House Dust Mite Dermatophagoides Research Articles

Lactobacillus acidophilus KBL409 Ameliorates Atopic Dermatitis in a Mouse Model

Atopic dermatitis (AD) is a chronic inflammatory skin disease with repeated exacerbations of eczema and pruritus. Probiotics can prevent or treat AD appropriately via modulation of immune responses and gut microbiota. In this study, we evaluated effects of Lactobacillus acidophilus (L. acidophilus) KBL409 using a house dust mite (Dermatophagoides farinae)-induced in vivo AD model. Oral administration of L. acidophilus KBL409 significantly reduced dermatitis scores and decreased infiltration of immune cells in skin tissues. L. acidophilus KBL409 reduced in serum immunoglobulin E and mRNA levels of T helper (Th)1 (Interferon-γ), Th2 (Interleukin [IL]-4, IL-5, IL-13, and IL-31), and Th17 (IL-17A) cytokines in skin tissues. The anti-inflammatory cytokine IL-10 was increased and Foxp3 expression was up-regulated in AD-induced mice with L. acidophilus KBL409. Furthermore, L. acidophilus KBL409 significantly modulated gut microbiota and concentrations of short-chain fatty acids and amino acids, which could explain its effects on AD. Our results suggest that L. acidophilus KBL409 is the potential probiotic for AD treatment by modulating of immune responses and gut microbiota of host.

The distribution of sensitization to common aeroallergens in patients with rhinitis and asthma in Şanlıurfa, Türkiye.

Sensitization to common environmental aeroallergens plays a significant role in the pathogenesis and severity of asthma and allergic rhinitis. Knowledge on the sensitization pattern helps allergen avoidance, prediction of the severity of the disease, and use of specific immunotherapy for the most common allergens. The distribution of sensitization to aeroallergens differs in every region of Türkiye. In this study, it was aimed to investigate the allergen sensitization profiles of patients with asthma and rhinitis in Şanlıurfa, which is in Southeast Türkiye. Patients with rhinitis and asthma who presented to the outpatient clinic of adult immunology and allergy between April 2021- 2022 were retrospectively evaluated. Demographic information (age, sex), rhinitis and asthma duration, location of residence, allergic and non-allergic comorbidities, smoking history and skin prick test results were extracted from medical records. A total of 472 skin prick tests were performed on patients (35.4% males; 64.6% females), with a mean age of 33.8 years, and 120 (25.4%) were negative for skin reaction. The frequency of sensitivity to allergens was: grass (42.6%), cereal mixtures (41.5%), timothy grass (37.9%), cockroach (37.3%), olive tree (35%), house dust mites (Dermatophagoides farinae 27.5%, Dermatophagoides pteronyssinus 20.8%). In patients with only rhinitis (n= 305), the most frequent aeroallergen was pollen (grasses 43.6%; cereal mixtures 43.3%; timothy grass 41.6%; olive pollen 37.4%). In patients with asthma and rhinitis (n= 134), the most frequent aeroallergen was grass (44.8%). In patients with only asthma (n= 33), the most frequent aeroallergens were D. farinae (27.3%) and cockroach (27.3%). The most frequently detected allergens in this study were pollen, cockroach, and house dust mites, respectively. The findings revealed that pollen was the most frequent aeroallergen in subjects with allergic rhinitis with and without asthma. In patients with only asthma, the most frequent aeroallergen was house dust mites.

Murine model identifies tropomyosin as IgE cross-reactive protein between house dust mite and coho salmon that possibly contributes to the development of salmon allergy.

