Clinical significance of cerebrospinal fluid presepsin as adjunctive biomarker for postneurosurgical meningitis: A single-center prospective observational study.

Background: Postneurosurgical meningitis (PNM) is a serious complication in neurocritical care patients, leading to clinical deterioration and worsening outcomes. Accurate diagnosis of PNM is often difficult due to the lack of definitive diagnostic criteria. This study investigates the potential utility of cerebrospinal fluid (CSF) presepsin (PSP), blood PSP, and the CSF/blood PSP ratio as adjunctive biomarkers for the diagnosis of PNM. Methods: We conducted a single-center prospective observational study at Nara Prefecture General Medical Center in Nara, Japan, from April 2020 to March 2022. The postoperative neurosurgical patients with suspected PNM were included in the study and divided into PNM and non-PNM groups. We evaluated the sensitivity, specificity, area under curves (AUCs), positive predictive value (PPV), and negative predictive value (NPV) for the diagnosis of PNM with CSF PSP, blood PSP, and CSF/blood PSP ratio compared in the two groups. Results: We screened 241 consecutive patients with postoperative neurosurgery. Diagnosis of PNM was suspected in 27 patients, and the clinical diagnosis was confirmed in nine patients. The results of CSF PSP (cutoff: 736 pg/mL) for the diagnosis of PNM were sensitivity 89%, specificity 78%, PPV 67%, NPV 93%, AUC 0.81 (95% confidence interval [CI], 0.60-1.00), blood PSP (cut-off: 264 pg/mL) was 56%, 78%, 56%, and 78%, 0.65 (95% CI, 0.42-0.88), and those of CSF/blood PSP ratio (cutoff: 3.45) was 89%, 67%, 57%, and 92%, 0.83 (95% CI, 0.65-1.00). Conclusion: Elevated CSF PSP and CSF/blood PSP ratio may be associated with PNM and could serve as valuable adjunctive biomarkers for improving diagnostic accuracy.