Dust Mite Allergen Research Articles

House dust mite allergen immunotherapy for monosensitized versus polysensitized patients with allergic rhinitis: A systematic review and meta-analysis.

Most patients with allergic rhinitis are polysensitized. The efficacy of house dust mite (HDM) allergen immunotherapy (AIT) compared between monosensitized and polysensitized patients remains limited. To systematically review the efficacy and safety of HDM AIT compared between monosensitized and polysensitized patients with allergic rhinitis. We searched PubMed/MEDLINE, Scopus, EMBASE, and the Cochrane central register of Controlled Trials (CENTRAL) until June 2022. The primary outcome was the changes from baseline in total nasal symptom score (TNSS). Secondary outcomes were changes from baseline in total medication score (TMS), combined symptom medication score (CSMS), visual analog scale (VAS), Rhinoconjunctivitis Quality of Life Questionnaire (RQLQ) score, immunological parameters, and adverse events (AEs). Of 13 eligible studies, 10 prospective cohorts, 2 retrospective cohorts, and 1 matched cohort, we identified 10 studies for quantitative synthesis. There were 1,113 patients with allergic rhinitis, 566 with HDM monosensitization and 547 with polysensitization to HDM and other allergens. There was no significant difference in the pooled mean changes of the 2 groups in TNSS (SMD -0.05, 95%CI: -0.22 to 0.11, p = 0.532) and VAS (SMD -0.20, 95%CI: -0.42 to 0.01, p = 0.060) with moderate certainty of evidence. The changes in TMS, CSMS, and RQLQ were similar between the 2 groups with very low certainty of evidence. The AEs were mild and comparable between the 2 groups. The immunological indices remained inconsistent and were not predictive of clinical responses. A single HDM AIT similarly improved clinical outcomes in monosensitized and polysensitized patients with allergic rhinitis.

Clinic and diagnostics of house dust mite allergy

SummaryHouse dust mite allergens are common triggers for allergic rhinoconjunctivitis and allergic asthma; they can aggravate atopic dermatitis and rarely lead to anaphylactic reactions due to dust mite allergens in food. Typical symptoms are nasal obstruction, sneezing, and irritation, and more often than in pollen allergy, allergic asthma also develops. The symptomatology exists in principle throughout the year with maximum complaints in autumn and winter. Of particular importance are sleep disturbances due to nasal obstruction, which lead to restrictions in the quality of life and performance of affected patients. Sensitization can be proven by skin tests and detection of serum allergen-specific IgE antibodies; proof of allergy is achieved by nasal or conjunctival provocation tests. The diagnosis of local allergic rhinitis can only be made by provocation or by determination of allergen-specific IgE antibodies in nasal secretions. The quality of the allergen extract used is essential for all tests; it must contain the allergens to which a patient is sensitized. The concentration of Der p 23 in house dust mite extracts is particularly critical.

Overcrowding and Hazardous Dwelling Condition Characteristics: A Systematic Search and Scoping Review of Relevance for Health

Crowding in dwellings is an important public health issue. We hypothesize that overcrowding may cause indirect health effects by adversely affecting the dwelling itself, for example, by increasing dampness leading to mold. We therefore performed a systematic search and a scoping review on overcrowding leading to dwelling condition characteristics of relevance for health. A literature search was performed using the PubMed and Scopus databases up to 5 March 2021. The search yielded 100 records with relevant information. We found that overcrowding is defined in numerous ways and often address "socially deprived" populations. Six studies report associations of overcrowding with at least one dwelling condition characteristic, namely lead, cadmium, microorganism distribution, dust mite and cockroach allergens in dust, cockroach infestation, peeling paint, and mold. One of the studies reports associations between several characteristics, e.g., association of mold with cleanliness and rodent infestation, and points out the common use of pesticides. Additional characteristics were extracted from the remaining 94 records, without data on statistical associations with overcrowding. Our review suggests that multiple potentially hazardous dwelling condition characteristics often coincide in overcrowded dwellings. The epidemiological attribution of health effects to any characteristic is therefore difficult. Causal relationships are even more difficult to establish, as overcrowding is also associated with a range of social and other circumstances that may affect health. The complexity should be considered by scientists and practitioners dealing with overcrowding in dwellings.

