Association of serum soluble Fas concentrations and mortality of septic patients.

Introduction: Scarce data on Fas, one of the main receptors that activates the apoptosis extrinsic pathway, in septic patients exists. Higher blood soluble Fas (sFas) concentrations in non-survivor septic patients compared with survivors have been found in small studies; however, the association of blood sFas concentrations with mortality controlling for sepsis severity has not been stablished due to this small sample size in those studies. Thus, our main objective study was to determine whether an association between blood sFas concentrations and sepsis mortality controlling for sepsis severity exists.

Methods: We included septic patients in this observational and prospective study carried out in three Spanish Intensive Care Units. We obtained serum samples at sepsis diagnosis sepsis for sFas levels determination.

Results: Thirty-day non-surviving patients (n=85) compared to surviving patients (n=151) had higher serum sFas levels (p<0.001). We found in multiple logistic regression analysis an association of serum sFas levels with mortality controlling for age and SOFA (OR=1.004; 95% CI=1.002-1.006; p<0.001), and for age and APACHE-II (OR=1.004; 95% CI=1.002-1.006; p<0.001). Serum sFas levels showed and area under the curve for mortality prediction of 71% (95% CI=65-71%; p<0.001). Kaplan-Meier analysis showed higher mortality rate in patients with serum sFas levels>83.5ng/mL (Hazard ratio=3.2; 95% CI=2.1-5.0; p<0.001).

Conclusions: That an association between blood sFas concentrations and sepsis mortality controlling for sepsis severity exists was our main new finding study.