODS

Colds were assessed in the AsthmaNet VIDA (Vitamin D Add-on Therapy Enhances Corticosteroid Responsiveness) trial, in which 408 adult patients were randomized to receive placebo or cholecalciferol (100,000 IU load plus 4,000 IU/d) for 28 weeks as add-on therapy. The primary outcome was cold symptom severity, which was assessed using daily scores on the 21-item Wisconsin Upper Respiratory Symptom Survey.

MEASUREMENTS AND MAIN RESULTS

A total of 203 participants experienced at least one cold. Despite achieving 25-hydroxyvitamin D levels of 41.9 ng/ml (95% confidence interval [CI], 40.1-43.7 ng/ml) by 12 weeks, vitamin D supplementation had no effect on the primary outcome: the average peak WURSS-21 scores (62.0 [95% CI, 55.1-68.9; placebo] and 58.7 [95% CI, 52.4-65.0; vitamin D]; P = 0.39). The rate of colds did not differ between groups (rate ratio [RR], 1.2; 95% CI, 0.9-1.5); however, among African Americans, those receiving vitamin D versus placebo had an increased rate of colds (RR, 1.7; 95% CI, 1.1-2.7; P = 0.02). This was also observed in a responder analysis of all subjects achieving vitamin D sufficiency, regardless of treatment assignment (RR, 1.4; 95% CI, 1.1-1.7; P = 0.009).

CONCLUSIONS

Our findings in patients with mild to moderate asthma undergoing an inhaled corticosteroid dose reduction do not support the use of vitamin D supplementation for the purpose of reducing cold severity or frequency.

Long-lived plasma cells are generated in mucosal immune responses and contribute to the bone marrow plasma cell pool in mice

During systemic immune responses, plasma blasts are generated in secondary lymphoid organs and migrate to the bone marrow, where they can become long-lived, being responsible for the maintenance of long-term antibody titers. Plasma blasts generated in mucosal immune responses of the small intestine home to the lamina propria (LP), producing mainly immunoglobulin A. The migration of these antibody-secreting cells is well characterized during acute immune responses. Less is known about their lifetime and contribution to the long-lived bone marrow compartment. Here we investigate the lifetime of plasma cells (PCs) and the relationship between the PC compartments of the gut and bone marrow after oral immunization. Our findings indicate that PCs in the LP can survive for extended time periods. PCs specific for orally administered antigens can be detected in the bone marrow for at least 9 months after immunization, indicating that the mucosal PC compartment can contribute to the long-lived PC pool in this organ, independent of the participation of splenic B cells. Our findings suggest that the compartmentalization between mucosal and systemic PC pools is less strict than previously thought. This may have implications for the development of vaccines as well as for autoantibody-mediated diseases.

[Narrow band imaging for early diagnosis of epithelial dysplasias and microinvasive tumors in the upper aerodigestive tract]

The various stages of tumor growth are characterized by typical epithelial, vascular, and secondary connective tissue changes. Narrow band imaging (NBI) endoscopy is a minimally invasive imaging technique that presents vascular structures in particular at a higher contrast than white light endoscopy alone. In combination with high-resolution image recording and reproduction (high-definition television, HDTV; ultra-high definition, 4K), progress has been made in otolaryngological differential diagnostics, both pre- and intraoperatively. This progress represents an important step towards a so-called optical biopsy. Flexible endoscopy in combination with NBI allows detailed assessment of areas of the upper aerodigestive tract which are difficult to assess by rigid endoscopy. Papillomas, precancerous, and cancerous lesions are characterized by epithelial and connective tissue changes, as well as by typical perpendicular vascular changes. Systematic use of NBI is recommended in the differential diagnosis of malignant lesions of the upper aerodigestive tract. NBI also convinces by a significant improvement in pre- and intraoperative assessment of superficial resection margins. In particular, the combination of NBI and contact endoscopy (compact endoscopy) permits excellent therapeutic decisions during tumor surgery. Intraoperative determination of resection margins at unprecedented precision is possible. In addition, assessment of the form and extent of the perpendicular vessel loops stimulated by epithelial signaling enables differential diagnostic decisions to be made, approximating our goal of an optical biopsy.

