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

Background

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.

Methods

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.

Results

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.

Conclusion

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.

Xin-Yi-Qing-Fei-Tang and its critical components reduce asthma symptoms by suppressing GM-CSF and COX-2 expression in RBL-2H3 cells

ETHNOPHARMACOLOGICAL RELEVANCE

The traditional Chinese medicine (TCM) XYQFT is composed of 10 herbs. According to the NHIRD, XYQFT is one of the top ten most commonly used TCM prescriptions for asthma treatment.

AIM OF THE STUDY

The aim of this study was to explore whether XYQFT reduces asthma symptoms in a mouse model of chronic asthma and determine the immunomodulatory mechanism of mast cells.

MATERIALS AND METHODS

BALB/c mice were intratracheally (it) stimulated with 40 μL (2.5 μg/μL) of Dermatophagoides pteronyssinus (Der p) once a week for 6 consecutive weeks and orally administered XYQFT at 1 g/kg 30 min before Der p stimulation. Airway hypersensitivity, inflammatory cells in the BALF and total IgE in the blood were assessed in mice. In addition, RBL-2H3 cells (mast cells) were stimulated with DNP-IgE, after which different concentrations of XYQFT were added for 30 min to evaluate the effect of XYQFT on the gene expression and degranulation of DNP-stimulated RBL-2H3 cells. After the compounds in XYQFT were identified using LC‒MS/MS, the PBD method was used to identify the chemical components that inhibited the expression of the GM-CSF and COX-2 genes in mast cells.

RESULTS

The airway hypersensitivity assay demonstrated that XYQFT significantly alleviated Der p-induced airway hypersensitivity. Moreover, cell counting and typing of bronchoalveolar lavage fluid revealed a significant reduction in Der p-induced inflammatory cell infiltration with XYQFT treatment. ELISA examination further indicated a significant decrease in Der p-induced total IgE levels in serum following XYQFT administration. In addition, XYQFT inhibited the degranulation and expression of genes (IL-3, IL-4, ALOX-5, IL-13, GM-CSF, COX-2, TNF-α, and MCP-1) in RBL-2H3 cells after DNP stimulation. The compounds timosaponin AIII and genkwanin in XYQFT were found to be key factors in the inhibition of COX-2 and GM-CSF gene expression in mast cells.

CONCLUSION

By regulating mast cells, XYQFT inhibited inflammatory cell infiltration, airway hypersensitivity and specific immunity in a mouse model of asthma. In addition, XYQFT synergistically inhibited the expression of the GM-CSF and COX-2 genes in mast cells through timosaponin AIII and genkwanin.

Der p 23 sensitization in patients with house dust mite respiratory allergy

Summary

Background. The sensitization profile of patients allergic to house dust mites (HDM) and its molecular diagnosis may determine treatment and evolution of the disease. The present study investigates the prevalence of Der p 23 sensitization and its relation to asthma in a population of HDM-allergic patients. Methods. We conducted a cross-sectional study of 891 patients with HDM allergy with symptoms of rhinitis and 52.1% of them with asthma. Total and specific IgE (sIgE) was measured against Dermatophagoides pteronyssinus and its molecular components and the storage mite Lepidoglyphus destructor using ImmunoCAP. Prevalence of sensitization and levels of sIgE were analyzed according to asthma diagnosis and asthma severity. Results. Der p 23 was the predominant allergen in this population (83.7%), but IgE levels were lower than those of sIgE to Der p 1 and Der p 2. A good correlation was found between sIgE to Der p 23 and the other allergens. A total of 8.2% patients were monosensitized to Der p 23. Asthma was more frequent in patients with positive sIgE against Der p 23 than in patients without this sensitization (p = 0.027). A tendency to increase both total IgE and sIgE was observed in relation to the severity of asthma from intermittent mild asthma to persistent moderate asthma, but a substantial decrease in total IgE and sIgE was detected in more severe asthmatics. Conclusions. Der p 23 might be a prevalent allergen in regions with high rates of HDM exposure and its presence could increase the risk of asthma.

[Pitfalls in the diagnosis of house dust mite allergy]

House dust mite (HDM) is the most significant indoor allergen, responsible for not only many cases of rhinoconjunctivitis but also for many cases of bronchial asthma, rendering it of considerable socioeconomic relevance. Besides symptomatic treatment and avoidance measures, allergen immunotherapy (AIT) is crucial, as the only causal, disease-modifying therapeutic approach. However, high diagnostic certainty is essential for initiating AIT. The challenge in making a correct diagnosis lies in interpreting the demonstrated HDM sensitization regarding its clinical relevance (clinically silent sensitization vs. allergy). While the risk of allergy increases with the level of IgE titers against HDM extract, Der p 1, or Der p 2, as well as with the breadth of the molecular sensitization profile against HDM components (Der p 1, Der p 2, Der p 23), no threshold can be defined for the presence of allergy, nor can sensitization to a specific component be confidently considered allergy inducing. It should be noted that at least in Southern Bavaria, the prevalence of Der p 23 sensitization is too low to be considered a major allergen, and Der p 23 is not able to molecularly differentiate all HDM sensitizations when added to the two major allergens Der p 1 and Der p 2. Evidently, HDM possesses a diverse profile of allergens, with some relevant ones possibly yet to be described. Unfortunately, patient history does not provide a sufficient assessment of the clinical relevance of a demonstrated HDM sensitization, necessitating allergen provocation testing before initiating AIT with HDM, despite the relatively large effort involved.

Differences in molecular sensitization profiles between a Spanish and Latin American mite allergic patients

BACKGROUND AND OBJECTIVE

To analyze the sensitization pattern to Dermatophagoides pteronyssinus and to associate the diagnostic findings and clinical severity in 218 allergic patients from two different continents.

METHODS

Mite allergic patients were recruited by the Allergology departments from Latin America (n=88: Colombia, Costa Rica and Guatemala) and Spain (N=130). All patients had allergic rhinitis with or without asthma and positive skin prick test results to D. pteronyssinus. Specific IgE levels to D. pteronyssinus, D. farinae, Der p 1, Der p 2, and Der p 23 were quantified by ImmunoCAP system (ThermoFisher Scientific). Allergenic profile was also determined by western blot. Comparative Statistical analysis was performed by GraphPad software.

RESULTS

Patients recognized most frequently Der p 2 (79%) followed by Der p 1 (73%), and Der p 23 (69%) allergens. The percentage of asthmatic patients increases with the number of sensitizations however none statistically significant differences were found. Interestingly, asthmatic patients presented the highest median levels of total IgE and specific IgE levels of D. pteronyssinus and molecular allergens, mainly Der p 2. Analysing the two different populations, Spanish patients were predominantly sensitized to Der p 2 (88.46%) and Der p 1 (83.84%), whereas Latin American population were more sensitized to Der p 23.

CONCLUSION

Our data support the relevance of Der p 2 in mite allergy as the major allergen, with the high number of patients sensitized to it and its importance in the development of asthma. Sensitization to Der p 23 was more important in Latin America.

Risk Factors for Acute Rhinosinusitis in Childhood Asthma

INTRODUCTION

Specific pathogen infections associated with acute rhinosinusitis (ARS) in infants are risk factors for allergic asthma in adolescents. However, the risk factors for ARS onset remain largely unknown in asthmatic children. In this study, we aim to investigate the risk factors for ARS in childhood asthma.

METHODS

This study retrospectively compared and analyzed the clinical characteristics of asthmatic children with (n = 194) or without ARS (n = 799). Univariate regression analyses were performed to identify ARS-associated risk factors in asthmatic children, and subsequent multivariate backward stepwise logistic regression analyses were performed to identify independent risk factors.

RESULTS

The onset age, values of blood eosinophils (EOS) (%), and total IgE were significantly lower in patients with ARS than in those without ARS. Moreover, the proportions of patients allergic to Dermatophagoides pteronyssinus (d1) and Dermatophagoides farinae (d2) were significantly smaller in children with ARS (all p values <0.05). Univariate analyses showed that an older onset age, a higher body mass index, a higher value of blood EOS (%) were protective factors, while a higher value of blood lymphocytes (%) and a higher degree of sensitization to d1 and d2 were risk factors for ARS. Further backward stepwise multivariate logistic regression analyses confirmed that a younger onset age and allergic sensitization to d1 were independent risk factors for ARS in childhood asthma.

CONCLUSION

Younger onset age and allergic sensitization to d1 are risk factors for the onset of ARS in childhood asthma, so allergen intervention should be performed as early as possible in asthmatic children.

Early Atopic Sensitization to House-Dust Mite in Children with Recurrent Wheeze-A Cross-Sectional Study

OBJECTIVES

To determine sensitization to house-dust mite (HDM) antigen in under-five children with recurrent wheeze, compare it with nonwheezers, and assess atopic comorbidities in them.

METHODS

A cross-sectional study was done in the Pediatric department of a teaching hospital in North India, in 190 children aged 1-5 y. Out of these, 127 had recurrent wheeze (RW), and 63 had no wheeze (NW). Sensitivity was done by skin prick test (SPT) for two dust mites antigens: Dermatophagoide farinae and Dermatophagoide pteronyssinus antigens. In addition, atopic comorbidities like atopic dermatitis and allergic rhinitis were assessed.

RESULTS

Mean age of the study population was 34.52 ± 20.50 mo. SPT positivity for either of the dust mites was 97 (76.4%) in RW and 13 (20.6%) in NW which was significant (p < 0.001, aOR = 12.27). HDM species sensitization for D. pteronyssinus was 55.1% vs. 15.9% (p < 0.001 aOR = 7.81) and D. farinae was 39.4% vs. 9.5% (p < 0.001, aOR = 5.45) in groups, respectively. Mean wheal size in RW Group was also significantly higher than NW group for D. pteronyssinus (2.39 ± 1.44 vs. 0.52 ± 1.19 mm, median (IQR) 3 (1-3), p < 0.001), D. farinae (1.80 ± 1.39 vs. 0.32 ± 1.00 mm, median (IQR) 2 (0-3), p < 0.001). Allergic rhinitis was present in 55 (43.3%) vs. 7 (11.1%) (p < 0.001), atopic dermatitis in 28 (22%) vs. 2 (3.2%) (p = 0.001) in group 1 and 2, respectively. All children with allergic rhinitis had HDM sensitization in both groups.

