Cat, Dog and Horse Allergens in Swedish Day Care Centres-Associations with Fractional Exhaled Nitric Oxide (FeNO) among Day Care Centre Staff

PURPOSE- To study associations between cat, dog and horse allergens in day care centres and fractional exhaled nitric oxide (FeNO), eosinophilic cationic protein (ECP) in serum, lung function (FEV1) and dyspnoea in day care centre staff. Totally 62 subjects, all females, from five Swedish day care centres participated (participation rate 90%).METHODS- Dust was collected by vacuum cleaning and Petri dish sampling and analysed for cat (Fel d 1), dog (Can f 1) and horse (Ecu cx) allergens by ELISA. Dyspnoea was measured on an analogue rating scale. FeNO, serum ECP and symptom ratings were log-transformed. Associations were analysed by linear mixed models, adjusting for personal and home environment factors. RESULTS- Geometric mean (GM) value for allergens in vacuumed dust were 1199 ng/g for Fel d 1, 666 ng/g for Can f 1 and 478 U/g for Equ cx, respectively. GM value for allergens in Petri dish samples (ng/m2 per day) was 29.8 for Fel d 1 and 9.1 for Can f 1, respectively. Cat allergen (Fel d 1) were positively associated with FeNO both in vacuumed dust (p=0.03) and in Petri dish samples (p=0.03). Dog allergen (Can f 1) in Petri dish samples was negatively associated with FeNO (p=0.02). Horse allergen (Equ cx) in vacuumed dust was negatively associated with FeNO (P=0.03).CONCLUSION- Cat, dog and horse allergens were commonly found and cat allergen in day care centres can be a risk factor for lower airway inflammation, measured as FeNO, while dog and horse allergens were associated with lower FeNO.