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Background: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection can lead to a variety of clinical outcomes, ranging from the absence of symptoms to severe acute respiratory disease and ultimately death. A feature of patients with severe coronavirus disease 2019 (COVID-19) is the abundance of inflammatory cytokines in the blood. Elevated levels of cytokines are predictive of infection severity and clinical outcome. In contrast, studies aimed at defining the driving forces behind the inflammation in lungs of subjects with severe COVID-19 remain scarce., Objective: Our aim was to analyze and compare the plasma and bronchoalveolar lavage (BAL) fluids of patients with severe COVID-19 (n = 45) for the presence of cytokines and lipid mediators of inflammation (LMIs)., Methods: Cytokines were measured by using Luminex multiplex assay, and LMIs were measured by using liquid chromatography-tandem mass spectrometry., Results: We revealed high concentrations of numerous cytokines, chemokines, and LMIs in the BAL fluid of patients with severe COVID-19. Of the 13 most abundant mediators in BAL fluid, 11 were chemokines, with CXCL1 and CXCL8 being 200 times more abundant than IL-6 and TNF-α. Eicosanoid levels were also elevated in the lungs of subjects with severe COVID-19. Consistent with the presence chemotactic molecules, BAL fluid samples were enriched for neutrophils, lymphocytes, and eosinophils. Inflammatory cytokines and LMIs in plasma showed limited correlations with those present in BAL fluid, arguing that circulating inflammatory molecules may not be a reliable proxy of the inflammation occurring in the lungs of patients with severe COVID-19., Conclusions: Our findings indicate that hyperinflammation of the lungs of patients with severe COVID-19 is fueled by excessive production of chemokines and eicosanoids. Therapeutic strategies to dampen inflammation in patients with COVID-19 should be tailored accordingly., (Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: The Airways Disease Endotyping for Personalized Therapeutics (ADEPT) study profiled patients with mild, moderate, and severe asthma and nonatopic healthy control subjects., Objective: We explored this data set to define type 2 inflammation based on airway mucosal IL-13-driven gene expression and how this related to clinically accessible biomarkers., Methods: IL-13-driven gene expression was evaluated in several human cell lines. We then defined type 2 status in 25 healthy subjects, 28 patients with mild asthma, 29 patients with moderate asthma, and 26 patients with severe asthma based on airway mucosal expression of (1) CCL26 (the most differentially expressed gene), (2) periostin, or (3) a multigene IL-13 in vitro signature (IVS). Clinically accessible biomarkers included fraction of exhaled nitric oxide (Feno) values, blood eosinophil (bEOS) counts, serum CCL26 expression, and serum CCL17 expression., Results: Expression of airway mucosal CCL26, periostin, and IL-13-IVS all facilitated segregation of subjects into type 2-high and type 2-low asthmatic groups, but in the ADEPT study population CCL26 expression was optimal. All subjects with high airway mucosal CCL26 expression and moderate-to-severe asthma had Feno values (≥35 ppb) and/or high bEOS counts (≥300 cells/mm 3 ) compared with a minority (36%) of subjects with low airway mucosal CCL26 expression. A combination of Feno values, bEOS counts, and serum CCL17 and CCL26 expression had 100% positive predictive value and 87% negative predictive value for airway mucosal CCL26-high status. Clinical variables did not differ between subjects with type 2-high and type 2-low status. Eosinophilic inflammation was associated with but not limited to airway mucosal type 2 gene expression., Conclusion: A panel of clinical biomarkers accurately classified type 2 status based on airway mucosal CCL26, periostin, or IL-13-IVS gene expression. Use of Feno values, bEOS counts, and serum marker levels (eg, CCL26 and CCL17) in combination might allow patient selection for novel type 2 therapeutics., (Copyright © 2017 American Academy of Allergy, Asthma & Immunology. All rights reserved.)

Background: Omalizumab is an established anti-IgE therapy for the treatment of allergic diseases that prevents IgE from binding to its receptor. QGE031 is an investigational anti-IgE antibody that binds IgE with higher affinity than omalizumab., Objective: This study compared the effects of QGE031 with those of omalizumab on clinical efficacy, IgE levels, and FcεRI expression in a clinical model of allergic asthma., Methods: Thirty-seven patients with mild allergic asthma were randomized to subcutaneous omalizumab, placebo, or QGE031 at 24, 72, or 240 mg every 2 weeks for 10 weeks in a double-blind, parallel-group multicenter study. Inhaled allergen challenges and skin tests were conducted before dosing and at weeks 6, 12, and 18, and blood was collected until 24 weeks after the first dose., Results: QGE031 elicited a concentration- and time-dependent change in the provocative concentration of allergen causing a 15% decrease in FEV 1 (allergen PC 15 ) that was maximal and approximately 3-fold greater than that of omalizumab (P = .10) and 16-fold greater than that of placebo (P = .0001) at week 12 in the 240-mg cohort. Skin responses reached 85% suppression at week 12 in the 240-mg cohort and were maximal at week 18. The top doses of QGE031 consistently suppressed skin test responses among subjects but had a variable effect on allergen PC 15 (2-fold to 500-fold change). QGE031 was well tolerated., Conclusion: QGE031 has greater efficacy than omalizumab on inhaled and skin allergen responses in patients with mild allergic asthma. These data support the clinical development of QGE031 as a treatment of asthma., (Copyright © 2016 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.)