CONCLUSION

This study showed early sensitization to HDM in children with recurrent wheeze. Atopic comorbidities were also present in them.

Immunomodulatory effects of modified Liu-Wei-Di-Huang-Wan Traditional Chinese medicine on allergic asthmatic mice

BACKGROUND

Allergic asthma occurs worldwide and is particularly prevalent in westernized countries characterized by chronic airway inflammation resulting in airway hyperresponsiveness. The house dust mites (HDM) including Dermatophagoides pteronyssinus are major sources of sensitization and triggering allergic symptoms in asthmatic patients. The Der p 2 is a major allergen and the predominant source of causative respiratory disorders which induce airway inflammation and bronchial constriction in mite-allergic patients. Few studies evaluate the ameliorating effects of modified Liu-Wei-Di-Huang-Wan (modified LWDHW) on allergic asthma.

METHODS

This study aimed to investigate the immunological mechanisms of modified LWDHW on the reductions of airway inflammation, signal transduction, inflammatory cytokine production, Th2 cell proliferation, and bronchial obstruction in Der p 2-induced asthmatic mice.

RESULTS

At least ten active ingredients were contained in the formula of modified LWDHW- 1217A and 1217B. Results showed that the immunoglobulin generations (Der p 2 specific- IgE and IgG1), inflammatory cytokine productions (IL-5 and IL-13) in the Sera and BALF could be down-regulated, and the Th1-cytokine productions (IL-12 and IFN-γ) be increased after immunotherapy with modified LWDHW of 1217A or 1217B. The inflammatory cell infiltrations (macrophages, eosinophils, and neutrophils) in the airway and the expressions of T_H2-related genes (IL-4, IL-5, and IL-13), T_H2-related transcription factor (GATA-3), and neutrophil chemotactic chemokine (IL-8) in the lung tissue of asthmatic mice were significantly decreased after the immunotherapy. The Th1/Th2 polarization had been identified that the IL-4⁺/CD4⁺ T cells were downregulated and IFN-γ⁺/CD4⁺ T cells were increased. The airway hyperresponsiveness to methacholine inhalation of Penh values was significantly decreased in the treated groups. There were significant improvements in the bronchus histopathology after immunotherapy with 1217A or 1217B which were evaluated by tracheal thickness, inflammatory cell count, and tracheal rupture of mouse lung.

CONCLUSION

It revealed that 1217A or 1217B could regulate the immune responses and improve pulmonary function. Data suggests that modified LWDHW of 1217A or 1217B have the potential for use as a therapeutic intervention for the treatment of mite allergen Der p 2-induced allergic asthma.

Evaluation of You-Gui-Wan critical compounds inhibiting ALOX-5 and HDC gene expression in RBL-2H3 cells using a fractional factorial design

ETHNOPHARMACOLOGICAL RELEVANCE

The traditional Chinese medicine (TCM) You-Gui-Wan (YGW) has been used to treat asthma for hundreds of years.

AIM OF THE STUDY

YGW is composed of 10 types of medicinal materials. However, the immune mechanism of YGW in asthma treatment has not been elucidated. Therefore, this study investigated asthma symptoms attenuated by YGW and the underlying immune regulatory mechanism.

MATERIALS AND METHODS

Intratracheal (i.t.) stimulation of BALB/c mice with Dermatophagoides pteronyssinus (Der p) was performed once per week (40 μL, 2.5 μg/μL). For six consecutive weeks, different doses of YGW (0.2 g/kg and 0.5 g/kg) were orally administered 30 min before stimulation with Der p. After the last stimulation, airway hyperreactivity, lung gene expression, and total immunoglobulin E (IgE) in blood were evaluated using a whole-body plethysmograph system, real-time PCR, and ELISA, respectively. In addition, DNP-IgE/DNP-BSA was added to stimulate mast cells (RBL-2H3), and YGW or various compound compositions (Trial) were added to RBL-2H3 cells for 30 min to evaluate the effects of the drug on mast cell degranulation and on gene expression. JMP 5.1 software was used to design and analyze YGW's critical compounds by which it inhibited ALOX-5 and HDC gene expression in RBL-2H3 cells.

RESULTS

YGW significantly decreased serum total IgE levels and airway hyperresponsiveness in asthmatic mice. YGW also reduced the gene expression of IL-6, TNF-α, IL-4, IL-13, and COX-2 in the lungs of asthmatic mice and RBL-2H3 cells. YGW and the compound (Trial 21) present in YGW inhibited the gene expression of ALOX-5 and HDC in RBL-2H3 cells.

CONCLUSION

The experimental results indicate that YGW exhibits anti-airway hyperresponsiveness and specific immunomodulatory effects. In addition, YGW synergistically inhibits ALOX-5 and HDC gene expression in mast cells through a combination of 21 compounds, including luteolin, quercetin, and β-carotene.

Characteristics of Allergen Components of Dermatophagoides pteronyssinus in Shrimp and Mite Co-Sensitized Patients in Southern China

INTRODUCTION

Dermatophagoides pteronyssinus (Dp) and shrimp are common air allergens and allergenic food sources, respectively, in southern China. This study aimed to analyze the specific immunoglobulin E (sIgE) characteristics and relationships of Dp components among co-sensitized patients with Dp and shrimp.

MATERIALS AND METHODS

Serum samples were collected from 112 patients with Dp sensitization (61 with shrimp sensitization and 51 without) from southern China. The sIgE concentrations of Dp and shrimp crude extracts were determined by ImmunoCAP, and the sIgE of Dp allergen components (Der p 1, Der p 2, Der p 5, Der p 7, Der p 10, Der p 21, and Der p 23) was detected by protein chip.

RESULTS

Overall, in the Dp-allergic patients, Der p 1 had the highest positive rate (72.3%), followed by Der p 2 (65.2%), Der p 23 (46.4%), Der p 7 (32.14%), Der p 21 (29.46%), Der p 5 (22.32%), and Der p 10 (17.86%). Compared with that in the shrimp nonsensitized group, the positive rate of sIgE for Der p 10 (27.87% vs. 5.88%, p = 0.002) in the shrimp sensitization group was significantly higher; however, the positive rate of sIgE for Der p 7 (22.95% vs. 43.14%, p = 0.023) was significantly lower. Moreover, the concentration of sIgE for Der p 10 increased statistically in the shrimp-sensitized group. The correlation analysis also showed that shrimp sensitization was significantly correlated with Der p 10.

CONCLUSION

Among patients with Dp sensitization, Der p 1 had the highest positive rate, followed by Der p 2 and Der p 23. Meanwhile, Der p 10 may play an important role in patients with shrimp sensitization, while Der p 7 may be the meaningful allergen component in patients with Dp sensitization alone. In general, component-resolved diagnosis technology in clinical practice can effectively guide patients with polysensitization to avoid allergic substances.

EphA2 recognizes Dermatophagoidespteronyssinus to mediate airway inflammation in asthma

Most of the asthma with low Th2 is severe steroid-resistant asthma, the exact pathogenesis of which has not yet been fully elucidated. We found that IL-6 and IL-8 were highly expressed in the sputum supernatant of severe asthma and ephrin type-A receptor 2 (EphA2) was highly expressed on bronchial epithelial cells. So, is there a connection between these two phenomena? To clarify this issue, we stimulated bronchial epithelial cells 16HBE with Dermatophagoides pteronyssinus and its compontents LPS, respectively, and detected the activation of EphA2, activation of downstream pathways and secretion of inflammatory cytokines. A mouse asthma model was established, and the therapeutic effects of inhibiting or blocking EphA2 on mouse asthma were investigated. The results showed that D. pteronyssinus and its component LPS phosphorylated EphA2 on 16HBE, activated downstream signaling pathways STAT3 and p38 MAPK, and promoted the secretion of IL-6 and IL-8. After knockout of EphA2 on 16HBE, the activation of inflammatory pathways was attenuated and the secretion of IL-6 and IL-8 was significantly reduced. Inhibition or blockade of EphA2 on mouse airways resulted in a significant reduction in airway hyperresponsiveness and airway inflammation, and a significant decrease in the expression levels of IL-6, IL-17F, IL-1α, IL-1β and TNF in bronchoalveolar lavage fluid and lung tissue. Our study uncovers a novel role for EphA2 expressed on airway epithelial cells in the pathogenesis of asthma; EphA2 recognizes D. pteronyssinus or its component LPS and promotes the secretion of IL-6 and IL-8 by airway epithelial cell, thereby mediating airway inflammation. Thus, it is possible to provide a new molecular therapy for severe asthma.

Serodominance Profile in a Dust Mite Complex Region

BACKGROUND/OBJECTIVE

The objective of this study was to describe the molecular sensitization profile of mite allergy in an area with a high environmental exposure of house dust mites (HDM) and storage mites.

METHODS

Skin prick tests were performed with standardized extracts (DIATER, Madrid, Spain). A specific commercial molecular panel (MADx) for Dermatophagoides pteronyssinus (Dpt), Dermatophagoides farinae (Dfar), Lepidoglyphus destructor (Ldt), Tyrophagus putrescentiae (Tput), and Blomia tropicalis (Blot) was correlated with clinical parameters in Galician (northwestern of Spain) HDM allergic patients.

RESULTS

Fifty patients (60% female) met the inclusion and exclusion criteria. All of the patient's present rhinitis (50), 28% (14) rhinitis and asthma, and 18% (9) atopic dermatitis (AD). Hundred patients had a positive prick test for Dpt, followed by Dfar (92%), Ldt and Tput (74%), and Blot (68%). More than 50% recognized specific IgE for Der p 1, Der p 2, reaching 86% in the case of Der p 23. No statistically significant differences in IgE levels were found between patients with/without asthma and those with mild or moderate-severe rhinitis. Der p 7 was higher among rhinitis patients (p value 0.05). AD relative risk (RR) was increased in patients sensitized to Der f 2, Der p 2, and Der p 23. Der p 10 decreases the risk to have AD (RR 0.80).

