Biomarkers in Pediatric ARDS: Future Directions

Orwoll, Benjamin E.; Sapru, Anil

There has been growing literature resulting from interest in studying biological markers of acute lung diseases, including ARDS, in both the plasma or serum as well as bronchoalveolar lavage (BAL) fluid, with the hope to better elucidate pathophysiological mechanisms of ALI and to identify the potential markers of severity and outcome (6) . The vast majority of these investigations have involved adult patients, and findings have subsequently been extrapolated to children. Large pediatric studies have been infrequent and limited in their findings because of the small numbers of ARDS patients, heterogeneity of underlying disease processes leading to pARDS, and the overall low mortality of pARDS. Multiple clinical outcome predictors in pARDS have been identified, with findings indicating that the severity of oxygenation defects, dead space fraction, organ failures, and underlying immunodeficiency are important factors (2, (9) (10) (11) . However, the utility of clinical predictors is limited by the relatively low and decreasing rates of mortality in pARDS (12) . Additionally, some clinical predictors may have less specificity for ARDS than molecular markers and have not yet led to the development of novel therapies targeting specific patient groups. Therefore, in addition to clinical findings there has been an ongoing interest in using biomarkers, specifically of endothelial and epithelial integrity/injury, coagulation/ fibrinolysis, inflammation, and inflammation-associated cellular derangements, as surrogate markers of patient outcomes in pARDS.