Apelin-13 facilitates mitochondria homeostasis via mitophagy to prevent against airway oxidative injury in asthma

Oxidative stress is a major mediator in the pathogenesis of allergens-induced asthma. Mitochondria damage and dysfunction is considered to be closely related with oxidative stress. Apelin-13 is a novel multifunctional protein with anti-inflammatory and anti-oxidative properties in neuroinflammation and ischemia-reperfusion injury. However, its role in mitochondria homeostasis under asthma-associated airway oxidative injury and the potential mechanisms have not been elucidated. A murine model of asthma was established by house dust mite (HDM) allergen sensitization and challenge. The mice were received Apelin-13 protein through intraperitoneal administration before HDM challenge. Airway inflammation, histopathological changes and oxidative stress were examined. The regulatory effects of Apelin-13 on mitochondria function were evaluated using airway epithelial BEAS-2B cells, including mitochondria membrane potential (MMP), mitophagy and the possible signaling pathway. The HDM-challenged mice group exhibited robust inflammation and apoptosis in airway epithelium compared to the control group. The airway impairment in asthmatic mice was partly lessened after Apelin-13 administration. Meanwhile, protein expressions of mitophagy-related markers PINK1, Parkin, Tomm20 and LC3 were significantly increased in the lungs of Apelin-13-treated asthmatic mice. In vitro, Apelin-13 treatment significantly improved MMP levels and reduced ROS production in BEAS-2B cells exposed to HDM, accompanied with the increase of cell viability. Furthermore, Apelin-13 was found to promote the activation of PINK1/Parkin signaling in BEAS-2B cells, thereby increasing mitophagy activity and facilitating mitochondria homeostasis. These results demonstrate that Apelin-13 acts as a regulator of mitochondria homeostasis by driving mitophagy to protect against HDM allergen-induced airway oxidative injury. Apelin-13 may serve as a promising protective agent for treating asthma.

Histamine-Releasing Factor Is a Novel Alarmin Induced by House Dust Mite Allergen, Cytokines, and Cell Death.

Histamine-releasing factor (HRF) is a multifunctional protein with fundamental intracellular functions controlling cell survival and proliferation. HRF is also secreted during allergic reactions and promotes IgE-mediated activation of mast cells and basophils. In this study, we investigated HRF secretion and its relevance to airway inflammation. HRF monomers were constitutively secreted from BEAS-2B human bronchial epithelial cells (HBECs) and converted to oligomers over the course of culture. Stimulation with house dust mite (HDM) extract increased HRF secretion substantially. Several cytokines involved in asthma pathogenesis showed moderate effects on HRF secretion but dramatically enhanced HDM-induced HRF secretion. HDM-induced HRF secretion from BEAS-2B cells and normal HBECs proceeded via TLR2. Consistent with this, multiple TLR2 ligands, including Der p 2, Der p 5, Der p 13, and Der p 21, induced HRF secretion. Der p 10 (tropomyosin) also promoted HRF secretion. Cell death or incubation with adenosine and ATP, compounds released upon cell death, also enhanced HRF secretion. Furthermore, intranasal administration of recombinant HRF elicited robust airway inflammation in HDM-sensitized mice in an FcεRI-dependent manner. Therefore, we conclude that HRF is a novel alarmin that promotes allergic airway inflammation.

Exposure to House Dust Mite Allergen and Endotoxin in Early Life and Sensitization and Allergic Rhinitis: The JECS.

The association between endotoxin and allergic rhinitis (AR) is not conclusive. The aim of this study was to determine the association between endotoxin and house dust mite (HDM) allergens in dust, and HDM sensitization and AR among Japanese infants. This study included 4188 participants in the Sub-Cohort Study of the Japan Environment and Children's Study. Dust was collected from children's mattresses at age 18 months and endotoxin and HDM allergen levels were measured. A logistic regression model was used to analyze the association between endotoxin or HDM allergen and the sensitization to HDM (specific-IgE) at age 2 and AR at age 3. The median (interquartile range) endotoxin level was 375.1(186.9-826.5) EU/m2 and the Der 1 (Der p 1 + Der f 1) level was 51.2 (14.8-168.6) ng/m2. There were significant positive associations between endotoxin and HDM sensitization (Der f 1, adjusted odds ratio [aOR] quartile [Q] 4 vs. Q1, 1.44, 95% CI, 1.04-2.00; Der p 1, aOR Q4 vs. Q1, 1.56, 95% CI, 1.12-2.16). There were also significant positive associations between Der 1 exposure and HDM sensitization (Der f 1, aOR Q3 vs. Q1, 1.75, 95% CI, 1.26-2.44; aOR Q4 vs. Q1, 2.98, 95% CI, 2.15-4.13; Der p 1, aOR Q3 vs. Q1, 1.91, 95% CI, 1.37-2.66; aOR Q4 vs. Q1, 2.91, 95% CI, 2.09-4.05). There were, however, no associations between endotoxin or Der 1 and AR. In the population residing mostly in non-farming settings, both endotoxin and HDM allergens in dust were associated with an increased risk of HDM allergen sensitization, but not with AR.

