Biomarkers in Pediatric ARDS: Future Directions

Orwoll, Benjamin E.; Sapru, Anil

The alveolar-capillary barrier is also maintained in part by cellular adhesion molecules, and one of these proteins that has become established as an important marker of both epithelial and endothelial integrity is soluble intercellular adhesion molecule 1 (sICAM-1) (128) (129) (130) (131) . In adults, there are multiple studies associating blood and BAL fluid sICAM-1 levels with the development of ARDS as well as with ARDS outcomes, such as mortality (132) (133) (134) . These findings have been confirmed in studies of children, first when Flori et al. described increased mortality in children with ARDS, which was independently associated with elevations of sICAM early in the disease course, especially at levels >1000 ng/mL (31) . This was reproduced in children with ARDS receiving high frequency oscillating ventilation, and further elevations were seen in patients who did not respond to lung recruitment maneuvers (32, 33) . A recent study also demonstrated early increases in sICAM-1 levels in children with ALI compared with controls and found associations between those levels and both durations of ventilation and mortality (34) . sICAM has been studied in tracheal aspirates of infants with RDS, and concentrations were significantly higher in those who went on to develop CLD (67) . These findings are highly consistent and underscore the importance of adhesion molecules and the pulmonary alveolar-capillary barrier in the pathogenesis of pediatric lung injury.