Twenty-four Months Longitudinal Study of Acute Exacerbations in a Cohort of Chronic Obstructive Pulmonary Disease Patients

Background: This study aims to follow a cohort of COPD patients so as to measure the frequency of acute exacerbation and annually correlate it with the BODE index and with the cellularity of induced sputum (IS) at admission. Methods: The longitudinal study followed 44 COPD patients for 30 months. COPD severity was determined according to the GOLD criteria and the cellularity of induced sputum was quantified. For two years, COPD patients were assessed for acute exacerbation, characterized by an intensification of COPD symptoms that required additional antibiotics or/and systemic corticosteroids. All patients were smokers and returned for regular clinical visits. IS was collected from all patients when admitted to the study and cellularity was quantified. BODE index was measured in the 1st and 2nd years. Results: Data showed that the GOLD criteria did not correlate with acute exacerbation, but the BODE index did (r = 0.587). Neutrophils and macrophages from induced sputum had good correlation with FEV1 and there is a phenotypic profile for which acute exacerbation is more recurrent, which is chronic bronchitis (p<0.038). Conclusions: The frequency of acute exacerbation is similar to that of world medical literature, approximately 2 episodes per annum. The results suggest that BODE index could be used to identification of subgroup of COPD patients which has more acute exacerbation.