Alteration of glycosphingolipid metabolism by ozone is associated with exacerbation of allergic asthma characteristics in mice.

Asthma is a common chronic respiratory disease exacerbated by multiple environmental factors. Acute ozone exposure has previously been implicated in airway inflammation, airway hyperreactivity, and other characteristics of asthma, which may be attributable to altered sphingolipid metabolism. This study tested the hypothesis that acute ozone exposure alters sphingolipid metabolism within the lung, which contributes to exacerbations in characteristics of asthma in allergen-sensitized mice. Adult male and female BALB/c mice were sensitized intranasally to house dust mite (HDM) allergen on days 1, 3, and 5 and challenged on days 12-14. Mice were exposed to ozone following each HDM challenge for 6 h/day. Bronchoalveolar lavage, lung lobes, and microdissected lung airways were collected for metabolomics analysis (N = 8/sex/group). Another subset of mice underwent methacholine challenge using a forced oscillation technique to measure airway resistance (N = 6/sex/group). Combined HDM and ozone exposure in male mice synergistically increased airway hyperreactivity that was not observed in females and was accompanied by increased airway inflammation and eosinophilia relative to control mice. Importantly, glycosphingolipids were significantly increased following combined HDM and ozone exposure relative to controls in both male and female airways, which was also associated with both airway resistance and eosinophilia. However, 15 glycosphingolipid species were increased in females compared with only 6 in males, which was concomitant with significant associations between glycosphingolipids and airway resistance that ranged from R2 = 0.33-0.51 for females and R2 = 0.20-0.34 in male mice. These observed sex differences demonstrate that glycosphingolipids potentially serve to mitigate exacerbations in characteristics of allergic asthma.

Specific IgE against the house dust mite allergens Der p 5, 20 and 21 influences the phenotype and severity of atopic diseases.

House dust mites (HDM) are among the most important sources for airborne allergens with high relevance for atopic diseases. Routine tests contain only 4 of 32 registered allergens of Dermatophagoides pteronyssinus. Clinical relevance and pathomechanistic properties of many allergens are not well understood. The association of several HDM allergens with allergic rhinitis, allergic asthma, and atopic dermatitis was investigated to identify allergens with biomarker potential and to transfer them into diagnostics. Eight out of nine D. pteronyssinus allergens (nDer p 1, rDer p 2, rDer p 5, rDer p 7, rDer p 10, rDer p 13, rDer p 20, rDer p 21, rDer p 23) were recombinantly expressed and purified. Sensitization patterns of 384 HDM-allergic individuals exhibiting different clinical phenotypes were analyzed with a serum-saving multiplex array. Sensitization to more than three mite allergens (sensitization count) was associated with allergic asthma and/or atopic dermatitis. Reactions to Der p 5 and Der p 21 were more frequent in allergic asthma compared to allergic rhinitis. Atopic dermatitis patients were more often sensitized to Der p 5, Der p 20, and Der p 21 among others. Der p 20-IgE > 80 kU/L was associated with severe atopic dermatitis in 75% of patients. This study demonstrates the clinical importance of the sensitization count and of certain allergens (Der p 5, Der p 20, and Der p 21) not available for routine diagnostics yet. Implementing them as well as the sensitization count in diagnostic measures will improve diagnosis and risk assessment of HDM-allergic patients.

