Identifying Potential Co-Sensitization and Cross-Reactivity Patterns Based on Component-Resolved Diagnosis

Airborne indoor allergen serine proteases and their contribution to sensitisation and activation of innate immunity in allergic airway disease

Common airborne allergens (pollen, animal dander and those from fungi and insects) are the main triggers of type I allergic disorder in the respiratory system and are associated with allergic rhinitis, allergic asthma, as well as immunoglobulin E (IgE)-mediated allergic bronchopulmonary aspergillosis. These allergens promote IgE crosslinking, vasodilation, infiltration of inflammatory cells, mucosal barrier dysfunction, extracellular matrix deposition and smooth muscle spasm, which collectively cause remodelling of the airways. Fungus and insect (house dust mite and cockroaches) indoor allergens are particularly rich in proteases. Indeed, more than 40 different types of aeroallergen proteases, which have both IgE-neutralising and tissue-destructive activities, have been documented in the Allergen Nomenclature database. Of all the inhaled protease allergens, 85% are classed as serine protease activities and include trypsin-like, chymotrypsin-like and collagenolytic serine proteases. In this article, we review and compare the allergenicity and proteolytic effect of allergen serine proteases as listed in the Allergen Nomenclature and MEROPS databases and highlight their contribution to allergic sensitisation, disruption of the epithelial barrier and activation of innate immunity in allergic airways disease. The utility of small-molecule inhibitors of allergen serine proteases as a potential treatment strategy for allergic airways disease will also be discussed.

Relationship between indoor inhalant allergen concentrations, serum IgE, and allergic diseases: A cross-sectional study from the NHANES 2005-2006 program

This research analyzed data from 5106 participants in the National Health and Nutrition Examination Survey 2005-2006 to explore the link between indoor allergen concentrations, serum IgE levels, and allergic diseases. The study found that 14.9% of participants reported having asthma, with significant differences noted in the concentrations of certain indoor allergens, specifically dust dog, mite, and cat allergens, between asthma and non-asthma groups. Furthermore, positivity rates for inhalant allergen-specific IgE and total IgE were higher in the asthma group. However, the correlations between most inhalant allergen IgE, including total IgE, and indoor allergen concentrations were very weak. These findings suggest that the relationship between indoor allergen concentrations and asthma incidence is complex, indicating a potential need for personalized allergen prevention strategies based on disease type and patient sensitization.

Sensitisation to House Dust Mite Component Der p 23 Is Associated with Severe Symptoms and Asthma in Allergic Rhinitis Patients

INTRODUCTION

House dust mite (HDM) is an important source of airborne allergens in China as it contains several allergenic components that can cause allergic rhinitis (AR) and other allergic diseases. This study aimed to determine the clinical characteristics and disease severity in AR patients sensitised to different allergenic HDM components.

METHODS

This was a retrospective study, which examined 129 patients who were first diagnosed with only HDM-induced AR at the Department of Allergy of Beijing Tongren Hospital from December 2019 to April 2021. Clinical characteristics and disease severity of the patients were assessed based on the sensitisation to specific Dermatophagoides pteronyssinus (Der p) and Dermatophagoides farinae (Der f) allergenic components, including Der p 1, Der p 2, Der p 23, Der f 1, and Der f 2, employing multiple correspondence analysis (MCA) with correspondence analysis chart of MCA.

RESULTS

Among HDM-induced AR cases, the positive rate of Der p 1 was the highest (87.6%), followed by Der p 2 (78.3%), Der f 2 (76.64%), Der f 1 (68.2%), and Der p 23 (37.2%). Multiple correspondence analyses showed that sensitisation to Der p 23 was associated with severe AR symptoms and asthma; sensitisation to Der p 2, Der f 1, and Der f 2 was associated with moderate AR; and no sensitisation to Der p 23 was associated with mild AR.

CONCLUSION

Der p 23 sensitisation is prevalent in northern China and may be associated with severe symptoms and asthma in AR patients.

