RT Journal Article SR Electronic T1 Similar adaptive immune response in COPD patients with and without α1 antitrypsin deficiency JF European Respiratory Journal JO Eur Respir J FD European Respiratory Society SP P599 VO 42 IS Suppl 57 A1 Simonetta Baraldo A1 Erica Bazzan A1 Graziella Turato A1 Beatrice Molena A1 Francesca Lunardi A1 Nazarena Nannini A1 Marco Damin A1 Marco Schiavon A1 Elisabetta Balestro A1 Monica Loy A1 Federico Rea A1 Manuel Cosio A1 Fiorella Calabrese A1 Marina Saetta YR 2013 UL http://erj.ersjournals.com/content/42/Suppl_57/P599.abstract AB Rationale. COPD is a complex disease characterized by variable degree of lung damage in response to cigarette smoke. An elastase/antielastase imbalance, along with innate immunity, is believed to account for lung destruction in α1-antitrypsin deficiency (AATD), however it is now apparent that AAT has important immune regulatory roles.Aim. To assess adaptive immunity in COPD patients with AATD and compare it to that present in COPD patients with similar disease severity but with normal AAT-levels.Methods. By immunohistochemistry we quantified the number of B cells, T-cells (CD4,CD8), neutrophils and macrophages in lung tissue of severe COPD patients with (n=10) and without (n=22) AATD undergoing lung transplantation, as well as smoking (n=16) and non-smoking (n=8) controls.Results. The two groups of patients with severe COPD, with and without AATD, had similar numbers of B-lymphocytes [median (range): 1.9 (0-4.4) and 1.1 (0-5) cells/mm], CD8 [3.4 (0.6-6.8) and 4.1 (3.1-6.8)] and CD4 T-lymphocytes [5.5 (1-10.8) and 6.0 (1.6-11.9)] that were higher when compared to the control groups (p<0.05). The number of neutrophils and alveolar macrophages was similar in the 4 groups. Lymphocytes in alveolar walls, particularly B-lymphocytes, correlated with the number of lymphoid follicles (r=0.59 p<0.0001) and with FEV1 (r=-0.49 p<0.001).Conclusions. The lung inflammatory pattern in severe COPD with AATD is indistinguishable from the one found in COPD without AATD, suggesting that in both conditions an adaptive immune response is an important pathogenetic factor.Funded by Padua University, CARIPARO, Chiesi.