Recently, we have developed a method to identify IgE cross-reactive allergens. However, the mechanism by which IgE cross-reactive allergens cause food allergy is not yet fully understood how. In this study, we aimed to understand the underlying pathogenesis by identifying food allergens that cross-react with house dust mite allergens in a murine model. Allergenic protein microarray analysis was conducted using serum from mice intraperitoneally injected with Dermatophagoides pteronyssinus (Der p) extract plus alum or alum alone as controls. Der p, Dermatophagoides farinae (Der f), coho salmon extract-sensitized and control mice were analyzed. Serum levels of IgE against Der p, Der f, coho salmon extract, protein fractions of coho salmon extract separated by ammonium sulfate precipitation and anion exchange chromatography, and recombinant coho salmon tropomyosin or actin were measured by an enzyme-linked immunosorbent assay. A murine model of cutaneous anaphylaxis or oral allergy syndrome (OAS) was established in Der p extract-sensitized mice stimulated with coho salmon extract, tropomyosin, or actin. Protein microarray analysis showed that coho salmon-derived proteins were highly bound to serum IgE in Der p extract-sensitized mice. Serum IgE from Der p or Der f extract-sensitized mice was bound to coho salmon extract, whereas serum IgE from coho salmon extract-sensitized mice was bound to Der p or Der f extract. Analysis of the murine model showed that cutaneous anaphylaxis and oral allergic reaction were evident in Der p extract-sensitized mice stimulated by coho salmon extract. Serum IgE from Der p or Der f extract-sensitized mice was bound strongly to protein fractions separated by anion exchange chromatography of coho salmon proteins precipitated with 50% ammonium sulfate, which massively contained the approximately 38 kDa protein. We found that serum IgE from Der p extract-sensitized mice was bound to recombinant coho salmon tropomyosin. Der p extract-sensitized mice exhibited cutaneous anaphylaxis in response to coho salmon tropomyosin. Our results showed IgE cross-reactivity of tropomyosin between Dermatophagoides and coho salmon which illustrates salmon allergy following sensitization with the house dust mite Dermatophagoides. Our method for identifying IgE cross-reactive allergens will help understand the underlying mechanisms of food allergies.

Cloning and bioinformatics analysis of aquaporin proteins in the European house dust mite, Dermatophagoides pteronyssinus

Aquaporins are highly conserved water channel proteins involved in the transport of solutes across membranes. The few aquaporins identified to date play major roles in excretion in insects. Excretion is a major source of indoor allergens from the house dust mite species, but, to date, aquaporins have not been well studied in these species. We used RNA sequencing to study the transcriptome of the house dust mite Dermatophagoides pteronyssinus to identify putative aquaporin family members. RNA was isolated from more than 2000 mites for 5΄-RACE and 3΄-RACE. Putative aquaporins were identified through BLAST alignments, and primers were designed to amplify the five identified sequences. These cDNA fragments were then inserted into bacterial plasmids for molecular cloning and sequencing of DerpAQP1, DerpAQP2, DerpAQP3, DerpAQP4, and DerpAQP5 (GenBank accessions nos. KY305293, KY305294, KY305295, KY305296, and KY305298, respectively). Phylogenetic analysis of cloned sequences revealed the clustering of these putative aquaporins into two groups with human aquaporins (hAQPs): DerpAQP3 was clustered with hAQP8, hAQP11, and hAQP12; and DerpAQP1, DerpAQP2, DerpAQP4, DerpAQP5 were clustered with hAQP3, hAQP7 hAQP9, and hAQP10. This study provides a foundation for future studies of the importance of these proteins to dust mite functions and allergenicity.

Macrophage P2Y6 Receptor Signaling Selectively Activates NFATC2 and Suppresses Allergic Lung Inflammation.

Innate immune responses to innocuous Ags can either prevent or facilitate adaptive type 2 allergic inflammation, but the mechanisms are incompletely understood. We now demonstrate that macrophage UDP-specific type 6 purinergic (P2Y6) receptors selectively activate NFATC2, a member of the NFAT family, to drive an innate IL-12/IFN-γ axis that prevents type 2 allergic inflammation. UDP priming potentiated IL-12p40 production in bone marrow-derived macrophages (BMMs) stimulated by the house dust mite Dermatophagoides farinae (Df) in a P2Y6-dependent manner. Inhibitions of phospholipase C, calcium increase, and calcineurin eliminated UDP-potentiated Df-induced IL-12p40 production. UDP specifically induced nuclear translocation of NFATC2, but not NFATC1 and NFATC3, in BMMs in a P2Y6-dependent manner. UDP-potentiated IL-12p40 production by BMMs and Df-induced IL-12p40 gene expression by alveolar macrophages were abrogated in cells from Nfatc2 knockout mice. Pulmonary transplantation of wild-type but not Nfatc2 knockout macrophages increased Df-induced IL-12 production and IFN-γ expression in P2ry6 fl/fl/Cre/+ recipient mice. Finally, Nfatc2 knockout mice showed significantly increased indices of type 2 immunopathology in response to Df challenge, similar to P2ry6 fl/fl/Cre/+ mice. Thus, macrophage P2Y6 receptor signaling selectively utilizes NFATC2 to potentiate an innate IL-12/IFN-γ axis, a potential mechanism that protects against inappropriate type 2 immune responses.