Serological analysis of allergic components of house dust mite provides more insight in epidemiological characteristics and clinical symptom development in North China

Background

House dust mite (HDM) is the most common airborne source causing complex allergy symptoms. There are geographic differences in the allergen molecule sensitization profiles. Serological testing with allergen components may provide more clues for diagnosis and clinical management.

Objective

This study aims to investigate the sensitization profile of eight HDM allergen components in a large number of patients enrolled in the clinic and to analyze the relation of gender, age, and clinical symptoms in North China.

Methods

The 548 serum samples of HDM-allergic patients (ImmunoCAP^® d1 or d2 IgE ≥0.35) were collected in Beijing City and divided in four different age groups and three allergic symptoms. The specific IgE of HDM allergenic components, Der p 1/Der f 1, Der p 2/Der f 2, Der p 7, Der p 10, Der p 21, and Der p 23, was measured using the micro-arrayed allergen test kit developed by Hangzhou Zheda Dixun Biological Gene Engineering Co., Ltd. The new system was validated by comparing to single-component Der p 1, Der p 2, and Der p 23 tests by ImmunoCAP in 39 sera. The epidemiological study of these IgE profiles and the relation to age and clinical phenotypes were analyzed.

Results

A greater proportion of male patients was in the younger age groups, while more female patients were in the adult groups. Both the sIgE levels and the positive rates (approximately 60%) against Der p 1/Der f 1 and Der p 2/Der f 2 were higher than for the Der p 7, Der p 10, and Der p 21 components (below 25%). The Der f 1 and Der p 2 positive rates were higher in 2-12-year-old children. The Der p 2 and Der f 2 IgE levels and positive rates were higher in the allergic rhinitis group. The positive rates of Der p 10 increased significantly with age. Der p 21 is relevant in allergic dermatitis symptom, while Der p 23 contributes to asthma development.

Conclusion

HDM groups 1 and 2 were the major sensitizing allergens, with group 2 being the most important component relevant to respiratory symptoms in North China. The Der p 10 sensitization tends to increase with age. Der p 21 and Der p 23 might be associated with the development of allergic skin disease and asthma, respectively. Multiple allergen sensitizations increased the risk of allergic asthma.

Mobile health app for monitoring allergic rhinitis and asthma in real life in Lithuanian MASK-air users

Background

MASK‐air^® is an app whose aim is to reduce the global burden of allergic rhinitis (AR) and asthma. A transfer of innovative practices was performed to disseminate and implement MASK‐air^® in European regions. The aim of the study was to examine the implementation of the MASK‐air^® app in Lithuanian adults in order to investigate (i) the rate of acceptance in this population, (ii) the duration of app use and (iii) the evaluation of the app after its use.

Methods

In a longitudinal study, Lithuanian adults with AR and/or asthma were recruited by allergists. They were informed about how to use MASK‐air^® and were followed closely. They were reviewed after one to 3 months to evaluate satisfaction and were asked to continue using the app.

Results

Among the 149 patients recruited (37.2 ± 10.4 years), 52.4% had rhinitis alone, 42.9% had rhinitis, asthma and/or conjunctivitis multimorbidity, and 2.7% isolated asthma. According to the MASK‐air^® baseline questionnaire, 88.3% of patients considered that their symptoms were troublesome. Data were available for 102 (68.4%) patients. The duration of app usage in patients ranged from 1 to 680 days (median, 25–75 percentile: 54, 23.2–151 days). Forty‐two (41.1% of patients who were reviewed) patients agreed to share their opinion on MASK‐air^®. Most users of the app were satisfied, from 46.5% thinking their allergy was treated more successfully to 90.4% recommending this app to other allergy sufferers.

Discussion

When recommended by physicians, MASK‐air® was used for a longer period of time.