Background: High pulmonary eosinophil counts are associated with asthma symptoms and severity. Bronchial epithelial cells (BECs) produce CC chemokines, notably CCL26 (eotaxin-3), which recruits and activates eosinophils from asthmatic patients. This suggests that CCL26 production by BECs might be involved in persistent eosinophilia in patients with severe asthma despite treatment with high corticosteroid doses., Objective: We sought to determine whether CCL26 levels correlate with eosinophilia and asthma severity., Methods: Human CC chemokine expression was assessed by means of quantitative PCR or a quantitative PCR array in vehicle- or IL-13-treated BECs. CCL26 was quantitated by means of ELISA. Immunohistochemistry analyses of CCL26 and major basic protein were done on bronchial biopsy specimens., Results: IL-13 selectively induced CCL26 expression by BECs. This increase was time-dependent and more prominent in BECs from patients with severe eosinophilic asthma. CCL26 levels measured in supernatants of IL-13-stimulated BECs also increased with asthma severity as follows: patients with severe eosinophilic asthma > patients with mild asthma ≈ healthy subjects. Immunohistochemistry analyses of bronchial biopsy specimens confirmed increased levels of CCL26 in the epithelium of patients with mild and those with severe eosinophilic asthma. Tissue eosinophil counts did not correlate with CCL26 staining. However, sputum CCL26 levels significantly correlated with sputum eosinophil counts (P < .0001), suggesting that CCL26 participates in the movement of eosinophils from the tissues to the airway lumen., Conclusions: These results show a relation between CCL26 production by IL-13-stimulated BECs, sputum eosinophil counts, and asthma severity. They also suggest a role for CCL26 in the sustained inflammation observed in patients with severe eosinophilic asthma and reveal CCL26 as a potential target for treating patients with eosinophilic asthma that are refractory to classic therapies., (Copyright © 2015 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.)

Background: Bronchial thermoplasty (BT) has previously been shown to improve asthma control out to 2 years in patients with severe persistent asthma., Objective: We sought to assess the effectiveness and safety of BT in asthmatic patients 5 years after therapy., Methods: BT-treated subjects from the Asthma Intervention Research 2 trial (ClinicalTrials.govNCT01350414) were evaluated annually for 5 years to assess the long-term safety of BT and the durability of its treatment effect. Outcomes assessed after BT included severe exacerbations, adverse events, health care use, spirometric data, and high-resolution computed tomographic scans., Results: One hundred sixty-two (85.3%) of 190 BT-treated subjects from the Asthma Intervention Research 2 trial completed 5 years of follow-up. The proportion of subjects experiencing severe exacerbations and emergency department (ED) visits and the rates of events in each of years 1 to 5 remained low and were less than those observed in the 12 months before BT treatment (average 5-year reduction in proportions: 44% for exacerbations and 78% for ED visits). Respiratory adverse events and respiratory-related hospitalizations remained unchanged in years 2 through 5 compared with the first year after BT. Prebronchodilator FEV₁ values remained stable between years 1 and 5 after BT, despite a 18% reduction in average daily inhaled corticosteroid dose. High-resolution computed tomographic scans from baseline to 5 years after BT showed no structural abnormalities that could be attributed to BT., Conclusions: These data demonstrate the 5-year durability of the benefits of BT with regard to both asthma control (based on maintained reduction in severe exacerbations and ED visits for respiratory symptoms) and safety. BT has become an important addition to our treatment armamentarium and should be considered for patients with severe persistent asthma who remain symptomatic despite taking inhaled corticosteroids and long-acting β₂-agonists., (Copyright © 2013 American Academy of Allergy, Asthma & Immunology. Published by Mosby, Inc. All rights reserved.)

Background: Many asthmatic patients exhibit sputum eosinophilia associated with exacerbations. Benralizumab targets eosinophils by binding IL-5 receptor α, inducing apoptosis through antibody-dependent cell-mediated cytotoxicity., Objectives: We sought to evaluate the safety of benralizumab in adults with eosinophilic asthma and its effects on eosinophil counts in airway mucosal/submucosal biopsy specimens, sputum, bone marrow, and peripheral blood., Methods: In this multicenter, double-blind, placebo-controlled phase I study, 13 subjects were randomized to single-dose intravenous placebo or 1 mg/kg benralizumab (day 0; cohort 1), and 14 subjects were randomized to 3 monthly subcutaneous doses of placebo or 100 or 200 mg of benralizumab (days 0, 28, and 56; cohort 2). Cohorts 1 and 2 were consecutive., Results: The incidence of adverse events was similar between groups. No serious adverse events related to benralizumab occurred. In cohort 1 intravenous benralizumab produced a median decrease from baseline of 61.9% in airway mucosal eosinophil counts (day 28; placebo: +19.6%; P = .28), as well as an 18.7% decrease (day 21) in sputum and a 100% decrease (day 28) in blood counts. Eosinophils were not detectable in bone marrow of benralizumab-treated subjects (day 28, n = 4). In cohort 2 subcutaneous benralizumab demonstrated a combined (100 + 200 mg) median reduction of 95.8% in airway eosinophil counts (day 84; placebo, 46.7%; P = .06), as well as an 89.9% decrease (day 28) in sputum and a 100% decrease (day 84) in blood counts., Conclusion: Single-dose intravenous and multiple-dose subcutaneous benralizumab reduced eosinophil counts in airway mucosa/submucosa and sputum and suppressed eosinophil counts in bone marrow and peripheral blood. The safety profile supports further development. Additional studies are needed to assess the clinical benefit in asthmatic patients., (Copyright © 2013 American Academy of Allergy, Asthma & Immunology. Published by Mosby, Inc. All rights reserved.)

