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Normalisation of eosinophil counts in sputum of asthmatic patients reduces eosinophilic exacerbations. However, the effect of this strategy on airway remodelling remains to be determined. We compared bronchial inflammation and collagen deposition after 2 yrs of treatment guided by either sputum eosinophils (sputum strategy, SS) or by clinical criteria (clinical strategy, CS). As a pilot study, 20 mild asthmatic patients were randomly assigned to CS or SS strategies. Bronchial biopsies were obtained when minimum treatment needed to maintain control was identified and this was continued for 2 yrs. Biopsies were immunostained for inflammatory cells, mucin 5A (MUC5A) and collagen. The mean dose of inhaled corticosteroids at the start and end of the study was similar in both SS and CS groups. Forced expiratory volume in 1 s increased in both groups at the study end. In SS, mucosal lymphocyte and eosinophil counts, but not neutrophils, were reduced at the end of the study. In CS, only activated eosinophil and neutrophil counts decreased. MUC5A staining decreased in SS but not CS. No change in collagen deposition underneath the basement membrane was observed in either strategy. Treatment strategies that normalise sputum eosinophils also reduce mucosal inflammatory cells and MUC5A expression, but do not change subepithelial collagen deposition in mild to moderate asthma.

Background Thymic stromal lymphopoietin (TSLP) plays a pivotal role in the initiation of allergic airway inflammation. This cytokine is produced by several cell types, including human epithelial cells. Objective We sought to determine the effect of TSLP on proliferation and repair of epithelial cells isolated from asthmatic patients and healthy subjects. Methods Expression of TSLP receptor (TSLPR) and its response to inhaled corticosteroids was evaluated on bronchial biopsy specimens of healthy control subjects and asthmatic patients by means of immunohistochemistry. TSLPR, TSLP, and IL-13 mRNA expression was determined by means of quantitative PCR, and protein expression was measured by means of ELISA and Western blotting in epithelial cells isolated from asthmatic subjects compared with those isolated from healthy control subjects. The effect of TSLP on cell proliferation and wound healing was performed. Results TSLPR is expressed by bronchial epithelial cells in bronchial biopsy specimens and in cultured cells, with no difference between asthmatic patients and healthy control subjects. Inhaled corticosteroids did not affect this expression. TSLP mRNA and protein levels were significantly higher in epithelial cells isolated from asthmatic patients compared with those from healthy control subjects. TSLP stimulated IL-13 production by bronchial epithelial cells. TSLP induced airway epithelial cell proliferation and enhanced epithelial injury repair. This effect was abrogated with IL-13 neutralization. Conclusions Our data indicate that epithelial cells express TSLPR and that TSLP induces bronchial epithelial cell proliferation and increases injury repair through IL-13 production. This suggests that TSLP and IL-13 loops play a homeostatic role on epithelial cell proliferation and repair.

Background Inflammatory changes such as subepithelial edema and excessive inflammatory cell infiltration have been observed in uvular tissues of obstructive sleep apnea (OSA) subjects. The levels of proinflammatory cytokines such as tumor necrosis factor (TNF)-α and interleukin-6 are elevated in the serum of apneic patients and have been proposed as mediators of muscle weakness. TNF-α has been shown to affect diaphragm contractility in mice and rabbit in vivo . Objectives To assess total and compartmental TNF-α expression in uvular tissues of apneic and nonapneic patients. Methods Uvular tissues were collected from 14 snorers without sleep disorders breathing, 14 subjects with OSA (OSA 1 group) whose body mass index (BMI) was similar to that of snorers, and 12 additional obese OSA subjects (OSA 2 group) who underwent an uvulopalatopharyngoplasty. Sections were examined using immunohistochemistry and Western blot analysis. TNF-α expression was evaluated in the musculus uvulae (MU), epithelial layer, and perimuscular tissues from proximal uvular sections. Results TNF-α was more highly expressed in whole uvular protein extracts of apneic groups than in snorers ([mean ± SEM] snorers, 100.5 ± 3.0%; OSA 1 group, 127.1 ± 6.9%; OSA 2 group, 140.7 ± 11.0%; p = 0.01). In the muscular area, TNF-α levels were higher in the more obese OSA subjects than in the other two groups (snorers, 100.3 ± 3%; OSA 1 group, 107.4 ± 0.7%; OSA 2 group, 124.1 ± 4.2%; p = 0.007). In the muscular area, TNF-α was correlated with BMI, but no relationship was found with the apnea-hypopnea index. Conclusions We conclude that MU is the major TNF-α source in uvular tissue and that TNF-α is more highly expressed in the heaviest OSA patients compared to less obese OSA patients and nonapneic snorers.

