Climate advocacy among Italian pediatric pulmonologists: A national survey on the effects of climate change on respiratory allergies.

Climate change (CC) is expected to negatively impact respiratory health due to air pollution and increased aeroallergen exposure. Children are among the most vulnerable populations due to high ventilation rates, small peripheral airways, and developing respiratory and immunological systems. To assess the current knowledge among Italian pediatric pulmonologists on the potential effects of CC on pediatric respiratory allergic diseases, a national survey was launched online from February 2020 to February 2021. The members of the Italian Pediatric Respiratory Society (SIMRI) were contacted by email and 117 questionnaires were returned (response rate 16.4%). 72.6% of respondents were females, 53.8% were academic pediatricians, 42.7% had been working >10 years. Most of the participants were aware of the potential health effects of CC and stated that they had noticed an increase in the incidence (90.6%) and severity (67.5%) of allergic respiratory diseases among their patients. About 61% and 41% of participants respectively felt that there had been an increase in the number of children sensitized to pollen and molds. When applying latent class analysis to identify the features characterizing participants with greater awareness and knowledge of CC-related health effects, two classes were identified: almost 60% of the participants were labeled as "poor knowledge" and those with greater awareness were older, had longer work experience, and were those using the Internet to gather information about CC. There is urgent need to increase pediatricians' awareness of the detrimental effects of CC on children's respiratory health and integrate them in the educational programs of healthcare professionals.

Dexmedetomidine alleviates airway hyperresponsiveness and allergic airway inflammation through the TLR4/NF­κB signaling pathway in mice.

Dexmedetomidine (DEX) suppresses inflammatory responses and protects against organ injury. The aim of the present study was to investigate the effect of DEX on airway hyperresponsiveness (AHR) and allergic airway inflammation, as well as its underlying mechanism of action in a murine model of ovalbumin (OVA)­induced asthma. A total of 30 female BALB/c mice were divided into 6 groups (n=5 mice/group): Control, OVA, OVA + DEX (20, 30 or 50 µg/kg) and OVA + TAK­242 [a toll­like receptor 4 (TLR4) inhibitor]. The mice were intraperitoneally injected with 20, 30 or 50 µg/kg DEX 1 h before OVA challenge. AHR to inhaled methacholine (Mch) was measured, and the mice were sacrificed 24 h after the last challenge. AHR following Mch inhalation was measured using the FlexiVent apparatus. Hematoxylin and eosin, periodic acid­Schiff and Wright­Giemsa staining was performed to evaluate inflammatory cell infiltration in the lung tissue. The levels of IL­4, IL­5 and IL­13 in the bronchoalveolar lavage fluid were analyzed using ELISA, and their mRNA expression levels in the lung tissue were examined using reverse transcription­quantitative PCR. The protein expression of TLR4, NF­κB and phosphorylated (p)NF­κB in the lung tissue was also detected using immunohistochemistry. In the murine OVA­induced asthma model, DEX decreased AHR following Mch inhalation and reduced the infiltration of inflammatory cells. IL­4, IL­5 and IL­13 levels in the bronchoalveolar lavage fluid were significantly lower following DEX treatment. Furthermore, DEX treatment inhibited the expression of TLR4, NF­κB and p­NF­κB in the lung tissue and exhibited a similar effect to TAK­242 treatment. In conclusion, DEX may attenuate AHR and allergic airway inflammation by inhibiting the TLR4/NF­κB pathway. These results suggested that DEX may represent a potential anti­inflammatory agent for the treatment and management of patients with asthma.

Airway hyperresponsiveness induced by intermittent hypoxia in rats.

