Pteronyssinus Allergen Research Articles

Assessment of Hypersensitivity to House Dust Mites in Selected Skin Diseases Using the Basophil Activation Test: A Preliminary Study

Background and Objectives: Allergy to dust mites (HDMs) plays an important role in atopic dermatitis (AD). However, the role of this allergy in other dermatoses is little known. The aim of this study was to assess hypersensitivity to HDMs in patients with AD or hand disease using the basophil activation test. Material and Methods: A total of 52 patients with AD, 57 with hand eczema disease, and 68 healthy volunteers qualified for this study. Diagnosis was based on the Hanifin and Rajka criteria, dermatological assessment, and exclusion of other dermatoses. The participants underwent skin prick tests (SPTs), a basophil activation test (BAT) with D. pteronyssinus allergen extract, and the concentration of specific IgE (sIgE) for the same allergen in blood serum was determined. Results: Positive results in all tests (SPT, sIgE, and BAT) were obtained (24 (46.2%) patients with AD, 9 (15.8%) with hand disease, and none in the control group for p < 0.05). The results of the SPT, sIgE, and BAT correlated with each other in the AD and hand eczema groups (Spearmen correlation test, r = 0.72 or 0.85, p < 0.05). However, the BAT was positive more often than the SPT and sIgE for D. pteronyssinus. Conclusions: House dust mite hypersensitivity is common in patients with AD and eczema. The BAT may be more sensitive for assessing sensitization to house dust mites, especially in patients with hand eczema.

Optimization of Basophil Activation Test in the Diagnosis and Qualification for Allergen-Specific Immunotherapy in Children with Respiratory Allergy to the House Dust Mite Dermatophagoides pteronyssinus.

The aim of this study was to optimize a basophil activation test in the detection of allergy to the house dust mite Dermatophagoides pteronyssinus in children with allergic respiratory diseases. This study involved 32 cases, 13 girls and 19 boys aged 4-17 years, with perennial asthma or allergic rhinitis caused by D. pteronyssinus. The control group consisted of 13 girls and 19 boys aged 4-17 years with seasonal allergic asthma or rhinitis provoked by Timothy or birch pollen. House dust mite (HDM) allergy was excluded in the controls based on their medical history, skin prick test (SPT) results and sIgE determination. In all patients, a basophil activation test (BAT) was performed with five dilutions of D. pteronyssinus allergen (the dilution series ranged from 22.5 to 0.00225 ng/mL). The results were analyzed by using the receiver operating characteristics (ROC) to determine the optimal allergen concentrations, outcome measures and cut-off points that would differentiate most accurately between HDM-allergic and non-allergic patients. As a "gold standard", criteria for allergen-specific immunotherapy with D. pteronyssinus or respective pollens were applied by an experienced pediatric allergist following the guidelines of the European Academy of Allergy and Clinical Immunology. The highest diagnostic efficiency was yielded by the protocol assuming a cut-off value of 9.76% activated basophils after activation with a single allergen concentration of 2.25 ng/mL (sensitivity 90.6%, specificity 100%). This protocol yielded 3 (4.7%) misclassifications, all false negative, when compared with the "gold standard". There was a strong correlation with the BAT results at 22.5, 2.25 and 0.225 ng/mL (respectively r = 0.90 and r = 0.78, p < 0.001), as well as between the BAT at 2.25 ng/mL and SPT (r = 0.82, p < 0.001) and between the SPT and sIgE levels (r = 0.78, p < 0.001). High cross-reactivity between D. pteronyssinus and D. farinae was confirmed based on the BAT at 22.5 ng/mL (r = 0.82, p < 0.001). In conclusion, the BAT showed very good concordance with the result of a meticulous process of decision-making that combined validated allergy tests (SPT, sIgE) with expert guidelines, specialist knowledge and experience. Facing the risk of the incorrect qualification of patients for costly, long-lasting and potentially risky allergen-specific immunotherapy, the inclusion of a basophil activation test into diagnostic process seems fully justified.

