Several clinical studies have evaluated the role of COPD in patients with community-acquired pneumonia (CAP). We investigated the systemic inflammatory response of patients with CAP (CAP + COPD) and patients without associated COPD (CAP only).
Clinical, microbiologic, and immunologic data were collected from 367 prospective patients on admission to hospital during a 3-year period. Comparative analyses were performed between patients with CAP + COPD (n = 117) and those with CAP only (n = 250) and between patients with and without domiciliary use of inhaled corticosteroids (ICSs) and oral corticosteroids.
Detailed characteristics of clinical severity and prognosis (mortality on hospitalization and at 30 and 90 days) were similar between the CAP + COPD and CAP-only groups. The readmission rate and the frequency of previous pneumonia were higher in the group of patients with CAP + COPD. On day 1 (admission to hospital), patients with CAP + COPD had significantly lower serum levels of tumor necrosis factor-α, IL-1, and IL-6 compared with the CAP-only group; levels of the remaining inflammatory biomarkers (C-reactive protein, procalcitonin, IL-8, and IL-10) were similar at days 1 and 3. The exclusion of patients with domiciliary use of ICS and oral corticosteroids confirmed lower levels of TNF-α on day 1 in patients with CAP + COPD. Finally, lower levels of IL-6 were found only among those patients with COPD who were currently using ICS.
Our prospective study demonstrates a different, disease-specific, early inflammatory pattern between patients with CAP with and without associated COPD. These findings are not completely corticosteroid mediated.