Algorithm for selecting patients for house dust mite allergen specific immunotherapy in children with bronchial asthma and allergic rhinitis

Objective. Based on literature data and own research, on the selection of pediatric patients for the treatment of allergen immunotherapy (AIT) with house dust mite (HDM) allergens, to develop an Algorithm for selecting patients for AIT with HDM allergens in children with bronchial asthma (BA) and allergic rhinitis (AR). 
 Methods. Data from our own studies included 420 patients with AR and complaints indicating domestic sensitization (256 boys, 164 girls), aged 5 to 17,.9 years (mean age 8,.44 ± 3.,06), of which 176 have had BA. Patients underwent skin prick tests (SPT) with household allergens, determination of sIgE for HDM allergens by the ImmunoCAP method, and nasal provocative test (NPT) with HDM. If the results were negative, the allergological examination was repeated again in 12-–18 months. 
 Results: The Patient Selection Algorithm was constructed on the basis of the obtained data on the significance of the examination methods used. The primary role of SPT, the possibility of repeating the examination in case of negative results, indications for NPT with HDM allergens were taken into account. The algorithm makes it possible to organize an examination of a patient with HDM allergy in order to develop indications for AIT.

Simultaneous assessment of chemical and biological contaminants in settled house dust

BACKGROUND AND AIM Settled house dust (SHD) is a reservoir for various contaminants, including endocrine-disrupting chemicals (EDCs), trace metals, and house dust mite allergens. This study aimed to characterize various chemical and biological contaminants in SHD and identify determinants of the indoor contaminants. METHODS In total, 106 SHD samples were collected from 106 houses in Seoul and Gyeonggi Province, Korea in 2021. Thirty of the 106 houses were recruited for collecting bedding dust samples. All participants completed a questionnaire comprised of housing and lifestyle-related factors. Samples were analyzed for 18 organophosphate flame retardants (OPFRs), 16 phthalates, five alternative plasticizers (APs), seven trace metals, and two house dust mite allergens (Dermatophagoides farinae type 1 [Der f1] and Dermatophagoides pteronyssinus type 1 [Der p1]). A multiple regression analysis was conducted to identify the determinants governing the concentrations and profiles of various contaminants. RESULTS OPFRs, phthalates, APs, and trace metals were detected in all SHD samples, indicating ubiquitous contamination in indoor environments. Among the three EDC groups, APs were detected most frequently with the highest concentrations, followed by phthalates and OPFRs. Der f1 was detected in all bedding dust samples with significantly higher levels than Der p1. The concentrations of OPFRs, plasticizers, and trace metals in SHD were significantly associated with the type and number of electronic appliances and combustion activities. Der f1 was significantly associated with the number of occupants and water penetration. Ventilation, vacuum cleaning, and wet cleaning or dry mopping significantly reduced the levels of most contaminants in SHD. CONCLUSIONS As residents are persistently exposed to a wide array of pollutants, comprehensive and adequate measures are required to prevent potential exposures. KEYWORDS Settled house dust; OPFR; Plasticizer; Alternative plasticizer; House dust mite allergens

Clinical significance of sensitization to house dust mite allergens using flow cytometry-based basophil activation test

Respiratory allergy takes a significant place among allergic diseases. Similar clinical manifestations occur in sensitized patients in response to various airborne allergens. Accordingly, the allergen testing by means of in vivo and in vitro techniques is necessary to identify a causally significant allergen. The main laboratory assay to estimate sensitization to the airborne allergens is based on detection of specific immunoglobulin E (sIgE). However, clinical manifestations cannot be always confirmed by this test. The aim of this work was to evaluate the potential of basophil activation test (BAT) using flow cytometry, in order to confirm sensitization to house dust mite allergens. The BAT was carried out with allergens from Dermatofagoides in 34 volunteers, 130 patients were examined at the Russian Centre of Emergency and Radiation Medicine (33 people with household and 97 people with polysensitization), and 10 patients with allergy to house dust mites confirmed by skin testing. The sensitization was assessed using two laboratory kits (Allergenicity and BD FastImmune). The total IgE and sIgE to house dust mites, as well as concentrations of eosinophilic cationic protein, were determined. Specificity of the BAT with Allergenicity kit for the house dust mites was 94%. The sensitivity was 88% in the patients with household sensitization, thus being comparable with skin testing results available from the literature. An absolute correlation was found between positive results of skin testing and the BAT. In patients with household sensitization, sIgE levels > 0.35 UA/mL were detected in 39% of cases. A positive correlation was shown between the indices of basophil activation in response to testing allergens, and total immunoglobulin E and sIgE concentrations. High degree of correlation was found between the results of Dermatofagoides sensitization testing with both BAT kits. It was shown that the use of H1 histamine receptor blockers had no effect on BAT results. A decrease in sensitivity assay for airborne allergens was revealed upon therapy with glucocorticosteroids. Due to the proven clinical significance of the basophil activation test for diagnosing sensitization to inhaled allergens, one may require to supplement the range of approved assays in Russian Clinical Guidelines with BAT testing to prove sensitization in patients with allergic rhinitis and bronchial asthma, thus contributing to better diagnosis of causally significant allergens and, accordingly, administration of proper therapy.