Background: Airway disorders are common in regular chlorinated swimming pool attendees, particularly competitive athletes, but the impact of intense swimming training on airway function and structure remains unclear., Objective: This study aimed to evaluate airway inflammation and remodeling in elite swimmers., Methods: Twenty-three elite swimmers were tested during off-training season. All had exhaled nitric oxide measurement, methacholine test, eucapnic voluntary hyperpnea challenge, allergy skin prick tests, and bronchoscopy with bronchial biopsies. Clinical data and tissues from 10 age-matched mild-asthmatic and 10 healthy nonallergic subjects were used for comparison., Results: Swimmers had increased airway mucosa eosinophil and mast cell counts than did controls (P < .05). They had more goblet cell hyperplasia and higher mucin expression than did healthy or asthmatic subjects (P < .05). A greater submucosal type I and III collagen expression and tenascin deposition was also observed in swimmers than in controls (P < .05). Neither exhaled nitric oxide nor airway responsiveness to methacholine or eucapnic voluntary hyperpnea challenge correlated with these inflammatory and remodeling changes., Conclusion: Intense, long-term swimming training in indoor chlorinated swimming pools is associated with airway changes similar to those seen in mild asthma, but with higher mucin expression. These changes were independent from airway hyperresponsiveness. The long-term physiological and clinical consequences of these changes remain to be clarified., (Copyright © 2011 American Academy of Allergy, Asthma & Immunology. Published by Mosby, Inc. All rights reserved.)

Background: Eight genes in the immune signaling pathway shown to be differentially expressed in asthmatic lung biopsy specimens in a previous microarray experiment were selected as candidate genes for asthma susceptibility., Objective: We sought to perform an association study with these genes and asthma-related phenotypes in 3 independent Canadian familial asthma collections and 1 Australian asthma case-control study., Methods: Tagging single nucleotide polymorphisms were selected by using the HapMap public database (r(2) > 0.8; minor allele frequency >0.10) and genotyped with the Illumina platform. Family-based association and trend tests for asthma, atopy, airway hyperresponsiveness, and allergic asthma phenotypes were done in each sample, correcting for multiple testing., Results: Uncorrected associations with polymorphisms within 7 genes were detected with 1 or more of the phenotypes in 1 or more of the 4 populations (.001

Background: Up to 30% of asthmatic subjects are smokers, and smoking might be an important contributor to asthma pathology. Inducible nitric oxide synthase (iNOS), ornithine decarboxylase (ODC), and arginase I are involved in the arginine pathway. We have shown that arginase I and iNOS are upregulated in asthma. Smoking asthmatic subjects are reported to have low exhaled nitric oxide levels. The effect of cigarette smoking on the expression of arginase I in asthma is unknown., Objectives: The aims of this study were to investigate the expression of arginase I, ODC, and iNOS in asthmatic airways of smokers and nonsmokers and in vitro after nicotine stimulation., Methods: Endobronchial biopsies were performed on 24 steroid-naive subjects with mild asthma: 12 smokers and 12 nonsmokers. Arginase I, ODC, and iNOS levels were assessed by means of immunohistochemistry and in situ hybridization (arginase I). In vitro stimulation of airway cells with nicotine was performed, followed by real-time PCR., Results: Arginase I, ODC, and iNOS were expressed in the epithelium and smooth muscle bundles of both subgroups of asthmatic subjects. There was an increase of arginase I and ODC immunoreactivities in smoking compared with nonsmoking asthmatic subjects. There was no significant difference in immunoreactivity for iNOS between groups. Nicotine induced a 2-fold increase in arginase I and ODC expression in airway epithelial cells and fibroblasts., Conclusion: This study demonstrates that the expression of arginase I and ODC is increased in airways of smoking compared with nonsmoking asthmatic subjects and in vitro by nicotine., Clinical Implications: Increased expression of arginase I might lead to low exhaled nitric oxide and chronic obstructive pulmonary disease-like airway remodeling in smoking asthmatic subjects.