Rationale Airway remodeling is believed to be important in the pathophysiology of asthma, and myofibroblasts are increased in the airways of asthmatic individuals 24 h after allergen challenge. Leukotriene receptor antagonists exert antiinflammatory activity in asthma, but it is unknown whether they influence indices of airway remodeling. In the present study, we evaluated the effect of montelukast on airway myofibroblasts following low-dose allergen challenge (LDAC). Methods Stable subjects with mild asthma were included in a two-center, randomized, parallel-group study. A 2-week run-in period was followed by LDAC and endobronchial biopsy. Subjects were then randomized to receive either montelukast, 10 mg/d, or placebo (n = 10 in each group) for 8 weeks in a double-blind manner; at the end of the treatment period, subjects underwent a second LDAC and endobronchial biopsy. The effect of treatment on myofibroblasts, fibroblasts, and inflammatory cells was examined using electron microscopy techniques. Results Treatment with montelukast showed no significant difference by comparison with placebo but did show a significant within-group treatment-related decrease in airway wall myofibroblasts not seen in the placebo group. In addition, the montelukast-treated group also showed a significant within-group reduction in lymphomononuclear cells and increased neutrophils. Conclusions The results suggest that montelukast has an inhibitory effect on airway structural cells that play a key role in airway remodeling in allergic airway inflammation, and that montelukast may be a useful therapy to attenuate airway remodeling in asthma.

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 (α 1 ), IL-4Rα, IL-13Rα 1 , and IL-13Rα 2 gene expression by bronchial fibroblasts and IL-4 and IL-4δ2 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 (α 1 ) 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-4δ2, an alternative splice variant of IL-4. Coculture significantly increased the expression of IL-4 but not IL-4δ2 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-4Rα or IL-13Rα 1 . However, IL-13Rα 2 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.

Increased eosinophil counts are a major feature of asthmatic airways. Eosinophil recruitment requires migration through epithelium and tissue extracellular matrix by activation of proteases. We assessed the capacity of IL-16, a CD4+ cell chemotactic factor, to induce migration of eosinophils through a reconstituted basement membrane and evaluated the proteases, mediators, and receptors involved in this migration. IL-16 added to lower chambers of Invasion Chambers elicited eosinophil migration through Matrigel. This effect was decreased by inhibition of the plasminogen-plasmin system (Abs against urokinase plasminogen activator receptor or plasminogen depletion), but not by anti-matrix metalloproteinase-9 Abs. Abs against CD4 also inhibited IL-16-induced eosinophil migration. At the baseline level, few eosinophils (4.6% positive cells with a mean fluorescence of 0.9) expressed surface membrane CD4, while most permeabilized eosinophils (68% positive cells with a mean fluorescence of 18) express the CD4 Ag. TNF-pretreatment increased surface membrane CD4+ expression by 6-fold as previously described, and increased IL-16-induced cell migration by 2.2-fold. Incubation of eosinophils with IL-16 also increased surface membrane CD4 expression by 5.4-fold, supporting the role of CD4 as receptor for IL-16. Abs against CCR3, eotaxin, or RANTES blocked IL-16-induced migration. In conclusion, IL-16 promotes eosinophil migration in vitro, by activating the plasminogen-plasmin system and increasing the membrane expression of its receptor. This effect is initiated via CD4 and mediated via the release of CCR3 ligand chemokines. Interestingly, most eosinophils express intracellular CD4. Hence, IL-16 may play an important role in the recruitment of blood eosinophils to the bronchial mucosa of asthmatics.

We investigated the influence of weight and obstructive sleep apnea status on inflammatory and histologic features of the uvula. Tissue samples resected during uvulopalatopharyngoplasty in 11 snorers without obstructive sleep apnea, 11 subjects with obstructive sleep apnea and of similar body mass index and age, and 8 additional obese subjects with obstructive sleep apnea were examined by immunohistochemistry and histologic staining techniques. The frequency and distribution of immune cells, the amount of collagen, and the integrity of the elastin fiber network were evaluated in proximal and distal uvular sections. T cell (CD4+, CD8+) and macrophage counts were higher in the more obese apneic subjects than in the other two groups. In all patients, T cell counts correlated with body mass index, but there was no relationship with the apnea-hypopnea index. A positive correlation was found between elastin fiber network disorganization score and apnea-hypopnea index. We conclude that (1) the amount of inflammatory markers is linked to obesity rather than to sleep-related breathing disorders, and (2) obstructive sleep apnea is associated with a structural alteration of the extracellular matrix of upper airway tissue.

Asthma is considered an airway inflammatory disorder characterized by variable airflow obstruction and airway hyperresponsiveness (1). The inflammatory component of asthma has been studied extensively over the past few years, but, more recently, the potential contribution of airway wall remodeling to functional and clinical changes has been emphasized (2,3). Although the methods of sampling of bronchial tissue were previously limited, being obtained mostly from autopsic or surgical specimens, they have improved recently.

