Reduced sputum expression of interferon-stimulated genes in severe COPD
Received 6 February 2016
Accepted for publication 7 March 2016
Published 30 June 2016 Volume 2016:11(1) Pages 1485—1494
Checked for plagiarism Yes
Review by Single-blind
Peer reviewers approved by Dr Lucy Goodman
Peer reviewer comments 2
Editor who approved publication: Dr Richard Russell
Clarissa Hilzendeger,1 Jane da Silva,2 Monique Henket,1 Florence Schleich,1 Jean Louis Corhay,1 Tatiana Kebadze,3 Michael R Edwards,3 Patrick Mallia,3 Sebastian L Johnston,3 Renaud Louis1
1Department of Respiratory Medicine, Centre Hospitalier Universitaire (CHU) Liege, Groupe Interdisciplinaire de Génoprotéomique Appliquée (GIGA) I3 University of Liege, Belgium; 2Department of Medicine, Post-graduate Program in Health Sciences, University of Southern Santa Catarina, Palhoça-SC, Brazil; 3Airway Disease Division, Airway Disease Infection Section, National Heart and Lung Institute, Imperial College, London, UK
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.
Conclusion: ISGs expression was reduced in severe COPD that may favor exacerbation and contribute to disease progress by altering response to infection.
Keywords: COPD, innate immunity, interferon-β, interferon-λ1, interferon-stimulated genes
This work is published and licensed by Dove Medical Press Limited. The full terms of this license are available at https://www.dovepress.com/terms.php and incorporate the Creative Commons Attribution - Non Commercial (unported, v3.0) License. By accessing the work you hereby accept the Terms. Non-commercial uses of the work are permitted without any further permission from Dove Medical Press Limited, provided the work is properly attributed. For permission for commercial use of this work, please see paragraphs 4.2 and 5 of our Terms.Download Article [PDF] View Full Text [HTML][Machine readable]