House Dust Mite Allergen Research Articles

Reactividad IgE de sueros en pacientes con enfermedades autoinmunes, frente a una proteína multi-epítopes construida a partir de epítopes T de alérgenos de Ascaris lumbricoides

Background: Helminth infections for Ascaris lumbricoides and exposure to mite allergens stimulate a Th2 immune response present in allergic diseases. Helminth proteins are well known can modulate the host immune response and lessen the inflammation response. We evaluate the Ig E reactivity to a molecule constructed from A. lumbricoides T epitopes (MP1) in sera from patients suffering from T1D, LN, and JIA Methods: We designed and expressed a synthetic multi-epítope protein named MP1 from A. lumbricoides and house dust mites allergens. By indirect ELISA, we evaluated IgE-reactivity to MP1 and to the whole-body extract of Ascaris lumbricoidesin 45 sera from Colombian Caribbean patients with lupus nephritis (LN; n=25), type 1 diabetes (T1D; n=10) and Juvenil idiopathic arthritis (JIA; n=10). Individuals with poly autoimmunity were excluded. All patients were referred to the study by their specialist doctor. Results: IgE to whole-body extract of A. lumbricoides showed the following median concentrations: 484.2 ng/ml (IQR: 203.4) in JIA patients, 325.6 ng/ml (IQR: 179.3) in individuals with LN, and 424.7 ng/ml (IQR: 80.1) in T1D group. On the other hand, IgE-reactivity to MP1 was 126.4 ng/ml (IQR: 90.9) in JIA patients, 130.7 ng/ml (IQR: 94.8) in an individual with LN, and 148.8 ng/ml (IQR: 102.1) in T1D group. Although no statistical differences were observed between patient groups, the IgE to MP1 in all patients (n: 45) (IgE median: 134.2 ng/ml; IQR: 100) were significantly less compared to Ascaris extract (IgE median: 380.7 ng/ml; IQR: 175.8); (W:0.732; p-value: 1.034x10-7). Conclusions: These preliminary results suggest that MP1 showed antigenic properties with low IgE-reactivity compared to Ascaris lumbricoides extract in individuals with autoimmune diseases. Further studies are needed to understand better the immune response induced by this molecule.

Tyrosine nitration enhances the allergenic potential of house dust mite allergen Der p 2

Nitration of allergenic proteins caused by atmospheric pollutants O3 and NO2 may enhance their allergenic potential. In the study, the influence of nitration was investigated on the allergenicity of Der p 2, which is a main allergen from house dust mites and plays an important role in allergenic rhinitis and asthma. The results reveal that nitrated Der p 2 enhanced the IgE-binding capacity, upregulated the mRNA expression and release of IL-6 and IL-8 from bronchial epithelial cells, and induced higher levels of specific-IgE, TH2 cytokines and white blood cells in mice. Besides, nitrated Der p 2 caused more severe oxidative stress and allergenic symptoms in mice. It is concluded that nitration enhanced the allergenicity of Der p 2 through not only directly inducing higher amount of specific-IgE and stronger responses of TH2 cytokines, but also indirectly aggravating allergic symptoms by oxidative stress and adjuvant-like activation airway epithelial cells. The study suggests that the contribution of nitration to the promotion in allergenicity should not be ignored when precisely assessing the risk of house dust mite allergens in real environment.

The safety and tolerability of a one strength dose-escalation scheme for subcutaneous immunotherapy with a native house dust mite extract in Chinese children: A multicenter, randomized, open label clinical trial