CONCLUSION

The evaluation of IgE results in a comprehensive panel of allergens allows differentiation of serological reactivity profiles with their clinical expression, to perform an optimal management. Improvements in component resolved diagnosis and more research on the clinical relevance of mite allergens are needed to achieve a genuine diagnosis leading to specific immunotherapy.

Identification of Glycycometus malaysiensis (for the first time in Brazil), Blomia tropicalis and Dermatophagoides pteronyssinus through multiplex PCR

Blomia tropicalis and Dermatophagoides pteronyssinus play an important role in triggering allergy. Glycycometus malaysiensis causes IgE reaction in sensitive people, but is rarely reported in domestic dust, because it is morphologically similar to B. tropicalis making the identification of these species difficult. The identification of mites is mostly based on morphology, a time-consuming and ambiguous approach. Herein, we describe a multiplex polymerase chain reaction (mPCR) assay based on ribosomal DNA capable to identify mixed cultures of B. tropicalis, D. pteronyssinus and G. malaysiensis, and/or to identify these species from environmental dust. For this, the internal transcribed spacer 2 (ITS2) regions, flanked by partial sequences of the 5.8S and 28S genes, were PCR-amplified, cloned and sequenced. The sequences obtained were aligned with co-specific sequences available in the GenBank database for primer design and phylogenetic studies. Three pairs of primers were chosen to compose the mPCR assay, which was used to verify the frequency of different mites in house dust samples (n = 20) from homes of Salvador, Brazil. Blomia tropicalis was the most frequent, found in 95% of the samples, followed by G. malaysiensis (70%) and D. pteronyssinus (60%). Besides reporting for the first time the occurrence of G. malaysiensis in Brazil, our results confirm the good resolution of the ITS2 region for mite identification. Furthermore, the mPCR assay proved to be a fast and reliable tool for identifying these mites in mixed cultures and could be applied in future epidemiological studies, and for quality control of mite extract production for general use.

House Dust Mite Precision Allergy Molecular Diagnosis (PAMD@) in the Th2-prone Atopic Dermatitis Endotype

Atopic dermatitis (AD) endotyping might be important for developing personalized diagnostic and therapeutic strategies to the different phenotypes. The current study investigated the IgE molecular profile to Dermatophagoides pteronyssinus (D. pteronyssinus) in a subset of patients afflicted with varying severity stages of atopic dermatitis in a subtropical region subjected to a high perennial house dust mite (HDM) exposure. We selected patients showing a clinically relevant sensitization to HDM with mild-to-moderate and severe AD according to their basal Severity Scoring Atopic Dermatitis (SCORAD) index. Skin prick test (SPT) with standardized mite extracts, as well as a Precision Allergy Molecular Diagnosis (PAMD@) panel including nine different D. pteronyssinus allergens and the related protein allergenic characterization, were assessed in all serum samples. A total of 80 European American AD patients with the marked T2 endotype confirmed their eligibility for the study. Major allergens (Der p 23, Der p 2, and Der p 1) were present in more than 86% of all subjects, with mid-tier allergens (Der p 5, Der p 7, and Der p 21) reaching up to 65%. A serodominant role for Der p 11 could not be quantitatively confirmed in the present cohort. The proposed component resolved diagnosis (CRD) panel appeared to be sufficient to obtain a precise D. pteronyssinus molecular diagnosis in AD patients subjected to a climate-dependent high-mite allergen exposure. The raised seroprevalence of IgE response to Der p 23 confirmed this constituent as a major D. pteronyssinus allergen in severe stages of atopic dermatitis. A clinically driven molecular approach appears to be essential to frame a more precise diagnosis and therapy of this heterogeneous allergic condition.

Efficacy of mite allergen immunotherapy in allergic rhinitis and the immune synergistic effect on cross-allergens

Aim: To compare the efficacy of single- and double-species mite allergen immunotherapy. Materials and methods: An open, pseudo-randomized, controlled study was conducted (n = 125 allergic rhinitis patients). The primary end point involved the visual analogue scale. Secondary end points included a basophil activation test and serum specific IgE and IgG4 assays. Results: Visual analogue scale analysis indicated considerable reductions in both groups. Both treatments improved quality of life and induced sIgG4 antibody production. Basophil activation and serum IgE inhibition were not evident in either treatment. Neither treatment displayed an early stage immune synergistic effect on cross-allergens. Conclusions: Both treatments were effective against allergic rhinitis, and statistical differences were not observed. Future studies may require long-term, large-scale research.

[A CASE OF PANCAKE SYNDROME IN WHICH MITES COULD BE DETECTED FROM COOKED TAKOYAKI]

A 12-year-old girl experienced anaphylactic shock and respiratory failure immediately after eating 4 pieces of takoyaki made at home. We suspected pancake syndrome because of the three reasons: First, the patient had a history of bronchial asthma and allergic rhinitis without any history of food allergies; Second, takoyaki flour that had been stored at room temperature for one month after opening the package had been used; and Third, both the specific IgE (ImmunoCAP^® method) of Dermatophagoides farinae and Dermatophagoides pteronyssinus were found to be above the detection limit. Since the suspected flour had been discarded, a specimen of tako yaki was examined microscopically and 430 mites/g were identified. Although only 21.1ng/g of Der f 1 was detected by an ELISA, this amount was less than expected, based on the number of mites that had been observed. The decrease in the antigenicity of mite allergens due to heating and reducing agents, and the insolubilization of mite allergens due to disulfide bonds between the mite allergens and gluten were thought have made it difficult to identify mite antigens by ELISA.When pancake syndrome is suspected, and the flour that is thought to have caused the condition is difficult to obtain, microscopic identification of mites in cooked food should be considered.

Designing an epitope vaccine against Dermatophagoides pteronyssinus: An in silico study

The house dust mite, Dermatophagoides pteronyssinus, is a major source of the inhaled allergen Der p 1, which causes immunoglobulin E (IgE)-mediated hypersensitivity reactions manifesting in allergic diseases. To date, no drugs or vaccines effectively treat or prevent Der p 1 sensitization. We applied in silico immunoinformatics to design T-cell and B-cell epitopes that were specified and developed from the allergen Der p 1 of D. pteronyssinus. We identified the conserved epitope areas by predicting the accessibility and flexibility of B-cell epitopes, and the percentage of human leukocyte antigen representing T cells. Molecular docking using HADDOCK software indicated three optimal clusters: cluster 6 (z-score: -2.1), cluster 1 (z-score: -1.2), and cluster 3 (z-score: -0.6). The most negative Z-score was found in cluster 6, which represented three epitopes. The interaction between A chain proteins (IgE protein residues) and B chains (Der p 1 protein residues) exhibited a knowledge-based FADE and contact value >1, suggesting the best protein interactions occurred in the conserved area. Molecular dynamic simulation further predicted the stable nature of Der p 1 protein. The IQRDNGYQP region is the best candidate to be utilized as a D. pteronyssinus epitope vaccine, which could be used in the development of allergen-specific immunotherapy.

The Importance of Nasal Provocation Testing in the Diagnosis of Dermatophagoides pteronyssinus-Induced Allergic Rhinitis

BACKGROUND

Allergen identification is the first step for allergen-specific immunotherapy (AIT) of allergic rhinitis (AR). Currently, the diagnosis of AR is based mainly on the positive results of the skin prick test (SPT) and/or serum specific immunoglobulin E (sIgE) measurement. However, the results of these two tests may not always directly correlate with AR.

OBJECTIVE

To investigate the importance of nasal provocation testing (NPT) in the diagnosis of Dermatophagoides pteronyssinus (Der p)-induced AR.

METHODS

Rhinitis patients willing to undergo AIT (n = 171) were enrolled. The correlations of Der p SPT, sIgE, NPT, and clinical symptom severity were assessed.

RESULTS

NPT-positive responses were more common in patients with higher SPT and sIgE levels. The optimal cut-off value for a NPT-positive response for SPT was 5.5 mm and for sIgE was 2.77 kUA/L, based on the respective receiver operating characteristic (ROC) curves. The area under the curve (AUC) of the ROCs was 0.814 (SPT only) and 0.794 (sIgE only) and increased to 0.828 with the combination of SPT and sIgE. The Der p-NPT concentration was inversely correlated with SPT and sIgE levels (r = -0.477, P < .001, and r = -0.461, P < .001, respectively), but none was correlated with the total nasal symptom score.

CONCLUSION

For patients who are willing to receive Der p AIT, NPT is a useful and safe test to confirm diagnosis prior to treatment initiation, especially in patients with lower levels of Der p SPT (< 5.5 mm) or sIgE (< 2.77 kUA/L).

Is Body Mass Index Related to Skin Reactivity to Histamine but not to Specific Allergens? A 2-Year Follow-up Study on Korean Children

BACKGROUND

Skin prick tests are widely used to diagnose allergic sensitization. The influence of obesity on the skin prick test result has not been clearly established, even though the association between allergic disease and obesity is relatively well known.

OBJECTIVE

To determine whether a change in body mass index (BMI) contributes to skin reactivity to histamine and allergens in a skin prick test, we performed a 2-year follow-up study on Korean children.

METHODS

Skin prick tests for common aeroallergens were performed on elementary school students from Jeju Island, Korea. BMI was calculated using weight and height after measuring both, and demographic characteristics were surveyed. The same tests were repeated after 2 years.

RESULTS

The sensitization rate increased during the 2 years between tests and the children's mean BMI also increased, along with their age. The wheal sizes induced by Dermatophagoides pteronyssinus, Dermatophagoides farinae, Japanese cedar, and histamine were significantly increased during 2 years; however, only the histamine reaction associated with increased BMI had statistical significance. Furthermore, other variables-including the number of sensitized allergens-were not related to histamine skin reactivity.