Background: Migration of eosinophils into bronchial mucosa requires proteolysis. Montelukast, a cysteinyl leukotriene (CysLT) 1 receptor antagonist used in asthma treatment, decreases eosinophil infiltration into the asthmatic airways, suggesting that CysLTs modulate eosinophil protease activity., Objective: We sought to determine whether CysLTs and montelukast regulate eosinophil protease activity., Methods: Purified blood eosinophils were treated with or without montelukast; MK-0591, a 5-lipoxygenase-activating protein inhibitor; or leukotriene (LT) D(4). Migration assays through Matrigel were performed in the presence of 5-oxo-6,8,11,14-eicosatetraenoic acid (5-oxo-ETE), a potent eosinophil chemotactic factor, or LTD(4). Expression of molecules implicated in plasmin generation and matrix metalloproteinase (MMP) 9 release were also evaluated., Results: Montelukast and MK-0591 decreased eosinophil migration promoted by 5-oxo-ETE, whereas LTD(4) failed to induce eosinophil migration. However, LTD(4) significantly boosted the migration rate obtained with a suboptimal concentration of 5-oxo-ETE and partially reversed the inhibition obtained with MK-0591. Montelukast significantly reduced the maximal rate of activation of plasminogen into plasmin by eosinophils obtained with 5-oxo-ETE. 5-Oxo-ETE increased the number of eosinophils expressing urokinase plasminogen activator receptor and stimulated secretion of MMP-9. Montelukast, but neither MK-0591 nor LTD(4), reduced the expression of urokinase plasminogen activator receptor and the secretion of MMP-9 and increased total cellular activity of urokinase plasminogen activator and the expression of plasminogen activator inhibitor 2 mRNA., Conclusion: Montelukast inhibits eosinophil protease activity in vitro through a mechanism that might be independent of its antagonist effect on CysLT 1 receptor., Clinical Implications: This could partially explain montelukast's anti-inflammatory effect in asthma and eventually amplify to improve its therapeutic efficacy.

Background: Inhaled corticosteroids (ICSs) have been shown to reverse epithelial damage and decrease lamina reticularis thickness in patients with asthma., Objective: This study investigated whether clinical asthma control and airway inflammation could be maintained after switching therapy from medium-dose fluticasone propionate (FP) to low-dose FP administered with the long-acting beta2-agonist (LABA) salmeterol., Methods: Eighty-eight subjects (age, > or =18 years) who, during open-label screening, demonstrated improved asthma control after an increase from 100 microg of FP twice daily to 250 microg of FP twice daily were randomized to receive 100/50 microg of FP/salmeterol through a Diskus inhaler (GlaxoSmithKline, Research Triangle Park, NC) twice daily or continue 250 microg of FP twice daily through a Diskus inhaler for 24 weeks. Clinical outcomes were monitored, and bronchial biopsy specimens and bronchoalveolar lavage fluid were obtained before and after 24 weeks of treatment., Results: There were no significant differences between treatments with respect to eosinophils in the bronchial mucosa and bronchoalveolar lavage fluid; mucosal mast cells, neutrophils, or CD3+, CD4+, CD8+, or CD25+ T lymphocytes; or concentration of mediators (GM-CSF, IL-8, and eosinophil cationic protein). The 2 treatments were not different with respect to lamina reticularis thickness. Consistent with the airway inflammatory measures, clinical and physiologic measures of asthma control were also similar., Conclusion: This study demonstrates that control of asthma and airway inflammation is maintained over the 24-week treatment period when patients requiring a medium-dose ICS are switched to a lower-dose ICS with a LABA., Clinical Implications: A lower-dose ICS with a LABA is effective in controlling inflammation and providing clinical asthma control, confirming current guideline recommendations.

Background: Asthma is characterized by inflammation and remodeling. Mast cells are generally increased in bronchial mucosa of subjects with asthma. These cells release a wide variety of cytokines and mediators that have the capacity to stimulate other resident cells such as smooth muscle cells and fibroblasts., Objective: This study was designed to evaluate whether mast cells modulate collagen production by bronchial fibroblasts isolated from subjects with asthma and normal subjects through cytokine production., Methods: Human mast cells were cocultured for 72 hours with primary bronchial fibroblasts isolated from bronchial biopsies of subjects with mild asthma and normal controls. Procollagen I (alpha1), IL-4Ralpha, IL-13Ralpha1, and IL-13Ralpha2 gene expression by bronchial fibroblasts and IL-4 and IL-4delta2 gene expression by mast cells were quantified by real-time RT-PCR. IL-4 production was also measured by ELISA in culture supernatants., Results: Procollagen I (alpha1) gene expression by fibroblasts from subjects with asthma was significantly higher compared with cells from normal controls when cocultured with mast cells. Mast cells expressed IL-4 isoform and IL-4delta2, an alternative splice variant of IL-4. Coculture significantly increased the expression of IL-4 but not IL-4delta2 by mast cells when they were cultured with fibroblasts from subjects with asthma compared with cells from normal controls. Neutralization of IL-4 abrogated collagen mRNA expression. There was no significant change in IL-4Ralpha or IL-13Ralpha1. However, IL-13Ralpha2 gene expression was significantly reduced in fibroblasts from subjects with asthma., Conclusion: These results suggest that inflammatory process may regulate airway remodelling through crosstalk between inflammatory and structural cells. Targeting this crosstalk may have therapeutic application., Clinical Implications: Understanding mechanisms that govern airway remodeling and collagen deposition in asthma is a step toward therapeutic management of this disease. In this work, we found that mast cell-fibroblast crosstalk may be a potential future target to control some aspects of airway remodeling.

