title: Airway function, inflammation and regulatory T cell function in subjects in asthma remission.
abstract: BACKGROUND
  Factors associated with asthma remission need to be determined, particularly when remission occurs in adulthood.
  
  
  OBJECTIVE
  To evaluate airway responsiveness and inflammation in adult patients in asthma remission compared with adults with mild, persistent symptomatic asthma.
  
  
  METHODS
  Adenosine monophosphate and methacholine responsiveness were evaluated in 26 patients in complete remission of asthma, 16 patients in symptomatic remission of asthma, 29 mild asthmatic patients and 15 healthy controls. Blood sampling and induced sputum were also obtained to measure inflammatory parameters.
  
  
  RESULTS
  Perception of breathlessness at 20% fall in forced expiratory volume in 1 s was similar among groups. In subjects with symptomatic remission of asthma, responsiveness to adenosine monophosphate and methacholine was intermediate between mild asthma and complete asthma remission, with the latter group similar to controls. Asthma remission was associated with a shorter duration of disease. Blood immunoglobulin E levels were significantly increased in the asthma group, and blood eosinophils were significantly elevated in the complete asthma remission, symptomatic remission and asthma groups compared with controls. The suppressive function of regulatory T cells was lower in asthma and remission groups compared with controls.
  
  
  CONCLUSIONS
  A continuum of asthma remission was observed, with patients in complete asthma remission presenting features similar to controls, while patients in symptomatic asthma remission appeared to be in an intermediate state between complete asthma remission and symptomatic asthma. Remission was associated with a shorter disease duration. Despite remission of asthma, a decreased suppressor function of regulatory T cells was observed, which may predispose patients to future recurrence of the disease.
authors.affiliation: Centre de recherche, Institut universitarie de cardiologie et de pneumologie de Québec, Québec. lpboulet@med.ulaval.ca
authors.forename: Louis-Philippe
authors.initials: LP
authors.lastname: Boulet
authors.forename: Hélène
authors.initials: H
authors.lastname: Turcott
authors.forename: Sophie
authors.initials: S
authors.lastname: Plante
authors.forename: Jamila
authors.initials: J
authors.lastname: Chakir
mesh_terms: D000249:Adenosine Monophosphate; D000328:Adult; D001249:Asthma / Q000276:immunology* / Q000503:physiopathology; D016535:Bronchial Hyperreactivity / Q000503:physiopathology*; D001985:Bronchial Provocation Tests; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D007073:Immunoglobulin E / Q000097:blood*; D008297:Male; D016210:Methacholine Chloride; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D016210:Methacholine Chloride; D007073:Immunoglobulin E; D000249:Adenosine Monophosphate