Elevation of KL-6, a lung epithelial cell marker, in plasma and epithelial lining fluid in acute respiratory distress syndrome. Am J Physiol Lung Cell Mol Physiol 286: L1088 -L1094, 2004. First published September 5, 2003 10.1152 10. /ajplung. 00420.2002 is a pulmonary epithelial mucin more prominently expressed on the surface membrane of alveolar type II cells when these cells are proliferating, stimulated, and/or injured. We hypothesized that high levels of KL-6 in epithelial lining fluid and plasma would reflect the severity of lung injury in patients with acute lung injury (ALI). Epithelial lining fluid was obtained at onset (day 0) and day 1 of acute respiratory distress syndrome (ARDS)/ALI by bronchoscopic microsampling procedure in 35 patients. On day 0, KL-6 and albumin concentrations in epithelial lining fluid were significantly higher than in normal controls (P Ͻ 0.001), and the concentrations of KL-6 in epithelial lining fluid (P Ͻ 0.002) and in plasma (P Ͻ 0.0001) were higher in nonsurvivors than in survivors of ALI/ARDS. These observations were corroborated by the immunohistochemical localization of KL-6 protein expression in the lungs of nonsurvivors with ALI and KL-6 secretion from cultured human alveolar type II cells stimulated by proinflammatory cytokines. Because injury to distal lung epithelial cells, including alveolar type II cells, is important in the pathogenesis of ALI, the elevation of KL-6 concentrations in plasma and epithelial lining fluid could be valuable indicators for poor prognosis in clinical ALI. alveolar type II cell; pulmonary edema; microsampling

ObjectivesTo examine whether the extent of fibroproliferative changes on high-resolution CT (HRCT) scan influences prognosis, ventilator dependency and the associated outcomes in patients with early acute respiratory distress syndrome (ARDS).DesignA prospective observational cohort study.SettingIntensive care unit in a teaching hospital.Participants85 patients with ARDS who met American-European Consensus Conference Criteria and eligible criteria.InterventionsHRCT scans were performed and prospectively evaluated by two independent observers on the day of diagnosis and graded into six findings according to the extent of fibroproliferation. An overall HRCT score was obtained by previously published method.Primary and secondary outcomesThe primary outcome was 60-day mortality. Secondary outcomes included the number of ventilator-free days, organ failure-free days, the incidence of barotraumas and the occurrence of ventilator-associated pneumonia.ResultsHigher HRCT scores were associated with statistically significant decreases in organ failure-free days as well as ventilator-free days. Multivariate Cox proportional hazards model showed that the HRCT score remained an independent risk factor for mortality (HR 1.20; 95% CI 1.06 to 1.36; p=0.005). Multivariate analysis also revealed that the CT score had predictive value for ventilator weaning within 28 days (OR 0.63; 95% CI 0.48 to 0.82; p=0.0006) as well as for an incidence of barotraumas (OR 1.61; 95% CI 1.08 to 2.38; p=0.018) and for an occurrence of ventilator-associated pneumonia (OR 1.46; 95% CI 1.13 to 1.89; p=0.004). A HRCT score <210 enabled prediction of 60-day survival with 71% sensitivity and 72% specificity and of ventilator-weaning within 28 days with 75% sensitivity and 76% specificity.ConclusionsPulmonary fibroproliferation assessed by HRCT in patients with early ARDS predicts increased mortality with an increased susceptibility to multiple organ failure, including ventilator dependency and its associated outcomes.

These observations suggest that HMGB1 could be one of the deteriorating factors in the development of VILI.

These results suggest that BMS is safe and useful to monitor pulmonary biochemical events in ARDS.