BackgroundAllergen immunotherapy (AIT) is still the only treatment that may affect the natural cause of allergic disease. This study is to investigate whether an accelerated up-dosing scheme for subcutaneous allergen immunotherapy (SCIT) using a native house dust mite (HDM) allergen extract is as safe as the standard 3-strengths dose-escalation scheme in children with moderate to severe allergic rhinitis or rhinoconjunctivitis with or without asthma in China. MethodsIn this multicenter, open label, randomized controlled trial, the children aged 5–14 years were randomized 1:1 either to One Strength group or the Standard group. The dose escalation scheme for patients in the One Strength group included 6 injections of strength 3, whereas the Standard group comprised 14 injections using strength 1, 2, and 3. All treatment-emergent adverse events (TEAEs) were recorded and analyzed. The 5-point Likert scale was used to assess tolerability (ChiCTR2100050311). ResultsOverall, 101 children were included in the Safety Set (One Strength group: 50 vs. Standard group: 51). A total of 26 TEAEs were reported for 15 children. TEAEs related to AIT occurred in 10 % of the children in the One Strength group and 11.8 % of the Standard group. The number of systemic adverse reactions was comparable in both groups (One Strength: 5 vs. Standard: 4). No serious TEAEs was recorded for either group. 90.0 % of patients in the One Strength group reached the maintenance dose without an interventional dose adjustment due to adverse events, compared to 78.4 % in the Standard group. All patients who completed the dose-escalation phase reached the recommended maintenance dose of 1.0 ml of strength 3.Investigators and patients rated the tolerability of the One Strength regimen slightly better than the Standard scheme. ConclusionsThis exploratory study suggests that the accelerated One Strength dose-escalation scheme is comparable in safety and tolerability to the Standard regimen. However, due to the preliminary nature and small sample size, further research with larger sample sizes and robust study designs is necessary for confirmation.

Characteristics of house dust mite allergens in Southeast and East Asia with the effect of hygienic practices

House dust mite allergens (HDMAs) are a major allergen that can cause severe adverse health effects, such as allergic rhinitis, asthma, and dermatitis. This study aimed to characterize the HDMA levels in bedding dust from Southeast and East Asian countries and evaluate the impact of hygiene practices on these levels. Bedding dust samples were collected from 29, 82, 32, 31, and 86 households in Indonesia, Malaysia, Thailand, Vietnam, and South Korea, respectively. Of the households in Malaysia and South Korea, 57 each had received mattress care services. The samples were analyzed for Dermatophagoides farinae type 1 (Der f1) and Dermatophagoides pteronyssinus type 1 (Der p1). The detection rates of Der f1 and Der p1 varied among the countries, especially in households that had not received mattress care services. In Indonesia, the detection rates of Der f1 and Der p1 were similar (97%). In Malaysia, Thailand, and Vietnam, the detection rates of Der f1 were higher than those of Der p1. South Korea exhibited the lowest detection rates for both Der f1 (76%) and Der p1 (7%). In Indonesia and Malaysia, the levels of Der p1 were higher than those of Der f1. In Thailand and Vietnam, the levels of Der f1 were higher than those of Der p1. In both Malaysia and South Korea, households that had received mattress care services exhibited lower HDMA levels than those that had not. Furthermore, households serviced within the past month had notably lower HDMA levels than those serviced more than two months prior. This study observed significant regional differences in the detection rates and levels of HDMAs among Southeast and East Asian nations. In addition, the study observed significant decrease in the levels of HDMAs following routine mattress care service, highlighting the pivotal role of consistent hygienic practices for diminishing potential allergenic hazards. However, the study could not identify specific regional factors affecting the type and level of HDMAs.

Epithelium-derived kallistatin promotes CD4+ T-cell chemotaxis to TH2-type inflammation in chronic rhinosinusitis