Background: Blood eosinophils express CD16 on their surface when stimulated in vitro with platelet-activating factor or IFNγ. Transient expression of CD16 is also observed in vivo following aeroallergen challenge of asthmatic subjects. The present work is aimed at evaluating the possible mechanisms modulating eosinophil expression of CD16 and the biological functions of this receptor. Methods: First, purified blood eosinophils were incubated with IL-1β, IL-2, IL-4, IL-5, IL-9 or IL-16, GM-CSF, IFNγ, eotaxin or 5-oxo-ETE and CD16 expression was measured. Second, the capacity of CD16 to mediate degranulation induced by IgG immune complexes (IC) was evaluated in eosinophils with low and high CD16 expression. Finally, serum allergen-specific IgE and IgG, and total IgE levels were measured at baseline in allergic asthmatics and correlated with changes observed in blood eosinophil CD16 expression (ΔCD16) following allergen challenge. Results: Only IFNγ and IL-2 significantly increased the number of CD16+ eosinophils, respectively, 37 ± 10% (p = 0.0038) and 38 ± 8% (p = 0.0006), compared to control, 7 ± 2%. IgG IC induced degranulation in eosinophils with low and high CD16 expression and monoclonal anti-CD16 and anti-CD32 antibodies inhibited this. IgG IC increased eosinophil CD16 expression (14 ± 6%, p = 0.0008) and this effect was blocked by pretreatment with anti-CD32 antibodies. ΔCD16 following allergen challenge correlated with the specific IgG/total IgE ratio (r2 = 0.41, p = 0.036). Conclusion: These data suggest that formation of IgG IC is associated with surface eosinophil CD16 expression in asthma and that CD16 in cooperation with CD32 mediates IC-induced degranulation.

Background: Efalizumab is a humanized IgG 1 mAb against the lymphocyte function antigen-1 (LFA-1) alpha chain, CD11a. Blocking of LFA-1/intercellular adhesion molecule interactions could inhibit asthmatic inflammation by blocking adhesion and activation of LFA-1-positive leukocytes. Objective: A randomized, double-blinded, placebo-controlled, parallel group, multicenter study investigated the effects of efalizumab on allergen-induced airway responsiveness and airway inflammation. Methods: Thirty-five nonsmoking subjects with mild allergic asthma were randomized to receive efalizumab (n = 24) or placebo (n = 11) in 8 weekly subcutaneous doses (0.7 mg/kg conditioning dose followed by 7 weekly doses of 2.0 mg/kg). Allergen challenges were performed at screening and after 4 and 8 weeks of treatment. Samples of sputum (n = 18 subjects) and blood (n = 35 subjects) were collected the day before challenges, and sputum was collected again at 7 and 24 hours after each challenge. Nonparametric tests were used to compare allergen-induced differences between efalizumab and placebo groups. Results: Subjects receiving efalizumab developed headache (48%) and flu syndrome (28%) compared to subjects receiving placebo (0%). After 8 weeks of efalizumab, the maximum late percent fall in FEV 1 (late asthmatic response) was inhibited by 50%, but neither the late response nor the late area under the curve was statistically different than placebo ( P = .098 and .062, respectively). Efalizumab had no effect on the maximum early percent fall in FEV 1 (early asthmatic response) or early area under the curve compared to placebo ( P > .59). Efalizu-mab significantly reduced the postallergen increase in sputum EG2-positive cells and metachromatic cells ( P Conclusions: Blocking of LFA-1/intercellular adhesion module interactions by efalizumab inhibits the development of allergen-induced cellular inflammatory responses measured in induced sputum and might attenuate the late asthmatic response. Larger studies are needed to confirm this. (J Allergy Clin Immunol 2003;112:331-8.)

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.The purpose of this study was to investigate the effect of corticosteroids on the expression of these profibrotic cytokines and on extracellular matrix deposition.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.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.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: Asthma is characterized by airway inflammation and remodeling in which matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMP) play an important role. Allergen exposure activates the inflammatory/repair process in sensitized subjects. Induced-sputum analysis is a non-invasive method that allows the assessment of changes in inflammatory and remodeling mediators implicated in asthma. Objectives: To evaluate the changes in MMP-9 and its principal inhibitor (TIMP-1) in sputum and plasma of mild allergic asthmatic subjects after whole-lung allergen challenge. Methods: Induced sputum and blood samples were obtained at baseline, and 6 and 24 h after challenge. MMP-9 and TIMP-1 levels in sputum and plasma were measured by ELISA. Results: Allergen challenge increased the percentage of sputum eosinophils and MMP-9 levels 6 and 24 h after the challenge compared to baseline levels, but TIMP-1 levels did not vary significantly. A significant correlation was observed between MMP-9 levels at 6 h and the maximum percent fall in FEV1 during the late response. Throughout the study, MMP-9 levels correlated significantly with the number of neutrophils in sputum. Conclusions: This study shows that analysis of induced sputum is a useful tool to study the variations in MMP-9 and TIMP-1 levels following allergen challenge, therefore allowing to evaluate their role in allergen-induced airway damage and repair.

Oral candidiasis is a collective name for a group of disorders caused by the dimorphic fungusCandida albicans. Host defenses againstC. albicansessentially fall into two categories: specific immune mechanisms and local oral mucosal epithelial cell defenses. Since oral epithelial cells secrete a variety of cytokines and chemokines in response to oral microorganisms and sinceC. albicansis closely associated with oral epithelial cells as a commensal organism, we wanted to determine whether interleukin-18 (IL-18) and gamma interferon (IFN-γ) were produced by oral epithelial cells in response toC. albicansinfection and lipopolysaccharide (LPS) stimulation. Our results showed that IL-18 mRNA and protein were constitutively expressed by oral epithelial cells and were down-regulated byCandidainfections but increased following LPS stimulation. BothC. albicansand LPS significantly decreased pro-IL-18 (24 kDa) levels and increased active IL-18 (18 kDa) levels. This effect was IL-1β-converting-enzyme dependent. The increase in active IL-18 protein levels promoted the production of IFN-γ by infected cells. No effect was obtained with LPS. Although produced only at an early stage, secreted IFN-γ seemed to be a preferential response by oral epithelial cells toC. albicansgrowth. These results provide additional evidence for the contribution of oral epithelial cells to local (direct contact) and systemic (IL-18 and IFN-γ production) defense against exogenous stimulation such asC. albicansinfection or LPS stimulation.

