title: Sputum eosinophil counts predict asthma control after discontinuation of inhaled corticosteroids.
abstract: BACKGROUND
  Although inhaled corticosteroids (ICSs) are effective in preventing deterioration in asthma control, at least half of subjects with mild-to-moderate asthma will remain stable when these agents are discontinued.
  
  
  OBJECTIVE
  We sought to determine whether noninvasive markers of inflammation predict which individuals maintain asthma control after discontinuation of ICSs.
  
  
  METHODS
  We analyzed data obtained from 164 subjects with mild-to-moderate asthma who participated in a 16-week trial comparing the effects of continued ICS use with the effects of a switch to salmeterol or placebo.
  
  
  RESULTS
  In comparison with continued ICS use, a switch to salmeterol or placebo was associated with increased rates of asthma deterioration over 16 weeks (9.3% vs 24.1% and 37.5%, respectively; P = .04 and P < .001, respectively). We found that neither exhaled nitric oxide nor methacholine PC 20 , when measured at randomization or 2 weeks after randomization, were significant predictors of subsequent asthma control in subjects who discontinued ICSs. However, both induced sputum eosinophil counts measured 2 weeks after a switch from ICS to placebo and changes in sputum eosinophil counts from before cessation of ICSs to after a switch to placebo predicted subsequent asthma deterioration (area under the receiver-operating characteristic curve, 0.771 [ P < .001] and 0.825 [ P < .001], respectively).
  
  
  CONCLUSIONS
  On the basis of a model treatment strategy, we estimate that allocating subjects to ICS therapy on the basis of changes in sputum eosinophil counts after a trial discontinuation could allow 48% of subjects with mild-to-moderate asthma to discontinue ICS therapy without an increased risk of asthma deterioration over a period of at least 14 weeks.
authors.affiliation: Brigham and Women's Hospital and Harvard Medical School, 75 Francis Street, Boston, MA 02115, USA. adeykin@partners.org
authors.forename: Aaron
authors.initials: A
authors.lastname: Deykin
authors.forename: Stephen C
authors.initials: SC
authors.lastname: Lazarus
authors.forename: John V
authors.initials: JV
authors.lastname: Fahy
authors.forename: Michael E
authors.initials: ME
authors.lastname: Wechsler
authors.forename: Homer A
authors.initials: HA
authors.lastname: Boushey
authors.forename: Vernon M
authors.initials: VM
authors.lastname: Chinchilli
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: Craig
authors.forename: Emily
authors.initials: E
authors.lastname: Dimango
authors.forename: Monica
authors.initials: M
authors.lastname: Kraft
authors.forename: Frank
authors.initials: F
authors.lastname: Leone
authors.forename: Robert F
authors.initials: RF
authors.lastname: Lemanske
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Martin
authors.forename: Gene R
authors.initials: GR
authors.lastname: Pesola
authors.forename: Stephen P
authors.initials: SP
authors.lastname: Peters
authors.forename: Christine A
authors.initials: CA
authors.lastname: Sorkness
authors.forename: Stanley J
authors.initials: SJ
authors.lastname: Szefler
authors.forename: Elliot
authors.initials: E
authors.lastname: Israel
mesh_terms: D000280:Administration, Inhalation; D000305:Adrenal Cortex Hormones / Q000008:administration & dosage*; D000328:Adult; D000420:Albuterol / Q000008:administration & dosage / Q000031:analogs & derivatives*; D001249:Asthma / Q000188:drug therapy* / Q000276:immunology / Q000503:physiopathology; D015415:Biomarkers / Q000032:analysis*; D001993:Bronchodilator Agents / Q000008:administration & dosage; D002452:Cell Count; D004804:Eosinophils / Q000166:cytology / Q000187:drug effects*; D005260:Female; D006801:Humans; D008297:Male; D009569:Nitric Oxide / Q000378:metabolism; D012372:ROC Curve; D012129:Respiratory Function Tests; D012189:Retrospective Studies; D000068299:Salmeterol Xinafoate; D013183:Sputum / Q000166:cytology*
chemical_list: D000305:Adrenal Cortex Hormones; D015415:Biomarkers; D001993:Bronchodilator Agents; D009569:Nitric Oxide; D000068299:Salmeterol Xinafoate; D000420:Albuterol