RESUMO
PURPOSE: This case-control study aimed to evaluate the ability to use a panel of IL-31, IL-1ß and NLRP3 to differentiate sepsis from systemic inflammatory response syndrome (SIRS) and to predict septic shock. METHODS: Serum levels of IL-31, IL-1ß and NLRP3 were measured by ELISA in 149 participants; 38 with sepsis, 51 with SIRS, 30 with septic shock and 30 healthy controls. RESULTS: Lower levels of IL-31 were found in sepsis (10.21 ± 4.34 pg/ml) compared to SIRS (16.74 ± 3.18 pg/ml) and to controls with the lowest levels detected in septic shock (6.26 ± 2.72 pg/ml). IL-1ß and NLRP3 levels were higher in sepsis (54.99 ± 14.11 pg/ml and 9.93 ± 2.38 ng/ml) compared to SIRS (27.8 ± 6.94 pg/ml and 4.86 ± 1.33 ng/ml) with the highest levels seen in septic shock (125.1 ± 32.79 pg/ml and 19.43 ± 6.48 ng/ml) respectively. IL-31 discriminated sepsis in patients showing SIRS with 80% sensitivity and 70% specificity and, identified septic shock with 78.6% sensitivity and 60.3% specificity. IL-1ß identified sepsis from SIRS with 93.3% and 83.3% specificity. NLRP3 discriminated sepsis from SIRS with 94.5% sensitivity and 93.3% specificity. And, with sensitivity 99.1% and 90.1% and specificity 98.9% and 80% IL-1ß and NLRP3 could respectively define septic shock. A panel of combined markers provided 100% sensitivity and specificity. The three biomarkers proved to be independent prognostic biomarkers. At 95% CI, IL-31 hazard ratio (HR) was 0.716, p = 0.001; IL-1ß HR was 1.023, p ≤ 0.001; and NLRP3 HR was 1.114, p ≤ 0.001. Additionally, IL-1ß proved to be an independent predictor of septic shock (ß = 0.355; p = 0.035). CONCLUSION: The cross-relation between IL-31, IL-1ß and NLRP3 in sepsis can provide a promising diagnostic and prognostic panel.