The mechanisms of fibrillar collagen accumulation in asthmatic bronchi remain unclear, an imbalance between synthesis and degradation of collagen may be implicated in this process. The aim of this study was to compare the capacities of normal (BNF) and asthmatic (BAF) bronchial fibroblasts to degrade collagen. Metalloproteinases and their inhibitors were measured by ELISA, types I and III procollagen synthesis was determined by liquid RIA and, finally, zymography was used to assess the presence of active and latent forms of MMPs. The capacity of fibroblasts to degrade collagen coated onto latex beads was evaluated by flow cytometry. Our results showed that MMP-2 secretion was significantly higher in BNF when compared to BAF and this was confirmed by gelatin zymography. In BNF culture, TIMP-1 and MMP-1 secretions positively correlated with types I and III procollagen synthesis. However, in BAF, this correlation was negative. This suggests that a balance exists between collagen synthesis and degradation in BNF and that this balance is compromised in BAF. On the other hand, BAF did show significantly reduced capacity to degrade collagen when compared to that of BNF. This reduced phagocytic activity was not associated with a decrease in collagen receptor expression. This study establishes for the first time that a relationship exists between metalloproteinases enzyme dysregulation and the reduced capacity of asthmatic bronchial fibroblast to degrade collagen. These events may shed light on why accumulation of collagen can be observed in asthmatic airways.

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. (J Allergy Clin Immunol 2001;107:36-40.)

Background Airway inflammation is an important characteristic of asthma and has been associated with airway remodelling and bronchial hyperreactivity. The mucosal microenvironment composed of structural cells and highly specialised extracellular matrix is able to amplify and promote inflammation. This microenvironment leads to the development and maintenance of a specific adaptive response characterized by Th2 and Th17. Bronchial fibroblasts produce multiple mediators that may play a role in maintaining and amplifying this response in asthma. Objective To investigate the role of bronchial fibroblasts obtained from asthmatic subjects and healthy controls in regulating Th17 response by creating a local micro-environment that promotes this response in the airways. Methods Human bronchial fibroblasts and CD4+T cells were isolated from atopic asthmatics and non-atopic healthy controls. CD4+T were co-cultured with bronchial fibroblasts of asthmatic subjects and healthy controls. RORc gene expression was detected by qPCR. Phosphorylated STAT-3 and RORγt were evaluated by western blots. Th17 phenotype was measured by flow cytometry. IL-22, IL17, IL-6 TGF-β and IL1-β were assessed by qPCR and ELISA. Results Co-culture of CD4+T cells with bronchial fibroblasts significantly stimulated RORc expression and induced a significant increase in Th17 cells as characterized by the percentage of IL-17+/CCR6+ staining in asthmatic conditions. IL-17 and IL-22 were increased in both normal and asthmatic conditions with a significantly higher amount in asthmatics compared to controls. IL-6, IL-1β, TGF-β and IL-23 were significantly elevated in fibroblasts from asthmatic subjects upon co-culture with CD4+T cells. IL-23 stimulates IL-6 and IL-1β expression by bronchial fibroblasts. Conclusion Interaction between bronchial fibroblasts and T cells seems to promote specifically Th17 cells profile in asthma. These results suggest that cellular interaction particularly between T cells and fibroblasts may play a pivotal role in the regulation of the inflammatory response in asthma.

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. (J Allergy Clin Immunol 2000;105:232-8.)

Asthma presents a variable clinical response to corticosteroids (CS). Because CS more likely act on inflammation than on tissue remodeling, the presence of bronchial structural changes in certain asthmatics may explain their limited clinical response to CS. Matrix metalloproteinase-9 (MMP-9) and its inhibitor, tissue inhibitor of metalloproteinase-1 (TIMP-1), are, respectively, involved in tissue inflammatory processes and fibrogenic processes. Previous reports have suggested that MMP-9:TIMP-1 ratio may reflect the balance between these two processes in various diseases. This study evaluated the relation of this ratio and the response to CS in severe asthma. Twenty asthmatics with low baseline FEV1 (59 +/- 4% predicted) and/= 30 % increase with beta2-agonist were recruited. Serum MMP-9 and TIMP-1 levels were measured and correlated with response to an oral CS trial (methylprenisolone 40 mg/d for 14 d). With oral CS, FEV1 changes (DeltaFEV1) ranged from -15 to +43%. The DeltaFEV1 closely correlated with the MMP-9:TIMP-1 ratios (rho = 0. 79, p = 0.0006). In conclusion, serum MMP-9: TIMP-1 ratio could predict the response of oral CS therapy in asthma. The low MMP-9:TIMP-1 ratio observed in subjects with little or no FEV1 improvement with CS supports the hypothesis that, in these asthmatic subjects, bronchial fibrogenesis predominates over inflammation.