CONCLUSION

Histamine skin reactivity increased in children over time and some allergens showed increased specific reactions; however, BMI gain is a specific predictor of histamine reactivity. Further studies are needed to elucidate the clinical significance of these changes.

Association between Temporary Housing Habitation after the 2011 Japan Earthquake and Mite Allergen Sensitization and Asthma Development

INTRODUCTION

We previously reported an increased prevalence of asthma in adults who lived in temporary housing after the 2011 Great East Japan Earthquake. The goal of the current study was to investigate changes in asthma prevalence and mite-specific immunoglobulin E (IgE) titers in temporary housing residents during 2014-2019.

METHODS

By using the Global Initiative for Asthma guidelines, we diagnosed asthma in Ishinomaki city temporary housing residents aged 15 years or older. We then analyzed serum antigen-specific IgE levels to Dermatophagoides farinae (Der f), Dermatophagoides pteronyssinus (Der p), and Aspergillus fumigatus.

RESULTS

The prevalence of asthma exceeded 20% across all age-groups throughout the study period. The proportion of study participants with a "positive" antigen-specific IgE titer (i.e., ≥0.35 IUA/mL) was higher in asthmatics than in nonasthmatics for Der f and Der p but not for Aspergillus fumigatus. Among residents ≥50 years old who were diagnosed with asthma, the percentage with a Der f-specific IgE titer ≥0.10 IUA/mL was higher than the proportion with ≥0.35 IUA/mL. Among study participants, asthma onset occurred before the earthquake, during residence in shelters or temporary housing, and (starting in 2016) after moving out of temporary housing. The Der p-specific IgE level was positively correlated with the duration of temporary housing (p < 0.05, r = 0.41) and inversely correlated with the time elapsed since moving out of temporary housing (p < 0.05, r = -0.35).

CONCLUSION

Mite allergen sensitization was found in both asthmatic and nonasthmatic temporary housing residents after the 2011 Japan earthquake and tsunami; asthma developed even after subjects moved out of temporary housing.

Antibodies to Der p 1 and Der p 2 in allergic patients

INTRODUCTION AND OBJECTIVES

Atopic individuals are characterized by increased IgE production and Th2 response if exposed to certain antigens. It is known that the mother transfers anti-mite antibodies to the fetus and newborn, IgG thru the placenta, and IgA thru breastfeeding, but it is not clear whether there is a protective mechanism mediated by them concerning the development of future allergies. This study aimed to compare the levels of IgA, IgG, and IgE antibodies specific to Der p 1 and Der p 2 between atopic and healthy individuals.

METHODS

Serum samples of 98 patients and 44 healthy controls were subjected to quantification for specific IgE, IgG, and IgA antibodies against Der p 1 and Der p 2 by ImmunoCap^® and ELISA, and subjected to statistical analysis as indicated.

RESULTS

Atopic patients had higher serum levels of IgE, IgG, and IgA specific to Der p 1 and Der p 2. The correlation was more robust between IgE and IgG antibodies.

CONCLUSIONS

Allergic patients produce higher levels of antibodies against Der p 1 and Der p 2 compared with healthy individuals. The mechanisms involved still require detailed studies.

Comprehensive analysis of allergen-specific IgE in COPD: mite-specific IgE specifically related to the diagnosis of asthma-COPD overlap

Background

Although the relationship between allergic sensitization and increased respiratory symptoms of chronic obstructive pulmonary disease (COPD) has been suggested, which allergen has a significant effect on COPD pathology is unclear. This study aimed to identify the specific IgE related to clinical features of COPD and the diagnosis of asthma-COPD overlap (ACO).

Methods

We recruited 76 patients with COPD and analyzed 39 IgE using panel IgE test (View Allergy 39^®). ACO was diagnosed according to the Japanese Respiratory Society Guidelines.

Results

As for perennial aeroallergens, the positivity for moth (31.5%), Candida (23.7%), Dermatophagoides pteronyssinus (22.4%) and house dust (22.4%), and concerning pollen, Japanese cedar (35.5%) and Japanese cypress (22.2%) exceeded 20%. Only the positivity of IgE for Dermatophagoides pteronyssinus and house dust was significantly higher in ACO compared with that in non-ACO COPD. Moreover, it contributed to the diagnosis of ACO in an IgE class-dependent manner. Patients with cockroach IgE exhibited higher residual volume, whereas those with Japanese cedar IgE exhibited better diffusion capacity than negative patients. The contribution for ACO diagnosis by the receiver operating characteristic curve analysis was comparable among total IgE (cutoff value: 158 IU/mL), blood eosinophil count (234/μL), and fraction of exhaled nitric oxide (31.0 ppb).

Conclusions

The prominent role of mite-specific IgE in the diagnosis and pathology of ACO and the potentially detrimental effect of cockroach sensitization on air trapping in COPD were suggested. The finding highlights the future development of a treatment targeting IgE as a treatable trait in COPD.

Mite Molecular Profile in the Th2-Polarized Moderate-to-Severe Persistent Asthma Endotype Subjected to High Allergen Exposure

BACKGROUND

The association among the IgE responses to prevailing groups of house dust mite (HDM) allergens in the concurrent asthma phenotypes has not been determined.

OBJECTIVE

The aim of the present study lays on a component-resolved diagnosis (CRD) model to investigate the mite molecular signature in subjects with type-2 inflammation asthma.

METHODS

We selected patients showing a clinically relevant sensitization to HDMs with moderate-to-severe persistent asthma. Skin prick test (SPT) with standardized mite extracts, a broad customized CRD serum sIgE panel including 9 Dermatophagoides pteronyssinus allergens and the related protein allergenic characterization, was investigated in all serum samples.

RESULTS

Ninety out of 93 (96.77%) patients with a positive SPT to HDM showed a concordant sIgE (≥0.35 kUA/L) to the crude extract of D. pteronyssinus. Major allergens (Der p 2, Der p 23, and Der p 1) were present in >70% of all subjects, with mid-tier allergens (Der p 5, Der p 7, and Der p 21) reaching up to 51% in the present cohort. A complex pleomorphic repertoire of HDM molecules recognized by IgE was depicted, including 38 distinct profiles.

CONCLUSIONS AND CLINICAL RELEVANCE

The proposed CRD panel approach, containing the most prevalent HDM allergens, appeared to be sufficient to obtain a precise D. pteronyssinus molecular diagnosis in asthmatics with a climate-dependent high-mite allergen exposure and coexisting sensitization. A dominant role of both major and mid-tier allergens has been confirmed in moderate and severe persistent asthmatics with the preponderant Th2-high endotype.

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.

Sensitization to major Dermatophagoides pteronyssinus allergens in house dust mite allergic patients from North Eastern Poland developing rhinitis or asthma

PURPOSE

Recognition of individual allergens by IgE is crucial for triggering symptoms in allergic rhinitis (AR) or asthmatic (AA) patients. House dust mite (HDM) allergy is frequent around the world, the sensitization profile to individual HDM allergens varies in individual HDM-allergic patients (APs). The aim of this study was to evaluate the pattern of IgE sensitization to three major Dermatophagoides pteronyssinus (Dp) allergens among patients from North Eastern Poland suffering from HDM-AR and/or AA.

PATIENTS AND METHODS

The study was performed on 323 HDM-AR and/or AA patients and 106 controls (CG) including 30 healthy non-atopic subjects, 32 AR patients not sensitized to Dp and 44 non-atopic asthmatics. IgE levels to natural (n)Der p 1, nDer p 2, recombinant (r)Der p 2.0101 and rDer p 23 allergens were measured by ELISA.

RESULTS

The majority of HDM-APs were sensitized to nDer p 1 (72.1%), nDer p 2 (81.7%), rDer p 2.0101 (78.3%) and rDer p 23 (70.9%). The frequency of positive results to individual allergens depended on clinical manifestations and the level of IgE to the whole Dp extract. In HDM-AA patients, reactivity to nDer p 1 and rDer p 23 was detected more frequently than in HDM-AR patients. The whole Dp extract completely inhibited IgE binding to nDer p 1 and nDer p 2 but only partially to rDer p 23.

CONCLUSIONS

HDM-APs from North-Eastern Poland display sensitization profile to major allergens which is similarly observed in western Europe. HDM-based diagnostic and therapeutic products should include all major allergens.

Depiction of Major Mite Allergens in Severe Allergic Rhinitis with High Mite Perennial Exposure

Objective

Airway diseases, including allergic rhinitis, are prompted by specific IgE antibodies against airborne allergens and notably those derived from mites. The presented study focused on the specific IgE immediate response to Dermatophagoides pteronyssinus (D. pteronyssinus) mite major allergens and the corresponding pertinence of molecular diagnosis in patients bothered with severe persistent rhinitis.

Methods

Individuals exhibiting confirmed sensitization to D. pteronyssinus along with a clinical diagnosis of coexisting severe allergic rhinitis were included in the study. In vivo investigations encompassed intradermal testing with a battery of standardized allergenic extracts, concurrent with in vitro specific IgE to the crude extract of D. pteronyssinus, and associated individual molecular allergens were assessed.

Results

Fifty-five out of 59 subjects showed serodominant IgE responses to the major allergens Der p 1, Der p 2 and Der p 23. Both Der p 2 and Der p 23 reached a prevalence above 80%, while group 10 allergen tropomyosin was scarcely depicted (<10%) and exclusively present in younger individuals.

Conclusion

The proposed component-resolved diagnosis panel accurately recognized 93.22% of D. pteronyssinus allergic patients. The raised seroprevalence of IgE response to Der p 23 also confirmed this constituent as a major D. pteronyssinus allergen in severe allergic rhinitis. A molecular approach appears to be essential to frame a more precise diagnosis and eventually a personalized immunotherapy regarding this allergic condition.

