title: Time course of inflammation resolution in patients with frequent exacerbations of chronic obstructive pulmonary disease.
abstract: BACKGROUND
  When exacerbation of chronic obstructive pulmonary disease (AECOPD) occurs frequently, patients have high levels of airway and systemic inflammation and a poor quality of life. This study compared the nature and course of systemic and airway inflammation during AECOPD between patients who experienced frequent exacerbations and those with non-frequent exacerbations.
  
  
  METHODS
  Consecutive hospitalized patients with AECOPD were recruited and divided into 2 groups according to the frequency of AECOPD they had experienced in the previous year. Frequent exacerbators (defined as 2 or more AECOPD in the previous year) and non-frequent exacerbators (defined as zero or 1 AECOPD in the previous year). Inflammatory (interleukin 6, interleukin 8, myeloperoxidase, and C-reactive protein) and clinical (dyspnea, COPD assessment test (CAT), and peak expiratory flow) indices were assessed on the day of admission before starting therapy, day 7 of treatment, the day of planned discharge (day 10-14), and 8 weeks after discharge.
  
  
  RESULTS
  We analyzed data from 135 patients; 78 (57.8%) were non-frequent exacerbators and 57 (42.2%) were frequent exacerbators. In both groups, the inflammatory and clinical indices at day 7, the day of planned discharge (day 10-14), and 8 weeks were significantly improved compared to those at admission. Frequent exacerbators had a smaller reduction in their inflammatory indices and CAT scores between exacerbation onset and all the other time points compared with infrequent exacerbators.
  
  
  CONCLUSIONS
  Frequent exacerbators have a reduced response to treatment of AECOPD in terms of inflammatory indices and quality of life.
authors.affiliation: Department of Respiratory Medicine, Peking University Third Hospital, Beijing, China (mainland).
authors.forename: Chun
authors.initials: C
authors.lastname: Chang
authors.affiliation: Department of Respiratory Medicine, Peking University Third Hospital, Beijing, China (mainland).
authors.forename: Wanzhen
authors.initials: W
authors.lastname: Yao
mesh_terms: D000368:Aged; D001991:Bronchitis / Q000209:etiology / Q000503:physiopathology*; D002097:C-Reactive Protein / Q000378:metabolism; D002681:China; D004417:Dyspnea / Q000473:pathology; D005260:Female; D006801:Humans; D007249:Inflammation / Q000209:etiology / Q000503:physiopathology*; D015850:Interleukin-6 / Q000378:metabolism; D016209:Interleukin-8 / Q000378:metabolism; D008173:Lung Diseases, Obstructive / Q000150:complications* / Q000175:diagnosis / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D010366:Peak Expiratory Flow Rate / Q000502:physiology; D009195:Peroxidase / Q000378:metabolism; D011446:Prospective Studies; D011788:Quality of Life; D012008:Recurrence; D018709:Statistics, Nonparametric; D013997:Time Factors
chemical_list: D015850:Interleukin-6; D016209:Interleukin-8; D002097:C-Reactive Protein; D009195:Peroxidase