[Profiles of IgE sensitization to dust mite allergen components in patients with allergic rhinitis and asthma]

Objective:To study the differences and clinical significance of dust mite allergen components in allergic rhinitis（AR） and allergic rhinitis with asthma syndrome（ARAS） patients. Methods:The clinical data of 42 AR patients were retrospectively analyzed and patients were divided into AR and ARAS group. The serum sIgE concentrations of house dust mites were detected by ImmunoCAP system. The allergen components of Der p（Der p 1, Der p 2, Der p 7, Der p 10, Der p 21, Der p 23） and Der f（Der f 1, Der f 2） were analyzed by protein microarray method. The concentration differences of dust mite allergen and its components in AR and ARAS groups were analyzed. Results:Thirty-one cases of AR and 11 cases of ARAS were included. The positive rate of Der p and Der f was 100.0% and 97.6%, respectively. The highest sensitization rates of Der p allergen components were as following: Der p 1（73.8%）, Der f 1（66.7%）, Der f 2（64.3%） and Der p 2（61.9%）. The sensitization rates of Der f 1（100.0% vs 54.8%, P=0.006）, Der p 2（90.9% vs 51.6%, P=0.021） and Der f 2（100.0% vs 51.6%, P=0.004） in ARAS group were significantly higher than those in AR group. The sIgE concentrations of Der p in AR group were significantly lower than those in ARAS group（[7.65±12.15]kUA/L vs[15.20±18.77]kUA/L, P<0.05）. The sIgE concentrations of Der p 1（[5.39±4.61]kUA/L vs[2.03±2.97]kUA/L, P=0.013）, Der p 2（[8.82± 13.58]kUA/L vs[2.78±5.80]kUA/L, P=0.001）, Der p 23（[1.76± 3.88]kUA/L vs[0.28±0.65]kUA/L, P<0.001） was significantly higher in ARAS group than that of AR group. Correlation analysis showed that Der p 1, Der p 2, Der f 1 and Der f 2 had high positive correlation（P<0.01）. The dust mite components sensitization showed a multiple-sensitized mode. 66.7% of the 42 patients were positive for two or more components while it was 58.1% of the AR group and 90.9% of the ARAS group. The sensitization rate of 3 or more components in ARAS group was significantly higher than that in AR group（54.6% vs 29.1%, P<0.05）. Conclusion:The concentration of dust mites allergens in ARAS group is higher than that in AR group. Der p 1, Der f 1, Der p 2 and Der f 2 are the main allergen components with a higher sensitization rate in ARAS group. The concentrations of Der p 1, Der p 2 and Der p 23 were higher in ARAS group. The ARAS group is prone to multi-sensitzed to allergen components.

Systematic Characterization of the Group 2 House Dust Mite Allergen in Dermatophagoides microceras

Background

Allergic asthma, a chronic airway inflammatory disease, is a critical public health problem. Indoor house dust mites (HDMs) could cause allergic asthma. The prevalence of sensitization to Dermatophagoides microceras (Der m) was approximately 80% and is related to the immunoglobulin E crossing-reactivity of mites belonging to the same genus, Dermatophagoides pteronyssinus (Der p) and Dermatophagoides farina (Der f). However, studies on Der m are scant.

Methods

We used integrated OMICs approaches to identify and characterize the group 2 mite allergen-like protein in Der m (Der m 2). We established a Der m 2-induced allergic asthma mouse model and treated the mice with a fungal immunomodulatory protein (FIP-fve) isolated from Flammulina veluptipes to evaluate the allergenicity of Der m 2 and the immunomodulatory effects of FIP-fve.

Results

By performing de novo draft genome assembly and comparative genome analysis, we identified the putative 144-amino acid Der m 2 in silico and further confirmed its existence through liquid chromatography–tandem mass spectrometry. Der m 2 is a lipopolysaccharides (LPS)-binding protein. Thus, we examined the LPS-binding activity of recombinant Der m 2 by performing molecular docking analysis, co-immunoprecipitation (Co-IP), and a pull-down assay. Der m 2 elicited the production of pro-inflammatory cytokines, interleukin (IL)-6, and IL-8 in BEAS-2B cells, a human bronchial epithelial cell line, and induced airway hyperresponsiveness in mice. Furthermore, in mice sensitized with Der m 2, the administration of FIP-fve in either the earlier stage or the late stage, FIP-fve alleviated allergic asthma by moderating airway inflammation and remodeling.

