title: Airway inflammatory responses following exposure to occupational agents.
abstract: BACKGROUND
  Airway inflammatory responses to specific inhalation challenges (SICs) with low-molecular-weight (LMW) and high-molecular-weight (HMW) agents have not been studied thoroughly. We assessed the changes in airway inflammatory cells following SIC in sensitized workers, and looked at the influence of various factors on the pattern of inflammatory responses to SIC.
  
  
  METHODS
  Induced sputum analysis was performed in workers sensitized to LMW (n = 41) or HMW agents (n = 41) after a control day and after a positive SIC. Cell counts were compared with lung function and various clinical parameters.
  
  
  RESULTS
  In the LMW group, eosinophils were increased following late asthmatic responses (median [interquartile range], 0.02 [0.04] × 10(6) cells/g vs 0.30 [0.80] × 10(6) cells/g and 1.0% [3.5] vs 8.9% [8.0], P < .05), as were neutrophil numbers (0.8 [1.3] × 10(6) cells/g vs 2.3 [5.4] × 10(6) cells/g, P = .04). In the HMW group, eosinophil percentages increased both after early (1.0% [2.2] vs 5.5% [14.5], P = .003) and dual asthmatic responses (4.5% [3.7] vs 15.0% [13.7], P = .02). In the LMW group, the increases in neutrophils were higher in current smokers than in ex-smokers or nonsmokers. The length of exposure to the agent, tobacco use, and baseline percentage of eosinophils were independent predictors of the change in eosinophils, whereas age and baseline neutrophil percentage were predictors of the change in neutrophils.
  
  
  CONCLUSIONS
  This study confirms that eosinophils and neutrophils are increased after SIC, whatever the causal agent. The type of agent is not predictive of the inflammatory response to SIC. Smoking is associated with a more neutrophilic response after SIC with an LMW agent.
authors: Centre de recherche de l'Institut universitaire de cardiologie et de pneumologie de Québec, Quebec City, QC, Canada.
authors: Philippe
authors: P
authors: Prince
authors: Service de pneumologie, Hôpital du Sacré-Cœur, Université de Montréal, Montreal, QC, Canada.
authors: Catherine
authors: C
authors: Lemière
authors: Centre de recherche de l'Institut universitaire de cardiologie et de pneumologie de Québec, Quebec City, QC, Canada.
authors: Marie-Hélène
authors: MH
authors: Dufour
authors: Service de pneumologie, Hôpital du Sacré-Cœur, Université de Montréal, Montreal, QC, Canada.
authors: Simone
authors: S
authors: Chaboillez
authors: Centre de recherche de l'Institut universitaire de cardiologie et de pneumologie de Québec, Quebec City, QC, Canada. Electronic address: lpboulet@med.ulaval.ca.
authors: Louis-Philippe
authors: LP
authors: Boulet
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D059366:Asthma, Occupational / Q000139:chemically induced* / Q000276:immunology / Q000503:physiopathology; D001985:Bronchial Provocation Tests; D004804:Eosinophils / Q000276:immunology; D005260:Female; D006801:Humans; D007958:Leukocyte Count; D008297:Male; D008970:Molecular Weight; D009504:Neutrophils / Q000276:immunology; D016273:Occupational Exposure / Q000009:adverse effects*; D011792:Quebec; D012044:Regression Analysis; D012129:Respiratory Function Tests; D012189:Retrospective Studies; D012907:Smoking / Q000009:adverse effects; D013183:Sputum / Q000166:cytology