title: Persistence of respiratory and inflammatory responses after dermal sensitization to persulfate salts in a mouse model of non-atopic asthma.
abstract: BACKGROUND
  Exposure to ammonium persulfate (AP) has been reported to be the main cause of occupational asthma in hairdressers. The aim of this study is to assess how long the asthmatic response to AP can be induced after dermal sensitization in a mouse model.
  
  
  METHODS
  BALB/c mice received dermal applications of AP or dimethylsulfoxide (DMSO) (control) on days 1 and 8. They then received a single nasal instillation (challenge) of AP or saline on days 15, 22, 29, 36, 45, 60 and 90. Respiratory responsiveness to methacholine was measured 24 h after the challenge using a non-specific methacholine provocation test. Pulmonary inflammation was analysed in bronchoalveolar lavage (BAL), and total serum immunoglobulin (Ig) E, IgG1 and IgG2a were measured in serum samples. Histological analysis of lung slides was performed.
  
  
  RESULTS
  Mice dermally sensitized and intranasally challenged with AP showed respiratory responsiveness to methacholine as long as 45 days after initial sensitization, as well as increased percentage of neutrophils in BAL compared with the control group. At day 60, dermally sensitized mice still presented bronchial hyperresponsiveness, while the percentage of neutrophils returned to baseline levels similar to those of controls. Total serum IgE increased significantly on day 22 after dermal sensitization. Total serum IgG1 and IgG2a increased from 45 days after dermal sensitization and remained high at 90 days.
  
  
  CONCLUSIONS
  Both respiratory responsiveness to methacholine and airway inflammation responses decrease with increasing time between sensitization and challenge. Respiratory responsiveness to methacholine tends to persist longer than inflammation.
authors.affiliation: Servicio de Neumologia, Hospital Universitario Vall d'Hebron, Passeig Vall d'Hebron, 119, 08035 Barcelona, Spain ; CIBER Enfermedades Respiratorias (CibeRes), Barcelona, Spain.
authors.forename: M J
authors.initials: MJ
authors.lastname: Cruz
authors.affiliation: Servicio de Neumologia, Hospital Universitario Vall d'Hebron, Passeig Vall d'Hebron, 119, 08035 Barcelona, Spain ; CIBER Enfermedades Respiratorias (CibeRes), Barcelona, Spain ; Departament de Medicina, Universitat Autònoma de Barcelona, Barcelona, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Olle-Monge
authors.affiliation: Centre of Environment and Health, KU Leuven, Leuven, Belgium.
authors.forename: J A
authors.initials: JA
authors.lastname: Vanoirbeek
authors.affiliation: Servicio de Neumologia, Hospital Universitario Vall d'Hebron, Passeig Vall d'Hebron, 119, 08035 Barcelona, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Assialioui
authors.affiliation: Servicio de Neumologia, Hospital Universitario Vall d'Hebron, Passeig Vall d'Hebron, 119, 08035 Barcelona, Spain ; CIBER Enfermedades Respiratorias (CibeRes), Barcelona, Spain.
authors.forename: S
authors.initials: S
authors.lastname: Gomez-Olles
authors.affiliation: Servicio de Neumologia, Hospital Universitario Vall d'Hebron, Passeig Vall d'Hebron, 119, 08035 Barcelona, Spain ; CIBER Enfermedades Respiratorias (CibeRes), Barcelona, Spain ; Department of Cell Biology, Physiology and Immunology, Universitat Autònoma de Barcelona, Barcelona, Spain.
authors.forename: X
authors.initials: X
authors.lastname: Muñoz
keywords: Airway hyperresponsiveness; Ammonium persulfate; Lung inflammation; Occupational asthma