TY - JOUR T1 - In search of ckit+ stem cells in lung tissue JF - European Respiratory Journal JO - Eur Respir J DO - 10.1183/13993003.congress-2015.PA5062 VL - 46 IS - suppl 59 SP - PA5062 AU - Alejandra López-Giraldo AU - Tamara Cruz AU - Rosa Faner AU - Alvar Agustí Y1 - 2015/09/01 UR - http://erj.ersjournals.com/content/46/suppl_59/PA5062.abstract N2 - Introduction: Self-renewing, multipotent and clonogenic stem cells (ckit+/CD45-/tryptase-/CD34-) have been described in lung tissue of healthy adults. Whether they are present and/or functional in smokers with and without chronic obstructive pulmonary disease (COPD) is unclear.Objectives: To characterize and compare the population of ckit + cells in lung tissue of COPD patients, smokers (S) and non-smokers (NS) with normal spirometry.Methods: Prospective study of 30 COPD patients, 11 S and 11 NS submitted to lung resection surgery. Fresh lung tissue was homogenized and used for flow cytometery (FC) determination of ckit/CD45/CD34 markers. Immunofluorescence (IF) analysis on frozen tissue was performed using ckit/CD45/tryptase.Results: By FC we observed three populations: a) ckit(high)/CD45+/CD34-; b) ckit(low)/CD45-/CD34+ and c) ckit(low)/CD45-/CD34-. The mean percentatge of each of them in COPD, S and NS, respectively, were: a) 4.5%, 4.8% and 3.7%, b) 1.1%, 1.0% and 1.1%, and c) 0.10%, 0.07% and 0.12%. None of them was statistically different between groups (p=0.2, p=0.9 and p=0.6 respectively). By IF, around 90% of cells are ckit+/CD45+/tryptase+, and the remaining cells were ckit+/tryptase-/CD45+, indicating that, using IF we were not able to identify ckit+/CD45- cells putative stem cells.Conclusions: In adult lung tissue by both FC and IF the most abundant ckit+ cells are mast cells. By FC we detected two additional cell populations: 1) a ckit (low)/CD45-/CD34+ cells which likely are endothelial cell progenitors, and 2) a rare and diffuse population of ckit (low)/CD45-/CD34- cells, which putative stem cells. Any of the detected populations differ between studied groups.Supported by FIS PI12/01117, FUCAP 2013,SEPAR PI192/2012. ER -