Circulating sFasL Levels Predict the Severity and Outcome of Burn Injury: A Prospective Observational Study

Background: Severe burn injury activates shock, inflammation, and blood cell system, but inappropriate reactions may lead to adverse outcomes. Soluble Fas ligand (sFasL) participates in apoptosis and inflammatory response. The circulating sFasL levels we investigated in association with the burn severity, shock, inflammation, blood cells, and mortality in patients with severe burns.

Methods: A total of 56 patients with severe burns were recruited. The levels of sFasL and the biomarkers reflecting shock, organ damage, inflammation, and blood cells at 48 h postburn were analyzed. We compared the practical situation of patients that stratified by median sFasL levels and investigated the predictive value of sFasL for mortality.

Results: High circulating sFasL levels were associated with the higher degrees of burn index, shock index, lactate, N-terminal probrain natriuretic peptide, total bilirubin, blood urea nitrogen, creatinine, tumor necrosis factor-α, interleukin-1β, interleukin-8, intercellular adhesion molecule 1, and complement 3, and the lower degrees of oxygenation index, lymphocytes, and platelets. Multiple linear regression analysis showed that the higher tumor necrosis factor-α (P < 0.001) and the lower oxygenation index (P = 0.031) and lymphocytes (P = 0.043) were associated with the higher sFasL. High sFasL (a unit is 50 ng/L) (odds ratio [OR] 5.50 [95% CI 1.04-29.20], P = 0.045) was an independent predictor of increased mortality by multivariate logistic regression analysis.

Conclusions: High circulating sFasL at 48 h postburn in patients with severe burns reflect shock, proinflammatory response, organ damage, and lymphocyte reductions and predict 30-day mortality.