Conclusions

Der m 2 induced inflammatory responses in cell and mouse models. FIP-fve alleviated inflammation in Der m 2-induced asthma in mice by exerting an immunomodulatory effect.

The Molecular Allergen Recognition Profile in China as Basis for Allergen-Specific Immunotherapy

Approximately 30% of the world population suffers from immunoglobulin-E (IgE)-mediated allergy. IgE-mediated allergy affects the respiratory tract, the skin and the gastrointestinal tract and may lead to life-threatening acute systemic manifestations such as anaphylactic shock. The symptoms of allergy are mediated by IgE-recognition of causative allergen molecules from different allergen sources. Today, molecular allergy diagnosis allows determining the disease-causing allergens to develop allergen-specific concepts for prevention and treatment of allergy. Allergen-specific preventive and therapeutic strategies include allergen avoidance, vaccination, and tolerance induction. The implementation of these preventive and therapeutic strategies requires a detailed knowledge of the relevant allergen molecules affecting a given population. China is the world´s most populous country with around 1.4 billion inhabitants and an estimated number of more than 400 million allergic patients. Research in allergy in China has dramatically increased in the last decade. We summarize in this review article what is known about the dominating allergen sources and allergen molecules in China and what further investigations could be performed to draw a molecular map of IgE sensitization for China as a basis for the implementation of systematic and rational allergen-specific preventive and therapeutic strategies to combat allergic diseases in this country.

Artificial intelligence in the diagnosis of pediatric allergic diseases

Artificial intelligence (AI) is a field of data science pertaining to advanced computing machines capable of learning from data and interacting with the human world. Early diagnosis and diagnostics, self-care, prevention and wellness, clinical decision support, care delivery, and chronic care management have been identified within the healthcare areas that could benefit from introducing AI. In pediatric allergy research, the recent developments in AI approach provided new perspectives for characterizing the heterogeneity of allergic diseases among patients. Moreover, the increasing use of electronic health records and personal healthcare records highlighted the relevance of AI in improving data quality and processing and setting-up advanced algorithms to interpret the data. This review aimed to summarize current knowledge about AI and discuss its impact on the diagnostic framework of pediatric allergic diseases such as eczema, food allergy, and respiratory allergy, along with the future opportunities that AI research can offer in this medical area.

Serum levels of specific immunoglobulin E to Dermatophagoides pteronyssinus allergen components in patients with allergic rhinitis or/and asthma

Background: House-dust mites (HDM) allergen is one of the most important allergens in southern China; however, studies on the Dermatophagoides pteronyssinus components are relatively lacking. Objective: This study analyzed the molecular components of D. pteronyssinus in patients with allergic asthma (AS) and/or allergic rhinitis (AR) sensitized to D. pteronyssinus, and aimed to improve HDM immunotherapy in southern China. Methods: Allergen component-resolved diagnosis detection technology was used to detect the serum levels of specific immunoglobulin E (sIgE) to D. pteronyssinus allergen components (Der p 1, 2, 3, 5, 7, 10, and 23) in patients who were sensitized to D. pteronyssinus and with AR (n = 106), AS (n = 144), or AR combined with AS (n = 134). Results: The highest positive rates of D. pteronyssinus components were Der p 1 (94.8%), followed by Der p 2 (77.6%), Der p 23 (62.5%), Der p 7 (34.6%), Der p 5 (17.7%), Der p 10 (12.2%), and Der p 3 (2.6%). Patients with AR+AS had the highest positive rates to Der p 2 (85.8%), Der p 23 (62.7%), Der p 7 (40.3%), Der p 5 (25.0%), and Der p 10 (16.4%). Der p 1 had the highest positive rate in patients with AR (95.3%). The Der p 3 positive rate in patients with AS (6.0%) was higher than that in patients with AR (0.0%, χ² = 6.872, p < 0.05) and patients with AR+AS (0.7%, χ² = 6.063, p < 0.05) Among the patients with AR+AS, 19.1% were co-sensitized to Der p 1, Der p 2, Der p 23, and Der p 7. Interestingly, only one patient with AR was exclusively sensitized to Der p 23. An optimal scale analysis showed that Der p 5, Der p 23, and Der p 7 had strong connection (Cronbach α = 93.7%). Conclusion: Der p 1 and Der p 2 were the main sensitization components of D. pteronyssinus, and patients with AS+AR had the highest positive rate for five of seven D. pteronyssinus allergen components. This research can provide suggestions for personalized HDM-specific immunotherapy in southern China.