Background: Cytokines and chemokines have been implicated in the pathogenesis of asthma. Inhaled corticosteroids have been shown to decrease the number of eosinophils and to downregulate T H 2 cytokines but to increase neutrophils. The effect of corticosteroids on chemokine expression in asthma has not yet been investigated., Objective: We sought to investigate the effect of a 2-week course of oral corticosteroid (methylprednisolone, 40 mg/d) on the expression of CXC chemokines (IL-8 and IFN-gamma-inducible protein 10 [IP-10]) and CC chemokines (eotaxin and monocyte chemotactic proteins [MCPs] 1-4) in endoscopic biopsy specimens of 13 patients with moderate-to-severe asthma., Methods: CD3, major basic protein, and elastase immunoreactivities were monitored before and after treatment by using immunocytochemistry. Eotaxin, IL-8, IP-10, MCP-1, MCP-2, MCP-3, and MCP-4 mRNA expression in epithelium and submucosa were studied by using in situ hybridization., Results: Corticosteroids reduced the number of CD3-positive T cells and major basic protein-positive eosinophils ( P < .05), whereas the number of neutrophils were increased ( P < .05). Corticosteroids also reduced the number of eotaxin ( P < .05), MCP-3, and MCP-4 mRNA-positive cells ( P < .001) in the epithelium and subepithelium. However, corticosteroids caused a significant increase in the epithelial expression of IL-8 ( P < .001), IP-10 ( P < .05), and MCP-2 mRNAs ( P < .01). Corticosteroids had no effects on MCP-1 mRNA expression., Conclusion: Our results demonstrate the dual nature of corticosteroids. Although corticosteroids can downregulate the expression of some asthma-associated chemokines, such as eotaxin, MCP-3, and MCP-4, they can also upregulate the expression of other chemokines, including IL-8, IP-10, and MCP-2. The failure of oral corticosteroids to inhibit IL-8 mRNA expression might contribute to persistent airway neutrophilia observed in patients with moderate-to-severe asthma, despite treatment with corticosteroids.

Background: Important features of airway remodeling in asthma include the formation of subepithelial fibrosis and increased deposition of types I and III collagen. TGF-beta, IL-11, and IL-17 are profibrotic cytokines involved in the formation of subepithelial fibrosis and are increased in patients with asthma, particularly in those with severe disease., Objective: The purpose of this study was to investigate the effect of corticosteroids on the expression of these profibrotic cytokines and on extracellular matrix deposition., Methods: We used immunocytochemistry to measure the expression of TGF-beta, IL-11, IL-17, and collagen types I and III in the airways of patients with mild asthma (n = 9), patients with moderate-to-severe asthma (n = 10), and control subjects without asthma (n = 6). Baseline bronchial biopsy specimens were obtained in all groups. In addition, repeat biopsies were obtained in the patients with moderate-to-severe asthma after a 2-week course of oral corticosteroids., Results: TGF-beta expression was significantly higher in all groups with asthma, and it did not decrease after treatment with oral corticosteroids. Levels of IL-11 and IL-17 were increased in patients with moderate-to-severe asthma compared with patients with mild asthma and normal controls (P <.05). The expression of these cytokines decreased with oral corticosteroids in the moderate-to-severe group to levels that were comparable to those seen in the patients with mild asthma and in the normal controls (P <.005). Expression of types I and III collagens was higher in the patients with moderate-to-severe asthma than in the patients with mild asthma and the controls (P <.05; P <.001). Treatment with corticosteroids did not decrease the expression of types I and III collagens., Conclusions: These results confirm the association of increased levels of TGF-beta, IL-11, IL-17, and types I and III collagens with severe disease and suggest that the failure of cortico-steroids to decrease collagen deposition might be due to persistently elevated TGF-beta expression.

Background: Blood eosinophils have mRNA for FcgammaRIIIB (CD16) but no or minimal spontaneous CD16 expression. Because IFN-gamma and chemotactic factors induce eosinophil CD16 expression in vitro, we postulated that blood eosinophils could express CD16., Objective: Blood of nonallergic controls and subjects with allergic rhinitis, allergic and nonallergic asthma, or hypereosinophilia of various etiologies were analyzed for leukocyte CD16 surface expression., Methods: CD16(+) eosinophils were identified on the basis of physico-optic characteristics, major basic protein, CD49b expression, and sorting by flow cytometry and microscope examination., Results: Subjects with allergic rhinitis and subjects with asthma had higher median percentages of CD16(+) eosinophils (8.1% [1% to 48.6%] and 7.3% [1.4% to 31.1%], respectively) than nonallergic controls and nonallergic asthmatics (3% [0% to 11%] and 4.6% [2.9% to 5.1%], respectively). In subjects with hypereosinophilia, CD16(+) eosinophils were increased only in a case of drug allergy. When subjects with mild allergic asthma were challenged with a relevant aeroallergen, blood CD16(+) eosinophils further increased during or after the late-phase response (6 to 48 hours after challenge; mean +/- SEM, 9.4% +/- 2.5% to 20.0% +/- 3.0%). CD16(+) eosinophils expressed more IL-5 receptor but less CD11b and IL-12p35 than did CD16(-) eosinophils., Conclusion: Upregulation of blood CD16(+) eosinophils in allergic conditions and its association with a modified phenotype suggest that CD16 receptor could play a role in eosinophil activation in allergy.

