Systemic inflammatory pattern of community-acquired pneumonia (CAP) patients with and without chronic obstructive pulmonary disease (COPD)

BackgroundSeveral clinical studies have evaluated the role of chronic obstructive pulmonary disease (COPD) in community-acquired pneumonia (CAP) patients. We investigated the systemic inflammatory response of CAP patients with (CAP+COPD) and patients without associated COPD (CAP only).MethodsClinical, microbiological and immunological data were collected from367 prospective patients on admission towere collected at hospital admission during a 3-year period. Comparative analyses were performed between CAP+COPD (n=117) and CAP only patients (n=250) and between patients with and without domiciliary use of inhaled (ICS) and oral corticosteroids.ResultsDetailed characteristics of clinical severity and prognosis (mortality on hospitalization, at 30 days and at 90 days) were similar between CAP+COPD and CAP only patients. The re-admission rate and the frequency of a previous pneumonia were higher in the group of CAP+COPD patients. On day -1 (admission to hospital) CAP+COPD patients had significantly lower serum levels of tumour necrosis factor (TNF) α, interleukin (IL) 1 and IL-6 compared with CAP only patients; 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 confirms lower levels of TNF-α on day 1 in CAP+COPD patients. Finally, lower levels of IL-6 was were found only among those COPD patients who were currently using habitually used ICS.ConclusionOur prospective study demonstrates a different, disease-specific early inflammatory pattern between CAP patients with and without associated COPD; these finding are not completely corticosteroid-mediated.