DNA metabarcoding-based study on bacteria and fungi associated with house dust mites (Dermatophagoidesspp.) in settled house dust.

House dust mites (HDMs) including Dermatophagoides spp. are an important cause of respiratory allergies. However, their relationship with microorganisms in house dust has not been fully elucidated. Here, we characterized bacteria and fungi associated with HDMs in house dust samples collected in 107 homes in Korea by using DNA barcode sequencing of bacterial 16S rRNA gene, fungal internal transcribed spacer 2 (ITS2) region, and arthropod cytochrome c oxidase I (COI) gene. Our inter-kingdom co-occurrence network analysis and/or indicator species analysis identified that HDMs were positively related with a xerophilic fungus Wallemia, mycoparasitic fungi such as Cystobasidium, and some human skin-related bacterial and fungal genera, and they were negatively related with the hygrophilous fungus Cephalotrichum. Overall, our study has succeeded in adding novel insights into HDM-related bacteria and fungi in the house dust ecosystem, and in confirming the historically recognized fact that HDMs are associated with xerophilic fungi such as Wallemia. Understanding the microbial ecology in house dust is thought to be important for elucidating the etiology of human diseases including allergies, and our study revealed baseline information of house dust ecology in relation to HDMs. The findings could be useful from a perspective of human health.

Integrated OMICs Approach for the Group 1 Protease Mite-Allergen of House Dust Mite Dermatophagoides microceras.

House dust mites (HDMs) are one of the most important allergy-causing agents of asthma. In central Taiwan, the prevalence of sensitization to Dermatophagoides microceras (Der m), a particular mite species of HDMs, is approximately 80% and is related to the IgE crossing reactivity of Dermatophagoides pteronyssinus (Der p) and Dermatophagoides farinae (Der f). Integrated OMICs examination was used to identify and characterize the specific group 1 mite-allergic component (Der m 1). De novo draft genomic assembly and comparative genome analysis predicted that the full-length Der m 1 allergen gene is 321 amino acids in silico. Proteomics verified this result, and its recombinant protein production implicated the cysteine protease and α chain of fibrinogen proteolytic activity. In the sensitized mice, pathophysiological features and increased neutrophils accumulation were evident in the lung tissues and BALF with the combination of Der m 1 and 2 inhalation, respectively. Principal component analysis (PCA) of mice cytokines revealed that the cytokine profiles of the allergen-sensitized mice model with combined Der m 1 and 2 were similar to those with Der m 2 alone but differed from those with Der m 1 alone. Regarding the possible sensitizing roles of Der m 1 in the cells, the fibrinogen cleavage products (FCPs) derived from combined Der m 1 and Der m 2 induced the expression of pro-inflammatory cytokines IL-6 and IL-8 in human bronchial epithelium cells. Der m 1 biologically functions as a cysteine protease and contributes to the α chain of fibrinogen digestion in vitro. The combination of Der m 1 and 2 could induce similar cytokines expression patterns to Der m 2 in mice, and the FCPs derived from Der m 1 has a synergistic effect with Der m 2 to induce the expression of pro-inflammatory cytokines in human bronchial epithelium cells.

Association between allergic sensitization and intestinal parasite infection in schoolchildren in Gqeberha, South Africa.

BackgroundInconsistent data exist regarding the influence of parasitic infection on the prevalence of allergic sensitization and disorders.ObjectiveTo investigate the impact of geohelminth and protozoan infections on sensitization patterns and allergic symptoms of children living in low‐income communities in Gqeberha, South Africa.MethodsIn a cross‐sectional study, 587 schoolchildren aged 8–12 years were recruited in June 2016 and screened for reactivity to common allergens by skin prick tests (SPTs) and for parasitic infections by stool examination. Additionally, questionnaires were completed to record allergic symptoms the children may have experienced.ResultsPositive SPTs were found in 237/587 children (40.4%), and about one‐third of whom were polysensitized. Sensitizations were most frequently detected against the house dust mites (HDM) Dermatophagoides spp. (31.9%) and Blomia tropicalis (21.0%). Infections with geohelminths (Ascaris lumbricoides, Trichuris trichiura) were found in 26.8% and protozoan infections (Giardia intestinalis, Cryptosporidia spp.) in 13.9% of study participants. Mixed logistic regression analyses revealed negative associations between parasite infection and sensitization to Blomia tropicalis (OR: 0.54, 95% CI 0.33–0.89) and to Dermatophagoides spp. (OR 0.65, 95% CI 0.43–0.96), and between protozoan infection and allergic sensitization to any aeroallergen, although these associations were not significant when adjusted for false discovery. Geohelminth infection and intensity of geohelminth infection were both associated with reduced risk of polysensitization (OR 0.41, 95% CI 0.21–0.86), and this association remained significant with adjustment for false discovery. Reported respiratory symptoms were associated with HDM sensitization (ORs from 1.54 to 2.48), but not with parasite infection.Conclusions and clinical relevanceOur data suggest that geohelminth infection and high geohelminth infection intensity are associated with a reduced risk of polysensitization.

