PT - JOURNAL ARTICLE AU - Isabelle Dupin AU - Matthieu Thumerel AU - Elise Maurat AU - Florence Coste AU - Edmée Eyraud AU - Hugues Begueret AU - Thomas Trian AU - Michel Montaudon AU - Roger Marthan AU - Pierre-Olivier Girodet AU - Patrick Berger TI - Fibrocyte accumulation in the airway walls of COPD patients AID - 10.1183/13993003.02173-2018 DP - 2019 Sep 01 TA - European Respiratory Journal PG - 1802173 VI - 54 IP - 3 4099 - http://erj.ersjournals.com/content/54/3/1802173.short 4100 - http://erj.ersjournals.com/content/54/3/1802173.full SO - Eur Respir J2019 Sep 01; 54 AB - The remodelling mechanism and cellular players causing persistent airflow limitation in COPD remain largely elusive. We have recently demonstrated that circulating fibrocytes, a rare population of fibroblast-like cells produced by the bone marrow stroma, are increased in COPD patients during an exacerbation. We aimed to quantify fibrocyte density in situ in bronchial specimens from both control subjects and COPD patients, to define associations with relevant clinical, functional and computed tomography (CT) parameters, and to investigate the effect of the epithelial microenvironment on fibrocyte survival in vitro (“Fibrochir” study).A total of 17 COPD patients and 25 control subjects, all requiring thoracic surgery, were recruited. Using co-immunostaining and image analysis, we identified CD45+ FSP1+ cells as tissue fibrocytes, and quantified their density in distal and proximal bronchial specimens. Fibrocytes, cultured from the blood samples of six COPD patients, were exposed to primary bronchial epithelial cell secretions from control subjects or COPD patients.We demonstrate that fibrocytes are increased in both distal and proximal tissue specimens of COPD patients. The density of fibrocytes is negatively correlated with lung function parameters and positively correlated with bronchial wall thickness as assessed by CT scan. A high density of distal bronchial fibrocytes predicts the presence of COPD with a sensitivity of 83% and a specificity of 70%. Exposure of fibrocytes to COPD epithelial cell supernatant favours cell survival.Our results thus demonstrate an increased density of fibrocytes within the bronchi of COPD patients, which may be promoted by epithelial-derived survival-mediating factors.A high density of tissue fibrocytes is associated with reduced lung function and an increase in airway wall thickness bit.ly/2JO71Dq