Detection of allergen-specific antibody-secreting cells in dogs by ELISPOT

Current laboratory tests are unable to distinguish healthy from allergic dogs. Unlike serum antibody responses, circulating antibody-secreting cells (ASC) are temporarily induced after each contact with the antigen. These ASC can be identified using ELISPOT and the observation of allergen-specific ASC might correlate with the causative allergens in dogs with an allergic dermatitis. In this study, blood was sampled from six privately-owned allergic dogs and six non-allergic laboratory beagles to determine the frequency of circulating allergen-specific ASC for common allergens. Blood IgE+, IgA + and IgG + cells were magnetically isolated to determine the number of allergen-specific ASC with ELISPOT for Dermatophagoides farinae, Dermatophagoides pteronyssinus, Alternaria alternata, birch, timothy grass, wheat, cow's milk, bovine, chicken and lamb meat. For IgA and IgG, allergen-specific spots were observed, however for IgE, no spots were detected for any of the allergens. ELISPOT could not differentiate allergic from non-allergic dogs. When the responses to the different allergens were compared, more IgA ASC for D. pteronyssinus were observed compared to some of the other allergens which was statistically significant for the non-allergic dogs and approached significance in the allergic dogs. These findings indicate that ELISPOT can be used to identify circulating allergen-specific IgA- and IgG-secreting cells. The technique did however not detect allergen-specific IgE ASC and was unable to distinguish allergic from non-allergic dogs. Only a small number of studies have studied allergen-specific IgA in dogs. The finding that dogs have higher numbers of D. pteronyssinus-specific IgA ASC points out that apart from IgE and IgG, it might be interesting to include IgA measurements for certain allergens to analyse the complete spectrum of both the protective and pro-allergic antibody responses.

Molecular Sensitization Profile to Dermatophagoides pteronyssinus Dust Mite in Portugal

OBJECTIVE

To analyze component resolved diagnosis to Dermatophagoides pteronyssinus (Der p) in patients with respiratory allergy and its relationship with clinical severity in different geographical areas.

METHODS

217 patients (mean age 25.85±12.7 years; 51.16% females) were included, selected from 13 centers in Portugal (5 from North, n=65). All had allergic rhinitis, with or without asthma, and had positive skin prick tests to at least one dust mite. Specific IgE (sIgE) to Der p, Dermatophagoides farinae, Lepidoglyphus destructor, Der p1, Der p 2, Der p 10 and Der p 23 were determined by ImmunoCAP. Statistical analysis (Mann Whitney U test) compared patients with rhinitis vs rhinitis and asthma; mild vsmoderate-to-severe rhinitis; North vs South.

RESULTS

Prevalence of sensitization was 98.2% to Der p, and 72.4%, 89.4%, 9.7% and 77% to Der p 1, Der p 2, Der p 10 and Der p 23, respectively. Corresponding median sIgE levelswere 8.56, 17.7, 0.01 and 3.95 kUA/L. sIgE to all allergens was higher in patients with moderate-to-severe rhinitis and rhinitis with asthma but not statistically significant (NSS). sIgE to Der p 2 was significantly higher in the South when compared with the North (p=0.0496).

CONCLUSIONS

sensitization to Der p is the most common in Portugal. Der p 2 had the highest prevalence and median sIgE levels. All sIgE to molecular components were higher in more symptomatic patients (NSS). sIgE to Der p 2 was higher in the South, which may be related to the warmer temperature and/or the larger sample size.

Qi-Wei-Du-Qi-Wan and its major constituents exert an anti-asthmatic effect by inhibiting mast cell degranulation

ETHNOPHARMACOLOGICAL RELEVANCE

In Asia, Qi-Wei-Du-Qi-Wan (QWDQW) is a traditional Chinese medicine that has been used to treat chest tightness, cough, shortness of breath, night sweats, frequent urination and asthma. QWDQW is recorded in Yi Zong Yi Ren Pian (Medical Physician's Compilation), which was written by Yang Cheng Liu during the Qing Dynasty.

AIM OF THE STUDY

The traditional Chinese medicine QWDQW is composed of 7 ingredients and has been used in the treatment of asthma in Asia for hundreds of years. However, the mechanism through which QWDQW affects the immune system in the treatment of asthma is not known. Therefore, this study aimed to investigate whether QWDQW alleviates asthmatic symptoms in mice with chronic asthma induced by repeated stimulation with Dermatophagoides pteronyssinus (Der p) and to explore the underlying immune modulatory mechanism.

MATERIALS AND METHODS

BALB/c mice were stimulated intratracheally (i.t.) with Der p (40 μl, 2.5 μg/μl) once weekly for 6 weeks. Thirty minutes prior to Der p stimulation, the mice were treated with QWDQW (0.5 g/kg and 0.17 g/kg) orally. Three days after the last stimulation, the mice were sacrificed, and infiltration of inflammatory cells, lung histological characteristics, gene expression of lung and serum total IgE were assessed. In other experiments, RBL-2H3 cells were stimulated with DNP-IgE/DNP-BSA and then treated with QWDQW, quercetin, β-carotene, luteolin or a mixture of the three chemicals (Mix13) for 30 min, and the effects of the drugs on RBL-2H3 cell degranulation after DNP stimulation were determined.

RESULTS

QWDQW significantly reduced Der p-induced airway hyperreactivity (AHR) and decreased total serum IgE and Der p-specific IgE levels. Histopathological examination showed that QWDQW reduced inflammatory cell infiltration and sputum secretion from goblet cells in the lungs. Gene expression analysis indicated that QWDQW reduced overproduction of IL-12、IFN-γ、IL-13、IL-4、RNATES、Eotaxin and MCP-1in lung. Additionally, QWDQW and Mix13 suppressed DNP induced RBL-2H3 degranulation, and the effect was maximal when quercetin, β-carotene and luteolin were administered together.

CONCLUSION

These results indicate that QWDQW plays a role in suppressing excessive airway reaction and in specific immune modulation in a mouse model of chronic asthma and that QWDQW suppresses mast cell degranulation at defined doses of quercetin, β-carotene and luteolin.

Whole genomic sequencing and sex-dependent abundance estimation of Cardinium sp., a common and hyperabundant bacterial endosymbiont of the American house dust mite, Dermatophagoides farinae

The two common species of house dust mites (HDMs), Dermatophagoides farinae and D. pteronyssinus, are major sources of allergens in human dwellings worldwide. Many allergens from HDMs have been described, but their extracts vary in immunogens. Mite strains may differ in their microbiomes, which affect mite allergen expression and contents of bacterial endotoxins. Some bacteria, such as the intracellular symbiont Cardinium, can affect both the sex ratio and biochemical pathways of mites, resulting in abundance variations of mite allergens/immunogens. Here, we investigated the bacterial microbiomes of D. farinae and D. pteronyssinus males and females using barcode 16S rDNA sequencing, qPCR, and genomic data analysis. We found a single species of Cardinium associated with D. farinae strains from the USA, China and Europe. Cardinium had high abundance relative to other bacterial taxa and represented 99% of all bacterial DNA reads from female mites from the USA. Cardinium was also abundant with respect to the number of host cells-we estimated 10.4-11.8 cells of Cardinium per single female mite cell. In a European D. farinae strain, Cardinium was more prevalent in females than in males (representing 92 and 67% of all bacterial taxa in females and males, respectively). In contrast, D. pteronyssinus lacked any Cardinium species, and the microbiomes of male and female mites were similar. We produced a Cardinium genome assembly (1.48 Mb; GenBank: PRJNA555788, GCA_007559345.1) associated with D. farinae. The ascertained ubiquity and abundance of Cardinium strongly suggest that this intracellular bacterium plays an important biological role in D. farinae.

Topical Vitamin D May Modulate Human Sinonasal Mucosal Responses to House Dust Mite Antigen

BACKGROUND

Respiratory epithelium is a key defense against inhaled pathogens. Vitamin D3 (VD) has been suggested to modulate airway inflammation; however, its effect on innate airway defenses, the physical barrier, mucociliary apparatus, and cytokine release remains unclear.

OBJECTIVE

To investigate the outcomes of VD application prior to challenge in an in vitro model of human sinonasal epithelium, through assessment of epithelial transepithelial resistance (TER), cilia beat frequency (CBF), and interleukin (IL)-6 release, and secondarily to determine whether topical VD is beneficial to patients with inflammatory sinonasal pathology.

METHODS

Primary human sinonasal epithelial cells from patients with eosinophilic chronic rhinosinusitis (eCRS) and healthy controls were cultured in air-liquid interface (ALI). Well-differentiated cultures from each patient were pretreated for 24 hours with 4 different VD doses. Toxicity was quantified at 24 hours in unchallenged ALI by lactate dehydrogenase (LDH) assay. Innate responses were assessed by measuring TER and CBF before and up to 24 hours after house dust mite Dermatophagoides pteronyssinus challenge. IL-6 release was evaluated 24-hour postchallenge.

RESULTS

Fifteen patients (53 ± 13.5 years, 60% females, 53% eCRS) representing 120 ALI wells were assessed. VD (0, 25, 50, 150 IU/mL) released less LDH than vehicle, indicating noncytotoxicity (0.15 ± 0.02; 0.15 ± 0.00; 0.14 ± 0.02; 0.11 ± 0.01 vs 0.17 ± 0.03, P = .004). VD increased TER for eCRS wells at 5 minutes (50 IU/mL: Δ6.76 ± 3.93 vs Δ3.87 ± 2.46, P = .04) and 24 hours (50 IU/mL: Δ0.88 ± 0.49 vs Δ0.40 ± 0.42, P = .02; 150 IU/mL: Δ1.06 ± 0.58 vs Δ0.47 ± 0.46, P = .01). CBF increased at 1 hour for eCRS wells (50 IU/mL: Δ0.62 ± 0.14 vs Δ0.41 ± 0.13, P = .001; 150 IU/ml: Δ0.60 ± 0.13 vs Δ0.38 ± 0.11, P < .001). IL-6 release was similar between normal and eCRS wells.

