Nitrated proteins in bronchoalveolar lavage fluid of patients at risk of ventilator-associated bronchopneumonia.

peer reviewedThe study was designed to identify markers of oxidative injury, related to the nitric oxide derived cascade, in bronchoalveolar lavage (BAL) fluid from intensive care patients suspected of ventilator-associated pneumonia (VAP) and/or acute respiratory distress syndrome (ARDS). Thirty-eight patients developing VAP and/or ARDS (VAP/ARDS group) were compared to 20 ventilated patients without VAP/ARDS (control group). Myeloperoxidase (MPO) and elastase, taken as markers of neutrophil activation were measured by enzymatic techniques, and nitrated proteins (NTPs) by an immunological method. The cytotoxicity of the BAL fluid was tested using cultured human epithelial alveolar cells by the release of pre-incorporated 51Cr. Mean NTP concentration and, MPO and elastase activities were different between the VAP/ARDS and control groups (p<0.05 for NTPs; p<0.005 for MPO; p