title: Will nonasthmatic eosinophilic bronchitis develop into chronic airway obstruction?: a prospective, observational study.
abstract: OBJECTIVE
  The long-term prognosis of nonasthmatic eosinophilic bronchitis (NAEB) is still unclear. The aim of this study was to observe the frequency of relapse among patients with NAEB and the likelihood of NAEB developing into chronic airflow obstruction over time.
  
  
  METHODS
  Patients with NAEB were followed for at least 1 year between 2003 and 2013. During this period, we evaluated clinical symptoms, sputum eosinophil count, spirometry, and bronchial hyperresponsiveness. A linear mixed model was adopted to determine the relationship between time and lung function.
  
  
  RESULTS
  A total of 234 patients with NAEB were identified, of whom 141 were followed for > 1 year (median, 4.1 years). Up to 59.6% of patients had a relapse after treatment. Both allergic rhinitis (OR, 4.37; 95% CI, 1.049-18.203; P = .043) and sputum eosinophilia after 4 weeks of treatment with inhaled corticosteroids (OR, 9.493; 95% CI, 2.381-37.850; P = .001) were risk factors for relapse. Among the 141 patients, mild asthma developed in eight (5.7%). During the follow-up period, no progressive decline in FVC, FEV1, and FEV1/FVC were observed (P > .05). Although the proportion of small airway dysfunction (maximum midexpiratory flow [MMEF] < 65%) significantly increased at the last visit in all groups (all P < .05), only the relapse group showed an MMEF decline at the end of follow-up (P < .05) in the linear mixed model.
  
  
  CONCLUSIONS
  More than 50% of patients with NAEB have repeated episodes associated with persistent sputum eosinophilia after treatment and allergic rhinitis. In the current cohort, chronic airway obstruction does not develop despite small airway dysfunction increases over time.
authors.affiliation: State Key Laboratory of Respiratory Disease, Guangzhou Institute of Respiratory Disease, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, China. Electronic address: klai@163.com.
authors.forename: Kefang
authors.initials: K
authors.lastname: Lai
authors.affiliation: State Key Laboratory of Respiratory Disease, Guangzhou Institute of Respiratory Disease, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, China.
authors.forename: Baojuan
authors.initials: B
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Respiratory Disease, Guangzhou Institute of Respiratory Disease, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, China.
authors.forename: Danyuan
authors.initials: D
authors.lastname: Xu
authors.affiliation: State Key Laboratory of Respiratory Disease, Guangzhou Institute of Respiratory Disease, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, China.
authors.forename: Lina
authors.initials: L
authors.lastname: Han
authors.affiliation: State Key Laboratory of Respiratory Disease, Guangzhou Institute of Respiratory Disease, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, China.
authors.forename: Ling
authors.initials: L
authors.lastname: Lin
authors.affiliation: State Key Laboratory of Respiratory Disease, Guangzhou Institute of Respiratory Disease, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, China.
authors.forename: Yin
authors.initials: Y
authors.lastname: Xi
authors.affiliation: State Key Laboratory of Respiratory Disease, Guangzhou Institute of Respiratory Disease, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, China.
authors.forename: Faxia
authors.initials: F
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Respiratory Disease, Guangzhou Institute of Respiratory Disease, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, China.
authors.forename: Ruchong
authors.initials: R
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Respiratory Disease, Guangzhou Institute of Respiratory Disease, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Luo
authors.affiliation: State Key Laboratory of Respiratory Disease, Guangzhou Institute of Respiratory Disease, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, China.
authors.forename: Qiaoli
authors.initials: Q
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Respiratory Disease, Guangzhou Institute of Respiratory Disease, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, China.
authors.forename: Nanshan
authors.initials: N
authors.lastname: Zhong
mesh_terms: D000328:Adult; D001249:Asthma; D001991:Bronchitis / Q000150:complications* / Q000175:diagnosis; D018450:Disease Progression; D004802:Eosinophilia / Q000150:complications* / Q000175:diagnosis; D005260:Female; D005500:Follow-Up Studies; D005540:Forced Expiratory Flow Rates / Q000502:physiology*; D006801:Humans; D008297:Male; D011446:Prospective Studies; D029424:Pulmonary Disease, Chronic Obstructive / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology; D013183:Sputum / Q000166:cytology; D013997:Time Factors