This study investigated whether intermittent hypoxia (IH) induces airway hyperresponsiveness (AHR) and associated with lung inflammation. Male Brown Norway rats were exposed to 14-day IH or room air (RA) for 6 h/day. One day after the last exposure, total lung resistance to various doses of methacholine was measured as an index of bronchoconstrictive responses. Compared with RA controls, methacholine significantly induced an augmented bronchoconstriction in IH-exposed rats. Moreover, IH exposure evoked lung inflammation which was reflected by increased inflammatory cell infiltration, concentrations of interleukin-6 and prostaglandin E2 in bronchoalveolar lavage fluid, and lung lipid peroxidation. IH-induced AHR and lung inflammation were completely abolished by daily intraperitoneal injection of N-acetylcysteine (an antioxidant) or ibuprofen (a cyclooxygenase inhibitor), but not by apocynin (an inhibitor of NADPH oxidase) or vehicle. In conclusion, AHR and lung inflammation occur after 14-day IH exposure, with endogenous reactive oxygen species and cyclooxygenase metabolites being responsible for these responses.

Systemic and local cytokine profile and risk factors for persistent allergic airway inflammation in patients sensitised to house dust mite allergens.

OBJECTIVE: To evaluate cytokine profile, vitamin D status, symptom score and quality of life in patients with persistent allergic airway diseases sensitised to house dust mites (HDM) in comparison with healthy individuals. MATERIAL AND METHODS: Patients sensitized to HDM with persistent AR and having symptoms for at least 2 years with or without AA were involved into the study. Measurements of vitamin D level in serum and IL-10, IL-13, IL-17, IL-22, IL-33 and IFN-gamma in serum and nasal lavage were performed by ELISA. RESULTS: Eighty-one subjects were involved into the study. Serum IL-10 concentration was higher in patients with AR than in patients with AR and AA (6.71 ± 1.73 vs. 1.98 ± 0.24, p < 0.05). IFN-gamma level in nasal lavage was higher in patients with AR and AA than in patients with AR (p < 0.01) and healthy individuals (p < 0.05) (7.50 ± 0.37 vs. 6.80 ± 0.99 vs. 6.50 ± 0.22). Serum IL-22 negatively correlated with IL-22 in nasal lavage, whereas serum IFN-gamma positively correlated with IFN-gamma in nasal lavage. Positive correlation between serum IL-17 and total IgE and negative correlation between IL-17 in nasal lavage and eosinophils in nasal smear were found in patients with AR and AA. Serum IFN-gamma decreased the risk of AR for healthy individuals. Serum IL-10 and vitamin D decreased risk for development of AA for patients with AR. IL-22 in serum and IL-10 and IL-33 in nasal lavage increased this risk. CONCLUSION: Novel cytokines such as IL-22, IL-17 and IL-33 and vitamin D may be involved in pathogenesis of persistent airway inflammation in patients sensitized to HDM.

[Recent Findings on the Mechanism of Cough Hypersensitivity as a Cause of Chronic Cough].

An increasing number of patients complain to medical institutions about a cough that persists for more than 8 weeks, namely chronic cough. The cough observed in patients with chronic cough is not responsive to conventional antitussive agents such as dihydrocodeine and dextromethorphan, and this is a major clinical problem. The most common pathology of chronic cough in Japan is dry cough. Two causes of dry cough are increased sensitivity of cough receptors (cough hypersensitivity) and increased contraction of bronchial smooth muscle. Among these, the mechanisms of cough hypersensitivity are diverse, and understanding these mechanisms is important for the diagnosis and treatment of chronic cough. In this paper I will review the regulatory mechanisms of cough hypersensitivity, especially the regulation of Aδ fiber excitability by C fibers. Furthermore, the central mechanisms involved cough reflex are discussed in relation to central acting antitussives.

Exchange Protein Directly Activated by cAMP 2 Enhances Respiratory Syncytial Virus-Induced Pulmonary Disease in Mice.