Impact of Age and Sex on Response to Asthma Therapy

RATIONALE

Age and sex are associated with differences in asthma prevalence and morbidity.

OBJECTIVES

To determine if age and sex associate with distinct phenotypes and a variable response to therapy in subjects with mild to moderate asthma.

METHODS

We used Asthma Clinical Research Network data to determine the impact of age and sex on phenotypes and treatment failures among subjects participating in 10 trials from 1993 to 2003.

MEASUREMENTS AND MAIN RESULTS

A total of 1,200 subjects were identified (median age, 30.4 yr; male, 520 [43.3%]; female, 680 [56.7%]) and analyzed. A higher proportion of subjects greater than or equal to 30 years old experienced treatment failures (17.3% vs. 10.3%; odds ratio [OR], 1.82; confidence interval [CI], 1.30-2.54; P < 0.001), and rates increased proportionally with increasing age older than 30 across the cohort (OR per yr, 1.02 [CI, 1.01-1.04]; OR per 5 yr, 1.13 [CI, 1.04-1.22]; P < 0.001). Lower lung function and longer duration of asthma were associated with a higher risk of treatment failures. A higher proportion of subjects greater than or equal to 30 years old receiving controller therapy experienced treatment failures. When stratified by specific therapy, treatment failures increased consistently for every year older than age 30 in subjects on inhaled corticosteroids (OR per year, 1.03; CI, 1.01-1.07). Females had a slightly higher FEV1 % predicted (84.5% vs. 81.1%; P < 0.001) but similar asthma control measures. There was not a statistically significant difference in treatment failures between females and males (15.2% vs. 11.7%; P = 0.088).

CONCLUSIONS

Older age is associated with an increased risk of treatment failure, particularly in subjects taking inhaled corticosteroids. There was no significant difference in treatment failures between sexes.

Targeting Persons With or At High Risk for Chronic Obstructive Pulmonary Disease by State-based Surveillance

The Behavioral Risk Factor Surveillance System (BRFSS) survey is used to estimate chronic obstructive pulmonary disease (COPD) prevalence and could be expanded to describe respiratory symptoms in the general population and to characterize persons with or at high risk for the disease. Tobacco duration and respiratory symptom questions were added to the 2012 South Carolina BRFSS. Data concerning sociodemographics, chronic illnesses, health behaviors, and respiratory symptoms were collected in 9438 adults ≥ 35 years-old. Respondents were categorized as having COPD, high risk, or low risk for the disease. High risk was defined as no self-reported COPD, ≥ 10 years' tobacco use, and ≥ 1 respiratory symptom (frequent productive cough or shortness of breath (SOB), or breathing problems affecting activities). Prevalence of self-reported and high-risk COPD were 9.1% and 8.0%, respectively. Overall, 17.3%, 10.6%, and 5.2% of all respondents reported activities limited by breathing problems, frequent productive cough, and frequent SOB, respectively. The high-risk group was more likely than the COPD group to report a productive cough and breathing problems limiting activities as well as being current smokers, male, and African-American. Health impairment was more severe in the COPD than the high-risk group, and both were worse than the low-risk group.

CONCLUSIONS

Persons at high risk for COPD share many, but not all, of the characteristics of persons diagnosed with the disease. Additional questions addressing smoking duration and respiratory symptoms in the BRFSS identifies groups at high risk for having or developing COPD who may benefit from smoking cessation and case-finding interventions.

Smoking duration, respiratory symptoms, and COPD in adults aged ≥45 years with a smoking history

BACKGROUND

The purpose of this study was to assess the relationship of smoking duration with respiratory symptoms and history of chronic obstructive pulmonary disease (COPD) in the South Carolina Behavioral Risk Factor Surveillance System survey in 2012.

METHODS

Data from 4,135 adults aged ≥45 years with a smoking history were analyzed using multivariable logistic regression that accounted for sex, age, race/ethnicity, education, and current smoking status, as well as the complex sampling design.

