Predictive value of C-reactive protein, procalcitonin, and interleukin-6 on 30-day mortality in patients with bloodstream infections

We aimed to assess the predictive performance of C-reactive protein (hsCRP), procalcitonin (PCT), and interleukin-6 (IL-6) at different times points of bloodstream infections (BSI) management.The cases were collected from January 2020 to June 2021 in the First Affiliated Hospital of Xinjiang Medical University (n=185). We collected patients' records of hsCRP, PCT, and IL-6 serum levels and calculated the clearance of these biomarkers on day 1, day 3, and day 5 (hsCRP-1, hsCRP-3, hsCRP-5, so do PCT, and IL-6). We analyzed these predictive performances for 30-day mortality with ROC and Logistic regression. The correlation between biomarkers and their clearance rates was performed by a rank correlation method.The 30-day mortality was 11.35% (21/185). Serial serum hsCRP-3, IL-6-3, PCT-1, PCT-3, and PCT-5 were statistically higher in BSI mortality than survivors. Significant predictive ability was found for 30-day mortality with blood culture (BC) reported fungi (OR, 0.033; 95% CI: 0.002-0.535) and PCT-5 (OR, 1.045; 95% CI: 1.013-1.078) levels, respectively. The AUC of PCT-5 levels for 30-day mortality was 0.784 (95% CI 0.678-0.949), and the cut-off value was 5.455ng/mL.PCT-5 is more valuable for the prognosis of 30-day mortality in patients with BSI compared to the other inflammatory biomarkers.