Presence Of Dust Mites Research Articles

Dermatophagoides farinae microRNAs released to external environments via exosomes regulate inflammation-related gene expression in human bronchial epithelial cells.

Dermatophagoides farinae (DFA) is an important species of house dust mites (HDMs) that causes allergic diseases. Previous studies have focused on allergens with protein components to explain the allergic effect of HDMs; however, there is little knowledge on the role of microRNAs (miRNAs) in the allergic effect of HDMs. This study aimed to unravel the new mechanism of dust mite sensitization from the perspective of cross-species transport of extracellular vesicles-encapsulated miRNAs from HDMs. Small RNA (sRNA) sequencing was performed to detect miRNAs expression profiles from DFA, DFA-derived exosomes and DFA culture supernatants. A quantitative fluorescent real-time PCR (qPCR) assay was used to detect miRNAs expression in dust specimens. BEAS-2B cells endocytosed exosomes were modeled in vitro to detect miRNAs from DFA and the expression of related inflammatory factors. Representative dfa-miR-276-3p and dfa-novel-miR2 were transfected into BEAS-2B cells, and then differentially expressed genes (DEGs) were analyzed by RNA sequencing. Protein-protein interaction (PPI) network analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway and Gene Ontology (GO) terms enrichment analyses were performed on the first 300 nodes of DEGs. sRNA sequencing identified 42 conserved miRNAs and 66 novel miRNAs in DFA, DFA-derived exosomes, and DFA culture supernatants. A homology analysis was performed on the top 18 conserved miRNAs with high expression levels. The presence of dust mites and miRNAs from HDMs in living environment were also validated. Following uptake of DFA-derived exosomes by BEAS-2B cells, exosomes transported miRNAs from DFA to target cells and produced pro-inflammatory effects in corresponding cells. RNA sequencing identified DEGs in dfa-miR-276-3p and dfa-novel-miR2 transfected BEAS-2B cells. GO and KEGG enrichment analyses revealed the role of exosomes with cross-species transporting of DFA miRNAs in inflammatory signaling pathways, such as JAK-STAT signaling pathway, PI3K/AKT signaling pathway and IL-6-mediated signaling pathway. Our findings demonstrate the miRNAs expression profiles in DFA for the first time. The DFA miRNAs are delivered into living environments via exosomes, and engulfed by human bronchial epithelial cells, and cross-species regulation may contribute to inflammation-related processes.

Systemic reactions to subcutaneous immunotherapy: Effects of dosing and aeroallergen content

BackgroundSystemic reactions are a known risk of subcutaneous immunotherapy (SCIT) for aeroallergens. ObjectiveTo identify the dose of SCIT that results in the most systemic reactions to SCIT (SCITSRs) and other risk factors for SCITSRs. MethodsWe performed a retrospective review of all SCIT encounters from 2013 to 2017 at a multisite allergy/immunology practice. SCITSRs were identified from the electronic health record through immunotherapy encounters in which epinephrine was administered. Collected data included patient demographics, the dose of immunotherapy at the time of the SCITSR, the presence or absence of asthma, and aeroallergen content. The control group was generated randomly from the same cohort during the same period. ResultsThere were 86,949 SCIT visits, with 81 SCITSRs (0.9 per 1000 injections). A total of 77.8% of reactions occurred at a dose of 1:1 0.1 mL and above. The presence of cat (81.5% vs 63.0%, P = .01), dog (67.9% vs 37.0%, P < .001), and grass extracts (85.2% vs 67.5%, P = .01) were associated with SCITSRs. Asthma was not significantly associated with SCITSRs. The presence of dust mites, trees, weeds, and molds was not associated with SCITSRs. There were no months or seasons where SCITSRs were more likely to occur. Individuals who experienced SCITSRs had a mean (SD) higher number of included aeroallergenic groups compared with controls (5.86 [1.88] vs 5.00 [1.92], P < .001). ConclusionRisk factors for SCITSRs in a multisite allergy/immunology practice included administration of the highest immunotherapy doses; inclusion of cat, dog, and grass extracts; and the number of aeroallergenic groups included in the extract. This information helps further characterize risk for patients receiving SCIT.

EXPOSURE AND SENSITIZATION TO DUST MITES IN PERUVIAN CITIES.

Background: Knowledge of the prevalence of different species of dust mites according geographical areas is important to support the diagnostic and specific treatment of allergic diseases that dust mites trigger.Methods: Dust samples were collected from mattresses in Peruvian cities grouped by regions; coast (Chiclayo, Trujillo, Chimbote, Lima, Tacna), sierra (Cajamarca, Cusco, Arequipa), jungle (Puerto Maldonado), using an adapted vacuum cleaner. After collection samples were frozen for 48 hours. Mites were extracted from 10 mg of each sample, under stereo microscope, by suspension method with saline solution. Mites were identified by optical microscope. We performed skin prick test (SPT) with standardized mites extracts (ALK-Abello, Laboratorios Leti and Inmunotek, Spain) to subjects who lived in the homes where dust samples were taken.Results: Presence of dust mites was confirmed in almost 90% of samples collected. The predominant species was Dermatophagoides pteronyssinus in cities of Peruvian coast, followed by Dermatophagoides farinae, Euroglyphus maynei and Blomia tropicalis. In the jungle, we identified two not previously cited species as Malayoglyphus intermedius and Tarsonemus sp, being this last the predominant specie. Regarding SPT, most of the participants were positive to Dermatophagoides pteronysssinus, followed by Dermatophagoides farinae, Blomia tropicalis, Euroglyphus maynei and Tyrophagus putrescentiae, with different percentages by geographic areas.Conclusions: To our knowledge this is the first study on mite count in dust and pattern of sensitization performed in Peru. The acarological fauna and sensitization profile show different percentages depending on geographic areas. Dermatophagoides pteronyssinus is the dominant species in the coast, and Tarsonemus sp. in the jungle, though other species can be considered important. Further studies about mite species and sensitization profile (SPT, specific IgE) will elucidate the clinical importance of these findings.

FC‐30 Presence of dust mites in the environment of dust mite‐sensitized atopic dogs

Dust mites (DM) are the most common offending aeroallergens in atopic dogs. The aim of this study was to compare the DM load of households with atopic dogs (Group A, n = 8) that had positive intradermal test reactions to Dermatophagoides farinae, D. pteronyssinus, Acarus siro, Lepidoglyphus destructor and/or Tyrophagus putrescentiae to the DM load of households with nonatopic dogs (Group B, n = 4) and of nonpet households (Group C, n = 8). Group A dogs presented with perennial pruritus, were free of pathogenic mites and fleas, did not respond to an elimination diet, and fulfilled the diagnostic criteria of atopic dermatitis. All Group B dogs tested intradermally negative and had no dermatological problems. Dust samples were vacuum collected in a standardized fashion from the human (all groups) and dog mattresses (Groups A and B) or from the couch (Group C) four times, once for each season of the year. The presence of DM was assessed with a commercial test (Acarex test) and stereoscopically. At least one DM was found in all Group A houses. The DM load was not significantly different between the seasons or the three animal groups. The sensitivity of the Acarex test was significantly lower than that of stereoscopic examination (P &lt; 0.001). In conclusion, the environmental DM load was similar between atopic and nonatopic dogs, the presence of dogs in a household didn't increase DM numbers, and stereoscopy was more sensitive than the Acarex test for the detection of DM. Funding: Self‐funded.