Severity Assessment and IL-5 Evaluation after Immunotherapy in Atopic Dermatitis Mice

Background: The effectiveness of immunotherapy in atopic dermatitis (AD) has been debated for many years. Immunotherapy suppresses Th2 cytokines, such as IL-5, which play a crucial role in the pathogenesis of AD. This study assessed the effect of immunotherapy on severity and IL-5 expression in AD mice.Methods: Male BALB/c mice were separated into three groups. The mice were sensitized with Dermatophagoides pteronyssinus allergen for seven days, except the mice in control group. The house dust mite (HDM) immunotherapy was injected subcutaneously every 3 days for 1.5 months with increasing doses (0.1, 1, 10, 100 μg in 100 μL PBS) every 4 injections. The mice in AD model and control group received placebo injections. Following immunotherapy, the mice were exposed to HDM allergen patch two times with 2 weeks interval in between. The mice were evaluated for severity score as the clinical marker and IL-5 expression with semiquantitative method as the histological marker.Results: The evaluation of severity score from two independent researchers showed a substantial agreement (Cohen’s kappa 0.613, p &lt;0.001). The severity score of the immunotherapy group was significantly lower than the AD model group, while both immunotherapy and AD model group had significantly higher score than control group. IL-5 expression in the immunotherapy group was lower than the AD model group and slightly higher than control group. The mean difference between groups was not significant.Conclusion: The severity of skin lesion and IL-5 expression in AD mice receiving immunotherapy were lower than AD model group.Keywords: Atopic dermatitis; BALB/c mice; House dust mites; IL-5, Skin severity score; Tropical disease

Establishment of fluorescence multi-flow cytometric immunoassay for the simultaneous quantitative detection of six allergen-sIgE antibodies

BackgroundThe in vitro specific IgE (sIgE) assays now commonly used in clinical laboratories are not only time-consuming and expensive but also require many serum samples. To address these limitations, a novel fluorescent microsphere-based multiplex flow cytometric immunoassay was developed. This innovative assay enables rapid and simultaneous quantitative detection of multiple allergen-sIgE antibodies. ObjectiveTo establish a new method for the simultaneous quantitative detection of 6 allergen-sIgE antibodies based on fluorescence multiplex flow cytometry. MethodsSix different encoded fluorescent microspheres were selected to covalently couple 6 allergens, and their antigen-coupling activities were verified. After optimizing the multiplexing procedure and reaction conditions, including the concentration of microspheres encapsulated by allergens, reaction temperature, and reaction time, standard curves were established to quantify the 6 allergen-sIgE, and their performance was evaluated according to clinical guidelines. ResultsThe chosen analytical mode was optimized for the detection of the 6 allergens-sIgE for 70 minutes. The established coefficients of variation for multiplex flow cytometry reproducibility and intermediate precision were less than 10%. Linear regression analysis showed a highly significant quantitative correlation between the results of the multiple analyses of Dermatophagoides pteronyssinus, Dermatophagoides farinae, Artemisia, and cat hair allergens and ImmunoCAP (Thermo Fisher Scientific): the r2 values ranged from 0.85 to 0.97 (P < .0001). In addition, there was a high correlation between the results of the multiplex analysis of dog hair allergens and the capture enzyme-linked immunosorbent assay (r2 = 0.92, P < .0001). ConclusionA high-throughput system called multiplex flow cytometry has been developed for the simultaneous detection of 6 inhalant allergens. The method has the advantage of being rapid and using less serum. Furthermore, it has the potential to be expanded to include other allergens and biologic agents.

Comparison of intradermal and serum testing for environmental allergen-specific immunoglobulin E determination in a laboratory colony of cats with naturally acquired atopic syndrome.

