Prevalence of allergic sensitization to storage mites in Northern Europe

[Allergen immunotherapy for rare allergens]

Among allergies to aeroallergens, approximately 20% are allotted to the so-called rare allergens. These include ash pollen, weed pollen, storage mites, molds, and animal allergens. The prevalences of allergies to these allergens are lower, but affected patients also suffer considerably from their "rare" allergy. Hence, these allergies should neither be overseen nor completely forgotten in daily practice. Especially mold, mite, and animal allergens often induce asthma, so that the significance of allergen-specific immunotherapy (AIT) should not be neglected in causal therapy. This work summarizes the current state of knowledge on the groups of rare aeroallergens in terms of characteristics, prevalences, and data on AIT. It is based on a systematic literature search performed in the MEDLINE (PubMed®) and Google Scholar databases. AIT preparations for rare allergens are classified as individual formulations and are not subject to the German Therapy Allergen Ordinance. Due to the low case numbers, the levels of evidence for these formulations are not as high as those for dust mites, grass, or birch pollen, but exhibit good efficacy in practical experience.

Polysensitisation is associated with more severe symptoms: The reality of patients with allergy

BACKGROUND

Studying the sensitisation profiles of patients with allergies allows for a deeper understanding of the disease which may facilitate the selection of the best-personalised allergen immunotherapy. This observational, cross-sectional, multicentre study aimed to demonstrate the heterogeneity of the German population with allergies by analysing specific immunoglobulin E (sIgE) patterns towards aeroallergens and exploring the relationship between sensitisation and clinical symptoms.

METHODS

In total, 500 patients with allergies from different regions of Germany were recruited based on their case histories, clinical allergic symptoms and skin prick test data for aeroallergens. Serum samples were analysed using ImmunoCAP assays to determine sIgE levels for 33 allergenic sources and 43 molecular allergens.

RESULTS

Most patients (81%) were polysensitised. Betula verrucosa pollen was the most common cause of sensitisation (59%), followed by Phleum pratense (58%) and Dermatophagoides pteronyssinus (44%). The highest prevalence rates of molecular allergens were observed for Bet v 1 (84%) from birch pollen, Phl p 1 from grass pollen (82%), Der p 2 (69%) from mites and Fel d 1 (69%) from cat. Polysensitisation was significantly associated with the presence of asthma and the severity of rhinitis symptoms.

CONCLUSIONS

Our findings show a high rate of polysensitisation and emphasise the importance of molecular diagnosis for more precise and comprehensive insights into sensitisation patterns and their association with clinical symptoms. These data may help improve personalised diagnosis and immunotherapy adapted to the needs of individual patients in the region.

Patterns of allergic sensitization in adults with severe asthma: the ATLAS non-interventional study

OBJECTIVES

Severe asthma is heterogeneous, with childhood-onset asthma believed more likely to be allergic, whereas adult-onset asthma is considered typically non-allergic. However, the allergic diagnosis is typically by exclusion: if patients do not react to an allergen panel, which is not standardized and often limited to few allergens, they are considered non-allergic. The overall aim of the ATLAS study was to characterize the sensitization to allergens in severe asthma (independent of phenotype).

METHODS

Single-visit, cross-sectional, non-interventional study in adults with severe asthma. Analyses were conducted for total and specific immunoglobulin E against 53 allergens, overall and in subgroups, including age at asthma onset (<20 [childhood-onset] and >40 years of age).

RESULTS

Among 1010 recruited patients, 28.4% reported childhood-onset asthma and 33.6% onset >40 years of age. After excluding patients receiving omalizumab/anti-IL5 therapy, 27.6% were not sensitized to any tested allergens, whereas 19.1% were sensitized to >10 allergens. All allergens triggered sensitization in some patients. Baseline characteristics in the two onset subgroups were similar; 23.2% with childhood-onset asthma were not sensitized to any allergen, compared to 32.0% with onset >40 years of age.

CONCLUSION

When a broad panel of allergens is used for sensitization testing, as many as three quarters of patients with severe asthma display sensitivity to at least one allergen, with substantial overlaps in all characteristics between the two age-at-onset subgroups. All of the tested allergens triggered a response in at least some patients, emphasizing the importance of including a broad range of allergens in any testing panel.

Storage Mite Precision Allergy Molecular Diagnosis in the Moderate-to-Severe T2-High Asthma Phenotype

Storage mites (SM) may induce allergic respiratory symptoms in sensitized individuals, in both rural and urban settings. The relationship among specific IgE reactions to determined groups of SM allergens in the coincident asthma pheno-endotypes has not yet been investigated. We aimed to study a Precision Allergy Molecular Diagnosis (PAMD@) model to depict the SM molecular profile in individuals presenting with Type-2 inflammation, in two different (moderate and severe) asthma phenotypes. A customized PAMD@ panel, including SM allergens and their concurrent protein allergenic characterization was investigated. Mite group 2 allergens were most frequently recognized, including Lep d 2 (83.45%), followed by Gly d 2 (69.17%) and Tyr p 2 (47,37%), in 133/164 asthmatic subjects. Blo t 5 and Blo t 21 exhibited significant higher titres in both asthma groups. Although relevant mite group 2 allergens cross-reactivity is suggested, individualized sensitization patterns were relevantly identified. The present PAMD@ panel confirmed the dominance of mite group 2 allergens in moderate-to-severe T2 asthmatics. A broadly heterogeneous molecular repertoire of SM allergens was found in all subjects, regardless of their asthma severity. Blomia tropicalis deserves special attention in certain territories, as diagnostic and/or therapeutic approaches merely based on Pyroglyphidae mites may be insufficient.

