Biologic Responses to House Dust Mite Exposure in the Environmental Exposure Unit

Introduction: Allergic rhinitis (AR) is an inflammatory disease of the nasal mucosa that can be modeled using Controlled Allergen Exposure Facilities (CACF). Recently, we clinically validated the house dust mite (HDM) Environmental Exposure Unit (EEU) facility. In the current study, we aimed to assess biological responses in the blood following HDM exposure in the HDM-EEU.Methods: Fifty-five participants passed a screening visit, where they provided consent and completed a skin prick test (SPT), then attended a modest or higher HDM exposure session. Baseline and post-exposure blood samples were collected. Complete blood counts with differentials were measured, and isolated serum was used to determine Dermatophagoides farinae- and Dermatophagoides pteronyssinus-specific IgE (sIgE) and cytokine concentrations (IL-4, IL-5, IL-6, IL-10, IL-13, TNF-α).Results: HDM-allergic participants had significantly greater SPT wheal sizes than healthy controls. sIgE concentrations were significantly greater in allergic participants, with a strong correlation between Dermatophagoides farinae and Dermatophagoides pteronyssinus. Serum eosinophil counts were significantly decreased post-exposure for allergic participants. White blood cell, neutrophil, and lymphocyte counts were significantly increased for both allergic and non-allergic participants post-exposure. Serum IL-13 concentrations were significantly reduced post-exposure in allergics while TNF-α was significantly reduced in non-allergics.Conclusion: The HDM-EEU is a useful model for investigating biologic mechanisms of HDM-induced AR. Allergic participants produced measurable biological changes compared to healthy controls following allergen exposure, specifically with serum expression of eosinophils and related markers, namely IL-5, which promotes the proliferation and differentiation of eosinophils, and IL-13, a cytokine released by eosinophils. The exact mechanisms at play require further investigation.

Immunoreactivity against Dermatophagoides pteronyssinus Assessed by the Leukocyte Adherence Inhibition Test in Patients with Intrinsic Atopic Dermatitis and Correlated “Intrinsic” Non–IgE-mediated Allergic Conditions

Background: Due to the lack of standardized laboratory procedures able to demonstrate specific immune responses against the culprit allergens, the non—IgE-mediated allergy syndromes are a group of conditions diagnosed mostly by clinical examination and exclusion criteria. Objective: To evaluate the opportunity of the Leukocyte Adherence Inhibition Test (LAIT) to discriminate specific immunoreactivity against Dermatophagoides pteronyssinus (Dp) in a group of patients with non–IgE-mediated chronic allergic conditions. Methods: Ex vivo challenge tests performed with Dp were monitored by LAIT in patients presenting diverse non–IgE-mediated allergic conditions: intrinsic Atopic Dermatitis (iAD), intrinsic Allergic Rhinitis (iAR), intrinsic Ocular Allergy (iOA), intrinsic Chronic Pharyngitis (iCP), and intrinsic Asthma (iAS). Results: The mean LAI of the control group was 7%; the mean LAI of the iAR group was 34%; the mean LAI of the iCP group was 44%; the mean LAI of the iAS group was 45%; the mean LAI of the iOA group was 47%; the mean LAI of the iAD group was 55%. The non-parametric Wilcoxon-Mann-Whitney U test comparing the control group with each other group showed significance with p-value < α = 0.05 for all groups. Conclusion: The Leukocyte Adherence Inhibition Test is an easy, quick, and inexpensive ex vivo immunoassay with the potential to predict individual immunoreactivity against HDM allergens in real-world patients with non–IgE-mediated allergies.