Respiratory syncytial virus (RSV) is the most common cause of lower respiratory tract infection in young children. It is also a significant contributor to upper respiratory tract infections, therefore, a major cause for visits to the pediatrician. High morbidity and mortality are associated with high-risk populations including premature infants, the elderly, and the immunocompromised. However, no effective and specific treatment is available. Recently, we discovered that an exchange protein directly activated by cyclic AMP 2 (EPAC2) can serve as a potential therapeutic target for RSV. In both lower and upper epithelial cells, EPAC2 promotes RSV replication and pro-inflammatory cytokine/chemokine induction. However, the overall role of EPAC2 in the pulmonary responses to RSV has not been investigated. Herein, we found that EPAC2-deficient mice (KO) or mice treated with an EPAC2-specific inhibitor showed a significant decrease in body weight loss, airway hyperresponsiveness, and pulmonary inflammation, compared with wild-type (WT) or vehicle-treated mice. Overall, this study demonstrates the critical contribution of the EPAC2-mediated pathway to airway diseases in experimental RSV infection, suggesting the possibility to target EPAC2 as a promising treatment modality for RSV.

Dysregulated retinoic acid signaling in airway smooth muscle cells in asthma.

Vitamin A deficiency has been shown to exacerbate allergic asthma. Previous studies have postulated that retinoic acid (RA), an active metabolite of vitamin A and high-affinity ligand for RA receptor (RAR), is reduced in airway inflammatory condition and contributes to multiple features of asthma including airway hyperresponsiveness and excessive accumulation of airway smooth muscle (ASM) cells. In this study, we directly quantified RA and examined the molecular basis for reduced RA levels and RA-mediated signaling in lungs and ASM cells obtained from asthmatic donors and in lungs from allergen-challenged mice. Levels of RA and retinol were significantly lower in lung tissues from asthmatic donors and house dust mite (HDM)-challenged mice compared to non-asthmatic human lungs and PBS-challenged mice, respectively. Quantification of mRNA and protein expression revealed dysregulation in the first step of RA biosynthesis consistent with reduced RA including decreased protein expression of retinol dehydrogenase (RDH)-10 and increased protein expression of RDH11 and dehydrogenase/reductase (DHRS)-4 in asthmatic lung. Proteomic profiling of non-asthmatic and asthmatic lungs also showed significant changes in the protein expression of AP-1 targets consistent with increased AP-1 activity. Further, basal RA levels and RA biosynthetic capabilities were decreased in asthmatic human ASM cells. Treatment of human ASM cells with all-trans RA (ATRA) or the RARγ-specific agonist (CD1530) resulted in the inhibition of mitogen-induced cell proliferation and AP-1-dependent transcription. These data suggest that RA metabolism is decreased in asthmatic lung and that enhancing RAR signaling using ATRA or RARγ agonists may mitigate airway remodeling associated with asthma.

Specific gut microbiome signatures and the associated pro-inflamatory functions are linked to pediatric allergy and acquisition of immune tolerance.

Understanding the functional potential of the gut microbiome is of primary importance for the design of innovative strategies for allergy treatment and prevention. Here we report the gut microbiome features of 90 children affected by food (FA) or respiratory (RA) allergies and 30 age-matched, healthy controls (CT). We identify specific microbial signatures in the gut microbiome of allergic children, such as higher abundance of Ruminococcus gnavus and Faecalibacterium prausnitzii, and a depletion of Bifidobacterium longum, Bacteroides dorei, B. vulgatus and fiber-degrading taxa. The metagenome of allergic children shows a pro-inflammatory potential, with an enrichment of genes involved in the production of bacterial lipo-polysaccharides and urease. We demonstrate that specific gut microbiome signatures at baseline can be predictable of immune tolerance acquisition. Finally, a strain-level selection occurring in the gut microbiome of allergic subjects is identified. R. gnavus strains enriched in FA and RA showed lower ability to degrade fiber, and genes involved in the production of a pro-inflammatory polysaccharide. We demonstrate that a gut microbiome dysbiosis occurs in allergic children, with R. gnavus emerging as a main player in pediatric allergy. These findings may open new strategies in the development of innovative preventive and therapeutic approaches. Trial: NCT04750980.

Variation in pulmonary function tests among children with sickle cell anemia: a systematic review and meta-analysis.