Allergen testing is used to select antigens included in the desensitisation vaccine. Intradermal skin test (IDT) is the gold standard in cats, yet allergen-specific immunoglobulin (Ig)E serological testing (ASIS) is often used. Feline data are lacking regarding the agreement between IDT and ASIS results. The first objective of the study was to establish a colony of cats with naturally acquired feline atopic syndrome (FAS). Further objectives were to define their hypersensitivity disorder to detail the allergen tests results, and to assess similarity between the allergen tests. Thirty-five cats with FAS and 10 control cats. Enrolled cats went through a five phase-screening and quarantine process before joining the colony. An elimination diet trial was performed on all FAS cats. ASIS and IDT were consecutively performed on all cats under sedation. Reactions to 34 allergens were compiled for the 45 cats. Global sensitivity and specificity of ASIS were 34.7% and 78.9%, respectively. Only flea (ICC = 0.26, p = 0.040) and Dermatophagoides pteronyssinus (ICC = 0.48, p < 0.001) allergens had a significant intraclass correlation (weak agreement). Two FAS cats had negative tests including one cat with a concomitant food allergy. This study depicts the first reported colony of cats with naturally acquired FAS. This is the first feline study to compare and show the poor agreement between allergen tests with a panel of 34 allergens. This colony also harbours two cats with FAS with negative allergen tests. These may represent the first described cats with an intrinsic form of atopic syndrome.

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

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. 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. 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. 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.

Oral administration of Lactobacillus delbrueckii subsp. lactis LDL557 attenuates airway inflammation and changes the gut microbiota in a Der p-sensitized mouse model of allergic asthma.

Atopic dermatitis (AD) is a chronic inflammatory skin disorder affecting up to 20% of children in developed countries. Although probiotics have shown promise as adjuvant treatments for AD, their mechanisms are not well understood. Building upon our previous studies, we investigated whether Lactobacillus gasseri and its moonlighting glyceraldehyde 3-phosphate dehydrogenase (GAPDH), namely LGp40, could be beneficial in AD management. In AD mouse models (SKH and C57BL/6J mice) with ovalbumin (OVA) and Dermatophagoides pteronyssinus (Der p) allergens, aligning with the "outside-in" and "inside-out" hypotheses, we administered L. gasseri orally and LGp40 intraperitoneally to investigate their protective effects. The evaluation involved measuring physiological, pathological, and immune function parameters. To delve deeper into the detailed mechanism of LGp40 protection in AD, additional assays were conducted using human skin keratinocytes (HaCaT) and monocytes (THP1) cell lines. L. gasseri and LGp40 enhanced skin barrier function and increased skin moisture retention. They also led to reduced infiltration of Langerhans cells in the dermis and mitigated skewed Th2 and Th17 immune responses. Moreover, LGp40 inhibited allergen-induced keratinocyte apoptosis through the blockade of the caspase-3 cascade and reduced the NLR family pyrin domain containing 3 (NLRP3) inflammasome in macrophages. These inhibitions were achieved through the activation of the peroxisome proliferator-activated receptor gamma (PPARγ) pathway. The results of this study provide a novel insight into the mechanism of action of probiotics in the prevention and treatment for allergic disorders through the moonlighting GAPDH protein.

A Case-Control Study Comparing the General Characteristics of Patients with Symptomatic Dermographism and Chronic Spontaneous Urticaria: Is Atopy a Risk Factor for Symptomatic Dermographism?