The Effect of IL-35 on the Expression of Nasal Epithelial-Derived Proinflammatory Cytokines

Background. Airway epithelium plays an important role during the development of allergic rhinitis (AR), which is characterized by production of thymic stromal lymphopoietin (TSLP), interleukin 33 (IL-33), and interleukin 25 (IL-25). IL-35, mainly expressed by Treg cells, have negative regulation in Th2, Th17, and ILC2 inflammation. However, the effect of IL-35 on human nasal epithelial cells (HNECs) especially the secretion of nasal epithelial-derived proinflammatory cytokines as well as the possible mechanism is still unclear. Methods. HNECs were cultured and stimulated by various stimulators. The expression of IL-33, IL-25, TSLP, eotaxin-1, eotaxin-2, and eotaxin-3 from supernatant was measured using real-time reverse transcription-polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay (ELISA). AR mice were developed to verify the effect of IL-35 on nasal epithelial cells in vivo. Results. After Poly I:C stimulation, IL-35 inhibited the production of IL-25, and TSLP from HNECs increased significantly compared with baseline levels ( P < 0.05 ). After Dermatophagoides pteronyssinus or Aspergillus fumigatus stimulation, IL-35 inhibited the production of IL-25, IL-33, and TSLP from HNECs increased significantly compared with baseline levels ( P < 0.05 ). After Dermatophagoides pteronyssinus, IL-35 inhibited the production of eotaxin-1, eotaxin-2, and eotaxin-3 released from HNECs increased significantly compared with baseline levels ( P < 0.05 ). Similarly, IL-35-treated AR mice presented with decreased expression of IL-33, IL-25, TSLP, eotaxin-1, eotaxin-2, and eotaxin-3 in nasal lavage fluid. Conclusion. IL-35 suppressed both type 2 inflammation-inducing cytokines and eosinophil chemotactic factor from HNECs, suggesting the important role of IL-35 during the development of AR.

HOUSE DUST MITE ALLERGENS: FROM NATIVE EXTRACTS TO MODIFIED PREPARATIONS

The growth of allergic diseases dictates the need to develop new forms of therapeutic allergens with high immunogenic and low allergenic activity. For many years, our laboratory has been developing drugs for the diagnosis and treatment of house dust mites (HDM) allergies. The purpose of this study is to summarize the results of the five-year development of therapeutic preparations of HDM allergens. During this period, we obtained the following forms of therapeutic allergens: a granular sublingual dosage form of a mixed allergen from Dermatophagoides pteronyssinus (Der.p) and Dermatophagoides farinaе (Der.f) and a succinylated monomeric HDM allergoid Der.p. The physicochemical and immunobiological properties of the obtained preparations were studied by methods: electrophoresis in PAGE in the presence of SDS-sodium, micropoint immunoblot, ELISA, inhibition of the binding reaction of allergen-specific IgE in the sera of patients. The research results showed that the obtained preparations have a reduced allergenic and increased immunogenic activity in comparison with native extracts. The created forms of mite allergens can be further used to treat patients sensitized to HDM of the genus Dermatophagoides.

Comparison of goose down and woolen pillows in terms of house dust mites

This study was conducted to compare the goose down and the woolen pillows in terms of number of house dust mites per gram of dust. The study was conducted in Kars province, Turkey in September 2020. A total of 180 house dust samples were collected from 45 randomly selected houses in various districts of the city. The number of houses in which at least one sample was positive regarding mites was found to be 39 (86.66%). Overall, 137 (76.11%) of dust samples were mite positive. This rate was 87.77% in dust samples of woolen and 64.44% in dust samples of goose down pillows. The number of mites/g dust varied between 15 and 625 in mite-positive woolen pillows, 10 and 420 in mite-positive goose down pillows. Mean number of mites per g of dust was 127.67 in woolen pillows and 79.39 in goose down pillows. A statistically significant difference was found between woolen and goose down pillows in terms of the number of mites per gram of dust (P<0.05). A total of 1,362 mite specimens were isolated from the dust samples. As a result of the identification of isolated specimens; a total of 16 species belong to 10 genera and 6 families were determined. Of these; Dermatophagoides pteronyssinus (Trouessart, 1897) (65.85%), Lepidoglyphus destructor (Schrank) (9.25%) and Acarus siro Linnaeus (6.16%) were the most dominant species in terms of number of specimens.

