title: Reduced sputum expression of interferon-stimulated genes in severe COPD.
abstract: BACKGROUND
  Exacerbations of COPD are frequent and commonly triggered by respiratory tract infections. The purpose of our study was to investigate innate immunity in stable COPD patients.
  
  
  METHODS
  Induced sputum was collected from 51 stable consecutive COPD patients recruited from the COPD Clinic of CHU Liege and 35 healthy subjects. Expression of interferons beta (IFN-β) and lambda1 (IL-29), IFN-stimulated genes (ISGs) MxA, OAS, and viperin were measured in total sputum cells by reverse transcription quantitative polymerase chain reaction (RT-qPCR). The presence of Picornaviruses was assessed by RT-PCR, while potential pathogenic microorganisms (PPM) were identified by sputum bacteriology.
  
  
  RESULTS
  Expression of IL-29 was found in 16 of 51 COPD patients (31%) and in nine of 35 healthy subjects (26%), while IFN-β was detected in six of 51 COPD patients (12%) and in two of 35 healthy subjects (6%). ISGs were easily detectable in both groups. In the whole group of COPD patients, OAS expression was decreased (P<0.05), while that of viperin was increased (P<0.01) compared to healthy subjects. No difference was found with respect to MxA. COPD patients from group D of Global Initiative for Chronic Obstructive Lung Disease (GOLD) had reduced expression of all three ISGs (P<0.01 for MxA, P<0.05 for OAS, and P<0.01 for viperin) as compared to those of group B patients. Picornaviruses were detected in eight of 51 (16%) COPD patients vs four of 33 (12%) healthy subjects, while PPM were detected in seven of 39 (18%) COPD patients and associated with raised sputum neutrophil counts. IFN-β expression was raised when either picornavirus or PPM were detected (P=0.06), but no difference was seen regarding IL-29 or ISGs.
  
  
  CONCLUSIONS
  ISGs expression was reduced in severe COPD that may favor exacerbation and contribute to disease progress by altering response to infection.
authors.affiliation: Department of Respiratory Medicine, Centre Hospitalier Universitaire (CHU) Liege, Groupe Interdisciplinaire de Génoprotéomique Appliquée (GIGA) I University of Liege, Belgium.
authors.forename: Clarissa
authors.initials: C
authors.lastname: Hilzendeger
authors.affiliation: Department of Medicine, Post-graduate Program in Health Sciences, University of Southern Santa Catarina, Palhoça-SC, Brazil.
authors.forename: Jane
authors.initials: J
authors.lastname: da Silva
authors.affiliation: Department of Respiratory Medicine, Centre Hospitalier Universitaire (CHU) Liege, Groupe Interdisciplinaire de Génoprotéomique Appliquée (GIGA) I University of Liege, Belgium.
authors.forename: Monique
authors.initials: M
authors.lastname: Henket
authors.affiliation: Department of Respiratory Medicine, Centre Hospitalier Universitaire (CHU) Liege, Groupe Interdisciplinaire de Génoprotéomique Appliquée (GIGA) I University of Liege, Belgium.
authors.forename: Florence
authors.initials: F
authors.lastname: Schleich
authors.affiliation: Department of Respiratory Medicine, Centre Hospitalier Universitaire (CHU) Liege, Groupe Interdisciplinaire de Génoprotéomique Appliquée (GIGA) I University of Liege, Belgium.
authors.forename: Jean Louis
authors.initials: JL
authors.lastname: Corhay
authors.affiliation: Airway Disease Division, Airway Disease Infection Section, National Heart and Lung Institute, Imperial College, London, UK.
authors.forename: Tatiana
authors.initials: T
authors.lastname: Kebadze
authors.affiliation: Airway Disease Division, Airway Disease Infection Section, National Heart and Lung Institute, Imperial College, London, UK.
authors.forename: Michael R
authors.initials: MR
authors.lastname: Edwards
authors.affiliation: Airway Disease Division, Airway Disease Infection Section, National Heart and Lung Institute, Imperial College, London, UK.
authors.forename: Patrick
authors.initials: P
authors.lastname: Mallia
authors.affiliation: Airway Disease Division, Airway Disease Infection Section, National Heart and Lung Institute, Imperial College, London, UK.
authors.forename: Sebastian L
authors.initials: SL
authors.lastname: Johnston
authors.affiliation: Department of Respiratory Medicine, Centre Hospitalier Universitaire (CHU) Liege, Groupe Interdisciplinaire de Génoprotéomique Appliquée (GIGA) I University of Liege, Belgium.
authors.forename: Renaud
authors.initials: R
authors.lastname: Louis
mesh_terms: D015088:2',5'-Oligoadenylate Synthetase / Q000235:genetics* / Q000276:immunology; D000368:Aged; D001530:Belgium; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D004279:DNA, Viral / Q000235:genetics; D018450:Disease Progression; D005260:Female; D005819:Genetic Markers; D054884:Host-Pathogen Interactions; D006801:Humans; D007113:Immunity, Innate / Q000235:genetics*; D016899:Interferon-beta / Q000235:genetics / Q000276:immunology; D007372:Interferons; D007378:Interleukins / Q000235:genetics / Q000276:immunology; D008297:Male; D008875:Middle Aged; D064547:Myxovirus Resistance Proteins / Q000235:genetics* / Q000276:immunology; D044925:Oxidoreductases Acting on CH-CH Group Donors; D010849:Picornaviridae / Q000235:genetics / Q000276:immunology; D010850:Picornaviridae Infections / Q000175:diagnosis / Q000235:genetics* / Q000276:immunology / Q000821:virology; D011506:Proteins / Q000235:genetics* / Q000276:immunology; D029424:Pulmonary Disease, Chronic Obstructive / Q000175:diagnosis / Q000235:genetics* / Q000276:immunology / Q000821:virology; D012141:Respiratory Tract Infections / Q000175:diagnosis / Q000235:genetics* / Q000276:immunology / Q000821:virology; D013183:Sputum / Q000737:chemistry* / Q000276:immunology / Q000821:virology; D000095022:Interferon Lambda; D000090123:Viperin Protein
chemical_list: D015088:2',5'-Oligoadenylate Synthetase; D004279:DNA, Viral; D005819:Genetic Markers; D016899:Interferon-beta; D007372:Interferons; D007378:Interleukins; D064547:Myxovirus Resistance Proteins; D044925:Oxidoreductases Acting on CH-CH Group Donors; D011506:Proteins; C000624353:interferon-lambda, human; D000095022:Interferon Lambda; C579071:MX1 protein, human; C444427:RSAD2 protein, human; D000090123:Viperin Protein
keywords: COPD; innate immunity; interferon-stimulated genes; interferon-β; interferon-λ1