Background Asthma is a major public health burden worldwide. Studies from our group and others have demonstrated that SERPINB3 and SERPINB4 are induced in patients with asthma; however, their mechanistic role in asthma has yet to be determined. Objective To evaluate the role of Serpin3a, the murine homolog of SERPINB3 and SERPINB4, in asthma. Methods We studied wild-type Balb/c and Serpinb3a-null mice in house dust mite or IL-13–induced asthma models and evaluated airway hyperresponsiveness, inflammation, and goblet cell hyperplasia. Results Airway hyperresponsiveness and goblet cell hyperplasia were markedly attenuated in the Serpinb3a-null mice compared with the wild-type mice after allergen challenge, with minimal effects on inflammation. Expression of sterile alpha motif pointed domain containing v-ets avian erythroblastosis virus E26 oncogene homolog transcription factor (SPDEF), a transcription factor that mediates goblet cell hyperplasia, was decreased in the absence of Serpinb3a. IL-13–treated Serpinb3a-null mice showed attenuated airway hyperresponsiveness, inflammation, and mucus production. Conclusion Excessive mucus production and mucus plugging are key pathologic features of asthma, yet the mechanisms responsible for mucus production are not well understood. Our data reveal a novel nonredundant role for Serpinb3a in mediating mucus production through regulation of SPDEF expression. This pathway may be used to target mucus hypersecretion effectively.

Objective/purpose In asthma, CD4+T cells are selectively recruited into the bronchial mucosa. CD4+ T cells consist of different subsets that express lineage specific transcription factors and play different roles either in initiating and supporting the development of immune response, but also in orchestrating and regulating them. The aim of our study was to evaluate the effect of T cells-bronchial fibroblasts interaction on CD4+T cell phenotype.

Asthma is a major public health burden worldwide. Excessive mucus production and mucus plugging are key pathologic features of asthma, yet the mechanisms responsible for mucus production remain largely unknown and therapies to effectively target mucus hypersecretion are lacking. Using a murine asthma model, we showed that SerpinB3a, the mouse ortholog of the serine protease inhibitors, SERPINB4 and B3, contribute to house dust mite induced airway hyperresponsiveness (AHR), mucus production and goblet cell hyperplasia and expression of SPDEF, a transcription factor that mediates goblet cell differentiation. Microarray analysis revealed attenuated expression of multiple IL-13 regulated genes that contribute to mucus production in the Serpinb3a null mice and IL-13 treated mice showed attenuated AHR and mucus production. Our data have revealed a novel non-redundant role for SERPINB4 and B3 in mediating mucus production through regulation of SPDEF expression.