Introduction: Symptomatic dermographism (SDerm) is the most common chronic inducible urticaria (CIndU) subtype. There is still limited information in the literature about clinical features, triggering factors, and accompanying comorbidities of SDerm. The aim of this study was to compare the clinical features and laboratory data of patients with SDerm and chronic spontaneous urticaria (CSU). Methods: The clinical features and laboratory data of patients with SDerm and CSU were compared retrospectively. The laboratory data and general characteristic features of the patients were obtained from the medical records. Results: The study included a total of 361 patients (CSU: 220, SDerm: 141). The rates of asthma (odds ratio [OR]: 1.79, p = 0.036), allergic rhinitis (OR: 6.03, p < 0.001), and thyroid disease (OR: 1.78, p = 0.039) were higher in patients with SDerm. The disease duration (median 12 months, p < 0.001) and regular antihistamine use (OR: 0.31, p < 0.001) were lower in patients with SDerm. Total IgE level (median: 193, p < 0.001), thyroid antibody positivity (OR: 1.93, p = 0.039), and atopy (OR: 8.81, p < 0.001) were higher in patients with SDerm. Dermatophagoides pteronyssinus (OR: 17.72, p < 0.001), Dermatophagoides farinae (OR: 17.20, p < 0.001), grass pollen (OR: 2.50, p < 0.026), cat epithelium (OR: 3.68, p < 0.023), and cockroach (OR: 4.93, p < 0.009) allergen positivity rates were higher in patients with SDerm. Conclusion: Atopic diseases such as asthma and allergic rhinitis and the sensitization rate to aeroallergens seem to be higher in patients with SDerm than in patients with CSU. The results of this study should be supported by multicenter studies of patients from different geographical regions.

Efficacy and Safety of Sublingual Immunotherapy using a Combination of Dermatophagoides Pteronyssinus and Blomia Tropicalis Extracts in Patients with Allergic Rhinitis: A Randomized, Double-Blind, Placebo-Controlled Trial

The aim of this study was to evaluate the safety and efficacy of sublingual immunotherapy (SLIT) with extracts of Dermatophagoides pteronyssinus and Blomia tropicalis in patients with moderate/severe persistent allergic rhinitis (AR). Methods: This was a double-blind, randomized, placebo-controlled trial of SLIT for the treatment of house dust mite-induced AR. A total of 65 patients, aged between 12 and 60 years, were treated for 12 months and randomized into two groups: SLIT and placebo. The SLIT group received a combination of extracts containing Dermatophagoides pteronyssinus and Blomia tropicalis allergens. All had their sensitization confirmed by skin prick test or serum-specific IgE. Total Nasal Symptom Score, RQLQ quality of life questionnaire, current treatment, and need for medication to control symptoms were recorded during the study. Total serum IgE, serum specific IgE, and IgG4 levels to Der p 1 and Blo t were assessed at baseline, 6 and 12 months after treatment. Results: There was no significant difference in the number of adverse events between groups. The SLIT group showed a significant reduction in the consumption of antihistamines to control symptoms (p &lt; 0.0001) when compared to placebo. There was no significant change in serum total IgE, serum specific IgE, and IgG4 to both allergens when comparing the SLIT and placebo groups. Conclusion: After one year, SLIT using a dose of 1 mcg of Der p 1/day and 753 UBE of Blo t/day proved to be effective and safe in controlling AR exacerbations.

The relationship of D. pteronyssinus allergic component sIgE and sIgG4 in house dust mite allergic rhinitis or/and allergic asthma patients

Objective: House-dust mite sensitization is an important cause of allergic asthma and/or rhinitis in southern China. This study aimed to analyze the immune effect and relationship between the Dermatophagoides pteronyssinus components specific immunoglobulin E (sIgE) and sIgG₄. Methods: The serum levels of sIgE and sIgG₄ to D. pteronyssinus allergen components Der p 1, 2, 3, 5, 7, 10, and 23 were detected in 112 patients with allergic rhinitis (AR) and/or allergic asthma (AA). Results: Overall, Der p 1 had the highest positive rate of sIgE (72.3%), followed by Der p 2 (65.2%) and Der p 23 (46.4%). Meanwhile, the highest positive rates of sIgG₄ were for Der p 2 (47.3%), Der p 1 (33.0%), and Der p 23 (25.0%). The patients with AR and AA had a higher positive rate (43.4%) of sIgG₄ than that in the patients with AR (42.4%) and the patients with AA (20.4%; p = 0.043). In patients with AR, the positive rate of sIgE in Der p 1 (84.8%) was higher than that in sIgG₄ (42.4%; p = 0.037), but the positive rate of sIgG₄ in Der p 10 (21.2%) was higher than that in sIgE (18.2%; p < 0.001). Most of the patients were positive for sIgE and sIgG₄ of Der p 2 and Der p 10 at the same time. However, positive results for sIgE alone were just found in Der p 7 and Der p 21. Optimal scale analysis showed that Der p 2, Der p 7, and Der p 21 sIgG₄ were closely related to AR and AA (Cronbach α = 0.917). Conclusion: Herein, the D. pteronyssinus allergen components showed different characteristics among the patients with AR, patients with AA, and patients with AR and AA in southern China. Thus, sIgG₄ may be play an important role in allergic reactions.