INTRODUCTION: the spectrum of pulmonary complications in sickle cell anemia (SCA) comprises mainly of acute chest syndrome (ACS), pulmonary hypertension (PH) and airway hyper-responsiveness (AHR). This study was conducted to examine the abnormalities in pulmonary function tests (PFTs) seen in children with SCA. METHODS: electronic databases (Cochrane library, PubMed, EMBASE, Scopus, Web of Science) were used as data sources. Two authors independently reviewed studies. All case-control studies with PFT performed in patients with SCA and normal controls were reviewed. Pulmonary functions were assessed with the help of spirometry, lung volume and gas diffusion findings. RESULTS: nine studies with 788 SCA children and 1101 controls were analyzed. For all studies, the pooled mean difference for forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC), FEV1/FVC ratio, peak expiratory flow rate (PEFR), total lung capacity (TLC) and carbon mono-oxide diffusing capacity (DLCO) were -12.67, (95% CI: -15.41,-9.94), -11.69, (95% CI: -14.24, -9.14), -1.90, (95% CI: -4.32, 0.52), -3.36 (95% CI: -6.69, -0.02), -7.35, (95% CI: -14.97, -0.27) and -4.68, (95% CI -20.64, -11.29) respectively. FEV1 and FVC and were the only parameters found to be significantly decreased. CONCLUSION: sickle cell anemia was associated with lower FEV1 and FVC, thus, supporting the role of routine monitoring for the progression of lung function decline in children with SCA with ACS. We recommend routine screening and lung function monitoring for early recognition of pulmonary function decline.

Ultra-high-resolution computed tomography shows changes in the lungs related with airway hyperresponsiveness in a murine asthma model.

In vivo presentation of airway hyper-responsiveness (AHR) at the different time points of the allergic reaction is not clearly understood. The purpose of this study was to investigate how AHR manifests in the airway and the lung parenchyma in vivo following exposure to different stimuli and in the early and late phases of asthma after allergen exposure. Ovalbumin (OVA)-induced allergic asthma model was established using 6-week female BALB/c mice. Enhanced pause was measured with a non-invasive method to assess AHR. The dynamic changes of the airway and lung parenchyma were evaluated with ultra-high-resolution computed tomography (128 multi-detector, 1024 × 1024 matrix) for 10 h. While the methacholine challenge showed no grossly visible changes in the proximal airway and lung parenchyma despite provoking AHR, the OVA challenge induced significant immediate changes manifesting as peribronchial ground glass opacities, consolidations, air-trapping, and paradoxical proximal airway dilatations. After resolution of immediate response, multiple episodes of AHRs occurred with paradoxical proximal airway dilatation and peripheral air-trapping in late phase over a prolonged time period in vivo. Understanding of airflow limitation based on the structural changes of asthmatic airway would be helpful to make an appropriate drug delivery strategy for the treatment of asthma.

Role of Interleukin-4 (IL-4) in Respiratory Infection and Allergy Caused by Early-Life Chlamydia Infection.

Chlamydia pneumoniae is a type of pathogenic gram-negative bacteria that causes various respiratory tract infections including asthma. Chlamydia species infect humans and cause respiratory infection by rupturing the lining of the respiratory which includes the throat, lungs and windpipe. Meanwhile, the function of interleukin-4 (IL-4) in Ch. pneumoniae respiratory infection and its association with the development of airway hyperresponsiveness (AHR) in adulthood and causing allergic airway disease (AAD) are not understood properly. We therefore investigated the role of IL-4 in respiratory infection and allergy caused by early life Chlamydia infection. In this study, Ch. pneumonia strain was propagated and cultured in HEp-2 cells according to standard protocol and infant C57BL/6 mice around 3-4 weeks old were infected to study the role of IL-4 in respiratory infection and allergy caused by early life Chlamydia infection. We observed that IL-4 is linked with Chlamydia respiratory infection and its absence lowers respiratory infection. IL-4R α2 is also responsible for controlling the IL-4 signaling pathway and averts the progression of infection and inflammation. Furthermore, the IL-4 signaling pathway also influences infection-induced AHR and aids in increasing AAD severity. STAT6 also promotes respiratory infection caused by Ch. pneumoniae and further enhanced its downstream process. Our study concluded that IL-4 is a potential target for preventing infection-induced AHR and severe asthma.