Regulatory roles of three miRNAs on allergen mRNA expression in Tyrophagus putrescentiae

BACKGROUND

Tyrophagus putresecentiae is an important mite species in rural and urban environments, causing sensitization and allergic disease. While evidence suggests that microRNAs (miRNAs) may regulate the expression of allergen-encoding genes, no study has directly investigated this possibility. Here, this gap was addressed by profiling miRNAs and elucidating their target allergen messenger RNAs (mRNAs) in this mite species.

METHODS

Small RNA and transcriptome libraries were constructed for eggs, larvae, nymphs, and adults. After deep miRNA and whole-transcriptome sequencing were performed, the miRNA and allergen-encoding mRNA regulatory networks were explored.

RESULTS

A total of 540 miRNAs were identified, including 155 with expression levels differing significantly across the four mite developmental stages (p < .01), 59 of which were novel. The mRNA expression for allergens was higher for Tyr p 1 in adults than in other developmental stages; Tyr p 2-5, 7, 10, 13, 33, and 34 in immature stages; and Tyr p 28, 35, and 36 in eggs and adults. A combined miRNA and transcriptome bioinformatics analysis showed that allergen Tyr p 3 was regulated by miRNA PC-5p-5698441_1, Tyr p 4 was regulated by PC-5p-7050653_1, and Tyr p 34 was regulated by PC-5p-5534223_1 and PC-5p-5698441_1. These three allergen mRNA and three miRNAs were identified using qRT-PCR, and their regulatory roles were confirmed by double-fluorescent reporter gene system and site-directed mutagenesis technology.

CONCLUSIONS

For the first time, allergen mRNA expression and miRNAs were profiled throughout the life cycle for an allergen-producing mite, and the results showed that miRNAs bind to target allergen mRNAs to regulate their expression.

Effects of Local Nasal Immunotherapy with FIP-fve Peptide and Denatured Tyrophagus putrescentiae for Storage Mite-Induced Airway Inflammation

Allergic diseases are affecting public health and have increased over the last decade. Sensitization to mite allergens is a considerable trigger for allergy development. Storage mite-Tyrophagus putrescentiae shows great significance of allergenic potential and clinical relevance. The fungal immunomodulatory peptide FIP-fve has been reported to possess immunomodulatory activity. We aimed to determine whether T. putrescentiae-induced sensitization and airway inflammation in mice could be downregulated by FIP-fve in conjunction with denatured T. putrescentiae (FIP-fve and DN-Tp). Immune responses and physiologic variations in immunoglobulins, leukocyte subpopulations, cytokine productions, pulmonary function, lung pathology, cytokines in CD4⁺ and Treg cells were evaluated after local nasal immunotherapy (LNIT). After the LNIT with FIP-fve and DN-Tp, levels of specific IgE, IgG1, and IgG2a in the sera and IgA in the bronchoalveolar lavage fluid (BALF) were significantly reduced. Infiltrations of inflammatory leukocytes (eosinophils, neutrophils, and lymphocytes) in the airway decreased significantly. Production of proinflammatory cytokines (IL-5, IL-13, IL-17F and IL-23) and chemokine (IL-8) were significantly reduced, and Th1-cytokine (IL-12) increased in the airway BALF after LNIT. Pulmonary functions of Penh values were significantly decreased after the methacholine challenge, which resulted in a reduction of airway hypersensitivity after LNIT. Bronchus pathology showed a reduction of inflammatory cell infiltration and epithelium damage after LNIT. The IL-4⁺/CD4⁺ T cells could be downregulated and the IFN-γ⁺/CD4⁺ T cells upregulated. The Treg-related immunity of IL-10 and Foxp3 expressions in CD4⁺CD25⁺ cells were both upregulated after LNIT. In conclusion, LNIT with FIP-fve and DN-Tp had an anti-inflammatory effect on mite-induced airway inflammations and possesses potential as an immunomodulatory therapy agent for allergic airway diseases.

Association between the prevalence of allergic reactions to skin prick tests and workplace types among agricultural workers in South Korea

Background

Farmers are often exposed to dust, molds, pollen, animal products, insects, and chemicals. Accordingly, they have a high prevalence of respiratory and allergic diseases. Some studies have shown that farmers have a high prevalence of respiratory diseases and symptoms depending on where farmers work. The objective of the present study was to investigate whether certain types of agricultural workplaces are associated with the prevalence of allergic reactions in skin prick tests (SPTs) in South Korea.