CONCLUSION

Topical VD supplementation in eCRS patients may be beneficial for innate epithelial defenses. VD is noncytotoxic and does not adversely affect the physical barrier, mucociliary apparatus, or IL-6 release. Further studies should clarify its potential as a therapeutic agent.

House dust mite allergens induce interleukin 33 (IL-33) synthesis and release from keratinocytes via ATP-mediated extracellular signaling

In atopic diseases, the epithelium releases cytokines and chemokines that initiate skin inflammation. Atopic dermatitis (AD) is characterized by a disrupted epidermal barrier and is triggered or exacerbated by environmental stimuli such as house dust mite (HDM) allergens. The proinflammatory cytokine interleukin 33 (IL-33) plays an important role in the pathogenesis of AD, but how IL-33 production in keratinocytes is elicited by HDM is unknown. To that end, here we stimulated monolayer-cultured human keratinocytes and human living skin equivalents with Dermatophagoides pteronyssinus HDM extract to investigate its effects on IL-33 production from keratinocytes. The HDM extract induced intracellular expression of IL-33 and modulated its processing and maturation, triggering rapid IL-33 release from keratinocytes. Group 1 HDM allergen but not group 2 HDM allergen elicited IL-33 production. An ATP assay of keratinocyte culture supernatants revealed an acute and transient accumulation of extracellular ATP immediately after the HDM extract stimulation. Using the broad-spectrum P2 antagonist suramin, the specific purinergic receptor P2Y2 (P2RY2) antagonist AR-C118925XX, and P2RY2-specific siRNA, we discovered that the HDM extract-induced IL-33 expression was mainly dependent on extracellular ATP/P2Y2 signaling mediated by transactivation of epidermal growth factor receptor, followed by activation of the ERK kinase signaling pathway. Moreover, HDM extract-induced release of 25-kDa IL-33 from the keratinocytes depended on an extracellular ATP/P2 signaling-mediated intracellular Ca²⁺ increase. Our study demonstrates the new mechanism controlling the induction and maturation of keratinocyte-produced IL-33 by HDM allergens, an innate immune process that might play a role in AD development or severity.

Dermatophagoides pteronyssinus-induced pro-inflammatory responses mediated via STAT3 and NF-kappaB signaling pathways in human bronchial epithelial cells - Inhibitory effects of Lafoensia pacari and ellagic acid

The house dust mite allergen Dermatophagoides pteronyssinus (Der p) is a major driver of allergic asthma. Studies from our group demonstrated anti-eosinophilic effects of ethanolic extract of Lafoensia pacari stem bark (and ellagic acid, isolated from L. pacari extract), used as traditional medicine in Brazil to naturally treat inflammatory conditions. Here, we extended these results through performing phytochemical analysis of the constituents of L. pacari using liquid chromatography-mass spectrometry and evaluating the anti-inflammatory effects of both L. pacari and ellagic acid in the human BEAS-2B bronchial epithelial cell line stimulated with Der p. Ellagic acid (major constituent), gallic acid, ferulic acid, chlorogenic acid and rosmarinic acid, but not flavonoids (rutin, kaempferol, luteolin and quercetin), were found in the L. pacari. Pro-inflammatory mediators, IL-6, IL-8 and CCL-2 production were increased in BEAS-2B stimulated with Der p (10 μg/mL, 24 h) compared to control. L. pacari (250 μg/mL) and ellagic acid (100 μM) significantly reduced the concentration of these mediators. L. pacari increased the production of the anti-inflammatory cytokine, IL-10. These results were associated with the downregulation of NF-κB and STAT3 pathways. These findings indicate a novel anti-inflammatory action for L. pacari and ellagic acid in the airways allergic inflammatory response.

Similarities and differences in the effects of sensitisation and challenge with Dermatophagoides farinae and Dermatophagoides pteronyssinus extracts in a murine asthma surrogate

Patients with atopic asthma may become sensitised to the grain storage mite Dermatophagoides farinae (Der f), the house dust mite Dermatophagoides pteronyssinus (Der p) or both, but thus far little attention has been paid to date to possible variation in their pathophysiological effects. Here we present a side by side comparison of the effects of extracts of these two dust mites in a murine surrogate of atopic asthma. Compared with the Der p-challenged mice, however, the mice-challenged with Der f had favour changes in lung tissue elasticity and expression in matrix metalloproteinases in lung tissue, while the mice challenged with Der p showed more neutrophils infiltrating around the airway and stronger expression of steroid-resistant related cytokines in the lung tissue. Our data suggest that different dust mite crude extracts might lead different pathological characteristics, at least in murine models of asthma.

Real-life effect of a microcrystalline tyrosine adjuvanted mite immunotherapy in patients with allergic rhinitis

Aim: Evaluate the effectiveness and safety of immunotherapy with Acarovac Plus^® in a 1-year prospective multicentered real-life study. Methods: A total of 118 adults with allergic rhinitis sensitized to Dermatophagoides received subcutaneous immunotherapy with Acarovac Plus. Treatment outcomes were evaluated at baseline, 6 months and 1 year after treatment initiation. Primary end point was the evolution of the combined symptom and medication score. Secondary end points included other effectiveness outcomes and measurement of product tolerability. Results: Acarovac Plus induced significant improvements in primary and secondary end points after 6 months compared with baseline. These differences persisted after 1 year of treatment (p < 0.001; baseline vs 1 year): combined symptom and medication score (1.60 vs 0.79). No serious adverse events were recorded. Conclusion: Acarovac Plus for 1 year was effective and well tolerated in a real-life setting.

[Sensitivity and specificity of the modified epicutaneous patch test in the diagnosis of respiratory allergy to Dermatophagoides pteronyssinus]

BACKGROUND

The skin prick test is recognized as the gold standard for the specific diagnosis of allergy.

OBJECTIVE

To determine the sensitivity and specificity of the epicutaneous patch test that has been modified for the diagnosis of respiratory allergy to Dermatophagoides pteronyssinus.

METHODS

An observational, interpretative, prolective, and transversal study. The included patients were between 6 and 49 years old, with symptoms of a respiratory allergy, and a skin test was performed on them by using the European standardized prick test and a modified epicutaneous patch test with the variable of the scarification that occurred before the antigen was applied, and its homogenization with a wooden applicator, which occurred after the antigen was applied. The levels of sensitivity, specificity, and prevalence influence and positive and negative predictive values were calculated.

RESULTS

104 patients were included, of which 72 (69.2%) were women. The age category of the patients was 24 ± 11.3 years of age. 78.9% of the patients were diagnosed with allergic rhinitis, 1.9% were diagnosed with asthma, and 19.2% were diagnosed with both rhinitis and asthma. The prevalence of the respiratory allergy to Dermatophagoides pteronyssinus was of 62.5%; 94.23% with a correct diagnosis. The sensitivity and specificity of the test was of 93.85% and 94.87%; the positive and negative predictive values were of 96.83% and 90.24%, and the positive and negative likelihood ratios were of 18.30 and 0.06.

CONCLUSIONS

The modified epicutaneous patch test was highly sensitive and specific; it decreased the risk of allergen carryover and it lowered the cost of the material that was used.

Antibody blockade of Dectin-2 suppresses house dust mite-induced Th2 cytokine production in dendritic cell- and monocyte-depleted peripheral blood mononuclear cell co-cultures from asthma patients

Background

Dectin-2, which is a C-type lectin, interacts with the house dust mite (HDM) Dermatophagoides pteronyssinus allergen. This study aimed to investigate whether Dectin-2 blockade by antagonistic monoclonal antibodies (MoAbs) attenuates HDM-induced allergic responses.

Methods

Two anti-Dectin-2 MoAbs were generated and validated for specific binding to Dectin-2 Fc fusion protein (Dectin-2.Fc) and inhibition of Dectin-2.Fc/HDM interaction. Patients with asthma exhibiting high titers of anti-D. pteronyssinus IgE were enrolled. Peripheral blood mononuclear cells with depleted CD14⁺ monocytes were obtained from these patients and co-cultured with autologous monocyte-derived conventional dendritic cells in the presence of D. pteronyssinus or its group 2 allergens (Der p 2). Interleukin (IL)-5 and IL-13 levels in the culture supernatants were determined using ELISA in the presence or absence of anti-Dectin-2 MoAbs.

Results

Two MoAbs, 6A4G7 and 17A1D10, showed specific binding to recombinant Dectin-2.Fc and inhibited HDM binding to Dectin-2.Fc. Both anti-Dectin-2 MoAbs inhibited IL-5 and IL-13 production in co-cultures with Der p 2 stimulation in a dose-dependent manner. 6A4G7 and 17A1D10 (3 μg/mL) significantly inhibited Der p 2-induced (3 μg/mL) IL-5 production by 69.7 and 86.4% and IL-13 production by 84.0 and 81.4%, respectively. Moreover, this inhibitory effect of the two MoAbs remained significant in the presence of D. pteronyssinus.

Conclusions

Anti-Dectin-2 MoAbs significantly inhibited HDM-induced allergic responses in vitro and therefore have the potential to become therapeutic agents in mite-induced allergic diseases.

Early Efficacy Analysis of Cluster and Conventional Immunotherapy in Patients With Allergic Rhinitis

BACKGROUND

Specific immunotherapy is an important immune-modifying treatment for patients with allergic rhinitis (AR). We compared the early efficacy and safety of cluster and conventional immunotherapies for patients with AR.

METHODS

One hundred forty-nine patients with persistent AR were enrolled in a randomized and open-label trial and were divided into the following 4 groups: 60 children treated conventionally, 33 children treated using the cluster schedule, 23 adults treated conventionally, and 33 adults treated using the cluster schedule. Patients in the cluster groups reached the maintenance dose within 6 weeks, while those receiving conventional therapy reached the maintenance dose within 14 weeks. Symptom scores and skin prick test scores (SPTs) were used to evaluate clinical efficacy and adverse reactions.