ß-caryophyllene ameliorated obesity-associated airway hyperresponsiveness through some non-conventional targets.

BACKGROUND: Obesity worsens airway hyperresponsiveness (AHR) in asthmatic subjects by up-regulating macrophage polarization that leads to excessive secretion of pro-inflammatory adipokines from white adipose tissue followed by generation of oxidative stress in the respiratory system. Treatment through conventional signaling pathways proved to be inadequate in obese asthmatics, so a therapeutical approach through a non-conventional pathway may prove to be effective. PURPOSE: This study aimed to investigate the efficacy of a FDA-approved food additive, ß-caryophyllene (BCP) in obesity-associated AHR. METHOD: A repertoire of protein expression, cytokine and adiponectin estimation, oxidative stress assays, histopathology, and fluorescence immune-histochemistry were performed to assess the efficacy of BCP in C57BL/6 mice model of obesity-associated AHR. Additionally, human adipocyte was utilized to study the effect of BCP on macrophage polarization in Boyden chamber cell culture inserts. RESULTS: Obesity-associated AHR is ameliorated by administration of BCP by inhibition of the macrophage polarization by activation of AMPKα, Nrf2/HO-1 and AdipoR1 and AdipoR2 signaling pathway, up-regulation of adiponectin, GLP-1, IFN-γ, SOD, catalase and down-regulation of NF-κB, leptin, IL-4, TNF, and IL-1ß. Browning of eWAT by induction of thermogenesis and activation of melanocortin pathway also contributed to the amelioration of obesity-associated AHR. We conclude that BCP ameliorated the obesity-associated AHR via inhibition of macrophage polarization, activation of AMPKα, Nrf2/HO-1, and up-regulation of AdipoR1 and AdipoR2 expression and down-regulation of NFκB expression in lung of animal. CONCLUSION: Being an FDA-approved food additive, BCP may prove to be a safe and potential agent against obesity-associated AHR.

Prevalence and associated factors of respiratory allergies in the Kingdom of Saudi Arabia: A cross-sectional investigation, September-December 2020.

BACKGROUND: Prevalence of different respiratory allergies is increasing in the Kingdom of Saudi Arabia (KSA). Environmental risk factors of respiratory allergy vary regionally, hence the prevalence. This necessitates the needs for regional studies. This article reports prevalence and symptoms of respiratory allergies in the Qassim region, and the factors associated with the prevalence. METHODS: Eight hundred and fifty individuals aged ≥18 years and were living in the Qassim region filled up our structured online questionnaire between September and December 2020. We estimated the prevalence of different respiratory allergies with 95% confidence intervals. Multi-variable logistic regression analyses were performed to investigate the risk factors of respiratory allergies. FINDINGS: The prevalence of any respiratory allergy in the Qassim region was 28.8%. Most families (58.1%) had at least one member with respiratory allergy. The prevalence of allergic rhinitis and bronchial asthma were 13.5% and 11.2% 4.1% respectively. The reported symptoms included runny nose (13.6%), red, watery, and itchy eyes (10.4%), difficulty sleeping at night (10.2%), difficulty breathing in cold weather (9.2%), noisy breathing (8.5%), sneezing (8%), repeated coughing (7.5%) and shortness of breath (6.4%). Individuals with a family history were more likely to report any respiratory allergy (OR: 7.8), bronchial asthma (OR: 4.2) and allergic rhinitis (OR: 8.1) compared to the individuals without such family history. Odds of respiratory allergies was higher among males (OR: 1.5). Saudi nationals were less likely to report allergic rhinitis than the non-Saudis (OR: 0.4). Among those who reported a respiratory allergy, most (73.5%) received treatment and majority (61.7%) demonstrated compliance to the treatment, 8.8% needed hospitalization, and 23.1% needed emergency nebulization. CONCLUSIONS: Prevalence reported in our study is different than that reported in other regions. Variability in the environmental exposures might explain this. We recommend a meta-analysis to estimate the national prevalence of respiratory allergies.

