Neutrophil elastase and interleukin-8 as inflammatory mediators in mechanically ventilated children.

ABSTRACT

BACKGROUND: Neutrophil elastase is a proteolytic enzyme which can have a destructive effect on respiratory tract structures. Interleukin-8 (IL-8), a proinflammatory cytokine, is an important chemoattractant for neutrophils. The aim of our study was to assess inflammatory states by determining elastase in complex with alpha1-proteinase inhibitor (E-alpha1PI) and IL-8 in children requiring mechanical ventilation. MATERIAL/METHODS: Plasma and respiratory tract lavage fluid (RTLF) levels of E-a1PI and IL-8 were measured (ELISA) in 31 children with (group I) and 22 without (group II) respiratory tract infection. Plasma results were compared with a group of healthy controls. Results are given as medians and ranges. Additionally, the percentage content of neutrophils in RTLF was determined. RESULTS: Significantly higher (p<0.00004) plasma levels of E-alpha1PI were found in group I than in group II. In group II, there were significantly higher (p<0.002) RTLF levels of E-alpha1PI and IL-8 than in group I. In both groups, the percentage content of neutrophils in RTLF exceeded 60%. A negative correlation was found between the plasma and RTLF levels of E-alpha1PI (r=-0.69; p<0.0004), between E-alpha1PI and percentage neutrophil content (r=-0.6; p<0.006), and between IL-8 and percentage neutrophil content (r=-0.5; p<0.04) in RTLF in group II. CONCLUSIONS: The determination of E-alpha1PI and IL-8 may be useful in the assessment of the inflammatory state in children requiring mechanical ventilation.