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.

Effect of Dermatophagoides pteronyssinus extract on the expression of genes involved in inflammation and tissue remodeling by peripheral blood mononuclear cells of allergic asthma patients

PurposeHouse dust mite allergy constitutes a risk factor for asthma development and is associated with a faster decline of lung function in allergic asthmatics (AAs).To evaluate the effect of Dermatophagoides pteronyssinus (Dp) allergens on the expression of genes involved in inflammation and tissue remodeling by peripheral blood mononuclear cells (PBMCs) isolated from the blood of AAs. Materials and methodsThe cells from AAs, allergic rhinitis without asthma patients (ARs), and healthy controls (HCs) were cultured in the presence of Dp, lipopolysaccharide (LPS), or without any stimulation. The expression of 84 genes was evaluated using a low-density microarray whereas, the quantitative expression analysis of selected genes was performed using a real-time polymerase chain reaction. The concentration of selected proteins in the cell culture supernatants was assessed using ELISA. ResultsStimulation of PBMCs with Dp and LPS resulted in a significant upregulation of 8 and 15 among 84 studied genes, respectively. The greatest upregulation was observed for CCL2 and CCL3 using Dp and LPS, respectively. In comparison with HCs, in AAs, significantly increased upregulation of CCL2 in response to Dp was found. The secretion of CCL2 and CCL3 by PBMCs reflected the pattern of gene expression at the mRNA level. The mean Dp-stimulated secretion of CCL2 by PBMCs of ARs was less than in AAs (p ​< ​0.01), both being notably greater than in the HCs (p ​< ​0.01). ConclusionRapid and potent upregulation of CCL2 expression by PBMCs in response to Dp may constitute an important contribution to the development of allergic asthma.

Identification of an immunodominant IgE epitope of Der p 39, a novel allergen of Dermatophagoides pteronyssinus

BackgroundHouse dust mites (HDMs) are the main source of indoor inhalatory allergens that cause IgE-mediated allergic diseases. The discovery and identification of HDM allergens are important for the diagnosis and treatment of allergic diseases. ObjectiveWe sought to identify a Group 39 Dermatophagoides pteronyssinus (Der p) allergen, namely Der p 39, and explore its immunodominant IgE epitopes. MethodsHomology analysis of amino acid (aa) sequences in HDM and human troponin C (TnC)-like protein was performed. Total RNA of Der p was extracted and used to amplify Der p 39 cDNA with specific primers. Recombinant Der p 39 protein was expressed with a pET-His prokaryotic expression system and purified with Ni-NTA resins. IgE binding was evaluated with western blot, dot blot, and enzyme-linked immunosorbent assay (ELISA) experiments. The IgE binding epitopes of Der p 39 were identified by observing HDM-allergic sera interactions with truncated and hybrid proteins formed from Der p 39 and human TnC-like proteins. ResultsThe Der p 39 open reading frame (ORF) cDNA was found to be 462 base pairs and registered in the NCBI library (GenBank no. MZ336019.1). Der p 39, which encoded 153 aa, was found to have 35.63% and 99.35% homology with human TnC and Dermatophagoides farina (Der f) 39, respectively. IgE-ELISA showed IgE binding with expressed and purified recombinant Der p 39 (18 kDa) in 5/87 (5.75%) HDM-allergic sera samples. Analyses of IgE binding with Der p 39-based truncated and hybrid proteins indicated that IgE binding epitopes are likely located in the C-terminal region and dependent on conformational structure. The data from this study were submitted to the World Health Organization and International Union of Immunological Societies (WHO/IUIS) Allergen Nomenclature database. ConclusionDer p 39 was identified as a minor HDM allergen with a conformational IgE binding epitope. These findings could have important theoretical implications in the development of HDM allergy diagnostics and therapeutics.

