Supplementary Material for: Soluble urokinase receptor levels are not affected by the systemic inflammatory response to anesthesia and operative trauma

Introduction: Soluble urokinase plasminogen activator receptor (suPAR) is an emerging biomarker of the level of chronic systemic inflammation and the general condition of the patient. We aimed to investigate the impact of general anesthesia and major surgery on suPAR and C-reactive protein (CRP) levels in patients undergoing elective major non-cardiac surgery. Methods: The study included patients undergoing elective major non-cardiac surgery with an expected duration of ≥2 hours under general anesthesia. Inclusion criteria were: age ≥18 years and American Society of Anesthesiologists’ physical status I to IV. Blood was drawn 30 minutes prior to anesthesia and surgery (preoperatively), as well as 30 minutes after emergence from anesthesia (postoperatively). Plasma suPAR levels were determined using the suPARnostic® quick triage lateral flow assay. CRP measurements were performed by particle-enhanced immunoturbidimetric assay. Results: Preoperative and postoperative suPAR levels were similar and not statistically significant [7.7 (5.28-10.4) ng/mL vs. 7.15 (5.68-9.8) ng/mL, p=0.462]. CRP levels increased significantly during surgery [from 0.81 (0.24-2.1) mg/dL to 5.76 (2.2-8.75) mg/dL, p<0.001]. However, no correlation was found between CRP and suPAR levels, both preoperatively (rho=0.127; p=0.208) and postoperatively (rho=0.017; p=0.87). A statistically significant increase was also observed in white blood cell count postoperatively (7.576 vs. 10.711, p<0.001). Conclusion: General anesthesia and operative trauma did not influence the perioperative suPAR levels despite the activation of systemic inflammatory reaction.