AEROBIC EXERCISE REDUCES SEVERE ASTHMA PHENOTYPE

TOPIC: Allergy and Airway TYPE: Original Investigations PURPOSE: Severe asthma is characterized by higher rates of airway hyperresponsiveness and concomitantly increased eosinophilic and neutrophilic airway and systemic inflammation in which bradykinin plays a central role. Aerobic exercise (AE) is the main component in a pulmonary rehabilitation inhibiting airway inflammation and hyperresponsiveness in mild and moderate asthmatics. In addition, AE in mouse models of allergic asthma is proven to reduce eosinophilic airway inflammation, airway remodeling, and hyperresponsiveness, by controlling exacerbated Th2 immune response. However, whether AE could inhibit a severe asthma phenotype is unknown METHODS: House dust mite (HDM; 200ug/mouse; 3x/week; 6 weeks) Dermatophagoides pteronisynuss was used. Eight C57Bl/6 male mice (Control; n=2x10), (Exercise; n=2x10), (Asthma; n=2x10) and (Asthma+Exercise; n=2x10) were assessed after 6 weeks protocol (2 initial weeks of intra-tracheal HDM without AE) followed by 4 weeks of treadmill AE (1h/session, 5x/week, moderate intensity) + (4 weeks of intra-tracheal HDM) RESULTS: The results showed that AE reduced HDM-increased total leukocytes, eosinophils, neutrophils, lymphocytes, and macrophages (p<0.01) in bronchoalveolar lavage (BAL) and total leukocytes, eosinophils, neutrophils, lymphocytes, and monocytes (p<0.01) in whole blood. The cytokines IL-1beta, IL-4, IL-5, IL-13, IL-17, IL-33, TNF-alpha (p<0.01) were reduced both in BAL and in plasma in HDM+Ex group compared with HDM group, while IL-10 was increased. The density of peribronchial eosinophils, neutrophils, lymphocytes and macrophages (p<0.01) and the percentage of airway collagen fibers, epithelial and smooth muscle thickness (p<0.01) were reduced in HDM+Ex group compared with HDM group. The levels of bradykinin in BAL and in lung homogenate (p<0.01) and the expression at mRNA levels by qRT-PCR of B1 receptor (p<0.001) were reduced in HDM+Ex group compared with HDM group. The lung mechanics revealed that exercise improved airway resistance (RAW; p<0.001), tissue resistance (HTIS; p<0.001), and tissue elastance (GTIS; p<0.001). In addition, once AE-induced IL-10 release, we tested the hypothesis that AE-induced IL-10 could inhibit bradykinin-induced airway epithelial cells (BEAS-2B), lung fibroblast cells (MRC5), and freshly isolated human eosinophils and neutrophils activation, measured by IL-1beta release. The results demonstrated that IL-10 inhibited bradykinin-induced IL-1beta release by BEAS-2B, MRC5, human eosinophils and neutrophils. In addition, IL-10 inhibited bradykinin-induced increased expression of B1 receptor in BEAS-2B, MRC5, human eosinophils, and neutrophils CONCLUSIONS: In conclusion, AE can inhibit severe asthma phenotype in vivo and in vitro, and further clinical trials to confirm these findings in severe asthmatic patients are guaranteed. CLINICAL IMPLICATIONS: The possible involvement of Bradikinin may be one of the keys to understanding the mechanisms of severe asthma and aerobic physical exercise may inhibit the action of the severe asthma phenotype. DISCLOSURES: no disclosure on file for Francine Almeida; No relevant relationships by Nilsa Regina Damaceno-Rodrigues, source=Web Response no disclosure on file for Fernanda Degobbi Tenorio Quirino Santos Lopes; No relevant relationships by RENILSON FERREIRA, source=Web Response No relevant relationships by Sara Hamaguchi, source=Web Response no disclosure on file for João Bosco Pesquero; No relevant relationships by 119 Maysa Alves Rodrigues Rangel, source=Web Response No relevant relationships by Anamei Silva-Reis, source=Web Response no disclosure on file for Rodolfo de Paula Vieira

