Ongoing airway inflammation in patients with COPD who do not currently smoke

Background-Inflammatory changes in the airways in chronic obstructive pulmonary disease (COPD) are largely attributed to smoking, yet they may be present even if patients do not currently smoke. The differences in inflammatory cells and the factors contributing to these differences were examined in the airways; of patients with COPD who do not currently smoke. Methods-Eighteen non-atopic subjects with COPD (14 men) of mean (SD) age 62 (8) years and forced expiratory volume in one second (EEV1) 59 (13)% predicted and II non-atopic healthy subjects (eight men) of mean (SD) age 58 (8) years, FEV1 104 (11)% predicted were studied. Sputum induction and bronchoscopy with bronchoalveolar lavage (BAL) and biopsies were performed. Results-Patients with COPD had more mucosal EG2+ cells (eosinophils) (median cells/mm(2), p = 0.049) and CD68+ cells (1115 (330-2920) versus 590 (450-1580) cells/mm(2), p = 0.03), and a tendency towards more CD4+ but not CD8+ lymphocytes than healthy controls. Furthermore, patients with COPD had higher percentages of sputum neutrophils (77 (29-94) versus 36 (18-60)%, p = 0.001) and eosinophils (1.2 (0-8.5) versus 0.2 (0-3.1)%, p = 0.008), BAL fluid eosinophills (0.4 (0-1.7) versus 0.2 (0-0.5)%, p = 0.03), and higher concentrations of sputum eosinophilic cationic protein (ECP) (838 (115-23 760) versus 121 (35-218) ng/ml, p < 0.001). Concentrations of ECP expressed per eosinophil were not: higher. Patients with COPD with high mucosal EG2+ cell numbers also had high mucosal CD4+ cell numbers. Sputum eosinophilia was associated with a decrease in FEV1/VC and BAL fluid eosinophilia with a decrease in mucosal NP57+ cells (neutrophils). Conclusions-Subjects with COPD who do not currently smoke have increased numbers of inflammatory cells. Eosinophils are increased in number in the airways in COPD but do not seem to be activated. The increased eosinophil numbers are probably due to recruitment as a result of ongoing inflammation. Macrophages and lymphocytes may play a part in this inflammation.