Background: Sepsis represents a dysregulated immune response to infection that leads to organ dysfunction. A wide range of biomarkers, measured by different technologies, are being investigated for sepsis diagnosis, prognosis, and differentiation from Systemic Inflammatory Response Syndrome (SIRS). Early diagnosis of sepsis with improved markers would allow prompt treatment, which is imperative in reducing mortality and morbidity.

Methods: In our case-series study, we enrolled 188 patients who were admitted to and received treatment in the Intensive Care Unit (ICU) of our hospital (Sepsis: n = 103, SIRS: n = 71, and n = 14 with bacterial infections without SIRS). Specific parameters measured included Procalcitonin (PCT), C-Reactive Protein (CRP), and Cytokines (IL-6, IL-8, TNF-α)

Results: We observed higher values of laboratory biomarkers in patients with sepsis compared to the SIRS group: PCT: 10.2 ± 18.7 ng/mL vs. 0.26 ± 0.18 ng/mL, CRP: 148 ± 100 mg/mL vs. 42 ± 45 mg/mL, IL-6: 286 ± 330 pg/mL vs. 21.01 ± 27.5 pg/mL, IL-8: 310 ± 292 pg/mL vs. 129 ± 32.69 pg/mL, TNF-α: 131.15 ± 125.96 pg/mL vs. 33.55 ± 118.87 pg/mL. A multiple comparison test demonstrated a highly statistically significant difference between groups for PCT, CRP, IL-6, IL-8, and TNF-α. ROC curve analysis showed high sensitivity (97%) and specificity (93%) for PCT at a threshold of 0.5 ng/mL, and 100% specificity at 2 ng/mL. Other parameters demonstrated lower diagnostic accuracy.

Conclusion: IL-6, IL-8, CRP, and TNF-α are sensitive tests for sepsis diagnosis but lack high specificity. Procalcitonin (PCT) is the best marker, as it demonstrates both high sensitivity and specificity. New biomarkers of sepsis: presepsin, pro-adrenomedullin, microRNAs, transcriptomics, proteomics, and markers of neutrophil activation are currently under investigation, but further validation is needed.

Anila Lika is a medical doctor specialized in Clinical Chemistry and Hematology at the University Hospital Center “Mother Teresa” in Tirana, Albania, and an Associate Professor at the University of Medicine, Tirana (UMT). She earned her PhD in Laboratory Science from UMT in 2015, focusing on sepsis diagnosis, and has published several articles and presentations including sepsis biomarkers, coagulation, thrombophilia, and COVID-19.