Predictors of airway hyperreactivity in house dust mite allergic patients.

INTRODUCTION: Airway hyperresponsiveness (AHR) is a cardinal feature of asthma. Asthma is a heterogenous disorder which consists of different phenotypes and endotypes. Mechanisms leading to AHR may differ in different asthma subtypes. Allergy to perennial allergens, including house dust mites (HDM) is a major risk factor for asthma development. The aim of this study was to determine predictors of AHR in a well-characterized population of HDM-allergic patients. MATERIAL AND METHODS: In a retrospective analysis 843 patients with HDM-allergic rhinitis with/without asthma were evaluated. The following parameters were included in the analysis: serum concentration of total (t)- and Dermatophagoides pteronyssinus (Dp)-specific IgE, fractional exhaled nitric oxide concentration (FeNO), lung function tests, bronchial challenge with histamine, age sex, and body mass index (BMI). Linear regression analysis was used to determine predictors of AHR. RESULTS: In a simple linear regression analysis baseline lung function results expressed as either forced expiratory volume in 1 s (FEV1) or maximal expiratory flow at 50% of the forced vital capacity (MEF50), FeNO, tIgE, DpIgE, age and BMI affected AHR. A multiple regression analysis demonstrated that in the whole group of HDM-allergic patients the most important, independent predictors of AHR were MEF50, FeNO and DpIgE. CONCLUSION: Even in a well-characterized asthma phenotype several processes participate in development of AHR. Major, independent predictors of AHR: lung function parameters, FeNO and DpIgE indicate possible targets for therapeutic intervention in a population of HDM-allergic patients.

Sensitivity to House Dust Mites Allergens in Patients with Allergic Asthma in Erzincan Province, Turkey.

OBJECTIVE: To investigate the sensitivity of allergic asthma (AA) patients to house dust mites (HDM) by conducting skin tests, measuring total and specific IgE antibodies to Dermatophagoides pteronyssinus and D. farinae mites, and examining HDM fauna in patients' homes. METHODS: The study included 25 patients with AA and 31 healthy controls, who were challenged with Der p and Der f allergens; serum levels of allergen-specific lgE and total IgE were measured. Dust samples were collected from the homes of all participants, and mite species and the number of mites per gram of dust were investigated. RESULTS: D. pteronyssinus was found in the homes of 94.7% patients with positive Der p reactions in the skin test (p<0.001). D. farinae was found in the homes of 22.2% patients with positive Der f reactions in the skin test (p>0.05). D. pteronyssinus-specific IgE was detected in 75% patients in whose homes D. pteronyssinus was also found, while D. farinae-specific IgE was detected in 16.6% patients in whose homes D. farinae was also found. CONCLUSION: A part of AA patients residing in Erzincan are sensitive to HDM allergens, and high numbers of mites leading to allergic sensitization are found in their homes.

House Dust Mites in Erzincan Province.

OBJECTIVE: We aimed to determine the species of the house dust mites seen in Erzincan, the number of mites per gram of dust in the houses, and the relationship between temperature and the number of mite specimens. METHODS: For this purpose, 54 dust samples collected from 18 houses located in different districts of Erzincan province between November 2013 and January 2014. These samples were examined by a lactic acid precipitation method. RESULTS: Of the houses in which the dust samples were collected, 94.44% were found to be positive in terms of mites. A total of 844 mite specimens were isolated from the dust samples, and the mean number of mites per gram of dust was found to be 18.34. The most common species was found to be Acarus siro (55.55%) and was followed by Dermatophagoides pteronyssinus (50.00%), Tyrophagus putrescentiae (22.22%), Histiostoma sp. (22.22%), Lepidoglyphus destructor (16.66%), T. perniciosus(11.11%), Euroglyphus maynei (11.11%), Glycyphagus privatus (11.11%), Cheyletus sp. (11.11%), Tarsonemus sp. (11.11%), and Tetranychus sp. (11.11%). CONCLUSION: Mite-holding rate of the houses in Erzincan province was found to be 94.44%. The mean number of mites per gram of dust was found to be 18.34. The most common mite species was A. siro, which was followed by D. pteronyssinus.