The function of kallistatin in airway inflammation, particularly chronic rhinosinusitis with nasal polyps (CRSwNP), has not been elucidated. We sought to investigate the role of kallistatin in airway inflammation. Kallistatin and proinflammatory cytokine expression levels were detected in nasal polyps. For the invivo studies, we constructed the kallistatin-overexpressing transgenic mice to elucidate the role of kallistatin in airway inflammation. Furthermore, the levels of plasma IgE and proinflammatory cytokines in the airways were evaluated in the kallistatin-/- rat invivo model under a type 2 inflammatory background. Finally, the Notch signaling pathway was explored to understand the role of kallistatin in CRSwNP. We showed that the expression of kallistatin was significantly higher in nasal polyps than in the normal nasal mucosa and correlated with IL-4 expression. We also discovered that the nasal mucosa of kallistatin-overexpressing transgenic mice expressed higher levels of IL-4 expression, associating to TH2-type inflammation. Interestingly, we observed lower IL-4 levels in the nasal mucosa and lower total plasma IgE of the kallistatin-/- group treated with house dust mite allergen compared with the wild-type house dust mite group. Finally, we observed a significant increase in the expression of Jagged2 in the nasal epithelium cells transduced with adenovirus-kallistatin. This heightened expression correlated with increased secretion of IL-4, attributed to the augmented population of CD4+CD45+Notch1+ T cells. These findings collectively may contribute to the induction of TH2-type inflammation. Kallistatin was demonstrated to be involved in the CRSwNP pathogenesis by enhancing the TH2 inflammation, which was found to be associated with more expression of IL-4, potentially facilitated through Jagged2-Notch1 signaling in CD4+ T cells.

House dust mite allergens induce Ca2+ signalling and alarmin responses in asthma airway epithelial cells

Type 2 inflammation in asthma develops with exposure to stimuli to include inhaled allergens from house dust mites (HDM). Features include mucus hypersecretion and the formation of pro-secretory ion transport characterised by elevated basal Cl− current. Studies using human sinonasal epithelial cells treated with HDM extract report a higher protease activated receptor-2 (PAR-2) agonist-induced calcium mobilisation that may be related to airway sensitisation by allergen-associated proteases. Herein, this study aimed to investigate the effect of HDM on Ca2+ signalling and inflammatory responses in asthmatic airway epithelial cells. Primary bronchial epithelial cells (hPBECs) from asthma donors cultured at air-liquid interface were used to assess electrophysiological, Ca2+ signalling and inflammatory responses. Differences were observed regarding Ca2+ signalling in response to PAR-2 agonist 2-Furoyl-LIGRLO-amide (2-FLI), and equivalent short-circuit current (Ieq) in response to trypsin and 2-FLI, in ALI-asthma and healthy hPBECs. HDM treatment led to increased levels of intracellular cations (Ca2+, Na+) and significantly reduced the 2-FLI-induced change of Ieq in asthma cells. Apical HDM-induced Ca2+ mobilisation was found to mainly involve the activation of PAR-2 and PAR-4-associated store-operated Ca2+ influx and TRPV1. In contrast, PAR-2, PAR-4 antagonists and TRPV1 antagonist only showed slight impact on basolateral HDM-induced Ca2+ mobilisation. HDM trypsin-like serine proteases were the main components leading to non-amiloride sensitive Ieq and also increased interleukin-33 (IL-33) and thymic stromal lymphopoietin (TSLP) from asthma hPBECs. These studies add further insight into the complex mechanisms associated with HDM-induced alterations in cell signalling and their relevance to pathological changes within asthma.

Accurate determination of house dust mite sensitization in asthma and allergic rhinitis through cytometric detection of Der p 1 and Der p 2 binding on basophils (CytoBas)

House dust mite (HDM) is the most common allergen trigger globally for allergic rhinitis and atopic asthma. To expedite accurate confirmation of allergen sensitization, we designed fluorescent allergen tetramers to directly stain specific IgE on basophils to detect specific allergen sensitization using the flow cytometric CytoBas assay. Recombinant proteins of major HDM allergens (component), Der f 1, Der p 1, and Der p 2 were biotinylated and conjugated with fluorochrome streptavidins as tetramers. Blood samples from 64 patients who are HDM-allergic and 26 controls that are non-HDM-sensitized were incubated with allergen tetramers for evaluation of basophil binding (CytoBas) and activation (BAT) with flow cytometry. The tetramers effectively bound and activated basophils from patients who are allergic but not from controls who are nonsensitized. CytoBas with Der p 1 as a single allergen had comparable sensitivity and specificity (92% and 100%) to BAT (91% and 100%) in detecting allergen sensitization, as did CytoBas with Der p 2 (95% and 96%) to BAT (95% and 87%). Apositive staining for Der p 1 and/or Der p 2 in CytoBas was 100% sensitive and 96% specific for HDM allergy. CytoBas has diagnostic accuracy for group 1 and group 2 HDM allergens that is comparable to BAT, but with additional advantages of multiple allergen components in a single tube and no requirement for invitro basophil activation. These findings endorse a single, multiplex CytoBas assay for accurate and component-resolved diagnosis of aeroallergen sensitization in patients with allergic asthma and/or rhinitis.

