title: Matrix metalloproteinase-9 increases in the sputum from allergic occupational asthma patients after specific inhalation challenge.
abstract: BACKGROUND
  Matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) play a role in the pathogenesis of asthma. MMP-9 increases in the sputum of asthmatic patients after bronchial challenge with common allergens. We sought to assess whether a high-molecular-weight occupational allergen was able to induce changes in MMP-9 as well as in other MMPs and TIMPs in subjects with occupational asthma.
  
  
  METHODS
  Ten patients underwent specific inhalation challenge (SIC) on 2 consecutive days. We monitored changes in lung function by measuring FEV(1) for 7 h. Induced sputum test was performed at 6 h after sham and flour challenge. The total and differential cell counts were analyzed. Levels of MMPs (specifically MMP-2, MMP-7, MMP-9 and MMP-13) were measured using Fluorokine® MultiAnalyte Profiling kits and a Luminex® Bioanalyzer, while levels of TIMP-1 and TIMP-2 were measured by ELISA.
  
  
  RESULTS
  Flour challenge increased the percentage of eosinophils in sputum samples. Asthmatic reactions induced by flour were associated with a significant increase in the sputum level of MMP-9 (p = 0.05), but not in the levels of MMP-2, MMP-7, MMP-13, TIMP-1 and TIMP-2. Sputum levels of MMP-9 measured after flour challenge were nearly significantly correlated (r = 0.67; p = 0.06) with the maximal fall in FEV(1) observed during the asthmatic reaction, but they did not correlate with the number of neutrophils (r = 0.18; p = 0.7) and eosinophils (r = 0.55; p = 0.2).
  
  
  CONCLUSIONS
  This study showed that MMP-9 increases in sputum samples from sensitized occupational asthma patients after SIC with flour.
authors.affiliation: Department of Surgery/Otolaryngology, Axe de recherche en santé respiratoire, Hôpital du Sacré-Coeur de Montréal, Montreal, Que., Canada. roberto.castano@umontreal.ca
authors.forename: Roberto
authors.initials: R
authors.lastname: Castano
authors.forename: David
authors.initials: D
authors.lastname: Miedinger
authors.forename: Karim
authors.initials: K
authors.lastname: Maghni
authors.forename: Heberto
authors.initials: H
authors.lastname: Ghezzo
authors.forename: Carole
authors.initials: C
authors.lastname: Trudeau
authors.forename: Lucero
authors.initials: L
authors.lastname: Castellanos
authors.forename: Mathieu
authors.initials: M
authors.lastname: Wattiez
authors.forename: Olivier
authors.initials: O
authors.lastname: Vandenplas
authors.forename: Jean-Luc
authors.initials: JL
authors.lastname: Malo
mesh_terms: D000328:Adult; D059366:Asthma, Occupational / Q000201:enzymology* / Q000209:etiology / Q000276:immunology; D001985:Bronchial Provocation Tests; D004797:Enzyme-Linked Immunosorbent Assay; D005433:Flour / Q000009:adverse effects; D006801:Humans; D006967:Hypersensitivity / Q000201:enzymology* / Q000209:etiology / Q000276:immunology; D008297:Male; D020780:Matrix Metalloproteinase 9 / Q000032:analysis / Q000378:metabolism*; D016273:Occupational Exposure / Q000009:adverse effects*; D012129:Respiratory Function Tests; D013183:Sputum / Q000737:chemistry* / Q000276:immunology
chemical_list: D020780:Matrix Metalloproteinase 9