Background: The expression of IL-4 and IL-5 is increased in patients with atopic asthma compared with control subjects and correlates with indices of pulmonary function. In nonatopic asthma the expression of IL-4, unlike IL-5, fails to correlate with pulmonary function, and compared with their atopic counterparts, these patients have fewer cells expressing IL-4 receptor (IL-4R). As such, a deficiency in the IL-4 signaling pathway may be implicated in nonatopic asthma. The transcription factors GATA-3 and cMAF mediate IL-4 and IL-5 synthesis, whereas signal transducer and activator of transcription 6 (STAT-6) is critical for IL-4R signaling., Objective: This study examines the expression profile of these transcription factors in asthma, according to atopic status., Methods: With immunocytochemistry, the expression of GATA-3, cMAF, and STAT-6 protein was determined in sections of bronchial biopsy specimens from patients with atopic asthma (n = 7), patients with nonatopic asthma (n = 8), and control subjects (n = 8)., Results: Higher numbers of cells expressing GATA-3 and cMAF were observed in patients with atopic and those with nonatopic asthma than in control subjects and patients with tuberculosis (P <.001). There were also more STAT-6-immunoreactive cells in patients with atopic and those with nonatopic asthma than in control subjects (P <.0001, P <.05). Notably, however, fewer cells expressing STAT-6 protein were observed in nonatopic versus atopic asthma (P <.0001)., Conclusions: These results demonstrate the upregulation of GATA-3 and cMAF in both variants of asthma and indicate that reduced IL-4R signaling, because of lower STAT-6 expression, may be a feature of nonatopic asthma.

Background: The use of fiberoptic bronchial biopsies has improved our understanding of the immunopathology of asthma. However, this approach offers a limited ability to perform mechanistic studies observing cell-cell and cell-matrix interactions, which are a key issue in the study of airway remodeling. Tissue engineering is a technique that combines the use of biology and engineering expertise to generate a limitless amount of tissue from small samples. This technology allows for the study of cell interactions under conditions as close as possible to the natural environment., Objective: The aim of this study was to evaluate the feasibility of an engineered human bronchial mucosa as a model to study cellular interactions in asthma., Methods: Human bronchial fibroblasts from normal and asthmatic donors were incorporated into collagen gel. Bronchial epithelial cells were seeded over this gel and then cultured in an air-liquid interface in the presence or the absence of T lymphocytes. Biopsy specimens from these engineered mucosa were taken for structural and ultrastructural analysis, and T lymphocytes were harvested and used to localize IL-5., Results: Histologic analysis showed that engineered mucosa with normal bronchial cells presented a pseudostratified ciliated epithelium with the presence of mucus secretory cells. The electron microscopy analysis confirmed these histologic results. These features were comparable with those observed in normal bronchial tissues. However, in engineered mucosa from asthmatic subjects, the tissue structure was disorganized, particularly the epithelial cell arrangement. The percentage of IL-5(+) lymphocytes was significantly (P =.03) higher in engineered bronchial mucosa from asthmatic subjects (87% +/- 2%) compared with mucosa from normal volunteers (2% +/- 0.3%)., Conclusion: Using tissue engineering, we produced an in vitro model of bronchial mucosa from normal and asthmatic subjects. These models could be a valuable tool to better understand key mechanisms involved in inflammation and airway repair.

Background: Natural exposure to pollen provokes an increase in airway responsiveness in nonasthmatic subjects with seasonal allergic rhinitis. This natural exposure may induce inflammatory cell recruitment and cytokine release, leading to lower airway inflammation., Objective: The aim of this study was to characterize lower airway inflammation in nonasthmatic pollen-sensitive subjects., Methods: We performed immunohistochemical tests on bronchial biopsy specimens from subjects with rhinitis who had no past or current history of asthma to evaluate cytokine expression and inflammatory cell numbers and activation both in and out of the pollen season., Results: The number of CD4(+), CD8(+), and CD45RO(+) lymphocyte subpopulations were significantly higher during the pollen season compared with the out-of-season period (P <.04). Furthermore, EG1(+) cells tended to increase after natural pollen exposure (P =.06). The number of IL-5(+) cells increased significantly after natural exposure to pollen compared with out-of-season numbers (P <.01). This increase in IL-5 expression was correlated with the numbers of CD3(+), CD4(+), CD45RO(+), and EG1(+) cells. The numbers of tryptase-positive, IFN-gamma(+), and IL-4(+) cells did not change after natural exposure., Conclusion: This study showed that natural pollen exposure was associated with an increase in lymphocyte numbers, eosinophil recruitment, and IL-5 expression in the bronchial mucosa of nonasthmatic subjects with allergic rhinitis.

