Background: There are scarce data on soluble Fas Ligand (sFasL), one of the main ligands that activate the apoptosis extrinsic pathway, in septic patients. In a small study of septic children were found higher plasma sFasL levels in non-survivors compared with survivors; however, an association between blood sFasL levels and mortality controlling for sepsis severity was not stablished due to the small sample size of the study. Therefore, the main objective of this study was to determine whether there is an association between blood sFasL concentrations and mortality in septic patients controlling for sepsis severity. Methods: Septic patients were included in this observational and prospective study conducted in three Spanish Intensive Care Units. Serum samples at diagnosis of sepsis were obtained for serum sFasL levels determination.
Results: Thirty-day non-surviving patients (n = 85) with respect to surviving patients (n = 151) showed higher serum sFasL levels (p<.001). Multiple logistic regression analysis found an association between serum sFasL levels and mortality (odds ratio [OR] = 1.007; 95% confidence interval [CI] = 1.003-1.010; p<.001) after controlling for age, septic shock, SOFA, INR and aPTT. The area under the curve (AUC) for mortality prediction by serum sFasL levels was of 62% (95% CI = 56-69%; p=.003). In Kaplan-Meier analysis was found that patients with serum sFasL levels >109 pg/mL had a higher mortality rate (hazard ratio = 3.6; 95% CI = 1.93-6.78; p<.001).
Conclusions: The main new finding from our study was that serum sFasL concentrations were associated with mortality in septic patients controlling for sepsis severity. Highlights Blood sFasL concentrations were higher in non-survivor than in survivor patients. There is an association between blood sFasL concentrations and mortality in septic patients. Blood sFasL concentrations could predict mortality of septic patients.
Keywords: Apoptosis; mortality; outcome; sFasL; sepsis.