RESULTS

After buildup phase of treatment, symptom scores, and SPTs were significantly lower than those prior to treatment in each group (P < .05). No significant differences were found in the efficacy of nasal symptoms scores among four groups (P > .05).However, the efficacy of SPTs using conventional schedule was higher than cluster schedule in children groups (group A and B, 57.7 vs 30.2%, P = .001). Besides, the efficacy of SPTs in adults was higher than children when using the cluster treatment (group D and B, 53.0 vs 30.2%, P = .008). No severe adverse reaction occurred.

CONCLUSIONS

Conventional and cluster immunotherapy schedules have similar efficacies, which do not vary with age; both schedules are safe and reliable. Also, SPT facilitate evaluation of clinical efficacy.

Molecular Allergen Profiling of Dual Mite Sensitization in Severe Allergic Rhinitis

BACKGROUND

Mites are the most prevalent source of indoor allergens. The present study used a component-resolved diagnosis (CRD) approach to investigate the mite-specific IgE sensitization profile for Dermatophagoides pteronyssinus and Blomia tropicalis. We also assessed the performance of a commercially available CRD approach in patients with severe allergic rhinitis.

METHODS

We selected 63 consecutive patients with dual sensitization to D pteronyssinus and B tropicalis and persistent severe rhinitis according to the ARIA guidelines. We performed skin prick tests with standardized extracts and determined specific serum IgE to both mites, along with serum specific IgE to Der p 1, Der p 2, Der p 23, Der p 10, and Blo t 5.

RESULTS

Fifty-eight and 59 patients had positive sIgE to the whole extracts of D pteronyssinus and B tropicalis, respectively. While 91.67% of patients were sensitized to specific IgE to Der p 1, Der p 2, and/or Der p 23, specific IgE to Blo t 5 (≥0.3 ISU-E) was not detected in most of the serum samples (55%).

CONCLUSIONS

Although the combination panel of the commercially available major allergens Der p 1, Der p 2, and Der p 23 identified more than 90% of the D pteronyssinus-allergic patients, Blo t 5 performed somewhat poorly in those sensitized to B tropicalis. Improvements in CRD and further research concerning the prevalence and clinical relevance of serodominant allergens are needed to achieve a genuine molecular diagnosis, as well as patient-centered mite allergy-specific immunotherapy.

Possibility of Local Allergic Rhinitis in Japan

Background

The concept of local allergic rhinitis (LAR) has been advocated recently. Allergic rhinitis in Japan is characterized by house dust mites (HDMs) and Japanese cedar pollen (JCP). To investigate LAR in Japan, total IgE and antigen-specific IgE (sIgE) were measured in inferior turbinate mucosa and their relationships with skin test (ST) and nasal allergen provocation test (NAPT) and as well as serum IgE levels were examined.

Methods

Subjects were 50 rhinosinusitis patients for surgery. ST was performed and serum total IgE and sIgE levels were measured preoperatively. Patients with class-0 serum anti-HDM or anti-JCP sIgE levels were subjected to NAPT with HDM or JCP, respectively, or both. In all patients, inferior turbinate mucosa was weighed and mashed, and total IgE and sIgE levels were then measured as local mucosal date per gram and per milligram. Because there is no clinical consensus how to evaluate nasal sIgE yet, both positive NAPT and detectable sIgE in obtained nasal mucosa were adopted as the diagnostic criteria of LAR in order to strictly elucidate the possibility of presence of LAR in Japan.

Results

JCP LAR was definitely diagnosed in 2 of 14 patients (14.3%) and HDM LAR in 5 of 21 (23.8%) in cases with rhinosinusitis symptoms in the absence of positive ST nor serum sIgE.

Conclusion

The present results positively support LAR by HDM or JCP being present in Japan.

Prevalence, molecular characterization, and clinical relevance of sensitization to Anisakis simplex in children with sensitization and/or allergy to Dermatophagoides pteronyssinus

Summary

Prevalence of the Anisakis Simplex's (AS) sensitization in children sensitized to Dermatophagoides pteronissynus (DP) is not known, neither it is to which percentage it might be due to cross-reactivity. The primary objective of the present retrospective cross-sectional study is to evaluate the prevalence of sensitization to AS in children sensitized or allergic to DP. Secondary outcomes were the prevalence of cross-reactivity and clinical relevance of the condition. The prevalence of sensitization to AS differs significantly among patients sensitized and not to DP (13.43% vs. 3.80%; p=0.019). The higher prevalence is mainly due to cross-reactivity with Der p10 (OR=8.86; 95% CI=4.33-40.74; p=0.0001). Currently, the sensitization to AS seems to have no clinical relevance in the pediatric population.

Synergistic effect of Dermatophagoides pteronyssinus allergens and dexamethasone on the expression of CD163 by peripheral blood mononuclear cells

BACKGROUND

The CD163 is a marker of monocyte/macrophage anti-inflammatory function. Its soluble form (sCD163) also exert anti-inflammatory activities including inhibition of T cell proliferation.

OBJECTIVE

To evaluate the effect of dexamethasone (Dx) and Dermatophagoides pteronyssinus (Dp) on ex vivo production of sCD163 by peripheral blood mononuclear cells (PBMCs).

METHODS

PBMCs from 26 allergic asthma patients (AAs) and 12 non-atopic healthy controls (HCs) were cultured with Dp, Dx, Dp + Dx or without any stimulation for up to 144 h (T₁₄₄). Concentration of sCD163, interleukin (IL) -6 and IL-10 in PMBC culture supernatants was evaluated using ELISA. The mRNA expression of CD163 by PBMCs was estimated using quantitative PCR (qPCR).

RESULTS

At T₁₄₄ the median concentration of CD163 in unstimulated PBMC cultures of AAs was greater than that in HCs (p = 0.008). Concomitant application of Dp and Dx resulted in a synergistic effect reflected by a dramatic increase of sCD163 concentration both in HCs (p = 0.0002) and AAs (p < 0.0001). Also a synergistic effect of Dp and Dx on CD163 mRNA expression was seen at T₂₄ and T₄₈ but not at T₆ or T₁₂. Among asthmatic patients the effect of Dx on sCD163 production was attenuated in severe in comparison to mild-to-moderate AAs (p = 0.0007). Moreover, Dp-induced production of IL-6 but not IL-10 was inhibited by Dx (p < 0.0001). Inhibition of IL-10 decreased sCD163 concentration by more than 50%.

CONCLUSIONS

Dx-triggered upregulation of anti-inflammatory CD163 expression by monocytes is synergistic with endogenous mechanisms involved in the resolution of Dp-induced inflammation. This effect is impaired in severe asthma patients.

Population and Culture Age Influence the Microbiome Profiles of House Dust Mites

Interactions with microorganisms might enable house dust mites (HDMs) to derive nutrients from difficult-to-digest structural proteins and to flourish in human houses. We tested this hypothesis by investigating the effects of changes in the mite culture growth and population of two HDM species on HDM microbiome composition and fitness. Growing cultures of laboratory and industrial allergen-producing populations of Dermatophagoides farinae (DFL and DFT, respectively) and Dermatophagoides pteronyssinus (DPL and DPT, respectively) were sampled at four time points. The symbiotic microorganisms of the mites were characterized by DNA barcode sequencing and quantified by qPCR using universal/specific primers. The population growth of mites and nutrient contents of mite bodies were measured and correlated with the changes in bacteria in the HDM microbiome. The results showed that both the population and culture age significantly influenced the microbiome profiles. Cardinium formed 93% and 32% of the total sequences of the DFL and DFT bacterial microbiomes, respectively, but this bacterial species was less abundant in the DPL and DPT microbiomes. Staphylococcus abundance was positively correlated with increased glycogen contents in the bodies of mites, and increased abundances of Aspergillus, Candida, and Kocuria were correlated with increased lipid contents in the bodies of mites. The xerophilic fungus Wallemia accounted for 39% of the fungal sequences in the DPL microbiome, but its abundance was low in the DPT, DFL, and DFT microbiomes. With respect to the mite culture age, we made three important observations: the mite population growth from young cultures was 5-8-fold higher than that from old cultures; specimens from old cultures had greater abundances of fungi and bacteria in their bodies; and yeasts predominated in the gut contents of specimens from young cultures, whereas filamentous mycelium prevailed in specimens from old cultures. Our results are consistent with the hypothesis that mites derive nutrients through associations with microorganisms.

Evaluation of major mite allergens from European standardized commercial extracts for in vivo diagnosis: addressing the need for precision medicine

Background

Skin prick testing is the first-line interventional method to diagnose IgE mediated allergic diseases. Methodological differences in manufacturing processes and extract standardization may lead to variations in the reagent quality and potency. The current study evaluates sixteen commercially available Dermatophagoides pteronyssinus and Blomia tropicalis extracts for allergy diagnosis from different European manufacturers regarding allergen composition and content and whether these differences could influence their biological activity.

Methods

Mite-allergic subjects (n = 21) were skin-tested with the extracts and studied for immunoglobulin E reactivity. Nine extracts from D. pteronyssinus and seven from B. tropicalis were analysed for total protein content by Bradford and ELISA double sandwich was used to quantify specific antibodies for D. pteronyssinus and B. tropicalis major allergens from nine different manufacturers.

Results

Mite extracts showed a 10–60 fold variation regarding the total protein content. The contents of the major allergens of D. pteronyssinus and B. tropicalis differed considerably (30–53 fold change) among the extracts. Blo t 5 was quantitatively present in < 50% of the of the B. tropicalis reagents and could not be clearly detected by immunoblotting in the majority of the B. tropicalis commercial extracts.

Conclusions

Certain natural D. pteronyssinus and B. tropicalis extracts lack important allergens showing a considerable variability in composition and content. A closer collaboration among clinicians, allergen manufacturing companies and regulatory agencies to improve the quality and consistency of D. pteronyssinus and B. tropicalis extracts is warranted to achieve a more precise diagnosis and treatment of house dust mite allergy.