A1 Role of fibrocytes in allergic rhinitis Marie-Ève Côté, Marie-Ève Boulay, Sophie Plante, Jamila Chakir, Louis-Philippe Boulet A2 Patterns of aeroallergens sensitization in Northern Alberta Hanan Ahmed, Maria-Beatriz Ospina, Kyriaki Sideri, Harissios Vliagoftis A3 Addressing acceptable risk for adolescents with Food-Induced Anaphylaxis (FIA) Sara F. Johnson, Roberta L. Woodgate A4 Outcomes of matched related and unrelated bone marrow transplantation after reduced-toxicity conditioning for children suffering from Chronic Granulomatous Disease Guilhem Cros, Pierre Teira, Sonia Cellot, Henrique Bittencourt, Helene Decaluwe, Marie France Vachon, Michel Duval, Elie Haddad A5 Outcomes of patients with severe combined immunodeficiency (SCID) prior to and after initiation of newborn screening for SCID in Ontario Vy H.D. Kim, Anne Pham-Huy, Eyal Grunebaum A6 Detection of regulatory B cells in the airways of subjects with asthma John-Paul Oliveria, Stephanie Phan, Mark W. Tenn, Damian Tworek, Steven G. Smith, Adrian J. Baatjes, Caitlin D. Obminski, Caroline E. Munoz, Tara X. Scime, Roma Sehmi, Gail M Gauvreau A7 Characterization of IgE-expressing B cells in the airways and peripheral blood of allergic asthmatic subjects John-Paul Oliveria, Stephanie Phan, Mark W. Tenn, Brittany M Salter, Steven G Smith, Caitlin D Obminski, Caroline E Munoz, Abbey Schlatman, Tara X Scime, Rick Watson, Roma Sehmi, Gail M Gauvreau A8 Pregnancy: could it be a risk factor for primary immunodeficient patients Roya Sherkat, Razieh Khoshnevisan, Saba Sheikhbahaei A9 Clinical experience with Octagam: a Canadian retrospective chart review Stephen Betschel, Richard Warrington, Robert Schellenberg A10 Kounis syndrome secondary to contrast media with inferior ST elevations and bilateral ischemic stroke Michael N Fein, Jean-Philippe Pelletier A11 Honey bee venom immunotherapy ineffective in bumble bee-induced anaphylaxis: case report and review of literature Manstein Kan, Robert Schellenberg A12 Delayed immune reconstitution occurring after multiple immune complications of hematological stem cell transplantation for a leaky SCID Roxane Labrosse, Guilhem Cros, Pierre Teira, Henrique Bittencourt, Helene Decaluwe, Michel Duval, Elie Haddad A13 Comparison of Three Case Reports of Acquired Angioedema: presentation, management and outcome Raymond Mak, James Loh, Amin Kanani A14 Sitagliptin-associated angioedema not related to concurrent use of ARB or ACE inhibitor Dominik A. Nowak, Paul K. Keith A15 Sneddon-Wilkinson subcorneal pustular dermatosis associated with an IgA monoclonal gammopathy Daniel Pannozzo, Dominik A. Nowak, Hermenio C. Lima A16 Omalizumab can be effective in patients with allergic bronchopulmonary aspergillosis Diana Pham, Hoang Pham, Gonzalo G. Alvarez, Istvan T. Bencze, Krishna B. Sharma, Mark Smith, Shawn Aaron, Jennifer Block, Tara Keays, Judith Leech, David Schneidermen, Jodi Cameron, Jennifer Forgie, Alicia Ring, John W. O’Quinn, Stephanie Santucci, William H. Yang A17 Efficacious use of omalizumab in the treatment of cystic fibrosis Diana Pham, Hoang Pham, Ena Gaudet, Shawn Aaron, Stephanie Santucci, William H. Yang A18 HAE with normal C1-INH with inconsistent response to C1 esterase inhibitor infusion but reliably responsive to icatibant Hoang Pham, Stephanie Santucci, William H. Yang A19 Anaphylaxis reaction to lactase enzyme Mathew R. Voisin, Rozita Borici-Mazi A20 Risk of solid tumor malignancies in patients with primary immune deficiency Kateryna Vostretsova, Donald F. Stark A21 Is it time to adopt the chromogenic assay for measuring C1 esterase inhibitor function in patients with HAE Type 2? Elizabeth Yeboah, Paul K. Keith A22 Emergency department visits for anaphylaxis and allergic reactions Michelle Martin-Rhee, Cheryl Gula, Clare Cheng, Geoff Paltser A23 START: Susceptibility To food Allergies in a Registry of Twins Alizée Dery, Ann Clarke, Kari Nadeau, Laurie Harada, Kimberley Weatherall, Celia Greenwood, Denise Daley, Yuka Asai, Moshe Ben-Shoshan A24 Qualifying the diagnostic approach employed by allergists when managing patients with self-diagnosed non-celiac gluten sensitivity (NCGS) Lee Horgan, Teresa Pun A25 Retrospective analysis on the agreement between skin prick test and serum food specific IgE antibody in adults with suspected food allergy Ling Ling, Maria B. Ospina, Kyriaki Sideri, Harissios Vliagoftis A26 Staple food hypersensitivity from infancy to adolescence: a report from the BAMSE cohort Jennifer L.P. Protudjer, Mirja Vetander, Marianne van Hage, Ola Olén, Magnus Wickman, Anna Bergström A27 Evaluating the impact of supervised epinephrine autoinjector administration during food challenges on perceived parent confidence Timothy Teoh, Christopher Mill, Tiffany Wong, Ingrid Baerg, Angela Alexander, Kyla J. Hildebrand, John Dean, Boris Kuzeljevic, Edmond S. Chan A28 Local immunoglobulin production to Aspergillus fumigatus cystic fibrosis Jonathan Argeny, Mia Gona-Hoepler, Petra Fucik, Edith Nachbaur, Saskia Gruber, Reto Crameri, Andreas Glaser, Zsolt Szépfalusi, Claudio Rhyner, Thomas Eiwegger A29 Extract consumption with skin prick test (SPT) devices Greg. Plunkett, Brad Mire A30 Evaluation of our cases with nonsteroidal anti-inflammatory drug reactions Mehtap Yazicioglu, Ceren Can, Gokce Ciplak A31 Reasons for referral and final diagnoses in a tertiary care pediatric allergy clinic Victoria E. Cook, Kyla J. Hildebrand, Elodie Portales-Casamar, Christopher Mill, Edmond S. Chan A32 Internist referral practices for inpatients with self-reported penicillin allergies at a tertiary care teaching hospital Michael N Fein, Emil P Nashi A33 Assessing the risk of reactions in children with a negative oral challenge after a subsequent use of amoxicillin Sofianne Gabrielli, Christopher Mill, Marie-Noel Primeau, Christine Lejtenyi, Elena Netchiporouk, Alizee Dery, Greg Shand, Moshe Ben-Shoshan A34 Validity of self-reported penicillin allergies Erica Hoe, Joel Liem A35 Effectiveness of allergy-test directed elimination diets in eosinophilic esophagitis Jason K. Ko, David J.T. Huang, Jorge A. Mazza A36 Allergy testing and dietary management in pediatric eosinophilic esophagitis (EoE): A retrospective review of a tertiary Canadian centre’s experience Mary McHenry, Anthony Otley,Wade Watson A37 Visualizing the impact of atopic and allergic skin disease Dominik A. Nowak, John N. Kraft A38 Cystic fibrosis with and without nasal polyposis in pediatric patients: a cross-sectional comparative study Mihaela Paina, Ahmed A. Darwish Hassan, Delia Heroux, Lynn Crawford, Gail Gauvreau, Judah Denburg, Linda Pedder, Paul K. Keith A39 Evaluation of macrolide antibiotic hypersensitivity: the role of oral challenges in children Bahar Torabi, Marie-Noel Primeau, Christine Lejtenyi, Elaine Medoff, Jennifer Mill, Moshe Ben-Shoshan A40 Venom allergy testing: is a graded approach necessary? Jaclyn A. Quirt, Xia Wen, Jonathan Kim, Angel Jimenez Herrero, Harold L. Kim A41 The role of oral challenges in evaluating cephalosporin hypersensitivity reactions in children Magdalena J. Grzyb, Marie-Noël Primeau, Christine Lejtenyi, Elaine Medoff, Jennifer Mill, Moshe Ben-Shoshan A42 Breastfeeding and infant wheeze, atopy and atopic dermatitis: findings from the Canadian Healthy Infant Longitudinal Development Study Meghan B. Azad, Zihang Lu, Allan B. Becker, Padmaja Subbarao, Piushkumar J. Mandhane, Stuart E. Turvey, Malcolm R. Sears, the CHILD Study Investigators A43 IL33 DNA methylation in bronchial epithelial cells is associated to asthma Anne-Marie Boucher-Lafleur, Valérie Gagné-Ouellet, Éric Jacques, Sophie Plante, Jamila Chakir, Catherine Laprise A44 NRF2 mediates the antioxidant response to organic dust-induced oxidative stress in bronchial epithelial cells Michael Chen, Toby McGovern, Mikael Adner, James G. Martin A45 The effects of perinatal distress, immune biomarkers and mother-infant interaction quality on childhood atopic dermatitis (rash) at 18 months Nela Cosic, Henry Ntanda, Gerald Giesbrecht, Anita Kozyrskyj, Nicole Letourneau A46 Examining the immunological mechanisms associated with cow’s milk allergy Bassel Dawod, Jean Marshall A47 Tryptase levels in children presenting with anaphylaxis to the Montréal Children’s Hospital Sarah De Schryver, Michelle Halbrich, Ann Clarke, Sebastian La Vieille, Harley Eisman, Reza Alizadehfar, Lawrence Joseph, Judy Morris, Moshe Ben-Shoshan A48 Secondhand tobacco smoke exposure in infancy and the development of food hypersensitivity from childhood to adolescence Laura Y. Feldman, Jesse D. Thacher, Inger Kull, Erik Melén, Göran Pershagen, Magnus Wickman, Jennifer L. P. Protudjer, Anna Bergström A49 Combined exposure to diesel exhaust and allergen enhances allergic inflammation in the bronchial submucosa of atopic subjects Ali Hosseini, Tillie L. Hackett, Jeremy Hirota, Kelly McNagny, Susan Wilson, Chris Carlsten A50 Comparison of skin-prick test measurements by an automated system against the manual method Saiful Huq, Rishma Chooniedass, Brenda Gerwing, Henry Huang, Diana Lefebvre, Allan Becker A51 The accurate identification and quantification of urinary biomarkers of asthma and COPD through the use of novel DIL- LC-MS/MS methods Mona M. Khamis, Hanan Awad, Kevin Allen, Darryl J. Adamko, Anas El-Aneed A52 Systemic immune pathways associated with the mechanism of Cat-Synthetic Peptide Immuno-Regulatory Epitopes, a novel immunotherapy, in whole blood of cat-allergic people Young Woong Kim, Daniel R. Gliddon, Casey P. Shannon, Amrit Singh, Pascal L. C. Hickey, Anne K. Ellis, Helen Neighbour, Mark Larche, Scott J. Tebbutt A53 Reducing the health disparities: online support for children with asthma and allergies from low-income families Erika Ladouceur, Miriam Stewart, Josh Evans, Jeff Masuda, Nicole Letourneau, Teresa To, Malcolm King A54 Epigenetic association of PSORS1C1 and asthma in the Saguenay-Lac-Saint-Jean asthma study Miriam Larouche, Liming Liang, Catherine Laprise A55 IL-33 induces cytokine and chemokine production in human mast cells Stephanie A. Legere, Ian D. Haidl, Jean-Francois Legaré, Jean S. Marshall A56 Reference ranges for lung clearance index from infancy to adolescence for Canadian population Zihang Lu, Malcolm Sears, Theo J. Moraes, Felix Ratjen, Per Gustafsson, Wendy Lou, Padmaja Subbarao A57 Kingston Allergy Birth Cohort: cohort profile and mother/child characteristics to age 2 Michelle L. North, Elizabeth Lee, Vanessa Omana, Jenny Thiele, Jeff Brook, Anne K. Ellis A58 Cow’s milk protein specific IgE, IgA and IgG4 as a predictor of outcome in oral immunotherapy Tanvir Rahman, Duncan Lejtenyi, Sarah De Schryver, Ryan Fiter, Ciriaco Piccirillo, Moshe Ben-Shoshan, Bruce Mazer A59 Age of peanut introduction and development of reactions and sensitization to peanut Elinor Simons, Allan B. Becker, Rishma Chooniedass, Kyla Hildebrand, Edmond S. Chan, Stuart Turvey, Padmaja Subbarao, Malcolm Sears A60 Multi-omic blood biomarker signatures of the late phase asthmatic response Amrit Singh, Casey P. Shannon, Young Woong Kim, Mari DeMarco, Kim-Anh Le Cao, Gail M. Gauvreau, J. Mark FitzGerald, Louis-Philippe Boulet, Paul M. O’Byrne, Scott J. Tebbutt A61 Early life gut microbial alterations in children diagnosed with asthma by three years of age Leah T. Stiemsma, Marie-Claire Arrieta, Jasmine Cheng, Pedro A. Dimitriu, Lisa Thorson, Sophie Yurist, Boris Kuzeljevic, Diana L. Lefebvre, Padmaja Subbarao, Piush Mandhane, Allan Becker, Malcolm R. Sears, Kelly M. McNagny, Tobias Kollmann, the CHILD Study Investigators, William W. Mohn, B. Brett Finlay, Stuart E. Turvey A62 The relationship between food sensitization and atopic dermatitis at age 1 year in a Canadian birth cohort Maxwell M. Tran, Diana L. Lefebvre, Chinthanie F. Ramasundarahettige, Allan B. Becker, Wei Hao Dai, Padmaja Subbarao, Piush J. Mandhane, Stuart E. Turvey, Malcolm R. Sears A63 Allergen inhalation enhances Toll-like receptor-induced thymic stromal lymphopoietin receptor expression by hematopoietic progenitor cells in mild asthmatics Damian Tworek, Delia Heroux, Seamus N. O’Byrne, Paul M. O’Byrne, Judah A. Denburg A64 The Allergic Rhinitis Clinical Investigator Collaborative – replicated eosinophilia on repeated cumulative allergen challenges in nasal lavage samples Laura Walsh, Mena Soliman, Jenny Thiele, Lisa M. Steacy, Daniel E. Adams, Anne K. Ellis A65 The CHILD Study: optimizing subject retention in pediatric longitudinal cohort research Linda Warner, Mary Ann Mauro, Robby Mamonluk, Stuart E. Turvey A66 Differential expression of C3a and C5a in allergic asthma ChenXi Yang, Amrit Singh, Casey P. Shannon, Young Woong Kim, Ed M. Conway, Scott J. Tebbutt