Method

A total of 149 farmers, grouped according to their workplaces in greenhouses, poultry houses, or outdoors, answered a self-reported questionnaire about the prevalence of respiratory diseases and symptoms. They were skin-tested using 12 allergens. The questionnaire and the prevalence of positive skin tests were determined for each of the participant groups, and the results were analyzed by multivariate logistic regression.

Results

There were significant differences in the prevalence of allergic reactions to the SPT, chronic obstructive pulmonary diseases (COPDs) and asthma symptoms (wheezing) among the subgroups. The allergic reaction to SPT was the highest in greenhouse workers (30.9%), followed by poultry house workers (15.9%), and outdoor workers (8.1%). The prevalence of COPD was 6.8% in poultry house workers alone and not in other groups. The prevalence of wheezing was the highest at 9.1% in poultry house workers. According to the results of the logistic analysis, the prevalence of allergic reactions to SPT had positive correlations with the types of workplaces. Greenhouse workers had higher risk of SPT sensitization compared to outdoor workers (adjusted odds ratio [OR]: 5.55, 95% confidence interval [CI]: 1.32-32.24). The prevalence of SPT positivity also had an association with the symptoms of sneezing, rhinorrhea, or nasal congestion (adjusted OR: 6.64, 95% CI: 2.06-23.63).

Conclusions

These data demonstrate that the types of workplaces were associated with the prevalence of allergic sensitization. This could be explained by the difference in the type or level of airborne exposures in each workplace. It is also likely that this was caused by differences between groups of individual factors such as age and BMI that influence SPT sensitization.

Developments in the field of allergy in 2020 through the eyes of Clinical and Experimental Allergy

While 2020 will be remembered for the global coronavirus pandemic, there were also important advances in the field of allergy. In this review article, we summarize key findings reported in Clinical and Experimental Allergy during 2020. We hope this provides readers with an accessible snapshot of the work published in our journal during this time.

Cardinium inhibits Wolbachia in its mite host, Tyrophagus putrescentiae, and affects host fitness

Interactions among endosymbiotic bacteria inside their eukaryotic hosts are poorly understood, particularly in mites. The mite Tyrophagus putrescentiae is a common, medically important generalist species that has many intracellular and gut bacterial symbionts. In the experiments, we examined bacterial abundances and composition in mite populations obtained by controlled mixing of stock mite populations that differed in the presence/absence of the major intracellular bacteria Wolbachia and Cardinium. Changes in microbial communities were characterized using 16S ribosomal RNA high-throughput sequencing (pooled mite individuals) and quantitative PCR for key microbial taxa (individual mites). Mite fitness was estimated as a parameter of population growth. We detected that in mixed mite populations, Cardinium and Wolbachia can co-occur in the same mite individual. The presence of Cardinium was negatively correlated with the presence of Wolbachia and Bartonella, while the Bartonella and Wolbachia were positively correlated in individual level samples. Since mixed populations had lower abundances of Wolbachia, while the abundance of Cardinium did not change, we suggest that the presence of Cardinium inhibits the growth of Wolbachia. The mixed mite populations had lower population growth than parental populations. The possible effect of symbionts on the fitness of mixed population is discussed.

House dust mite (HDM) and storage mite (SM) molecular sensitisation profiles and association with clinical outcomes in allergic asthma and rhinitis: protocol for a systematic review

INTRODUCTION

Identification and characterisation of single allergens at molecular level is important. Component-resolved diagnosis offers the possibility of higher diagnostic precision, thereby allowing better patient management. House dust mites (HDM) have a worldwide distribution. Studies from different countries have shown that IgE-mediated allergy to storage mites (SM) is important in rural and urban populations. With the availability of HDM and SM molecular allergen components, studies have investigated whether different molecular sensitisation profiles are associated with clinical disease outcomes. However, no previous systematic review has synthesised the underlying evidence.

METHODS AND ANALYSIS

We will search Cochrane Library (Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials (CENTRAL), Cochrane Methodology Register), MEDLINE, EMBASE, CINAHL, AMED, ISI Web of Science (Science and Social Science Index) from inception to March 2020. Unpublished and ongoing work, as well as research in progress will be searched in www.ClinicalTrials.gov; www.controlledtrials.com and wwwanzctrorgau. We will contact an international panel of experts in this field. No language restrictions will apply; translations will be undertaken where necessary. The Critical Appraisal Skills Programme quality assessment tool will be used to appraise the methodological quality of included studies. A descriptive summary with data tables will be constructed, and if adequate, meta-analysis using random effects will be performed. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses checklist will be followed for reporting.

ETHICS AND DISSEMINATION

Since this systematic review will be only based on published and retrievable literature, no ethics approval is required. We will publish the systematic review in an international peer-reviewed journal.

TRIAL REGISTRATION NUMBER

reviewregistry959.

Developments allergy in 2019 through the eyes of Clinical and Experimental Allergy, Part II clinical allergy

In the second of two linked articles, we describe the development in clinical as described by Clinical & Experimental Allergy and other journals in 2019. Epidemiology, clinical allergy, asthma and rhinitis are all covered. In this article, we described the development in the field of allergy as described by Clinical and Experimental Allergy in 2019. Epidemiology, clinical allergy, asthma and rhinitis are all covered.

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.