title: Sputum cell counts to manage prednisone-dependent asthma: effects on FEV1and eosinophilic exacerbations.
abstract: BACKGROUND
  Prednisone dependence in asthma is usually described based on clinical and spirometric characteristics. It is generally believed that these patients have frequent exacerbations and lose lung function rapidly because of uncontrolled airway eosinophilia.
  
  
  OBJECTIVE
  The objectives of this study are to report the effect on asthma exacerbations and the change in lung function over time in prednisone-dependent asthma when severe asthma is managed using a protocol that aims to maintain normal sputum cell counts.
  
  
  METHODS
  A retrospective survey of patients prospectively assessed in a university tertiary care asthma clinic.
  
  
  RESULTS
  52 patients (30 males, mean age 51 years, 64% non-atopic) were followed for a median period of 5.4 years (min-max: 0.2-35.2). Monitoring with the aim of keeping sputum eosinophils below 3% resulted in higher doses of corticosteroids (median daily dose of prednisone was 10 mg and for inhaled corticosteroids was 1500 μg of fluticasone equivalent) than at baseline and this was associated with predictable adverse effects. Despite the disease severity, 10 patients (19%) did not require LABA for symptom control. Most importantly, over the period of follow-up, there were only 0.3 eosinophilic exacerbations/patient/year. Overall, there was an increase in FEV1 over the period of follow-up (mean +84.6 ml/year) rather than an expected decline.
  
  
  CONCLUSIONS
  Monitoring of eosinophils in sputum enables to maintain symptom control and preserve FEV1 in patients with severe prednisone-dependent asthma.
authors.affiliation: Department of Medicine, McMaster University and St Joseph's Healthcare Hamilton, Hamilton, ON Canada.
authors.forename: Afia
authors.initials: A
authors.lastname: Aziz-Ur-Rehman
authors.affiliation: Department of Medicine, McMaster University and St Joseph's Healthcare Hamilton, Hamilton, ON Canada.
authors.forename: Angira
authors.initials: A
authors.lastname: Dasgupta
authors.affiliation: Department of Medicine, McMaster University and St Joseph's Healthcare Hamilton, Hamilton, ON Canada.
authors.forename: Melanie
authors.initials: M
authors.lastname: Kjarsgaard
authors.affiliation: Department of Medicine, McMaster University and St Joseph's Healthcare Hamilton, Hamilton, ON Canada.
authors.forename: Frederick E
authors.initials: FE
authors.lastname: Hargreave
authors.affiliation: Department of Medicine, McMaster University and St Joseph's Healthcare Hamilton, Hamilton, ON Canada.|Firestone Institute for Respiratory Health, St. Joseph's Healthcare, 50 Charlton Avenue East, Hamilton, ON L8N 4A6 Canada.
authors.forename: Parameswaran
authors.identifier: 0000-0002-1041-9492
authors.initials: P
authors.lastname: Nair
keywords: Eosinophils; Exacerbations; FEV1; Prednisone; Severe asthma; Sputum cell counts