Presepsin, procalcitonin, interleukin-6, and high-sensitivity C-reactive protein for predicting bacterial DNAaemia among patients with sepsis.

Background: Anti-infective therapy against pathogens is the key to treatment of sepsis. Metagenomic next-generation sequencing (mNGS) has higher sensitivity than blood culture. The aim of this study was to use mNGS to identify DNAaemia of pathogens and to assess the diagnostic accuracy of presepsin (PSEP), procalcitonin (PCT), interleukin-6 (IL-6), and high-sensitivity C-reactive protein (hsCRP) in differentiating between bacterial and nonbacterial infections in patients with sepsis.

Methods: This retrospective study included patients with sepsis from November 2020 to September 2022 in the Shenzhen Second People's Hospital. Blood samples were sent for blood culture and mNGS when the patients were diagnosed with sepsis. Plasma PSEP, PCT, and IL-6 levels were measured using whole blood specimens that were collected and analyzed after a diagnosis of sepsis. Area under the receiver operating characteristic curve (AUC) was used to evaluate the accuracy of PSEP, PCT, IL-6, and hsCRP for prediction of bacterial DNAaemia detected by mNGS in patients with sepsis.

Results: This study included 230 patients with sepsis. The bacterial DNAaemia rate was 53.0% [Gram-positive DNAaemia (GPD), Gram-negative DNAaemia (GND), and fungi DNAaemia rate was 18.2%, 37.8%, and 10.9%, respectively]. Among GND, Klebsiella was the most common, followed by Escherichia coli; meanwhile, the GPD were mainly Enterococcus, and Aspergillus was identified in 5 patients with sepsis. The PSEP median values were significantly higher in GND than in non-GND [GND: 1,291 pg/mL, interquartile range (IQR) 456-3,502 pg/mL; non-GND: 707 pg/mL, IQR 332-2,417 pg/mL; P=0.035]. There was no significant difference in PSEP values between GPD and non-GPD groups, or between fungi DNAaemia and non-fungi DNAaemia groups. Receiver operating characteristics analysis indicated that the best cutoff values for PSEP, PCT, IL-6, and hsCRP were 869 pg/mL, 1.14 ng/mL, 85.5 pg/mL, and hsCRP 96.2 mg/L, respectively. Logistic regression indicated that PSEP, PCT, IL-6, and hsCRP had significant predictive value for GND in patients with sepsis. The levels of PCT and IL-6 were different between patients with GPD and those with non-GPD. Only PCT levels differed significantly between fungal DNAaemia and nonfungal DNAaemia.

Conclusions: Bacterial-DNAaemia was detected in half of the patients with sepsis. PSEP, PCT, IL-6, and hsCRP demonstrated significant predictive value for GND, PCT and IL-6 levels demonstrated significant predictive value for GPD. Meanwhile, only PCT demonstrated significant predictive value for fungal DNAaemia.