Design, production and immunomodulatory potency of a novel allergen bioparticle

Allergen immunotherapy (AIT) is the only disease-modifying treatment with evidence for sustained efficacy. However, it is poorly developed compared to symptomatic drugs. The main reasons come from treatment duration implying monthly injections during 3 to 5 years or daily sublingual use, and the risk of allergic side-effects. To become a more attractive alternative to lifelong symptomatic drug use, improvements to AIT are needed. Among the most promising new immunotherapy strategies is the use of bioparticles for the presentation of target antigen to the immune system as they can elicit strong T cell and B cell immune responses. Virus-like particles (VLPs) are a specific class of bioparticles in which the structural and immunogenic constituents are from viral origin. However, VLPs are ill-suited for use in AIT as their antigenicity is linked to structure. Recently, synthetic biology has been used to produce artificial modular bioparticles, in which supramolecular assemblies are made of elements from heterogeneous biological sources promoting the design and use of in vivo-assembling enveloped bioparticles for viral and non-viral antigens presentation. We have used a coiled-coil hybrid assembly for the design of an enveloped bioparticle (eBP) that present trimers of the Der p 2 allergen at its surface, This bioparticle was produced as recombinant and in vivo assembled eBPs in plant. This allergen biotherapeutic was used to demonstrate i) the capacity of plants to produce synthetic supramolecular allergen bioparticles, and ii) the immunomodulatory potential of naturally-assembled allergen bioparticles. Our results show that allergens exposed on eBPs induced a very strong IgG response consisting predominantly of IgG2a in favor of the TH1 response. Finally, our results demonstrate that rDer p 2 present on the surface of BPs show a very limited potential to stimulate the basophil degranulation of patient allergic to this allergen which is predictive of a high safety potential.

Identification the Cross-Reactive or Species-Specific Allergens of Tyrophagus putrescentiae and Development Molecular Diagnostic Kits for Allergic Diseases

Mite allergens are considerable factors in the genesis of allergic diseases. The storage mite Tyrophagus putrescentiae (Tp) appears in contaminated foods and household surroundings. The current diagnostic tools for Tp allergy are mostly based on crude extracts and still contain shortcomings. This study aimed to investigate the immunoglobulin E (IgE)- responsiveness profiles of Tp-allergic patients and develop a molecular diagnostic method using recombinant allergens. Allergenic components were characterized as cross-reacting or species-specific allergens, in which the effective combinations of recombinant allergens were developed and analyzed in terms of the prediction accuracy for clinical diagnosis. Seven recombinant allergens were cloned and generated to detect the IgE responsiveness of the Tp allergy. A survey on the prevalence of mite allergy showed there were higher sensitizations with IgE responsiveness to house dust mites (HDM) (78.9-80.9%) than to storage mites Tp (35.6%). Prevalence of sensitization to Tp was higher in elderly subjects. The principal IgE-binding components of Tp were Tyr p 1, Tyr p 2 and Tyr p 3. Prediction accuracy for Tp allergy by IgE-responsiveness combination D (Tyr p 1, Tyr p 2 & Tyr p 3) was with high precision (100%). Avoiding the cross-reactivity of Dermatophagoides pteronyssinus, the prediction accuracy of IgE-responsiveness combination H+ (Tyr p 1, Tyr p 2, Tyr p 3, Tyr p 7, Tyr p 8, Tyr p 10 & Tyr p 20) was suitable for Tp-specific diagnosis. Panels of Tp allergens were generated and developed a diagnostic kit able beneficial to identify IgE-mediated Tp hypersensitivity.