Abstract
Neutrophil activation state and its relationship with an inflammatory environment in community-acquired pneumonia (CAP) remain insufficiently elucidated. We aimed to evaluate the neutrophil apoptosis and cytokine pattern in CAP patients after 72 hours of treatment, and their impact on infection resolution.
Apoptosis of blood and bronchoalveolar lavage (BAL) neutrophils was measured in nonresponding CAP (NCAP), in responding CAP (blood only) and in patients without infection (control). Pro-inflammatory (IL-6, IL-8) and anti-inflammatory (IL-10) cytokines were measured. Main outcomes were clinical stability and days of hospitalization.
Basal neutrophil apoptosis was higher in BAL and blood of NCAP whereas spontaneous apoptosis (after 24 h culture) was lower. Cytokines in NCAP were higher than in responding CAP and control: IL-6 was increased in BAL and blood, IL-8 in BAL and IL-10 in blood. An increased basal apoptosis (≥20%) in BAL of NCAP was associated with lower systemic IL-10 (p<0.01), earlier clinical stability (p=0.05) and shorter hospital stay (p=0.02). A significant correlation was found for systemic IL-6 and IL-10 with days to reach stability and length of stay.
After 72 hours of treatment, an increased basal alveolar neutrophil apoptosis might contribute to downregulate inflammation and to faster clinical stability.
- Bronchoalveolar lavage
- cytokines
- length of stay
- neutrophil apoptosis
- nonresponding community-acquired pneumonia
- ERS