title: New data analysis in a population study raises the hypothesis that particle size contributes to the pro-asthmatic potential of small pet animal allergens.
abstract: BACKGROUND
  The size of inhaled particles influences where they deposit and theoretically should be important for the development of airway inflammation and responsiveness. Our aim was to assess if sensitization to smaller-sized aeroallergens relates to higher prevalence of treated asthma, increased airway responsiveness, and airway and systemic inflammation.
  
  
  METHODS
  Molecular-based IgE antibody determination was done in 467 subjects. Sensitized subjects were grouped based on the particle size of the aeroallergen: (1) Large particles only (mainly pollen); (2) Medium-sized particles (sensitized to mainly mite and mold and possibly to large particles); and 3) Small particles (sensitized to pet allergens and possibly to medium- and/or large-sized particles). Airway responsiveness to methacholine, exhaled nitric oxide (FENO), and serum eosinophil cationic protein (S-ECP) were measured. Asthma and rhinitis were questionnaire-assessed.
  
  
  RESULTS
  Subjects sensitized to small particles had higher prevalence of treated asthma (35% versus 10%, P < 0.001), higher FENO50 (32 versus 17 ppb, P < 0.001), higher S-ECP (10 versus 7.5 ng/mL, P = 0.04), and increased bronchial responsiveness (dose-response slope, 5.6 versus 7.5, P < 0.001) compared with non-atopics. This was consistent after adjusting for potential confounders. Sensitization to only large or to medium and possibly also large aeroallergen particles was not related to any of these outcomes after adjustments.
  
  
  CONCLUSIONS
  Sensitization to smaller particles was associated with a higher prevalence of asthma under treatment, higher airway responsiveness, and airway and systemic inflammation. Mapping of IgE sensitization to small particles might help to detect subjects having increased airway and systemic inflammation and bronchial responsiveness, indicating increased risk of developing asthma.
authors.affiliation: a Department of Medical Sciences , Respiratory, Allergy and Sleep Research, Uppsala University , Uppsala , Sweden ;
authors.forename: Antonios
authors.initials: A
authors.lastname: Patelis
authors.affiliation: b Department of Pediatrics , Scripps Hospital , San Diego , CA , USA ;
authors.forename: Amrita
authors.initials: A
authors.lastname: Dosanjh
authors.affiliation: a Department of Medical Sciences , Respiratory, Allergy and Sleep Research, Uppsala University , Uppsala , Sweden ;
authors.forename: Maria
authors.initials: M
authors.lastname: Gunnbjörnsdottir
authors.affiliation: c Thermo Fisher Scientific , Uppsala , Sweden ;|d Department of Women's and Children's Health , Uppsala University , Uppsala , Sweden ;
authors.forename: Magnus P
authors.initials: MP
authors.lastname: Borres
authors.affiliation: a Department of Medical Sciences , Respiratory, Allergy and Sleep Research, Uppsala University , Uppsala , Sweden ;|e Centre for Clinical Research, Uppsala University/Region Gävleborg , Sweden ;
authors.forename: Marieann
authors.initials: M
authors.lastname: Högman
authors.affiliation: d Department of Women's and Children's Health , Uppsala University , Uppsala , Sweden ;
authors.forename: Kjell
authors.initials: K
authors.lastname: Alving
authors.affiliation: a Department of Medical Sciences , Respiratory, Allergy and Sleep Research, Uppsala University , Uppsala , Sweden ;
authors.forename: Christer
authors.initials: C
authors.lastname: Janson
authors.affiliation: f Department of Medical Sciences , Clinical Physiology, Uppsala University , Uppsala , Sweden.
authors.forename: Andrei
authors.initials: A
authors.lastname: Malinovschi
mesh_terms: D000328:Adult; D000485:Allergens / Q000276:immunology*; D000818:Animals; D001249:Asthma / Q000453:epidemiology / Q000209:etiology*; D001944:Breath Tests; D047150:Eosinophil Cationic Protein / Q000032:analysis; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D007073:Immunoglobulin E / Q000276:immunology; D008297:Male; D008875:Middle Aged; D009569:Nitric Oxide / Q000032:analysis; D010316:Particle Size; D057805:Pets / Q000276:immunology*; D013223:Statistics as Topic
chemical_list: D000485:Allergens; D009569:Nitric Oxide; D007073:Immunoglobulin E; D047150:Eosinophil Cationic Protein
keywords: Asthma; S-ECP; components; inflammation; methacholine test; nitric oxide; particle size; respiratory medicine