Systemic and bronchoalveolar cytokines as predictors of in-hospital mortality in severe community-acquired pneumonia

Abstract

Objectives: The aim of this study was to determine whether cytokine expression (interleukin [IL]-1beta, IL-6, IL-8, IL-10, and tumor necrosis factor [TNF]-alpha), C-reactive protein, and endotoxins on the first day of intensive care unit (ICU) admission are associated with hospital mortality in severe community-acquired pneumonia (CAP).

Design: This was a prospective study with bronchoalveolar lavage (BAL) and blood sampling.

Setting: This study was carried out in a 44-bed medical ICU of a 1700-bed university hospital.

Patients: Participants included 112 mechanically ventilated patients with severe CAP.

Interventions: Serum and BAL fluid IL-1beta, IL-6, IL-8, IL-10, TNF-alpha, C-reactive protein, and endotoxins on the first day of ICU admission were obtained.

Measurements and main results: The concentrations of TNF-alpha in BALF and IL-6, IL-8, IL-10, and TNF-alpha in serum were higher in nonsurvivors than in survivor patients with CAP. Of these 112 patients with severe CAP (39%), 44 developed acute respiratory distress syndrome (ARDS); these patients seemed to have higher serum IL-6, IL-8, and IL-10 levels than did the non-ARDS group. Furthermore, in the ARDS population, we found that the endotoxin levels in the BAL fluid were higher in the survival than in the nonsurvival group and BAL fluid concentrations of IL-6, IL-8, and IL-1beta and sera levels of IL-6 and IL-10 were lower in the survival than in the nonsurvival group, and they were associated with a high negative predictive value.

Conclusions: Serum and BAL fluid levels of the studied cytokines on admission may provide valuable prognostic information for patients with severe CAP.