title: The etiologies of non-CF bronchiectasis in childhood: a systematic review of 989 subjects.
abstract: BACKGROUND
  While cystic fibrosis (CF) is the most common cause of bronchiectasis in childhood, non-CF bronchiectasis is associated with a wide variety of disorders. The objective of this study was to determine the relative prevalence and specific etiologies on non-CF bronchiectasis in childhood.
  
  
  METHODS
  EMBASE, Medline, OVID Cochrane Reviews, Directory of Open Access Journals, Open Science Directory, EPSCO information services, and OAlster were searched electronically and the bibliographies of selected studies were searched manually. The search was conducted independently by 2 authors.
  
  
  METHODS
  (1) any clinical trial, observational study or cross-sectional case series of 10 or more patients with a description of the conditions associated with bronchiectasis; (2) subjects aged 21 years or younger; (3) cystic fibrosis was excluded and; (4) the diagnosis was confirmed by computed tomography of the chest.
  
  
  METHODS
  Patient number, age range, inclusion criteria, diagnostic criteria, patient source, and categorical and specific etiology.
  
  
  RESULTS
  From 491 studies identified, 12 studies encompassing 989 children with non-CF bronchiectasis were selected. Sixty-three percent of the subjects had an underlying disorder. Infectious (17%), primary immunodeficiency (16%), aspiration (10%), ciliary dyskinesia (9%), congenital malformation (3%), and secondary immunodeficiency (3%) were the most common disease categories; 999 etiologies were identified. Severe pneumonia of bacterial or viral etiology and B cell defects were the most common disorders identified.
  
  
  CONCLUSIONS
  The majority of children with non-CF bronchiectasis have an underlying disorder. A focused history and laboratory investigated is recommended.
authors.affiliation: St. Christopher's Hospital for Children, Philadelphia, USA. kellysbrower@gmail.com.
authors.forename: Kelly S
authors.initials: KS
authors.lastname: Brower
authors.affiliation: St. Christopher's Hospital for Children, Philadelphia, USA. Michael.Delvecchio@tuhs.temple.edu.|Department of Pediatrics, Temple University School of Medicine, Philadelphia, PA, 19140, USA. Michael.Delvecchio@tuhs.temple.edu.
authors.forename: Michael T
authors.initials: MT
authors.lastname: Del Vecchio
authors.affiliation: St. Christopher's Hospital for Children, Philadelphia, USA. aronoff@temple.edu.|Department of Pediatrics, Temple University School of Medicine, Philadelphia, PA, 19140, USA. aronoff@temple.edu.
authors.forename: Stephen C
authors.initials: SC
authors.lastname: Aronoff
mesh_terms: D001987:Bronchiectasis / Q000453:epidemiology / Q000209:etiology*; D002648:Child; D002925:Ciliary Motility Disorders / Q000150:complications / Q000453:epidemiology; D015897:Comorbidity; D000013:Congenital Abnormalities / Q000453:epidemiology; D005547:Foreign Bodies / Q000150:complications / Q000453:epidemiology; D006801:Humans; D007153:Immunologic Deficiency Syndromes / Q000150:complications / Q000453:epidemiology; D007239:Infections / Q000150:complications / Q000453:epidemiology