Effects of Vacuuming Mattresses on Allergic Rhinitis Symptoms in Children

PURPOSE

To evaluate the effects of daily vacuuming of mattresses on the concentration of house dust mite (HDM) allergens and on allergic rhinitis (AR) symptoms in children sensitized to HDM.

METHODS

Forty children between the ages of 6 and 12 years with mild persistent AR and sensitized only to HDM were enrolled and randomly allocated to 2 groups. Caregivers of children in the experimental group cleaned the children's rooms and vacuumed their mattresses daily for 2 weeks. Caregivers of children in the control group cleaned the children's rooms without vacuuming mattresses. Symptoms of AR were checked weekly and dust samples were collected from the mattresses before and after the study.

RESULTS

Demographics at the beginning of the study were not significantly different between the 2 groups. In the experimental group, symptoms of AR and dust weight were significantly decreased after 2 weeks (total symptoms of AR, P <0.001; sneezing, P < 0.001; rhinorrhea, P <0.001; nasal obstruction, P < 0.001; itching, P <0.001; and dust weight, P = 0.006). The concentrations of HDM allergens were not changed significantly (Der p1, P = 0.333; Der f1, P = 0.841). In the control group, there were no significant changes in symptoms of AR, dust weight, or the concentration of HDM allergens.

CONCLUSIONS

Our findings showed that daily vacuuming of mattresses reduced dust weight and symptoms of AR. However, the concentration of HDM allergens did not significantly decrease.

Clinical Response to Subcutaneous Dermatophagoides pteronyssinus Immunotherapy in Children with Allergic Rhinitis and Asthma Is Independent of Sensitization to Blomia tropicalis Allergens

BACKGROUND

Dermatophagoides pteronyssinus (DP) and Blomia tropicalis (BT) are the dominant house dust mites inducing allergic diseases in tropical climates. It is not known whether the efficacy of DP subcutaneous immunotherapy (SCIT) is similar in patients sensitized to DP alone or to both DP and BT.

METHOD

Ninety-five children (5-17 years old) affected by asthma with rhinitis and sensitized to both DP and BT received 3 years of DP-SCIT. Clinical symptom and medication scores, serum-specific IgE and IgG4 were evaluated during DP-SCIT. Patients were grouped based on DP and BT co-sensitization or cross-reactivity, according to positive or negative IgE to BT major allergen (BTMA).

RESULTS

After 3 years of DP-SCIT, all patients had significant reductions in symptoms and medication use. In all, 65% of the patients were free of asthma symptoms and medication use; in addition, 3% was free of rhinitis symptoms. FEV1 in all patients were greater than 95% of predicted. DP-SCIT induced significant increases in DP- and BT-specific IgG4. In 50% of patients, DP-specific IgG4 increased more than 67-fold. BT-specific IgG4 increased more than 2.5 fold. A moderate correlation (r = 0.48-0.61, p < 0.01) was found between specific IgE against DP and BT in the BTMA- group (n = 34) before and after DP-SCIT, whereas no correlation was found in the BTMA+ group (n = 61). The 2 BTMA groups responded similarly with regard to clinical improvement and increase in specific IgG4 to both DP and BT. No safety finding of concern were reported in either group.

CONCLUSION

DP-SCIT may be of clinical benefit to patients with IgE sensitizations to both DP and BT. DP-SCIT induces IgG4 that cross-react with BT allergens.

Acaricidal toxicities and synergistic activities of Salvia lavandulifolia oil constituents against synanthropic mites

BACKGROUND

The acaricidal activity of Salvia lavandulifolia oil and its major components was evaluated using contact and vapor bioassays. Synergistic interactions among components contained in S. lavandulifolia oil were studied.

RESULTS

The 50% lethal dose (LD₅₀ ) of S. lavandulifolia oil was 3.66, 3.37, and 5.04 μg cm^-3 , respectively, in the vapor bioassay against Dermatophagoides farinae, Dermatophagoides pteronyssinus and Tyrophagus putrescentiae. The major components of S. lavandulifolia oil were (-)-camphor, camphene, 1,8-cineole, (±)-limonene, and α-pinene (79.11% combined). Several combinations of these components exhibited synergistic effects against D. farinae, D. pteronyssinus, and T. putrescentiae, particularly (-)-camphor, camphene, and α-pinene. (-)-Camphor usually had synergistic interactive effects in the mixtures. For the vapor action, the mixture of (-)-camphor, camphene and α-pinene was the most potent combination against D. farinae (R = 2.34), D. pteronyssinus (R = 2.75), and T. putrescentiae (R = 2.30) when used at their naturally occurring ratio.

CONCLUSION

This study is the first report on the acaricidal activity of S. lavandulifolia oil and the synergistic interactive effects of its components against D. farinae, D. pteronyssinus and T. putrescentiae. The oil may be an alternative tool for the control of synanthropic mites. © 2018 Society of Chemical Industry.

Brazilian experience with atopy patch tests for Dermatophagoides pteronyssinus, Dermatophagoides farinae and Blomia tropicalis

Background

The aim of this study was to evaluate the positivity rates of atopy patch tests for Dermatophagoides pteronyssinus, Dermatophagoides farinae and Blomia tropicalis in patients with respiratory diseases such as asthma and allergic rhinitis with or without atopic dermatitis.

Methods

The patients’ clinical histories were collected, and the patients were subjected to skin prick and patch tests with the three different house dust mites on the same day. The patch tests were examined 48 hours later, and then patients were divided into two groups: I- patients with respiratory diseases, such as asthma and/or rhinitis, and atopic dermatitis and II-patients with only respiratory diseases. A total of 74 patients ranging in age from 2 to 60 years were included in this study; 16 patients were included in group I and 58 were included in group II. This study was approved by the human ethics committee of the Faculty of Medical Science and Health SUPREMA (number 2.007.135), and written informed consent was collected from each patient or their parents prior to enrollment.

Results

In the skin prick tests, the most prevalent mite that evoked a reaction was Dermatophagoides pteronyssinus, followed by Dermatophagoides farinae and Blomia tropicalis. Regarding the atopy patch tests, the mite that most frequently induced a positive reaction was Dermatophagoides farinae (78.4%), followed by Dermatophagoides pteronyssinus (77%) and Blomia tropicalis (52.7%). A comparison of the skin prick and atopy patch tests revealed that 53 patients (71.6%) were positive on both tests, and 30 (56.6%) patients were positivite for the same mite. We found six patients (8%) who had a positive clinical history of allergy and only exhibited positivity on the atopy patch test.

Discussion

Most studies have been performed with atopic dermatitis patients, but in this study, most of the patients had respiratory conditions. Blomia tropicalis is a mite that is prevalent in tropical areas, such as Brazil, and only two publications include these three mites, wich are present in Brazil. The APT may produce positive results in concordance with the SPT resuts, but may also be the only positive test ( 8%) as we observed in our study. These results suggest that the mite atopy patch test is relevant and should be considered as an additional test for patients with clinical histories of allergic respiratory disease who have negative prick test results.

Conclusion

The APT should be considered as an additional test when the SPT and specific serum IgE tests are negative in patients with clinical histories of allergies.

House dust mites among allergic patients at the Allergy and Immunology Unit, Zagazig University: an immunologic and serologic study

In the twenty-first century, the occurrence of allergic diseases has increased. Prevention and control of house dust mites (HDMs) are required as they play a major role in allergic conditions. The present work aimed to detect HDM allergy (Dermatophagoides pteronyssinus and Dermatophagoides farinae) among allergic patients attending the Allergy and Immunology Unit, Zagazig University. Ninety-six patients with a history of allergic diseases were included in this study. They were examined for allergy to D. pteronyssinus and D. farinae using different diagnostic tools: the skin prick test (SPT) and measurement of specific IgE antibodies to HDM allergen extracts. Ninety-six allergic patients were recruited in this study [60 females (62.5%) and 36 males (37.5%) aged between 5-60 years]. SPT (81.2 and 79.2%) and IgE (70.9 and 75%) gave positive results for both D. pteronyssinus and D. pteronyssinus, respectively. The common risk factors were use of cotton bedding > 10 years old, older homes > 20 years, crowded homes, family history, home dampness and homes at the ground floor. It was concluded that allergies to D. pteronyssinus and D. farinae contribute to allergic diseases in Zagazig City. Use of the SPT and IgE level is a promising diagnostic tool in the diagnosis of D. pteronyssinus and D. farinae.

The Dermatophagoides pteronyssinus Molecular Sensitization Profile of Allergic Rhinitis Patients in Central China

Background House dust mites (HDMs) are the major aeroallergens in patients with rhinitis and/or asthma in China. However, the molecular sensitization of HDM is varied in different regions. Objective To investigate the Dermatophagoides pteronyssinus ( Der p) molecular sensitization profile of allergic rhinitis (AR) patients in Central China. Methods AR patients with positive skin prick tests to Der p were enrolled in our study. Specific immunoglobulin E (sIgE) for Der p, Dermatophagoides farinae ( Der f), Acarus siro ( Aca s), Blomia tropicalis ( Blo t), and Der p components Der p1, Der p2, and Der p10 were measured in all patients. Results A total of 130 patients were included. The overall prevalence of positive serum sIgE was 99.2% for Der p, 98.5% for Der f, 81.5% for Aca s, 83.1% for Blo t, 71.5% for Der p1, 64.6% for Der p2, and 11.5% for Der p10. HDM-AR patients with asthma displayed significantly higher concentrations of sIgE to Der p, Der f, Der p1, and Der p2 than did those without asthma ( P < .001). The prevalence of asthma in HDM-AR patients was higher among the patients sensitized to both Der p1 and Der p2 (62.8%) than those sensitized to only 1 allergen ( Der p1 26.7% or Der p2 16.7%; P < .05) or nonsensitized to Der p1 and Der p2 (19.4%; P < .001). Conclusion Der p has high cross-reactivity with other mite species. Der p1 and Der p2 are the major components to induce Der p sensitization among AR patients in Central China. Sensitization to both Der p1 and Der p2 may be a risk factor for developing asthma in HDM-AR patients.