Concordance of skin test reactivity between indoor inhalant allergens among children with allergic respiratory disease

BackgroundIn vitro studies have demonstrated cross-reactivity among indoor allergen proteins in children with allergic respiratory diseases. However, there are only few studies evaluating in vivo response. A skin prick test (SPT) with commercial indoor solutions is widely used in clinical practice. We aimed to evaluate SPT agreement in children with allergic respiratory disease between pairs of common indoor allergens.MethodsWe reviewed SPT results of children 2 to 18 years old, diagnosed with respiratory allergic disease. Results from house dust mite (Dermatophagoides farinae, Dermatophagoides pteronyssinus), cockroach (Periplaneta americana, Blatella germanica), cat and dog were collected. Sensitization was defined as ≥ 3 mm in wheal diameter. Kappa coefficient (κ) was used to analyze sensitization concordance for each allergen pair.ResultsThe charts of 300 children, 187 (62.33%) males, were reviewed. Mean age was 7.43 ± 3.29 years with 183 (61%), 140 (46.67%), 45 (15%), 30 (10%) sensitizations to house dust mite (HDM), cockroach, cat and dog, respectively. Sensitization concordance between HDM and cockroach was moderate: κ = 0.53 (95% CI: 0.42–0.64). Moderate agreement occurred between dog and cat: κ = 0.41 (95%CI: 0.30–0.52). HDM-sensitized children showed poor concordance with both cat κ = 0.17 (95%CI: 0.09–0.24) and dog κ = 0.09 (95%CI: 0.03–0.14). There was also poor concordance between cockroach-sensitized children to cat κ = 0.19 (95%CI; 0.11–0.28) and dog κ = 0.11 (95%CI; 0.04–0.18).ConclusionWe demonstrated moderate agreement of SPT response between HDM and cockroach as well as dog and cat. This may be due to cross-reactivity. Component-resolved diagnosis should be considered in children with co-sensitization of these allergen pairs.

Immunological parameters as biomarkers of response to MicroCrystalline Tyrosine-adjuvanted mite immunotherapy

BackgroundDespite the effectiveness of allergen immunotherapy (AIT), some patients are unresponsive for reasons still unknown; yet validated response biomarkers remain unavailable. ObjectiveTo analyze immunological parameters as biomarkers to monitor and predict clinical response to a MicroCrystalline Tyrosine-adjuvanted house dust mite (HDM) AIT in patients with allergic rhinitis (AR). MethodsObservational, prospective, multicenter study including adult patients (aged 18–65 years) with AR, with and without asthma, sensitized to the HDM Dermatophagoides pteronyssinus (DP) and prescribed Acarovac Plus® DP 100% in the routine practice. Serum concentrations of total IgE, specific IgE, specific IgG4, IL-4, IL-5, IL-10, IL-13, and IFN-γ were compared between baseline and 12 months after AIT. The relationship between patients’ baseline immunological profiles and classification as low, high, and non-responders and between their sensitization profile to DP allergens and effectiveness were analyzed. ResultsOf 141 patients recruited, 118 (mean [SD] age of 33.6 [9.5] years) were evaluable. One year after treatment, Der p 1-specific IgE, DP-specific IgG4, and IL-10 increased by a mean (SD) of 3.4 (13.6) kU/L (p = 0.016), 0.43 (0.55) mg/L (p < 0.0001), and 1.35 (7.56) pg/mL (p = 0.033), respectively. Non-responders showed increased baseline levels of IL-13 compared to high responders (p = 0.037). Changes in effectiveness variables between baseline and after AIT were similar regardless of the sensitization profile. ConclusionNon-responsive patients to AIT showed increased baseline IL-13 concentrations, suggesting its value as prognostic biomarker. DP-specific AIT increased Der p 1-specific IgE, DP-specific IgG4, and IL-10 concentrations in patients with AR. All patients benefited from treatment regardless of their sensitization profile to major DP allergens.

