Cleaved caspase-3 in lung epithelium of children who died with acute respiratory distress syndrome

OBJECTIVE: To investigate the extent of cleaved caspase-3 immunostaining in lung epithelial cells in children with acute respiratory distress syndrome. DESIGN: Observational study in sixteen children who died with acute respiratory distress syndrome and diffuse alveolar damage. SETTING: Pediatric intensive care unit. PATIENTS: Sixteen children with fatal acute respiratory distress syndrome and diffuse alveolar damage. INTERVENTION: None. MEASUREMENTS AND MAIN RESULTS: Double immunohistochemistry for cleaved caspase-3 and (pan)cytokeratin in lung tissues obtained at autopsy. Spectral imaging was used for the quantification of immunohistochemistry colocalization of these markers. We found a wide range in the percentage of alveolar epithelial cell surface area with positive cleaved caspase-3 staining in the lungs of children with acute respiratory distress syndrome (from 1% to almost 20%). The degree of caspase-3 immunostaining in epithelial cells positively correlated with age. CONCLUSION: There is a high variability in the extent of classic apoptosis in lung epithelial cells in pediatric acute respiratory distress syndrome, potentially in part dependent on age