Bile Acid Aspiration in Suspected Ventilator-Associated Pneumonia.
Chest. 2009 Mar 24;
Authors: Wu YC, Hsu PK, Su KC, Liu LY, Tsai CC, Tsai SH, Hsu WH, Lee YC, Perng DW
The aims of this study were to measure the levels of bile acids in patients with suspected ventilator-associated pneumonia (VAP) and provide a possible pathway for neutrophilic inflammation to explain its proinflammatory effect on the airway. Bile acid levels were measured by spectrophotometric enzymatic assay, and liquid chromatography mass spectrometry was used to quantify the major bile acids. Alveolar cells were grown on modified air-liquid interface culture inserts and bile acids were then employed to stimulate the cells. RT-PCR and western blots were used to determine the involved gene expression and protein levels. The mean concentration of total bile acids in tracheal aspirates was 6.2 +/- 2.1 and 1.1 +/- 0.4 muM/g sputum for patients with and without VAP, respectively (p < 0.05). The IL-8 level was significantly higher in the VAP group (p < 0.05). The major bile acid, chenodeoxycholic acid, stimulated alveolar epithelial cells to increase IL-8 production at both the messenger RNA and protein level through p38 and JNK kinase activation. The selective p38 and JNK inhibitors, as well as dexamethasone, successfully inhibited IL-8 production. These data suggest that early intervention to prevent bile acid aspiration may reduce the intensity of neutrophilic inflammation in intubated and mechanically-ventilated patients in the ICU.
PMID: 19318678 [PubMed - as supplied by publisher]