title: Blood eosinophils and inhaled corticosteroid/long-acting β-2 agonist efficacy in COPD.
abstract: OBJECTIVE
  We performed a review of studies of fluticasone propionate (FP)/salmeterol (SAL) (combination inhaled corticosteroid (ICS)/long-acting β2-agonist (LABA)) in patients with COPD, which measured baseline (pretreatment) blood eosinophil levels, to test whether blood eosinophil levels ≥2% were associated with a greater reduction in exacerbation rates with ICS therapy.
  
  
  METHODS
  Three studies of ≥1-year duration met the inclusion criteria. Moderate and severe exacerbation rates were analysed according to baseline blood eosinophil levels (<2% vs ≥2%). At baseline, 57-75% of patients had ≥2% blood eosinophils. Changes in FEV1 and St George's Respiratory Questionnaire (SGRQ) scores were compared by eosinophil level.
  
  
  RESULTS
  For patients with ≥2% eosinophils, FP/SAL was associated with significant reductions in exacerbation rates versus tiotropium (INSPIRE: n=719, rate ratio (RR)=0.75, 95% CI 0.60 to 0.92, p=0.006) and versus placebo (TRISTAN: n=1049, RR=0.63, 95% CI 0.50 to 0.79, p<0.001). No significant difference was seen in the <2% eosinophil subgroup in either study (INSPIRE: n=550, RR=1.18, 95% CI 0.92 to 1.51, p=0.186; TRISTAN: n=354, RR=0.99, 95% CI 0.67 to 1.47, p=0.957, respectively). In SCO30002 (n=373), no significant effects were observed (FP or FP/SAL vs placebo). No relationship was observed in any study between eosinophil subgroup and treatment effect on FEV1 and SGRQ.
  
  
  CONCLUSIONS
  Baseline blood eosinophil levels may represent an informative marker for exacerbation reduction with ICS/LABA in patients with COPD and a history of moderate/severe exacerbations.
authors.affiliation: Respiratory Medicine Unit, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK.
authors.forename: Ian D
authors.initials: ID
authors.lastname: Pavord
authors.affiliation: GSK, Uxbridge, UK.
authors.forename: Sally
authors.initials: S
authors.lastname: Lettis
authors.affiliation: Respiratory Medicine Development Center, GSK, Research Triangle Park, North Carolina, USA.
authors.forename: Nicholas
authors.initials: N
authors.lastname: Locantore
authors.affiliation: Respiratory Medicine Development Center, GSK, Research Triangle Park, North Carolina, USA.
authors.forename: Steve
authors.initials: S
authors.lastname: Pascoe
authors.affiliation: St George's, University of London, London, UK.
authors.forename: Paul W
authors.initials: PW
authors.lastname: Jones
authors.affiliation: National Heart and Lung Institute, Royal Brompton Campus, Imperial College London, London, UK.
authors.forename: Jadwiga A
authors.initials: JA
authors.lastname: Wedzicha
authors.affiliation: Respiratory Medical Franchise, GSK, Uxbridge, UK William Harvey Institute, Barts and The London School of Medicine and Dentistry, London, UK.
authors.forename: Neil C
authors.initials: NC
authors.lastname: Barnes
mesh_terms: D000280:Administration, Inhalation; D058666:Adrenergic beta-2 Receptor Agonists / Q000008:administration & dosage*; D003692:Delayed-Action Preparations; D004311:Double-Blind Method; D004804:Eosinophils / Q000166:cytology*; D005260:Female; D000068297:Fluticasone-Salmeterol Drug Combination / Q000008:administration & dosage; D005541:Forced Expiratory Volume / Q000502:physiology; D005938:Glucocorticoids / Q000008:administration & dosage; D006801:Humans; D008297:Male; D008875:Middle Aged; D029424:Pulmonary Disease, Chronic Obstructive / Q000097:blood / Q000188:drug therapy* / Q000503:physiopathology; D012189:Retrospective Studies; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires; D016896:Treatment Outcome
chemical_list: D058666:Adrenergic beta-2 Receptor Agonists; D003692:Delayed-Action Preparations; D000068297:Fluticasone-Salmeterol Drug Combination; D005938:Glucocorticoids
keywords: COPD Exacerbations