RESULTS

The distribution of smoking duration ranged from 19.2% (1-9 years) to 36.2% (≥30 years). Among 1,454 respondents who had smoked for ≥30 years, 58.3% were current smokers, 25.0% had frequent productive cough, 11.2% had frequent shortness of breath, 16.7% strongly agreed that shortness of breath affected physical activity, and 25.6% had been diagnosed with COPD. Prevalence of COPD and each respiratory symptom was lower among former smokers who quit ≥10 years earlier compared with current smokers. Smoking duration had a linear relationship with COPD (P<0.001) and all three respiratory symptoms (P<0.001) after adjusting for smoking status and other covariates. While COPD prevalence increased with prolonged smoking duration in both men and women, women had a higher age-adjusted prevalence of COPD in the 1-9 years, 20-29 years, and ≥30 years duration periods.

CONCLUSION

These state population data confirm that prolonged tobacco use is associated with respiratory symptoms and COPD after controlling for current smoking behavior.

Body mass index, respiratory conditions, asthma, and chronic obstructive pulmonary disease

BACKGROUND

This study aims to assess the relationship of body mass index (BMI) status with respiratory conditions, asthma, and chronic obstructive pulmonary disease (COPD) in a state population.

METHODS

Self-reported data from 11,868 adults aged ≥18 years in the 2012 South Carolina Behavioral Risk Factor Surveillance System telephone survey were analyzed using multivariable logistic regression that accounted for the complex sampling design and adjusted for sex, age, race/ethnicity, education, smoking status, physical inactivity, and cancer history.

RESULTS

The distribution of BMI (kg/m(2)) was 1.5% for underweight (<18.5), 32.3% for normal weight (18.5-24.9), 34.6% for overweight (25.0-29.9), 26.5% for obese (30.0-39.9), and 5.1% for morbidly obese (≥40.0). Among respondents, 10.0% had frequent productive cough, 4.3% had frequent shortness of breath (SOB), 7.3% strongly agreed that SOB affected physical activity, 8.4% had current asthma, and 7.4% had COPD. Adults at extremes of body weight were more likely to report having asthma or COPD, and to report respiratory conditions. Age-adjusted U-shaped relationships of BMI categories with current asthma and strongly agreeing that SOB affected physical activity, but not U-shaped relationship with COPD, persisted after controlling for the covariates (p < 0.001). Morbidly obese but not underweight or obese respondents were significantly more likely to have frequent productive cough and frequent SOB than normal weight adults after adjustment.

CONCLUSION

Our data confirm that both underweight and obesity are associated with current asthma and obesity with COPD. Increased emphasis on exercise and nutrition may improve respiratory conditions.

Genetic variation in SP-A2 leads to differential binding to Mycoplasma pneumoniae membranes and regulation of host responses

Mycoplasma pneumoniae is an extracellular pathogen that colonizes mucosal surfaces of the respiratory tract and is associated with asthma exacerbations. Previous reports demonstrate that surfactant protein-A (SP-A) binds live M. pneumoniae and mycoplasma membrane fractions (MMF) with high affinity. Humans express a repertoire of single-amino acid genetic variants of SP-A that may be associated with lung disease, and our findings demonstrate that allelic differences in SP-A2 (Gln223Lys) affect the binding to MMF. We show that SP-A(-/-) mice are more susceptible to MMF exposure and have significant increases in mucin production and neutrophil recruitment. Novel humanized SP-A2-transgenic mice harboring the hSP-A2 223K allele exhibit reduced neutrophil influx and mucin production in the lungs when challenged with MMF compared with SP-A(-/-) mice. Conversely, mice expressing hSP-A2 223Q have increased neutrophil influx and mucin production that are similar to SP-A(-/-) mice. Using tracheal epithelial cell cultures, we show that enhanced mucin production to MMF occurs in the absence of SP-A and is not dependent upon neutrophil recruitment. Increased phosphorylation of the epidermal growth factor receptor (EGFR) was evident in the lungs of MMF-challenged mice when SP-A was absent. Pharmacologic inhibition of EGFR prior to MMF challenge dramatically reduced mucin production in SP-A(-/-) mice. These findings suggest a protective role for SP-A in limiting MMF-stimulated mucin production that occurs through interference with EGFR-mediated signaling. SP-A interaction with the EGFR signaling pathway appears to occur in an allele-specific manner that may have important implications for SP-A polymorphisms in human diseases.