Neutrophil extracellular traps in bronchial aspirates: a quantitative analysis

Neutrophil extracellular traps (NETs) are structures composed of DNA and granular proteins, which rapidly trap and kill pathogens. The formation of NETs has been detected during infection in animal experiments, but their role in humans is unclear. The purposes of this study were to quantitatively evaluate the production of NETs during acute respiratory infection and to study the relationship between the NET length and various inflammatory mediators. We examined bronchial aspirates collected from nine intubated patients in an intensive care unit. Samples were collected at the onset of acute respiratory infection (day 0) and on days 1, 3-5, and 6-8. The NET length was visualised by immunohistochemistry and quantified using computer tracing software. The NET length was measured and compared at each time point. The length differed significantly between time points (p