Comparison of sensitization patterns to dust mite allergens between atopic dermatitis patients and dogs, and non-specific reactivity of canine IgE to the storage mite Tyrophagus putrescentiae.

House dust mite is a common cause of atopic dermatitis (AD) both in humans and dogs. Detection of serum IgE to allergens is commonly used to diagnose allergic diseases. However, false-positive reactions due to cross-reactivity and non-specific reactivity may lead to misdiagnosis. We compared human and canine IgE reactivities to mite component allergens. Canine IgE-reactive components of Dermatophagoides farinae and Tyrophagus putrescentiae were identified by tandem mass spectrometry. Recombinant proteins were produced and IgE reactivities to component allergens were assessed by ELISA and inhibition assays using sera from AD patients and dogs. Canine IgE-reactive proteins (Der f 1, Der f 11, Tyr p 4, Tyr p 8, Tyr p 11, Tyr p 28) were identified by proteome analysis. Most patients were sensitized to Der f 1 (93.3%) and Der f 2 (86.7%). Dogs showed high sensitization to Der f 2 (94.1%) and Der f 18 (84.6%). Both patients and dogs showed low IgE binding frequency to Tyr p 8, 43.3% and 4%, respectively. The ELISA inhibition study indicated that canine IgE reactivity to T. putrescentiae is mostly due to non-specific reaction and cross-reaction with D. farinae. Different IgE sensitization patterns were shown between allergic humans and dogs with AD, especially to Der f 18, for the first time in Korea. Furthermore, non-specific canine IgE reactivity to storage mite indicates the possibility of misdiagnoses. Standardizations focused on the major canine allergen content of extracts should be developed. This will allow precision diagnosis and individuated treatments for each patient and atopic dog.

Efficacy and safety of subcutaneous immunotherapy with a mixture of glutaraldehyde-modified extracts of Dermatophagoides pteronyssinus, Dermatophagoides farinae, and Blomia tropicalis

BackgroundAllergen Immunotherapy (AIT) is an effective treatment of allergic respiratory diseases induced by the inhalation of house dust mite allergens. ObjectivesTo evaluate the efficacy and safety of glutaraldehyde polymerized allergen extracts using a mixture of Dermatophagoides pteronyssinus, D. farinae and Blomia tropicalis in mite allergic individuals residing in Colombia. MethodsTwo hundred and fifty (250) patients with allergic rhinoconjunctivitis with, or without asthma and sensitized to D. pteronyssinus, D. farinae and B. tropicalis were included. A glutaraldehyde-modified extract containing a mixture of D. pteronyssinus, D. farinae and B. tropicalis was employed, using a cluster up-dosing schedule followed by a monthly maintenance dose. The primary endpoints to evaluate the clinical impact were the Combined Symptom and Medication Scores (CSMS) for allergic rhinitis, the Asthma Control Test (ACT) and the reduction in medication consumption. ResultsSignificant improvement was found after 3 months of treatment regarding CSMS (p < 0.0001) and ACT (p < 0.0001). Additionally, a significant decrease in medication consumption was found after 3 months of treatment (p < 0.0001). Adverse reactions, either local or systemic were mild and no severe reactions related to the vaccines were observed. ConclusionAfter 12 months of allergen immunotherapy, glutaraldehyde-modified mixture of D. pteronyssinus, D. farinae and B. tropicalis proved to be safe and effective in the treatment of patients with rhinoconjunctivitis with or without asthma due to allergy to mites.