Impact of Aeroallergen Sensitization on Chronic Rhinosinusitis.

This study investigated the impact of aeroallergens on the development and progression of chronic rhinosinusitis (CRS), with a focus on the specific associations between aeroallergens and CRS according to allergen type, number, and extent of sensitization. The medical records of 256 CRS patients were retrospectively analyzed. All were divided into nonallergic, house dust mite (HDM)-allergic, pollen-allergic, and double allergic groups via specific immunoglobulin E (IgE) testing. Clinical characteristics, computed tomography (CT) scores, olfactory functions, and demographic data were compared. Correlation analysis was performed to explore the relationships between the extent of allergen sensitization and CRS severity. Binary logistic regression analysis was used to identify risk factors for hyposmia and anosmia. The allergic group exhibited higher total CT scores than the nonallergic group (P = 0.001). Sensitivity to HDM or pollen allergens alone was not significantly associated with increased CRS severity. No significant differences were observed between the effects of HDM and pollen allergens on CRS severity. However, the double allergic group exhibited significantly higher CT scores (P < 0.001, < 0.001, and 0.003) than the other groups. Although the prevalence rates of anosmia and hyposmia were notably higher in the double allergic group, the difference was not statistically significant. The maximum specific IgE levels to HDM and pollen allergens positively correlated with the CT scores (P = 0.001 and 0.001, respectively). Allergen sensitization, particularly to multiple common allergens, contributed to CRS severity. CRS patients sensitized to both HDM and pollen allergens tended to experience the diminished olfactory function. These findings underscore the importance of considering the allergen sensitization pattern when assessing CRS severity and its potential progression.

Novel monoclonal antibodies against house dust mite allergen Der p 21 and their application to analyze allergen extracts.

Allergen extracts and recombinant allergens are used in allergy diagnostics and immunotherapy. Since allergen extracts from different manufacturers lack proper standardization regarding their composition, monoclonal antibodies (MAbs) against specific allergen components can be used for their identification and quantification in allergen extracts. This study aimed to generate MAbs against allergen Der p 21 of Dermatophagoides pteronyssinus for the analysis of allergen extracts. Recombinant Der p 21 was expressed in E. coli and purified using affinity chromatography. MAbs against Der p 21 were generated using hybridoma technology. House dust mite (HDM) allergen extracts were analyzed using the newly developed sandwich enzyme-linked immunosorbent assay, Western blotting and microarray immunoassay. MAbs raised against recombinant Der p 21 were characterized in detail and proven to be reactive with natural Der p 21. Highly specific sandwich enzyme-linked immunosorbent assay for the quantification of Der p 21 was developed and optimized. The allergen was detected and its concentration was determined in only three of six analyzed HDM allergen extracts from different manufacturers. HDM analysis by MAb-based immunoassays shows their differences in allergen composition. The results demonstrate the importance of allergen-specific MAbs as a tool for the characterization of allergen extracts and the need for their appropriate standardization before their use for allergy diagnostics or immunotherapy.

Individual wearable air purifier protects against pollen, house dust mite, and cat allergens: Report from anallergen exposure chamber.