Atypical food protein-induced enterocolitis syndrome in children: Is IgE sensitisation an issue longitudinally?

BACKGROUND: Food Protein-Induced Enterocolitis Syndrome (FPIES) is a clinically well-characterised, non-Immunoglobulin E (IgE)-mediated food allergy syndrome, yet its rare atypical presentation remains poorly understood. OBJECTIVE: Aim of this study was to present the 10-year experience of a referral centre highlighting the atypical FPIES cases and their long-term outcome. METHODS: FPIES cases were prospectively evaluated longitudinally in respect of food outgrowth and developing other allergic diseases with or without concomitant IgE sensitisation. RESULTS: One hundred subjects out of a total of 14,188 referrals (0.7%) were identified. At presentation, 15 patients were found sensitised to the offending food. Fish was the most frequent eliciting food, followed by cow's milk and egg. Tolerance acquisition was earlier for cow's milk, followed by egg and fish, while found not to be protracted in atypical cases. Resolution was not achieved in half of the fish subjects during the 10-year follow-up time. Sensitisation to food was not related to infantile eczema or culprit food, but was related to sensitisation to aeroallergens. In the long-term evaluation, persistence of the FPIES or aeroallergen sensitisation was significantly associated with an increased hazard risk of developing early asthma symptoms. CONCLUSION: Sensitisation to food was related neither to eczema or culprit food nor to tolerance acquisition but rather to the development of allergic asthma through aeroallergen sensitisation. In addition to an IgE profile at an early age, FPIES persistence may also trigger mechanisms switching FPIES cases to a T-helper 2 cells immune response later in life, predisposing to atopic respiratory symptoms; albeit further research is required.

Immune-Associated Proteins Are Enriched in Lung Tissue-Derived Extracellular Vesicles during Allergen-Induced Eosinophilic Airway Inflammation.

Studying the proteomes of tissue-derived extracellular vesicles (EVs) can lead to the identification of biomarkers of disease and can provide a better understanding of cell-to-cell communication in both healthy and diseased tissue. The aim of this study was to apply our previously established tissue-derived EV isolation protocol to mouse lungs in order to determine the changes in the proteomes of lung tissue-derived EVs during allergen-induced eosinophilic airway inflammation. A mouse model for allergic airway inflammation was used by sensitizing the mice intraperitoneal with ovalbumin (OVA), and one week after the final sensitization, the mice were challenged intranasal with OVA or PBS. The animals were sacrificed 24 h after the final challenge, and their lungs were removed and sliced into smaller pieces that were incubated in culture media with DNase I and Collagenase D for 30 min at 37 °C. Vesicles were isolated from the medium by ultracentrifugation and bottom-loaded iodixanol density cushions, and the proteomes were determined using quantitative mass spectrometry. More EVs were present in the lungs of the OVA-challenged mice compared to the PBS-challenged control mice. In total, 4510 proteins were quantified in all samples. Among them, over 1000 proteins were significantly altered (fold change >2), with 614 proteins being increased and 425 proteins being decreased in the EVs from OVA-challenged mice compared to EVs from PBS-challenged animals. The associated cellular components and biological processes were analyzed for the altered EV proteins, and the proteins enriched during allergen-induced airway inflammation were mainly associated with gene ontology (GO) terms related to immune responses. In conclusion, EVs can be isolated from mouse lung tissue, and the EVs' proteomes undergo changes in response to allergen-induced airway inflammation. This suggests that the composition of lung-derived EVs is altered in diseases associated with inflammation of the lung, which may have implications in type-2 driven eosinophilic asthma pathogenesis.

Persistent Airway Hyperresponsiveness Following Recovery from Infection with Pneumonia Virus of Mice.