The molecular diagnosis of house dust mite allergy: a short review

Introduction: House dust mite (HDM) allergens are considered among the most essential elicitors of allergic rhinitis and asthma worldwide [1]. How can we determine the individual sensitization profile of a patient? Is there a way to monitor the development of allergic symptoms? Is it possible to tailor different forms of therapy based on the individual sensitization profile of a patient?&#x0D; Purpose: The study aims to show the benefits of molecular diagnostics of allergies based on the example of HDM allergy.&#x0D; Description of the state of knowledge: Clinical manifestation is the most important aspect of diagnosing HDM allergy. The determination of allergen specific immunoglobulins E (asIgE) against HDM extracts may be helpful in the identification of the cause of allergy symptoms. However, the diagnosis using allergen extracts cannot be established in all cases. What revolutionised the diagnosing process of HDM allergy is the molecular diagnostics of allergy. Based on the presence of asIgE against allergen molecules it is possible to identify the allergen responsible for the sensitisation as well as personalise the therapeutic recommendations. &#x0D; Summary: The molecular diagnostics of allergy significantly improved the specificity and sensitivity of HDM allergy diagnostics. Molecular diagnostics in individuals with HDM allergy make it possible to establish the individual patient’s allergy profile, and consequently personalise therapeutic recommendations. It is especially important regarding the selection of patients who may benefit from immunotherapy. The component-resolved diagnostics in allergology is a step toward personalised medicine.

Detection and assessment of dust mite allergens in an indoor environment in Anhui, China

Dust in the home environment is thought to be a potential trigger for increasing allergic diseases, such as allergic rash, rhinitis, asthma, and other conditions, associated with dust mites. To verify the status of dust mite prevalence in indoor surroundings, we collected 189 dust samples from the air conditioner filters (n = 75) and floors (n = 114) of households, schools, and hotels in the Anhui area, China. All samples were measured for dust mite breeding rate and breeding density under light microscopy and analyzed for dust mite species Dermatophagoides farinae 1 (Der f 1) and Dermatophagoides pteronyssinus 1 (Der p 1) allergen using enzyme-linked immunosorbent assay (ELISA). The dust mite breeding rates were 34.67% (26/75) and 20.18% (23/114), respectively, in the dust samples from the floor and air conditioning filters. The breeding density was the highest in households (10/g), followed by schools (9/g) and hotels (4/g). ELISA indicated that the allergen threshold (2.0 µg/g dust) of Der f 1 was exceeded in only two samples and Der p 1 in one sample. Additionally, a questionnaire was used to investigate the health knowledge on allergic diseases involved in indoor facilities, finding that most allergy sufferers were aware that indoor dust might be responsible for their conditions. The findings suggest that regular maintenance of indoor hygiene and cleaning of air-conditioning filters should reduce the risks of exposure to indoor allergens.

House dust mite-induced Akt-ERK1/2-C/EBP beta pathway triggers CCL20-mediated inflammation and epithelial-mesenchymal transition for airway remodeling.

House dust mite (HDM) allergens cause inflammatory responses and chronic allergic diseases such as bronchial asthma and atopic dermatitis. Here, we investigate the mechanism by which HDM induces C-C chemokine ligand 20 (CCL20) expression to promote chronic inflammation and airway remodeling in an HDM-induced bronchial asthma mouse model. We showed that HDM increased CCL20 levels via the Akt-ERK1/2-C/EBPβ pathway. To investigate the role of CCL20 in chronic airway inflammation and remodeling, we made a mouse model of CCL20-induced bronchial asthma. Treatment of anti-CCL20Ab in this mouse model showed the reduced airway hyper-responsiveness and inflammatory cell infiltration into peribronchial region by neutralizing CCL20. In addition, CCL20 induced the Nod-like receptor family, pyrin domain containing 3 (NLRP3) inflammasome activation through NLRP3 deubiquitination and transcriptional upregulation in BEAS-2B cells. As expected, anti-CCL20Ab markedly suppressed NLRP3 activation induced by CCL20. Moreover, HDM-induced CCL20 leads to epithelial-mesenchymal transition in the lung epithelium which appears to be an important regulator of airway remodeling in allergic asthma. We also found that anti-CCL20Ab attenuates airway inflammation and remodeling in an HDM-induced mouse model of bronchial asthma. Taken together, our results suggest that HDM-induced CCL20 is required for chronic inflammation that contributes airway remodeling in a mouse model of asthma.