Pemeriksaan Tungau Debu Rumah (TDR) Pada Debu Kasur Di Pondok Pesantren Attamadun Kota Batam

Tungau Debu Rumah (TDR) merupakan salah satu substansi alergen yang dapat memicu reaksi alergi. Keberadaan TDR dikaitkan dengan manifestasi alergi pada saluran pernafasan dan kulit. Pengabdian ini bertujuan mengetahui hasil pemeriksaan TDR pada debu kasur di Pondok Pesantren Attamadun Kota Batam. Metode Pemeriksaan yang digunakan dengan teknik flotasi. Pemeriksaan TDR dilakukan pada 20 sampel debu kasur santri di Pondok Pesantren Attamadun Kota Batam. Hasil pemeriksaan diperoleh, 15 (75%) sampel positif TDR dari 20 sampel yang di periksa. Spesies TDR yang ditemukan, yaitu Dermatophagoides pteronyssinus sebanyak 18 (46%) ekor TDR, Dermatophagoides sp sebanyak 15 (39%) ekor TDR dan Dermatophagoides farinae sebanyak 6 (15%) ekor TDR. Hasil perhitungan kepadatan TDR diperoleh rerata kepadatan TDR adalah 22,85 tungau/gram debu, dengan kategori rendah. Berdasarkan hasil yang diperoleh diharapkan kepada pengurus Pesantren Attamadun agar mengedukasi kepada santri untuk merawat kasur dan menjaga kebersihan kamar agar tidak menjadi tempat perkembangbiakan TDR, melakukan pemeriksaan kesehatan rutin santri.

Abundance of domestic mites in dwellings of children and adolescents with asthma in relation to environmental factors and allergy symptoms

Exposure to house dust allergens, mainly from domestic mites, is an important cause of allergic reactions in sensitized asthmatic patients. A total of 63 dust samples were collected from 16 flats in Bytom (south Poland); in each flat a person (age 4–17 years) suffering from bronchial asthma lived with his/her family. Mite density was calculated as the number of specimens per g of dust. The results were compared with household features and the data were statistically analyzed. In total 566 mite specimens were isolated, including 526 members of the family Pyroglyphidae (93%). The dominant species were Dermatophagoides pteronyssinus (60% of the total count) and Dermatophagoides farinae (32%). Pyroglyphids were found in all mite positive samples (68%) of which 35% also contained non-pyroglyphids, including glycyphagids, cheyletids and gamasids. The results suggest associations between the density of some mite taxa (per g of dust) and the following indoor environmental factors: presence of pets, number of inhabitants, coal-stoves as a type of heating, cleaning frequency, higher relative humidity, presence of flowers and PVC windows. The severity of asthma seems to be associated with the numbers of D. farinae, total domestic mites and live mites per g of dust.

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

Background Allergen identification is the first step for allergen-specific immunotherapy (AIT) of allergic rhinitis (AR). Currently, the diagnosis of AR is based mainly on the positive results of the skin prick test (SPT) and/or serum specific immunoglobulin E (sIgE) measurement. However, the results of these two tests may not always directly correlate with AR. Objective To investigate the importance of nasal provocation testing (NPT) in the diagnosis of Dermatophagoides pteronyssinus (Der p)-induced AR. Methods Rhinitis patients willing to undergo AIT (n = 171) were enrolled. The correlations of Der p SPT, sIgE, NPT, and clinical symptom severity were assessed. Results NPT-positive responses were more common in patients with higher SPT and sIgE levels. The optimal cut-off value for a NPT-positive response for SPT was 5.5 mm and for sIgE was 2.77 kUA/L, based on the respective receiver operating characteristic (ROC) curves. The area under the curve (AUC) of the ROCs was 0.814 (SPT only) and 0.794 (sIgE only) and increased to 0.828 with the combination of SPT and sIgE. The Der p-NPT concentration was inversely correlated with SPT and sIgE levels ( r = −0.477, P < .001, and r = −0.461, P < .001, respectively), but none was correlated with the total nasal symptom score. Conclusion For patients who are willing to receive Der p AIT, NPT is a useful and safe test to confirm diagnosis prior to treatment initiation, especially in patients with lower levels of Der p SPT (< 5.5 mm) or sIgE (< 2.77 kUA/L).