Evaluation of a new individual wearable air purifier (Respiray Wear A+) for birch pollen, house dust mite (HDM), and cat-allergic rhinoconjunctivitis (ARC) patients in a standardized allergen exposure chamber (AEC). Eligible allergic patients were exposed to birch pollen, HDM raw material, and cat allergen in an AEC for 60 minutes without (V1) and with (V3) the use of the Respiray device. Nasal, ocular, bronchial, and other symptoms were rated by the patients every 10 minutes, and their wellbeing, peak nasal inspiratory flow (PNIF), and lung function parameters were assessed every 30 minutes. The primary endpoint was the change in the median of the total symptom score (TSS) at V3 compared to V1 at 60 minutes of exposure. The secondary endpoints consisted of the total nasal symptom score (TNSS) and total eye symptom score (TESS). 23 patients with birch pollen allergy, 37 patients with HDM allergy, and 41 patients with cat allergy were included in the analysis. Significant reduced symptom scores of ~49% were observed when using Respiray Wea A+ under birch pollen exposure (p<0.05) in the primary endpoint TSS (V3 2.43 compared to V1 4.78). An 48% reduction of symptoms was seen in TSS in case of HDM exposure (V3 3.59; V1 6.92, (t-test: p<0.01)) and the highest reduction of TSS (60%) under Respiray A+ using cat allergens (V3 2.95, V1 7.44, (t-test p<0.01) after 60 minutes of exposure. The personal wellbeing revealed clinically meaningful improvements over time in all three studies which manifested in a lower symptom increase during the final allergen exposures. The individual wearable air purifier Respiray Wear A+ protects significantly against airborne pollen, HDM, and cat allergens and may be a very useful device for avoiding indoor allergens in a new way.

CD11c+ dendritic cells PlexinD1 deficiency exacerbates airway hyperresponsiveness, IgE and mucus production in a mouse model of allergic asthma.

Dendritic cells (DCs) are pivotal in regulating allergic asthma. Our research has shown that the absence of Sema3E worsens asthma symptoms in acute and chronic asthma models. However, the specific role of PlexinD1 in these processes, particularly in DCs, remains unclear. This study investigates the role of PlexinD1 in CD11c+ DCs using a house dust mite (HDM) model of asthma. We generated CD11c+ DC-specific PlexinD1 knockout (CD11cPLXND1 KO) mice and subjected them, alongside wild-type controls (PLXND1fl/fl), to an HDM allergen protocol. Airway hyperresponsiveness (AHR) was measured using FlexiVent, and immune cell populations were analyzed via flow cytometry. Cytokine levels and immunoglobulin concentrations were assessed using mesoscale and ELISA, while collagen deposition and mucus production were examined through Sirius-red and periodic acid Schiff (PAS) staining respectively. Our results indicate that CD11cPLXND1 KO mice exhibit significantly exacerbated AHR, characterized by increased airway resistance and tissue elastance. Enhanced mucus production and collagen gene expression were observed in these mice compared to wild-type counterparts. Flow cytometry revealed higher CD11c+ MHCIIhigh CD11b+ cell recruitment into the lungs, and elevated total and HDM-specific serum IgE levels in CD11cPLXND1 KO mice. Mechanistically, co-cultures of B cells with DCs from CD11cPLXND1 KO mice showed significantly increased IgE production compared to wild-type mice.These findings highlight the critical regulatory role of the plexinD1 signaling pathway in CD11c+ DCs in modulating asthma features.

Sensitization profiles to house dust mite Dermatophagoides pteronyssinus molecular allergens in the Lithuanian population: Understanding allergic sensitization patterns.

House dust mite (HDM) allergy is a prevalent global health concern, with varying sensitization profiles observed across populations. We aimed to provide a comprehensive assessment of molecular allergen sensitization patterns in the Lithuanian population, with a focus on Dermatophagoides pteronyssinus (Der p), and investigate patterns of concomitant reactivity among different allergens to enhance the accuracy of HDM allergy diagnostics. A comprehensive analysis of 1520 patient test results in Lithuania from 2020 to 2022 was performed. Sensitization patterns to major (Der p 1, Der p 2, and Der p 23) and minor (Der p 5, Der p 7, and Der p 21) Der p allergen components were described using molecular-based diagnostics. Additionally, we investigated sensitization to allergen components from other allergen sources, including tropomyosins (Der p 10, Per a 7, Pen m 1, Ani s 3, Blo t 10) and arginine kinases (Pen m 2, Bla g 9, Der p 20). This study reveals a high prevalence of HDM sensitization in Lithuania - 481 individuals (45.38% of the sensitized group) exhibited sensitization to at least one Der p allergen component. Importantly, within the sensitized group, 37.21% of patients were sensitized to Der p 5, Der p 7, or Der p 21 in addition to major allergenic components. Distinct sensitization patterns were observed across different age groups, indicating the influence of age-related factors. Furthermore, we confirmed cross-reactivity between Der p 5 and Blo t 5 as well as between Der p21 and Blo t 21, emphasizing the clinical relevance of these associations. We also highlighted the complexity of sensitization patterns among tropomyosins and arginine kinases. This study provides valuable insights into HDM allergy sensitization profiles in Lithuania, emphasizing the importance of considering major and minor HDM allergen components for accurate diagnosis and management of HDM-related allergic diseases. Differences between populations and age-related factors impact sensitization patterns. Understanding concomitant reactivity among allergens, such as Der p 5 and Blo t 5, Der p 21 and Blo t 21, tropomyosins, and arginine kinases, is crucial for improving diagnostic strategies and developing targeted interventions for allergic individuals.

