Sputum inflammatory cells in COPD patients classified according to GOLD 2011 guidelines. Categories: Cerebrovascular Reactivity to Carbon Dioxide Author: Antonelli S, Bartoli ML, Cianchetti S, Costa F, Decusatis G, Latorre M, Malagrinò L, Nieri D, Paggiaro P, Santerini S, Simone CD, Vagaggini B