Background: IL-11 is a pleiotropic cytokine produced by a variety of stromal cells. Targeted overexpression of this cytokine in mice results in a remodeling of the airways and the development of airway hyperresponsiveness and airway obstruction., Objectives: Because these alterations mimic important pathologic and physiologic changes in the airways of some asthmatic patients, we investigated the expression of IL-11 messenger RNA (mRNA) within the airways of patients with mild to severe asthma and nonasthmatic control subjects., Methods: Fiberoptic bronchoscopy to obtain bronchial biopsy specimens was performed on patients with mild (n = 13), moderate (n = 10), and severe (n = 9) asthma and on nonasthmatic control subjects (n = 9)., Results: These patients differed in their extent of airway fibrosis with types I and III collagens being noted in greater quantities in the biopsy specimens from the severe and moderate asthmatics than in those from controls (P <.05). IL-11 mRNA expression was observed in the epithelial and subepithelial layers of asthmatic and nonasthmatic control subjects. The number of cells within the epithelium and subepithelium expressing IL-11 mRNA was greater in those with moderate and severe asthma compared with mild asthma and nonasthmatic subjects (P <.001). There were also greater numbers of IL-11 mRNA-positive cells within the subepithelium in severe compared with moderate asthma (P <.001). Immunostaining for IL-11 within the airway tissues confirmed translation of the mRNA into IL-11-immunoreactive protein in airway epithelial cells. Colocalization of IL-11 mRNA and immunoreactivity with resident inflammatory cells demonstrated that this cytokine was also expressed by major basic protein-positive eosinophils., Conclusion: These results suggest that IL-11 is involved in the chronic remodeling seen in asthmatic airways and is associated with increasing severity of the disease.

Background: A long-acting inhaled bronchodilator that is both well tolerated and effective could allow for improved control of both daytime and nighttime symptoms in patients with asthma who use frequent as-needed short-acting bronchodilators despite antiinflammatory treatment., Objective and Methods: We compared the efficacy and safety of inhaled salmeterol, 50 micrograms twice daily, with inhaled salbutamol, 200 micrograms four times daily, delivered through a metered-dose inhaler for 3 months in a multicenter, randomized, double-blind, parallel-group study of 228 patients (aged 12 to 76 years) with mild-to-moderate asthma., Results: A single morning dose of salmeterol produced improvement in FEV1 that was significantly greater (p < or = 0.012) than that produced by two doses of salbutamol (taken 6 hours apart) when patients were assessed 3 to 6 hours and 10 to 12 hours after the dose. This greater bronchodilation was present on day 1 of the study and after 4, 8, and 12 weeks of regular treatment. Over the 12 weeks, compared with salbutamol, salmeterol treatment was associated with a greater mean improvement in morning peak expiratory flow (35 L/min vs -3 L/min, p < 0.001), a higher percentage of days with no symptoms (29% vs 15%; p = 0.012), and a higher percentage of nights with no awakenings (14% vs -1%; p < 0.001). Adverse events were similar for both treatments., Conclusions: In this study salmeterol, 50 micrograms twice daily, was well tolerated and more effective than salbutamol, 200 micrograms four times daily, in improving symptoms and lung function in patients with mild-to-moderate asthma.

Background: Reactive airways dysfunction syndrome (RADS) or irritant-induced asthma is a syndrome that leaves subjects with asthma-like symptoms after one or more exposures to a high concentration of an irritant substance. The degree of reversibility of airway obstruction in subjects with RADS is nevertheless unknown, as is the degree of associated lesions at the airway level., Methods: We compared the acute reversibility of forced expiratory volume in 1 second (FEV1) after inhalation of albuterol (200 micrograms) in 15 subjects with RADS (12 cases caused by chlorine inhalation) with that of 30 subjects with occupational asthma (OA) caused by various agents. They were paired according to baseline airway obstruction (61% and 63% of predicted value in the RADS and OA groups), requirement for medication (bronchodilator only--7 of 15 subjects with RADS and 14 of 30 subjects with OA--as compared with bronchodilator + inhaled steroids in 8 of 15 subjects with RADS and 16 of 30 subjects with OA, respectively), and interval since removal from exposure (means of 30 and 24 months in the RADS and OA groups). In addition, five nonsmokers with RADS who had not received inhaled steroids underwent bronchoscopy with lavage and bronchial biopsies less than 2 years after the exposure., Results: The percentage increase in FEV1 over baseline after inhalation of albuterol was 10% +/- 9% in the RADS group and 19% +/- 16% in the OA group (p = 0.005). Only 2 of 15 subjects (13%) with RADS and 12 of 30 subjects (40%) with OA showed an improvement in FEV1 of 20% or greater after inhalation of albuterol. Bronchoalveolar lavage showed an increased number of cells with a predominance of lymphocytes, and biopsy specimens showed increased basement membrane thickness in the five subjects with RADS who underwent bronchoscopy., Conclusion: Subjects with RADS are generally left with less airway reversibility than those with OA. We suggest that this difference is secondary to distinct pathologic changes.