Respiratory virus infections can have long-term effects on lung function that persist even after the acute responses have resolved. Numerous studies have linked severe early childhood infection with respiratory syncytial virus (RSV) to the development of wheezing and asthma, although the underlying mechanisms connecting these observations remain unclear. Here, we examine airway hyperresponsiveness (AHR) that develops in wild-type mice after recovery from symptomatic but sublethal infection with the natural rodent pathogen, pneumonia virus of mice (PVM). We found that BALB/c mice respond to a limited inoculum of PVM with significant but reversible weight loss accompanied by virus replication, acute inflammation, and neutrophil recruitment to the airways. At day 21 post-inoculation, virus was no longer detected in the airways and the acute inflammatory response had largely resolved. However, and in contrast to most earlier studies using the PVM infection model, all mice survived the initial infection and all went on to develop serum anti-PVM IgG antibodies. Furthermore, using both invasive plethysmography and precision-cut lung slices, we found that these mice exhibited significant airway hyperresponsiveness at day 21 post-inoculation that persisted through day 45. Taken together, our findings extend an important and versatile respiratory virus infection model that can now be used to explore the role of virions and virion clearance as well as virus-induced inflammatory mediators and their signaling pathways in the development and persistence of post-viral AHR and lung dysfunction.

Chitinase-Induced Airway Hyperreactivity and Inflammation in a Mouse Model of Nonallergic Asthma.

INTRODUCTION: Environmental exposure to mites and fungi has been proposed to critically contribute to the development of IgE-mediated asthma. A common denominator of such organisms is chitin. Human chitinases have been reported to be upregulated by interleukin-13 secreted in the context of Th2-type immune responses and to induce asthma. We assessed whether chitin-containing components induced chitinases in an innate immune-dependent way and whether this results in bronchial hyperresponsiveness. MATERIALS AND METHODS: Monocyte/macrophage cell lines were stimulated with chitin-containing or bacterial components in vitro. Chitinase activity in the supernatant and the expression of the chitotriosidase gene were measured by enzyme assay and quantitative PCR, respectively. Non-sensitized mice were stimulated with chitin-containing components intranasally, and a chitinase inhibitor was administered intraperitoneally. As markers for inflammation leukocytes were counted in the bronchoalveolar lavage (BAL) fluid, and airway hyperresponsiveness was assessed via methacholine challenge. RESULTS: We found both whole chitin-containing dust mites as well as the fungal cell wall component zymosan A but not endotoxin-induced chitinase activity and chitotriosidase gene expression in vitro. The intranasal application of zymosan A into mice led to the induction of chitinase activity in the BAL fluid and to bronchial hyperresponsiveness, which could be reduced by applying the chitinase inhibitor allosamidin. DISCUSSION: We propose that environmental exposure to mites and fungi leads to the induction of chitinase, which in turn favors the development of bronchial hyperreactivity in an IgE-independent manner.

Sensitization against Fungi in Patients with Airway Allergies over 20 Years in Germany.

BACKGROUND: Fungal spores are ubiquitous allergens. Severe forms of asthma are particularly highly associated with fungal sensitization. National and international asthma guidelines recommend the implementation of allergen immunotherapy if indicated. Thus, detection and treatment of relevant allergies are key components of primary care of these patients. OBJECTIVES: The aims of the study were (i) to investigate trends in the prevalence of sensitization to twelve fungi in central Germany over the last 20 years and (ii) to dissect specific sensitization patterns among the 3 most important fungi: Aspergillus, Alternaria, and Cladosporium. METHODS: This single-center study evaluated skin prick test (SPT) results of 3,358 patients with suspected airway allergies over a period of 20 years (1998-2017). RESULTS: While 19.2% of all study patients had positive test results to at least 1 of the 3 fungi (Alternaria, Aspergillus, or Cladosporium) in the first study decade, this rate increased to 22.5% in the second decade. Slight increases in sensitization rates to almost all fungi were observed over the 20-year period. In the last decade, polysensitization to Alternaria, Aspergillus, and Cladosporium increased significantly. Sensitization to fungi is age-dependent and peaks in the age-group of 21-40 years during the second decade. CONCLUSION: Fungi are relevant allergens for perennial and seasonal allergy symptoms. We currently recommend including Aspergillus, Alternaria, and Cladosporium in the standard series of SPTs for airway allergies.