Evaluation of sensitization to the crude extract of Dermatophagoides farinae and its derived allergens, Der f 2 and Zen 1, in dogs with atopic dermatitis in Southern Brazil

BackgroundAtopic dermatitis is associated with the production of IgE antibodies against environmental allergens and allergens of the house dust miteDermatophagoides farinae are frequently implicated in the disease. ObjectivesWe aimed to observe the allergen-specific IgE against crudeD. farinae, Der f 2 and Zen 1 in dogs with atopic dermatitis and report if these dogs are in contact with material that could shelter mite allergens. Methods100 dogs with clinical diagnosis of atopic dermatitis were included after exclusion of other forms of pruritic skin disease and dogs that already received specific or non-specific immunotherapy. These dogs were of different breeds and ages and they were presented at a veterinary teaching hospital and a private service of veterinary dermatology, both located in Curitiba, Southern Brazil. At the time of anamnesis, some questions were applied to know the possibility of these dogs having had contact with furniture and textile material which could shelter house dust mites. Sera samples were obtained and further analyzed by ELISA assay to measure serum IgE levels against these allergens with an established cut-off of 0.200 IgE optical density. ResultsThe allergen-specific IgE positivity against crudeD. farinae (92 %) and Zen 1 (77 %) was higher than Der f 2 (56 %). There was a correlation in sensitization to crude D. farinae and Zen 1 that was not observed between crude D. farinae and Der f 2 and Der f 2 and Zen 1. The sensitization to D. farinae and its allergens was associated with an unrestricted exposition to furniture and textile material. Conclusion & clinical relevancedogs with atopic dermatitis are frequently sensitized to D. farinae and its allergens, Der f 2 and Zen 1, may be considered major allergens in these dogs. Zen 1 may be the main allergen responsible for the sensitization to crude D. farinae.

Análisis de las reacciones de hipersensibilidad tipo I a los lepidópteros nocturnos en una población alérgica costarricense

Allergic patients are routinely tested for various allergens including molds, food, pollen, cockroaches and house dust mites; however, there are patients who present allergy symptoms but show negative results in Prick tests with the available allergens. To determine the percentage of patients sensitized to the nocturnal Lepidoptera and its role as an important environmental allergen. A retrospective analysis was carried out in which we determined the percentage of patients allergic to nocturnal Lepidoptera, house dust mites (Blomia tropicalis, Dermatophagoides pteronyssinus, Dermatophagoides farinae and Tyrophagus putrescentiae) and insects (Periplaneta americana and Musca domestica). Also, we analyzed the demographics and symptoms of the patients. 63% of the patients were allergic to house dust mites, 39% to nocturnal Lepidoptera, 28% to Periplaneta americana and 24% to Musca domestica. Also, 2% of the patients allergic to only one allergen were mono-sensitized to nocturnal Lepidoptera. We strongly recommend that allergists constantly test for nocturnal Lepidoptera, because most of the studied patients had allergy to these insects.

Der p 1 gene sequence polymorphism in house dust mite Dermatophagoides pteronyssinus

Abstract. Adji A, Niode NJ, Memah VV, Posangi J, Wahongan GJP, Tallei TE. 2021. Der p 1 gene sequence polymorphism in house dust mite Dermatophagoides pteronyssinus. Biodiversitas 22: 72-78. Gene polymorphisms in Dermatophagoides pteronyssinus (DP) mite can affect the immune response that plays a role in atopic disease. This study aimed to determine the polymorphisms of Der p 1 gene from DP. House dust containing DP was used as a source of DNA containing the Der p 1 gene. The gene was amplified using specific primers DP Der 1 P 108F and DP Der 1 P 1509R. The amplified fragments were cloned using the Toyobo pTA2 vector and sorted then compared with the Gene Bank database. The result shows that there are 8 polymorphism sites in the Der p 1 gene positioned at 190 (GR), 463 (CT), 645 (AR), 751 (CY, CT), 787 (CG), 827 (TA; TW), and 1084 (CG). In the Der p 1 gene, there are 5 silent mutations and 3 nonsynonymous substitutions, resulting in amino acid polymorphisms as follows: Histidine H146 to Tyrosine Y146, Alanine A220 to Valine V220 and amino acid X220, and Tyrosine T232 to Serine S232. Polymorphisms in these amino acids lead to a polarity change, from polar to polar and non-polar to non-polar. These dynamics in polarity does not change the structure or function of the allergen protein. So that they can be used for vaccine design strategies.

