Assessment of Inflammatory Biomarkers in Sepsis

Abstract

Background: Sepsis is a clinical syndrome of life-threatening organ dysfunction due to a dysregulated host response to infection. Many biomarkers have been used clinically to assist in diagnosing sepsis. The aim of this study was to assess the blood levels of procalcitonin (PCT) and four inflammation markers, C-reactive protein (CRP), IL-6, IL-8, and TNF-α, with respect to sepsis diagnosis. Methods and Results: This case series study enrolled 188 patients (67 females and 121 males) treated in the University Hospital Centre “Mother Teresa” in Tirana with three different diagnoses: sepsis (n=103), systemic inflammatory response syndrome (SIRS) (n=71), and local bacterial infection (LBI) (n=14). Levels of PCT and serum cytokines TNF-α, IL-6, and IL-8 were measured by enzyme-linked immunosorbent assay (ELISA). Patients with sepsis had higher values of the studied biomarkers than those with SIRS and LBI (PCT: 10.0±18.7 ng/mL, 0.3±0.2 ng/mL, 0.4±0.4 ng/mL, respectively; CRP: 149±100 mg/L, 42.3±45.3 mg/L, and 74.4±75.6 mg/L, respectively; IL-6: 286.8±330.7 pg/mL, 21.0±27.5 pg/mL, and 34.6±75.1 mg/mL, respectively; IL-8: 310.2±292.5 pg/mL, 29.5±32.7 pg/mL, and 111.7±252.3 mg/mL, respectively; TNF-α: 131.2±254.0 pg/mL, 33.6±118.9 pg/mL, and 164.6±355.1 mg/mL, respectively). Multiple comparison tests demonstrated a statistically significant difference between the sepsis and SIRS group in PCT, CRP, IL-6, IL-8, and TNF-α (P<0.01 in all cases). ROC curves demonstrated high sensitivity and specificity for PCT (97% and 93% for 0.5 ng/mL and 60% and 100%, respectively, for 1.99 ng/mL), but the other biomarkers showed lower sensitivity and specificity values. Conclusion: Markers of inflammation are very helpful in diagnosing sepsis. CRP, IL-6, and IL-8 are sensitive parameters but do not have high specificity. PCT is the parameter chosen for the diagnosis of sepsis, with higher sensitivity and specificity than all other parameters included in this study.

Keywords

• crp
• il-6
• il-8
• procalcitonin
• sisr
• tnf-α
• sepsis
• albania