Background Mechanical strain alters protein expression. It results in phosphorylation of MAP kinases and up-regulation of extracellular matrix proteins. We investigated whether phosphorylation of MAP kinase family members was increased in response to mechanical strain in fibroblasts from asthmatic patients (AF) and normal controls (NF), and whether phosphorylation of these signaling molecules would be different in the two cell populations. Methods Fibroblasts were obtained from mild, atopic asthmatics and non-atopic volunteers using endobronchial biopsy. Cells were grown on flexible, collagen I-coated membranes, and subjected to mechanical strain (Flexercell). MAP kinase phosphorylation was measured at baseline, and during one hour of strain. We also examined the effect of strain on proteoglycan production. Results At baseline, there was increased phosphorylation of ERK1/2 and p38, and decreased phosphorylation of JNK in AF vs NF. During strain in NF, p38 phosphorylation was increased. Conversely in AF, strain resulted in an increase in JNK phosphorylation, had no effect on phosphorylation of p38, and resulted in a decrease in ERK1/2 phosphorylation. There was a significant increase in versican protein production after 24 h strain in both AF and NF. JNK inhibition reversed the strain-induced increase in versican in NF, but had no effect in AF. Conclusion These results show that there are phenotypic differences in MAP kinase phosphorylation in AF vs NF, and that different signaling pathways are involved in transducing mechanical stimuli in these two populations of cells.