Genetic and T2 biomarkers linked to the efficacy of HDM sublingual immunotherapy in asthma

BackgroundHypersensitivity to house dust mite (HDM) allergens is a common cause of allergic asthma symptoms and can be effectively treated with allergy immunotherapy (AIT).ObjectiveTo investigate whether genetic and type 2...

Оцінка сироваткового загального та специфічного імуноглобуліну Е в дітей з персистуючим алергічним ринітом і поєднаним із бронхіальною астмою при сенсибілізації до алергенів кліщів

Allergic rhinitis (AR) is a common immunoglobulin E (IgE) dependent disease among allergic patients worldwide. At the same time, the determination of specific IgE in the blood serum allows characterizing the relevant sensitizing allergens. Despite the existence of conditional thresholds for normal and elevated levels of total and specific IgE, there is no consensus in the literature on which IgE value unequivocally confirms the presence of atopy and what is the relationship between these levels and the severity of clinical manifestations. Purpose - to evaluate the levels of serum total and specific IgE and their relationship with severity and age in children with persistent AR and combined with bronchial asthma (BA) during sensitization to house dust mite (HDM) allergens. Materials and methods. A clinical, anamnestic and laboratory examination of 259 children aged 5 to 17 years with AR and combined AR with BA, who were sensitized to HDM allergens, was conducted. Results. In AR in children with sensitization to HDM, there is a dependence of serum total IgE level on the severity of AR and age of children. With increasing severity of AR manifestations, a significant (p&lt;0.05) increase in total IgE levels was noted. It was found that the content of sIgE also increased with increasing severity of AR. Thus, statistically significantly (p&lt;0.05) higher levels of sIgE were determined in sensitization to the major HDM molecules Der f 1, Der p 1, Der p 2, Der p 23 in children with severe AR. Sensitization to the tropomyosin Der p10 molecule, which usually has no effect on the clinical manifestations of respiratory allergy but indicates cross-reactivity to seafood, was significantly more common (p&lt;0.05) in children aged 3-7 years compared to children aged 13-17 years. Conclusions. The data obtained partially define the pathogenetic features in the formation of sensitization to HDM and their individual molecules, confirming that this process begins at an early age, which may indicate the need to start allergen-specific immunotherapy in such children if clinically necessary. The research was carried out in accordance with the principles of the Helsinki Declaration. The study protocol was approved by the Local Ethics Committee of the participating institution. The informed consent of the patient was obtained for conducting the studies. No conflict of interests was declared by the authors.

Multiplexed transcriptional profiling of Dermatophagoides house dust mites allergens in human epithelium cells.

