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.

Acaricidal properties of 5-methylfurfural identified from Valeriana fauriei and its structural analogues against synanthropic mites and Asian longhorned tick with color alterations

Acaricidal activities and color alterations of 5-methylfurfural derived from Valeriana fauriei essential oil and its structural analogues against Dermatophagoides farinae, D. pteronyssinus, Haemaphysalis longicornis and Tyrophagus putrescentiae were evaluated in the present study. Based on the LD50 values of 5-methylfurfural and its analogues, 4,5-dimethylfurfural showed the highest acaricidal activity (LD50; 9.95, 9.91, and 7.12 μg/cm2), followed by 5-methylfurfural (11.87, 11.00, and 8.59 μg/cm2), furfural (12.94, 13.25, and 10.36 μg/cm2), and V. fauriei essential oil (15.15, 13.64, and 10.14 μg/cm2) against D. farinae, D. pteronyssinus and T. putrescentiae, respectively. However, all tested compounds did not show the acaricidal activities against H. longicornis. Interestingly, the color alterations of the mites and ticks were observed by furfural, 5-methylfurfural, and 4,5-dimethylfurfural from colorless to red brown during the acaricidal experiments. Furthermore, 4,5-dimethylfurfural which exhibited the highest acaricidal activity was formulated as nanoemulsion. The nanoemulsion of 4,5-dimethylfurfural showed higher acaricidal activity than it was emulsified in ethanol. The nanoemulsion was also found to show color changes of the mites and ticks from colorless to red brown. The results suggest that 5-methylfurfural and its analogues could be developed as an effective and easy-to-recognize acaricides to mites and ticks.

Anti-Allergic Effect of Low Molecular Weight Digest from Abalone Viscera on Atopic Dermatitis-Induced NC/Nga

Abalone viscera (AV) is one of the byproducts of the seafood processing industry. The low molecular weight (<5 kDa) peptides (LMW-AV) obtained from gastrointestinal digestion of AV could suppress allergenic responses on activated HMC-1 human mast cells in our previous study. Regarding the allergenic response of LMW-AV, in the present study, we further investigated the potential of oral administration of LMW-AV against atopic dermatitis (AD) in a dermatitis-induced model stimulated with Dermatophagoides farinae. The results demonstrated that the LMW-AV reduced a number of clinical symptoms, such as the severity of the dermatitis and serum immunoglobulin E levels. Moreover, LMW-AV could inhibit the expression of chemokines and cytokines. The histological analysis indicated that the LMW-AV has suppressed the eosinophil count and the mast cell infiltration into the upper dermis. The results suggest that LMW-AV can be considered as a promising candidate for AD treatment.

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.

Induction of atopic dermatitis by epicutaneous sensitisation with Dermatophagoides farinae in nongenetically predisposed Beagle dogs

This study was performed to induce atopic dermatitis (AD) using nongenetically predisposed Beagle dogs. Five healthy Beagle dogs were used. Twice weekly for 12 weeks, the dogs were painted on the axillae and groin with a solution of Dermatophagoides farinae (D. farinae). Each dog was thereafter placed in a cage where a house dust mite (HDM) solution was applied on the bottom of the cage. The dog remained in the cage for 3 h daily for 3 consecutive days for the environmental exposure to HDM. Serum samples were collected at 0 week and 6 weeks after sensitisation, and at 0 h and 72 h after the environmental exposure. During the environmental exposure, skin biopsies were obtained at 0 h, 36 h, and 72 hours. After the first environmental exposure, no dog had any marked clinical sign. An additional sensitisation was subsequently administered for 10–13 weeks. Three of the five dogs developed pruritic dermatitis with skin lesions after the second exposure. The histopathology of the lesions revealed severe infiltration of inflammatory cells and dermal oedema. The levels of D. farinae-specific IgE were also elevated. This study demonstrated that AD could be induced by epicutaneous sensitisation with HDM in nongenetically predisposed dogs.

The Additional Effects of Clarithromycin And Pranlukast On The Cytokine Suppression By Corticosteroids Using Murine Allergic Bronchopulmonary Aspergillosis Model

Few medicines other than oral corticosteroids and anti-fungal medicines are currently known as reliable treatments for allergic bronchopulmonary aspergillosis (ABPA). The efficacies of macrolide or leukotriene receptor antagonist (LTRA) with or without corticosteroid on ABPA are unknown. Mice were sensitized to Dermatophagoides farinae (Df) allergen intranasally and infected with Aspergillus fumigatus (Af). After Af infection, corticosteroid (Dexamethasone; Dex) was administered for five days in DfAf/Dex group. The effects of macrolide (clarithromycin; CAM) or LTRA (pranlukast; PRN) with or without Dex were also evaluated. Pathologically, the combined treatment with Dex and CAM decreased the airway inflammation. The interleukin (IL)-5, IL-13 and macrophage inflammatory protein (MIP)-2 concentrations in homogenized lungs were significantly elevated in DfAf mice compared to control mice (p < 0.05, each). CAM significantly decreased the elevations of MIP-2 of DfAf mice (p < 0.05). The addition of CAM on Dex suppressed both of the MIP-2 and IL-5 elevation (p < 0.05, each, DfAf/Dex vs DfAf/Dex/CAM group), but the addition of PRN on Dex did not. It was suggested that combination of CAM and corticosteroid enhanced the suppressing effect of both eosinophilic and neutrophilic airway inflammations. This finding will give a new hope for the treatment of severe fungus-related asthma.