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.

IgE recognition of the house dust mite allergen Der p 37 is associated with asthma

House dust mite (HDM) allergens are major elicitors of allergic reactions worldwide. Identification, characterization, and evaluation of diagnostic utility of a new important HDM allergen was performed. A cDNA coding for a new Dermatophagoides pteronyssinus (Dp) allergen, Der p 37, was isolated from a Dp expression library with allergic patients' IgE antibodies. Recombinant Der p 37 (rDer p 37) expressed in Escherichia coli was purified, then characterized by mass spectrometry, circular dichroism, and IgE reactivity by ImmunoCAP ISAC technology with sera from 111 clinically defined HDM-allergic patients. The allergenic activity of rDer p 37 was studied by basophil activation and CD4+ T-cell responses by carboxyfluorescein diacetate succinimidyl ester dilution assays. Specific antibodies raised against rDer p 37 were used for the ultrastructural localization of Der p 37 in mites by immunogold transmission electron microscopy. Der p 37, a 26 kDa allergen with homology to chitin-binding proteins, is immunologically distinct from Der p 15, 18, and 23. It is located in the peritrophic membrane of fecal pellets. Der p 37 reacted with IgE antibodies from a third of HDM-allergic patients and induced specific basophil- and CD4+ T-cell activation. Der p 37 IgE-positive patients had significantly higher IgE levels to major HDM allergens, reacted with more HDM allergens, and had a higher risk (odds ratio=3.1) of asthma compared to Der p 37-negative patients. Der p 37, a new Dp allergen recognized by a third of HDM-allergic patients, may serve as a surrogate marker for severe HDM sensitization and asthma.

Differential Correlations among Allergy Tests According to Indoor Allergens in Allergic Rhinitis

Several allergy tests are used for the diagnosis of allergic rhinitis; however, few studies have reported a direct comparison of the skin prick test (SPT), multiple allergen simultaneous test (MAST), and ImmunoCAP according to specific allergens. This study aimed to evaluate the correlations between each test and allergic rhinitis symptoms and to evaluate the correlations of the MAST and ImmunoCAP with the SPT for representative indoor allergens in Korea. Electronic medical charts were retrospectively reviewed, and 698 patients with allergic rhinitis who had performed SPT, MAST, and ImmunoCAP were enrolled. Correlations between each allergy test for 4 representative indoor allergens and the symptoms of allergic rhinitis were analyzed. Agreements of the MAST and ImmunoCAP with the SPT were compared according to each allergen. The SPT showed higher correlations with allergic rhinitis symptoms for 4 indoor allergens (Dermatophagoides pteronyssinus, Dermatophagoides farinae, cat, and dog allergens) than the MAST or ImmunoCAP. In comparison between the MAST and SPT, the least correlation was observed for the dog allergen, whereas between the ImmunoCAP and SPT, the least correlation was observed for the cat allergen. The correlation between the ImmunoCAP and SPT was higher than that between the MAST and SPT for the dog allergen, whereas no significant differences were noted for other allergens. Overall, the SPT showed a higher correlation with allergic rhinitis symptoms than the MAST or ImmunoCAP for 4 indoor allergens. ImmunoCAP showed similar reactivity to MAST; however, it showed better positivity with dog allergen in patients who were reactive to the allergen in the SPT. Care should be taken while evaluating dog allergen sensitization using the MAST.