The effect of eotaxin, a potent eosinophil chemotactic factor, on eosinophil transmigration through a reconstituted basal membrane (Matrigel®) was evaluated. Eotaxin induced significant eosinophil transmigration in the presence of 10% fetal bovine serum (FBS) and interleukin-5. Its effect was optimal at 0.01 μM, and it plateaued at 18 h. Eotaxin's effect was greater with eosinophils from asthmatic subjects (61.1 ± 3.4%) than with eosinophils from normal subjects (38.7 ± 4.2%) (P < 0.001). Inhibition of metalloproteinases decreased eotaxin-induced transmigration by ≤10.4%, whereas inhibition of the plasminogen-plasmin system decreased eotaxin's effect by ≤44.4% (P = 0.0002). Moreover, eotaxin-induced transmigration was largely diminished in medium with low concentrations of serum [0.5% FBS: 6.1 ± 2.4%; 10% FBS: 40.2 ± 5.8% (P = 0.0001)] but returned to its initial level with the addition of plasminogen (2 U/mL) to 0.5% FBS (43.1 ± 6.5%). These data show that eotaxin is an efficient promoter of eosinophil transmigration in vitro, that it is more potent with cells from asthmatics than with normal cells, and that its effect depends predominantly on the activation of the plasminogen-plasmin system.

Background Interleukin-33 (IL-33) is a novel cytokine that triggers inflammatory immune responses, but evidence of its role in human asthma, a common allergic airway disease, is lacking. There is also a paucity of information regarding which cells express IL-33, and what conditions promote its expression. We sought to investigate whether IL-33 is expressed in the lung tissue from patients with asthma.