Background: This study looked at respiratory symptoms, peak expiratory flow rates (PEFRs), airway responsiveness to methacholine and inflammatory changes on bronchial biopsies, bronchial lavage (BL), and bronchoalveolar lavage (BAL) during natural antigenic exposure in nine subjects with pollen-sensitized seasonal asthma., Methods: The subjects recorded daily symptoms of asthma, cough and rhinitis, and morning and evening PEFRs between January and September, during and out of the pollen exposure. Baseline forced expiratory volume in 1 second, forced vital capacity, and methacholine responsiveness were measured every 3 to 4 weeks. BAL, BL, and bronchial biopsies were performed in the pollen season at the initial increase of asthma symptoms and out of pollen exposure., Results: At the time of bronchoscopy during the pollen season compared with out of season, asthmatic subjects had an increase in asthma symptom score (1.18 +/- 0.24/0.44 +/- 0.18, p < 0.05), a reduction of PEFR (407 +/- 23/442 +/- 20 L/min, p = 0.02), and a decrease in PC20 (1.15/1.48 mg/ml, p = 0.05). In asthmatic subjects, median BAL and BL cell counts and cell differentials during or out of antigenic exposure were similar, but BAL and BL eosinophils and metachromatic cells counts were always higher than in healthy subjects. In comparison with controls, biopsies obtained in asthmatic subjects showed airway lesions such as epithelial desquamation, squamous cell metaplasia, thickening of basal membrane, inflammatory cells (p < 0.05 for neutrophils), edema, and ciliary abnormalities. During pollen exposure, inflammatory signs increased, but this change was only significant for the extent of epithelial desquamation and neutrophil counts. No significant correlation was found between the intensity of airway inflammation and changes in airway responsiveness., Conclusions: In subjects with mild allergic asthma and pollen-induced asthma, seasonal antigenic exposure was associated with an increase in epithelial shedding and in the number of neutrophils on bronchial biopsies, suggesting a mild increase in baseline airway inflammation. However, these changes were not correlated with increases in airway responsiveness.

To determine if atopic subjects without asthma naturally exposed to antigens to which they are sensitized demonstrate evidence of lower airway inflammation, we studied 10 subjects with recurrent seasonal allergic rhinitis to pollens. Each subject had a monthly methacholine challenge and two bronchoalveolar lavages (BAL), one during symptoms of allergic rhinitis and one out of season. The percentage of macrophages, lymphocytes, neutrophils, eosinophils, and mast cells in the lavage fluid were determined on Diff-Quik, nonspecific esterase, or toluidine blue-stained cytocentrifuge preparations. The total number of cells recovered on BAL was 23.2 +/- 3.5 X 10(6) (mean +/- SEM) (13.3 +/- 2.3 X 10(4) cells per milliliter) in season, during symptoms of allergic rhinitis, and 33.8 +/- 7.4 X 10(6) (15.2 +/- 3.1 X 10(4) cells per milliliter) out of season (p greater than 0.05). BAL cell-differential counts (percent) in/out season were similar for macrophages (89.0/84.6), lymphocytes (9.1/12.8), neutrophils (1.3/2.1), eosinophils (0.5/0.5), epithelial cells (0.37/0.46), and mast cells (0.0008/0.0013). Blood eosinophil counts, taken, respectively, in and out of season, were 135.5 +/- 26.8 X 10(6)/L and 102.8 +/- 20.6 X 10(6)/L (p greater than 0.05). Although overall airway responsiveness increased slightly during the pollen season, it did not reach statistical significance (geometric mean of provocative concentration causing a 20% fall in FEV1 [milligrams per milliliter], 98.8 during antigenic exposure compared to 121.4 out of season) (p greater than 0.05. These observations suggest that in subjects without asthma, no changes in cell differential are detected on BAL at the time of maximal symptoms of allergic rhinitis.

Blood samples were obtained from a group of 20 patients with hypereosinophilia (greater than or equal to 1500 eosinophils/mm3). The polymorphonuclear leukocytes (PMNLs) were prepared from blood treated with ethylenediaminetetra-acetic acid by successive dextran sedimentation of the red blood cells, separation of mononuclear leukocytes and PMNLs on Ficoll-Paque, and ammonium chloride treatment of the PMNL fraction. The eosinophil content of the final PMNL preparations ranged from 15% to 75%, as assessed by Wright-stained smears, and the remaining leukocytes were predominantly neutrophils with only 3% to 5% mononuclear cells. The eosinophil-rich PMNL preparations as well as PMNL preparations from normal volunteers were incubated under various conditions and the arachidonic acid metabolites were analyzed by reverse-phase high-performance liquid chromatography. The synthesis of 5-lipoxygenase products was strongly stimulated by the ionophore A23187 in both normal and eosinophil-rich PMNL preparations. Whereas the normal PMNL preparations, which were eosinophil poor, produced 10 to 25 times more leukotriene B4 than leukotriene C4, the eosinophil-rich PMNL preparations characteristically released leukotriene C4 in equal or up to 20 times greater amounts than leukotriene B4.