YKL-40 levels in cerebrospinal fluid serve as a diagnostic biomarker for post-neurosurgical bacterial meningitis in patients with stroke

Introduction: Previous studies have reported that YKL-40 can serve as a biomarker of infectious diseases and different stroke types. However, evidence supporting its role in diagnosing post-neurosurgical bacterial meningitis (PNBM) remains lacking. Methods: A total of 110 patients with stroke who underwent neurosurgical treatment were recruited. Among these, 36 were diagnosed with PNBM based on the results of bacterial culture/Gram staining or cerebrospinal fluid (CSF) characteristics. CSF levels of YKL-40 and other biomarkers with potential diagnostic utility for PNBM were statistically analysed using univariate and logistic regression models. Receiver operating characteristic (ROC) analysis was performed to investigate diagnostic efficiency. Results: According to univariate analysis, CSF levels of glucose, total protein, white blood cells, polymorphocytes, and YKL-40, as well as the CSF-to-blood glucose ratio, were significantly different between the PNBM and nonPNBM groups. Logistic regression analysis revealed that glucose (p = 0.026), total protein (p = 0.028), and YKL40 (p = 0.006) levels in the CSF may have independent diagnostic utility for PNBM. Among the three biomarkers, CSF-to-blood glucose (area under the receiver operating characteristic curve [AUC] 0.9208) and YKL-40 (AUC 0.9587) demonstrated strong diagnostic utility. Conclusion: CSF levels of YKL-40, glucose, and total protein played independent roles in the diagnosis of PNBM in patients with stroke.