Allergic asthma, a chronic disease characterized by airway inflammation, poses a significant public health concern. It is well-established that house dust mites (HDMs) are common inducers of allergic responses in individuals, particularly children. In central Taiwan, our research team observed that over 80% of allergic children exhibited sensitization to various HDMs species. This investigation aims to bridge the gap between these observations and a better understanding of the early fundamental mechanisms for preventing allergic diseases. Specifically, our study delves into the impact of crude extracts of HDMs on human epithelial BEAS-2B cells. Our findings, based on RNA sequencing (RNA-seq) analysis, shed light on how three major Dermatophagoides HDMs allergens activate a common Toll-like receptor signaling pathway in human epithelial cells within a 4-h treatment. During this process, the nuclear transcription factor NF-κB translocated into the cell nucleus within 30 min of allergen stimulation, triggering the expression of pro-inflammatory genes such as IL-6 and IL-8 over 4 h. Additionally, when the cells were treated with specific Dermatophagoides microceras (Der m) allergens, it resulted in the upregulation of genes that regulate type 1 diabetes mellitus (T1DM) signaling pathways. This led to the mediation of IL-12A inflammation. Furthermore, there was an increase in gene sets associated with cilia function and the microtubule cytoskeleton in human epithelial cells after treatment with a combination of Der m allergens and Dexamethasone. Additionally, OMICs analysis was conducted to examine the effects of HDMs allergenic stimulation on human epidermal cells. We aimed to improve our understanding of the molecular mechanisms within cells and identify potential targets and natural products in the treatment of asthma caused by HDMs allergens.

Residual profiles and health risk of indoor allergens in China

Exposure to indoor allergens is a principal risk factor for allergic diseases. However, most of the previous studies on indoor allergens focused on very limited kinds of allergens in China. Knowledge of the simultaneous exposure to multiple allergens is still lacking. In this study, the residual profiles of 8 allergens were investigated in 166 dust samples from 11 cities in China. The house dust mite allergens including Der p 1, Der f 1, and Der 2 were detected in the range of <0.02–283.83 μg/g dust. The concentrations of dog allergen Can f 1 and cat allergen Fel d 1 varied widely, from <0.84–22,896.46 μg/g dust for Can f 1 and from <0.02–6298.96 μg/g dust for Fel d 1. Cockroach allergen Bla g 2 was detected in 68% of the samples but at a low level with a maximum of 9.44 μg/g dust. Comparatively low detection frequencies were found for mouse allergen Mus m 1 as 37% and for fungi allergen Asp f 2 as 24%. The frequency of cleaning sheets/bedding was negatively correlated to the levels of house dust mite allergens. The presence of pets indoors was associated with higher levels of pet allergens and lower levels of house dust mite allergens and cockroach allergen. Risk evaluation reveals that at least 4 allergens were found in more than 80% of the rooms and more than 2 allergens with median/high risk were detected in 42% of the rooms, indicating that simultaneous exposure to multiple allergens is prevalent in China.

Advocacy of Precision Allergy Molecular Diagnosis in Decision Making for the Eligibility of Customized Allergen Immunotherapy.

Allergen immunotherapy (AIT) with aeroallergens is the only disease-modifying treatment for patients with different allergic conditions. Despite the effectiveness of AIT having been proven in both randomized controlled trials and real-world studies, it remains underused in less than 10% of subjects with allergic rhinitis (AR) and/or asthma (A). We aimed to determine the current eligibility for house dust mite (HDM) AIT by means of a precision allergy molecular diagnosis (PAMD@) model in a selected cohort of youngsters with different allergic phenotypes according to the available evidence. A complex response to both HDM and storage mite allergens was depicted regardless of the subjects' basal atopic condition. No solely specific IgE-binding responses to Der p 1, Der p 2, and/or Der p 23 were found in the studied cohort. Despite the patients with A and atopic dermatitis showing significantly higher serum titers to six mite allergens than subjects with AR, no specific molecular profile was regarded as disease specific. Given the increasing complexity of specific IgE responses to the local prevailing aeroallergens, the identification and presence of such molecules are needed in commercially available AIT in the era of precision medicine.