Minimum Allergen Screening Panel for Allergic Rhinitis in Bangalore: A Cross Sectional Study.

Allergic rhinitis (AR) is a very common condition presenting to an Otorhinolaryngologist. Prevalence of AR is on the increase and it has significant impact on quality of life of the patient. Skin prick test (SPT) is a simple test to determine allergen sensitization status in patients with AR. There is wide variation in allergen panel used in SPT among various allergy clinics and many centres use a large panel of allergens which requires multiple skin pricks for the patient undergoing the test. Our aim was to identify a minimum panel of allergens among patients with symptoms of AR undergoing SPT which could be used as a screening panel for AR. The present study is a cross sectional study in patients with symptoms of AR undergoing SPT at Allergy clinic of Bangalore Baptist hospital over a period of 18months from January 2018. 149 patients were included in the study and 26 patients who had negative SPT for all allergens tested were excluded. Prevalence of sensitization for individual allergens was calculated. House dust mite (Dermatophagoides pteronyssinus and Dermatophagoides farinae) was the most prevalent allergen to which 73.9% and 65.8% of our study population was sensitized respectively. We identified a minimum allergen panel of 3 allergens (Dermatophagoides pteronyssinus, Lambs quarter and Dermatophagoides farinae) which could identify > 90% of patients sensitized in the study group.

Dominant Aero-Allergens Involved in Causing Allergic Rhinitis with Special Reference to Dust Mite Allergy and Skin Prick Test in Tripura: A Prospective Study.

Allergic rhinitis (AR) is one of the commonest forms of allergy in the world which causes significant morbidity. The prevalence has all the more increased because of increasing air pollution. Though skin prick testing (SPT) and sublingual immunotherapy (SLIT) have now been widely accepted world wide as important tool, offering prospective long term remission or cure for allergic rhinitis yet some still debate the accuracy and efficacy of both. This prospective study was conducted from February 2018 to May 2020, from amongst the patients of allergic rhinitis, presenting to the author in his private clinic. There were total 37 patients who presented with symptoms suggestive of allergic rhinitis and who underwent SPT for various common aeroallergens, as suggested by their history. The age range of the patients was from 6 to 60years, with a mean age of 27.62years. There were 23 male and 14 female patients with a male to female ratio of 1.76:1. The commonest age group affected is 21-30year group. Out of the total 37 patients of allergic rhinitis, who underwent SPT, 32 (86.5%) had a positive response and 05 (13.5%) patients had a negative response. Out of the 32 patients with positive response, 30 (93.8%) had positive reactions to multiple allergens and just 2 (6.2%) had positive reaction to single allergen. The commonest aeroallergen detected by SPT was house dust mite (bed mite) Dermatophagoides ( D )-pteronyssinus, and another house dust mite (floor mite), D -farinae, followed by Blomia, another floor mite. Out of the 32 SPT positive cases 10 (31.3%) patients opted for SLIT, after knowing the pros and cons. It can be concluded from this preliminary study that there is no doubt that SPT is a very informative confirmatory test for diagnosing allergens causing allergic rhinitis. The commonest allergen involved in causing allergic rhinitis in and around Tripura are the dust mites, commonest being D -pteronyssinus and D -farinae. SLIT has a good acceptance in the allergic rhinitis patients and out of ten all of the patients reported significant symptomatic improvement. This allergen mapping in this area is probably the first of its kind, which will help in deciding future strategies in management of AR, by immunotherapy or avoidance measures. In future many more patients may get benefit of long term cure from it.

96 Sublingual allergen-specific immunotherapy in pediatric patients: biomarkers and molecular allergy diagnostics as predictors of therapeutic success