Dermatophagoides pteronyssinus allergen Der p 22: Cloning, expression, IgE‐binding in asthmatic children, and immunogenicity

Dust mite extract contains multiple components that, while useful in clinical allergy diagnosis and treatment, can cause serious side effects. Defining components of dust mite extract is important their contributions to allergic disease. This study aimed to characterize a novel dust mite allergen, Der p 22. We amplified the cDNA encoding Der p 22 from total RNA of the mite Dermatophagoides pteronyssinus, and inserted it into an expression construct for transformation to competent cells. Purified recombinant (r) Der p 22 was tested for IgE-binding reactivity in sera obtained from children with allergic asthma by the Affiliated Wuxi Children's Hospital of Nanjing Medical University (Jiangsu, China). rDer p 22 also was used to challenge BALB/c mice to assess effects on T helper cells and cytokine levels and applied to cultured lung epithelial cells to evaluate apoptosis and cytokine secretion. rDer p 22 bound to IgE in 93.75% of sera from pediatric allergic asthma patients. Mice challenged with rDer p 22 had altered Th1/Th2 ratios in spleen and lymph, and lower levels of cytokines IFN-γ but higher levels of IL-4 and IL-10 in alveolar lavage fluid compared with controls (p < .05). Cultured lung epithelial cells had greater apoptosis rates and exhibited higher levels of IL-6, IL-8, and GM-CSF when treated with rDer p 22 compared with control treatment (p < .05). Recombinant Der p 22 exhibited high IgE-binding rates in allergic children, indicating the activity of the recombinant protein and suggesting this novel allergen may be appropriate for inclusion in an allergy diagnostic workup. This finding is supported by in vitro and mouse in vivo studies showing rDer p 22 induced strong allergenic reactivity and apoptosis.

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

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

Role of ventilation and cleaning for controlling house dust mite allergen infestation: A study on associations of house dust mite allergen concentrations with home environment and life styles in Tianjin area, China.

House dust mites produce well-known allergens for asthma and allergy among children. To study house dust mite allergen exposure level in northeast China and characterize its association with indoor environmental factors and cleaning habits, we inspected 399 homes in Tianjin area and collected dust from mattresses. Dermatophagoides farinae (Der f) and Dermatophagoides pteronyssinus (Der p) were detected by the enzyme-linked immunosorbent assay (ELISA) method. The medians of total allergen concentrations for spring, summer, autumn, and winter were 524 ng/g, 351 ng/g, 1022 ng/g, and 1010 ng/g. High indoor air relative humidity (RH), low air change rate, indoor dampness, and frequent changing of quilt cover/bedsheet/pillow case were significantly associated with high house dust mite allergen concentration (relative risk [RR]: RH, 1.18-1.34; air change rate, 0.97-1.00; dampness, 2.92-3.83; changing quilt cover/bedsheet/pillow case, 0.66-0.75). The decrease in the absolute humidity gradient between indoors and outdoors that occurs with increased air change rate may explain why a high ventilation reduces house dust mite allergen concentration. The findings of this study show the importance of ventilation and cleaning for controlling house dust mite allergens. We found that the decrease in additional absolute humidity (e.g., humidity indoor -humidity outdoor ) with increased air change rate may be the main reason that a high ventilation rate reduces house dust mite allergen concentration. Ventilation and cleaning should be both considered for creating a healthy home environment.

House Dust Mite and Grass Pollen Allergen Extracts for Seasonal Allergic Rhinitis Treatment: A Systematic Review.

Background: The treatment of allergic rhinitis is important due to the burden that the disease causes globally. The objective of this review is to explore the efficiency of house dust mite and grass pollen extracts in allergic rhinitis treatment.Methods: We performed research in electronic databases and searched relevant articles on PubMed, CINAHL, OVID, ScienceDirect, Cochrane CENTRAL, and MEDLINE. We used keywords such as ‘allergic rhinitis', ‘sublingual immunotherapy’, ‘randomized controlled trials', ‘grass pollen’, 'allergen immunotherapy’, and ‘house dust mite’. We included nine randomized controlled trials (RCTs). Quality assessment of included studies was performed independently by two authors.Results: We included nine eligible RCTs in this review. Five RCTs were about grass pollen extracts and four RCTs were about house dust mite extracts. Most of the studies reported positive results and suggested further evaluation of sublingual immunotherapy (SLIT) treatment. Grass pollen extracts mostly used were Dactylis glomerata, Poa pratensis, Lolium perenne, Anthoxanthum odoratum, Phleum pratense, and Parietaria. House dust mite extracts used were from Dermatophagoides pteronyssinus and Dermatophagoides farina. According to the quality assessment, no bias was observed in the included studies.Conclusions: Although sublingual allergen immunotherapy shows a benefit compared to placebo in the treatment of allergic rhinitis and rhino-conjunctivitis in adults, the results are interpreted with caution due to the high heterogenicity among studies in treatment protocols and dosing. More standardization among studies is needed.