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 α[sub]1[/sub]-proteinase inhibitor (E-α[sub]1[/sub]PI) and IL-8 in children requiring mechanical ventilation.Material/Methods: Plasma and respiratory tract lavage fluid (RTLF) levels of E-α[sub]1[/sub]PI 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

Keywords: Child, Preschool, Enzyme Inhibitors - metabolism, Interleukin-8 - analysis, Interleukin-8 - blood, Leukocyte Elastase - analysis, Leukocyte Elastase - blood, Respiration, Artificial, Respiratory System Abnormalities, Child, Preschool, Enzyme Inhibitors - metabolism, Interleukin-8 - blood, Leukocyte Elastase - blood, Respiration, Artificial, Respiratory System Abnormalities