The preprogrammed anti-inflammatory phenotypes of CD11chigh macrophages by Streptococcus pneumoniae aminopeptidase N safeguard from allergic asthma

BackgroundEarly microbial exposure is associate with protective allergic asthma. We have previously demonstrated that Streptococcus pneumoniae aminopeptidase N (PepN), one of the pneumococcal components, inhibits ovalbumin (OVA) -induced airway inflammation in murine models of allergic asthma, but the underlying mechanism was incompletely determined.MethodsBALB/c mice were pretreated with the PepN protein and exposed intranasally to HDM allergen. The anti-inflammatory mechanisms were investigated using depletion and adoptive transfer experiments as well as transcriptome analysis and isolated lung CD11chigh macrophages.ResultsWe found pretreatment of mice with PepN promoted the proliferation of lung-resident F4/80+CD11chigh macrophages in situ but also mobilized bone marrow monocytes to infiltrate lung tissue that were then transformed into CD11high macrophages. PepN pre-programmed the macrophages during maturation to an anti-inflammatory phenotype by shaping the metabolic preference for oxidative phosphorylation (OXPHOS) and also inhibited the inflammatory response of macrophages by activating AMP-activated protein kinase. Furthermore, PepN treated macrophages also exhibited high-level costimulatory signaling molecules which directed the differentiation into Treg.ConclusionOur results demonstrated that the expansion of CD11chigh macrophages in lungs and the OXPHOS metabolic bias of macrophages are associated with reduced allergic airway inflammation after PepN exposure, which paves the way for its application in preventing allergic asthma.

House dust mite allergens, store-operated Ca2+ channels and asthma.

The house dust mite is the principal source of aero-allergen worldwide. Exposure to mite-derived allergens is associated with the development of asthma in susceptible individuals, and the majority of asthmatics are allergic to the mite. Mite-derived allergens are functionally diverse and activate multiple cell types within the lung that result in chronic inflammation. Allergens activate store-operated Ca2+ release-activated Ca2+ (CRAC) channels, which are widely expressed in multiple cell types within the lung that are associated with the pathogenesis of asthma. Opening of CRAC channels stimulates Ca2+ -dependent transcription factors, including nuclear factor of activated T cells and nuclear factor-κB, which drive expression of a plethora of pro-inflammatory cytokines and chemokines that help to sustain chronic inflammation. Here, I describe drivers of asthma, properties of mite-derived allergens, how the allergens are recognized by cells, the signalling pathways used by the receptors and how these are transduced into functional effects, with a focus on CRAC channels. In vivo experiments that demonstrate the effectiveness of targeting CRAC channels as a potential new therapy for treating mite-induced asthma are also discussed, in tandem with other possible approaches.

Environmental exposure and sensitization patterns in a Swiss alpine pediatric cohort

BackgroundThe level of environmental exposure throughout life may contribute to the prevalence of allergic sensitization and allergic disease. The alpine climate has been considered a healthy climate with little allergen exposure and pollution. We conducted a cross-sectional study to investigate local environmental exposure and concomitant prevalence of allergic sensitization among local school children born and raised in an alpine environment. MethodsClinical and demographic data were collected with a questionnaire. Allergen content was assessed in residential settled dust samples, lifetime exposure to pollen and air pollution was calculated using data from national pollen and air pollution monitoring stations, and the allergic sensitization profile was determined with component resolved diagnostics (ISAC®). Univariate and multivariate regression models were used to estimate the relation between exposure and sensitization. ResultsIn a cohort of children born and raised in an alpine environment, sensitization to aeroallergens is quite common (38%), especially to grass (33%) and cat (16%). House dust mite allergen was detected in up to 38% of residential dust samples, but sensitization to HDM was low (2.5%). Pollutant levels were low, but an increasing trend was observed in the amount of ozone and PM10. Living close to a busy road was associated with increased odds OR (95% CI) for being sensitized to any allergen 2.7 (1.0–7.2), to outdoor allergens 2.8 (1.1–7.1) and being sensitized plus reporting symptoms of rhinoconjunctivitis 4.4 (1.3–14.8) and asthma 5.5 (1.4–21). Indoor living conditions, including the presence of visible mold, increased the odds of being sensitized to indoor allergens (1.9 (1.1–3.2) and being sensitized plus reporting symptoms of rhinoconjunctivitis 1.9 (1.0–3.6) and asthma 2.1 (1.0–4.1). ConclusionIn a healthy alpine environment, pollution might still be an important factor contributing to allergic sensitization.