Expression of cPLA2γ mRNA and protein differs the response of PBMC from severe and non-severe asthmatics to bacterial lipopolysaccharide and house dust mite allergen

Chronic inflammation in asthmatics is initiated/exacerbated by many environmental factors, such as bacterial lipopolysaccharide and allergens. Phospholipase A2 and histone acetyltransferase/deacetylases are enzymes involved in inflammatory process, particularly in lipid inflammatory mediators production and control of transcription of many inflammatory genes, respectively. The aim of the study was to identify differences in the inflammatory process in patients with severe and non-severe asthma, taking as a criterion expression of two groups of enzymes: phospholipases A2 and histone acetyltransferases/deacetylases. Thirty-two patients with severe, non-severe atopic to house dust mite asthmatics and 14 healthy volunteers were recruited. Peripheral blood mononuclear cells were stimulated with Dermatophagoides pteronyssinus allergen (nDer p1) and bacterial lipopolysaccharide (LPS). The expression of phospholipases A2 and histone acetyltransferases and deacetylases were assessed using TaqMan Low Density Array Cards. The protein expression was analyzed with immunoblot. Increased expression of phospholipase A2 Group IVC (PLA2G4C) and cytosolic phospholipase A2 gamma (cPLA2γ) protein was observed in peripheral blood mononuclear cells (PBMC) from severe asthmatics in response to LPS and nDer p1, compared to non-severe asthmatics. nDer p1-stimulated PBMC from severe asthmatics exhibit induced expression of HDAC1 and similar trend was observed in protein concentration. Decreased expression of EP300 occurred in PBMC of severe asthmatics. PBMC from non-severe asthmatics showed decreased expression of HDAC2 and PLA2G15 after LPS treatment. In conclusion, in response to LPS and dust mite allergen, PBMC from severe and non-severe asthmatics modulate expression of selected phospholipase A2, histone acetyltransferases and deacetylases, while increased expression of cPLA2γ characterizes PBMC response from severe asthmatics.

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

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

Dendritic cell-CD4+ T cell interaction: The differential role of IL-4/IL-13 in serum IgE levels in house dust mite allergic patients.

Allergic asthma is a chronic airway inflammatory disorder triggered by inhalant allergens. Interleukin (IL)-4 and IL-13 play a main role in the generation of T helper cell type 2 (Th2) immune response, induction of immunoglobulin E (IgE) synthesis and persistence of airway inflammation. The aim of the present study was to investigate the influence of Dermatophagoides pteronyssinus allergen Der p 1, the major allergen of house dust mite, on the synthesis of IL-4 and IL-13 by monocyte-derived dendritic cells (DCs) and naive CD4+ T cells cocultured with DCs, as well as their role in the production of serum IgE, in house dust mite (HDM) allergic patients. Peripheral blood mononuclear cells (PBMCs) were isolated from venous blood of patients allergic to HDM and healthy donors and incubated with granulocyte-macrophage colony-stimulating factor (GM-CSF) and IL-4 to generate immature DCs. The obtained cells were stimulated for 24 h with Der p 1 to induce DC maturation, washed, and afterwards cocultured for 24 h with autologous naive CD4+ T cells. Culture supernatants were harvested for IL-4, IL-13 and IFN-γ level measurements. DCs stimulation with Der p 1 induced higher synthesis of IL-4 and IL-13 in HDM allergic patients, compared to healthy donors. The allergic group showed significant correlation between IL-13 production by Der p 1-pulsed DCs, and total serum IgE and IL-4 production of the same cells and Der p-specific IgE. To conclude, IL-4 and IL-13 are critically related to the regulation of serum IgE production in patients with allergic asthma. The relevance of these two cytokines in the pathophysiology of Th2 asthma endotype makes them an appropriate target in its management.

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

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. 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. 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. 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.