Identification of autophagy markers in clinical cases of sepsis

Abstract Apoptotic cell death plays a key role in sepsis-induced immunosuppression and organ dysfunction. Autophagy may serve as a compensatory protective mechanism in sepsis owing to its potential role in reversing cell death-induced immunosuppression. The goal of our study was to investigate for the presence of autophagy markers in septic patients. Our preliminary study design included patients diagnosed with, and treated for, sepsis in clinical settings (N =13). Healthy volunteers served as control subjects (N = 10). Markers of autophagy were assessed in serum, peripheral blood mononuclear cells (PBMCs) and PBMC lysates derived from patients and healthy controls. Samples were analyzed by ELISA and flow cytometry methods. Data and statistical analyses were performed using GraphPad Prism v7.0. Results from flow cytometry analysis showed significantly elevated levels of autophagy markers in PBMCs derived from septic patients compared to that observed in PBMCs from control subjects (p < 0.01 from unpaired t-test analysis). Results from ELISA experiments showed significantly lower levels of the autophagy marker in patient serum samples when compared to that seen in control serum samples (p < 0.01 from unpaired t-test analysis). ELISA analysis showed a concomitant increase in the same autophagy marker in PBMC lysates obtained from patients with sepsis compared to that observed in PBMC lysates from control subjects. Preliminary results serve as a basis for us to investigate the role of autophagy in the prediction of clinical outcomes in sepsis.