Abstract Background Efficacy of allergen-specific immunotherapy (ASIT) in patients with asthma could be significantly enhanced when physicians have an opportunity to identify those who are most likely to respond, determine when to stop treatment, and predict relapse. Thus, molecular allergy diagnostic is an effective tool that could help to individualize the diagnosis and treatment of asthma by accurate detection of the causative and cross-reactive allergens in pediatric patients. Cytokines are known as reliable diagnostic and prognostic biomarkers for asthma and can be used to evaluate the therapeutic effect. Objectives To evaluate the roles of molecular allergy diagnostic and biomarkers (L-10, IFNγ и TGFβ) as predictors of ASIT efficacy in pediatric patients with asthma. Design/Methods Eighty children aged 5 to 18 years with mild and moderate atopic bronchial asthma were included in the study. Sixty-eight out of 80 (85%) were found to have sensitization to house dust mites Dermatophagoides Pteronyssinus and/or Dermatophagoides Farinae. All these patients underwent molecular diagnostics using ImmunoCAP (Phadia 100) to determine the major (r Der p1, r Der p 2) and minor allergens (r Der p10) of the house dust mites. Twenty-eight patients with mild and moderate asthma were found to have a high sensitivity to these allergens and received SLIT with a mixture of house dust mites (Dermatophagoides Pteronyssinus and/or Dermatophagoides Farinae). To compare the efficacy of SLIT, we evaluated the severity of asthma clinical symptoms on a point scale from 0 to 3, and biomarker levels (IL-10, IFNγ и TGFβ) before and 6 months after SLIT. Twelve healthy children were included in the study as a reference group. Results At the beginning of the study, the average daily score in the SLIT group of 2.5 ± 0.7, and after 6 months of treatment, it decreased to 0.5 ± 0.2. The levels of biomarkers were markedly decreased prior to the treatment, especially TGFβ levels, and normalized at the end of treatment (Tab.1). Conclusion These findings support the efficacy of molecular diagnosis to determine the efficacy of allergen-specific immunotherapy in patients with asthma.

Glycoprotein profile from House Dust Mite Dermatophagoides pteronyssinus reveals distinct antigenic and allergenic profile among allergic patients and healthy subjects

Glycoprotein profile from House Dust Mite Dermatophagoides pteronyssinus reveals distinct antigenic and allergenic profile among allergic patients and healthy subjects

Molecular Dynamics Simulations of Mite Aquaporin DerfAQP1 from the Dust Mite Dermatophagoides farinae (Acariformes: Pyroglyphidae).

Aquaporins are a large family of transmembrane channel proteins that facilitate the passive but highly selective transport of water and other small solutes across biological membranes. House dust mite (Dermatophagoides farinae) is the major source of household immunogens, and we have recently reported six cDNA sequence encoding aquaporins from this mite species. To better understand the structure and role of mite aquaporin, we constructed a tertiary structure for DerfAQP1 by homology modeling from the X-ray structure of malaria aquaporin PfAQP (Protein Data Bank code No. 3C02) and conducted molecular dynamics simulation. The simulation arranged seven water molecules in a single file through the pores of the DerfAQP1. Further, two conserved Asn-Pro-Ala motifs were located on Asn203 and Asn77; residues Arg206, Trp57, Met190, Gly200, and Asp207 constituted an extracellular vestibule of the pore; and residues His75, Val80, Ile65, and Ile182 constituted the cytoplasmic portions. The overall free energy profile for water transport through DerfAQP1 revealed an energy barrier of ~2.5 kcal/mol. These results contribute to the understanding of mite physiology and pathology.

Allergic sensitisation in South Africa: Exploring regional variation in sensitisation.

Allergy is a common health problem in South Africa (SA), and a rational approach to allergy testing is essential to ensure cost-effective as well as optimal patient diagnosis and management. To review allergy testing data with respect to current national testing recommendations, and to explore the regional variations in sensitisation. Retrospective data review on allergy testing from a private pathology provider in SA over a 2-year period. Data on skin-prick testing (SPT) and allergen-specific IgE testing originating from all the provinces of SA were collected and analysed with regards to allergen positivity rate and regional sensitisation patterns. Among the patients (N=450320) tested for a suspected inhalant allergy, 46% tested positive. Only 45% of these received additional testing for the nine recommended inhalant allergens included in the current national testing protocol. Among the patients (N=6775) who received SPT for a suspected inhalant allergy, 59% yielded one or more positive results. The most frequent sensitising allergens were house dust mite (Dermatophagoides pteronyssinus) and grass pollen. The house dust mite, Blomia tropicalis, was a significant sensitiser in coastal regions. SPT identified two other important regional allergens which are not included in the current recommendations for inhalant allergen-specific IgE testing. The current diagnostic recommendations include allergens that demonstrate significant sensitisation in all regions of SA. Two additional allergens that show significant regional sensitisation in the South African population were identified. These findings may aid the recommendations for the most appropriate and cost-effective approach to allergy testing of symptomatic patients in SA.