Background Air cleaners have been promoted for respiratory allergic disease prevention, but there is no clear clinical proof of their efficacy in allergic asthma. Objective To examine the efficacy of a new air cleaner on early and late asthmatic responses in cat‐allergic patients. Methods This randomized, cross‐over, double‐blind placebo‐controlled study enrolled 24 cat‐asthmatic patients with GINA 1 asthma. At baseline, participants were exposed to 40 ng/m3 of airborne cat allergen for a maximum of 2 hours in ALYATEC® environmental exposure chamber (EEC). All participants were subsequently randomized into two groups that were exposed to cat allergen, either with active then placebo air cleaners or with placebo then active air cleaners with a 3‐week interval in the EEC. This study was registered under number (NCT03928561). Results Fewer patients experienced an EAR with active air cleaners (seven patients; 29.17%) than placebo (21 patients; 87.50%). The response incidence was lower with active than with placebo air cleaners. A Cox model demonstrated a significant treatment effect (hazard ratio, 0.10; P = .002). Active air cleaners also prevented late asthmatic response: four patients (16.67%) had a late asthmatic response with active air cleaners compared to 11 patients (45.83%) with placebo (Prescott test P = .002). Active air cleaners also decreased the maximal severity of bronchial response (FEV1 decrease of 17.24% with active vs 25.62% with placebo air cleaners; P = .001). Conclusions Our present results demonstrated that Intense Pure Air XL® air cleaners significantly prevented early and late asthmatic responses among cat‐allergic asthmatics during cat allergen exposure in the ALYATEC® EEC.

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Background Environmental exposure chambers (EECs) have been used extensively to study allergic rhinoconjunctivitis. Few studies have been published using EECs in conjunctivitis only, and none have used conjunctival allergen challenge as a selection criterion. The present study validated ALYATEC EEC in allergic conjunctivitis to birch pollen. Methods Sixteen patients with a positive conjunctival allergen challenge (CAC) were exposed to 60 ng/m 3 of Bet v 1 in an EEC on two consecutive days for a maximum of 4 h to validate EEC exposure to birch. Reproducibility was tested among seven of the patients. A conjunctival positive scoring during the CAC and the EEC exposure was defined as a Total Ocular Symptom Score (TOSS) ≥ 5. Results Fifty percent of patients had a conjunctival positive scoring during first exposure and 75% during second exposure. The mean time to a conjunctival response was 81.2 ± 33.9 min and 101.6 ± 57 ( P > 0.05) during first and second exposure, respectively. No difference in TOSS occurred between the two exposures. The time necessary to obtain a positive response during the CAC was significantly shorter than with the EEC. The estimated quantity of Bet v 1 inducing a positive response was 0.07 ± 0.03 ng (exposure 1), 0.07 ± 0.07 ng (exposure 2), 980 ± 784 ng (CAC). Conjunctival positive scoring and quantity of Bet v 1 was reproducible in all six EEC exposures. Conclusions Early conjunctival responses induced by birch allergen exposures in EEC were different than from those identified with direct instillation during CAC. EEC appears to be closer to natural exposure than CAC.

RATIONALE: Smoking is one of the most significant triggers for asthma patients. The aim of this study was to evaluate the differences between smoker asthma (S) patients with non-smoker (NS) and ex-smoking (ES) patients in terms of symptoms, risk factors and comorbidities. METHODS: A web-based data entry of 500 patients living in the urban area of Istanbul/Turkey who were followed for at least one year after asthma diagnosis was made via Microsoft Access 2013. The registered respiratory symptoms, habits, risk factors, comorbidities of NS, ES, and S patients were compared statistically. RESULTS: Number and percentage of the NS, ES and S groups and their mean age were respectively 353 (70.6%) 39.9 6 15.4; 88 (17.6) 44.8 6 12.7; and 59 (11.8%) 38.0 6 15.4. No group difference was found between cough, wheeze, chest tightness and dyspnea symptoms; asthma ratios in parents; body mass index; non-steroid anti-inflammatory hypersensitivity; pollen, mite, mold, pet sensitivity; heating methods in both home and workplace; allergic conjunctivitis, rhinitis and or sinusitis comorbidities (p>0.05). Percentage of allergic dermatitis and hypertension was lower in NS group (3.4%, 3.4% respectively) compared to ES and S groups (12.7% 17% and 13.9%, 10.2% respectively with p<0.02, p<0.03) and reflux was lower in S group (41.6%) compared to other groups (59.1%; 57.6% with p<0.003). CONCLUSIONS: Smoker and ex-smoker asthma patients of the urban area had similar asthma symptoms and risk factors but they had higher hypertension and allergic dermatitis comorbidities than non-smoker asthma patients.