title: Periostin levels and eosinophilic inflammation in poorly-controlled asthma.
abstract: BACKGROUND
  Periostin levels are associated with airway eosinophilia and are suppressed by corticosteroid treatment in asthma. This study sought to determine the relationship between serum and sputum periostin, airway inflammatory phenotype and asthma control.
  
  
  METHODS
  Adults with poorly-controlled asthma (n = 83) underwent a clinical assessment, sputum induction and blood sampling. Dispersed sputum was used for a differential cell count and periostin assessment (ELISA). Serum periostin was determined by the Elecsys® immunoassay.
  
  
  RESULTS
  Periostin levels were significantly higher in serum (median (IQR) of 51.6 (41.8, 62.6) ng/mL) than in sputum (1.1 (0.5, 2.0) ng/mL) (p < 0.001). Serum and sputum periostin were significantly higher in patients with eosinophilic asthma (n = 37) compared with non-eosinophilic asthma. Both serum and sputum periostin levels were significantly associated with proportion of sputum eosinophils (r = 0.422, p < 0.001 and r = 0.364, p = 0.005 respectively) but were not associated with asthma control. In receiver operator characteristic curve analysis, the area under the curve (AUC) for serum periostin (n = 83) was 0.679, p = 0.007. Peripheral blood eosinophils assessed in 67 matched samples, had a numerically greater AUC of 0.820 compared with serum periostin, p = 0.086 for the detection of eosinophilic asthma.
  
  
  CONCLUSIONS
  In poorly-controlled asthma, sputum and serum periostin levels are significantly related to sputum eosinophil proportions while their ability to predict the presence of eosinophilic asthma is modest.
authors.affiliation: Department of Respiratory and Sleep Medicine, Hunter Medical Research Institute, Level 2, West Wing, Lot 1 Kookaburra Circuit, New Lambton Heights, NSW, 2305, Australia. jodie.simpson@newcastle.edu.au.|Priority Research Centre for Asthma and Respiratory Disease, The University of Newcastle, Newcastle, NSW, Australia. jodie.simpson@newcastle.edu.au.
authors.forename: Jodie L
authors.initials: JL
authors.lastname: Simpson
authors.affiliation: School of Medicine, The University of Queensland, Brisbane, QLD, Australia.|Department of Thoracic Medicine, The Prince Charles Hospital, Brisbane, QLD, Australia.
authors.forename: Ian A
authors.initials: IA
authors.lastname: Yang
authors.affiliation: School of Medicine, The University of Queensland, Brisbane, QLD, Australia.|Department of Respiratory Medicine, Princess Alexandra Hospital, Brisbane, QLD, Australia.
authors.forename: John W
authors.initials: JW
authors.lastname: Upham
authors.affiliation: Department of Thoracic Medicine, Royal Adelaide Hospital, Adelaide, SA, Australia.|Lung Research Laboratory, Hanson Institute, Adelaide, SA, Australia.
authors.forename: Paul N
authors.initials: PN
authors.lastname: Reynolds
authors.affiliation: Department of Thoracic Medicine, Royal Adelaide Hospital, Adelaide, SA, Australia.|Lung Research Laboratory, Hanson Institute, Adelaide, SA, Australia.
authors.forename: Sandra
authors.initials: S
authors.lastname: Hodge
authors.affiliation: Department of Pulmonary Physiology and Sleep Medicine, Sir Charles Gairdner Hospital, Nedlands, WA, Australia.|School of Medicine and Pharmacology, The University of Western Australia, Crawley, WA, Australia.
authors.forename: Alan L
authors.initials: AL
authors.lastname: James
authors.affiliation: Respiratory Trials, The George Institute for Global Health, Sydney, NSW, Australia.|Department of Thoracic Medicine, Concord General Hospital, Concord, NSW, Australia.
authors.forename: Christine
authors.initials: C
authors.lastname: Jenkins
authors.affiliation: Australian School of Advanced Medicine, Macquarie University, Sydney, NSW, Australia.|Department of Thoracic Medicine, Concord General Hospital, Concord, NSW, Australia.
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Peters
authors.affiliation: Genentech Inc, South San Francisco, CA, USA.
authors.forename: Guiquan
authors.initials: G
authors.lastname: Jia
authors.affiliation: Genentech Inc, South San Francisco, CA, USA.
authors.forename: Cecile T J
authors.initials: CT
authors.lastname: Holweg
authors.affiliation: Department of Respiratory and Sleep Medicine, Hunter Medical Research Institute, Level 2, West Wing, Lot 1 Kookaburra Circuit, New Lambton Heights, NSW, 2305, Australia.|Priority Research Centre for Asthma and Respiratory Disease, The University of Newcastle, Newcastle, NSW, Australia.|Woolcock Institute of Medical Research, Glebe, NSW, Australia.
authors.forename: Peter G
authors.initials: PG
authors.lastname: Gibson
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001249:Asthma / Q000150:complications* / Q000188:drug therapy / Q000378:metabolism; D015415:Biomarkers / Q000378:metabolism; D015815:Cell Adhesion Molecules / Q000378:metabolism*; D003430:Cross-Sectional Studies; D004804:Eosinophils / Q000473:pathology*; D005260:Female; D005938:Glucocorticoids / Q000627:therapeutic use*; D006801:Humans; D007118:Immunoassay; D007958:Leukocyte Count; D008297:Male; D008875:Middle Aged; D010641:Phenotype; D011379:Prognosis; D011657:Pulmonary Eosinophilia / Q000175:diagnosis / Q000209:etiology / Q000378:metabolism*; D012372:ROC Curve; D013183:Sputum / Q000737:chemistry* / Q000166:cytology; D055815:Young Adult
chemical_list: D015415:Biomarkers; D015815:Cell Adhesion Molecules; D005938:Glucocorticoids; C512835:POSTN protein, human
keywords: Eosinophilic asthma; Inflammation; Non-eosinophillic asthma; Periostin; Phenotype