Diagnostic Utility of Procalcitonin and Lactate Determination in Cerebrospinal Fluid for the Diagnosis of Neonatal Meningitis

<b>Objectives</b>: The diagnosis of meningitis is based on microbiological analysis of the cerebrospinal fluid, and the evaluation of cytosis and biochemical parameters such as protein and glucose levels. Sometimes when there is a traumatic lumber puncture, the cerebrospinal fluid is bloody, which makes it difficult to diagnose. The objective of the study was to examine the performance of cerebrospinal fluid (CSF) procalcitonin (PCT) and lactate as potential markers for the diagnosis of meningitis in neonates. <b>Methods</b>: 110 neonates who qualified for lumbar puncture were enrolled in the study. On the basis of CSF analysis, the neonates were classified into two groups: the meningitis group (<i>n</i> = 33) and the non-meningitis group (<i>n</i> = 77). PCT and lactate in CSF and established CSF parameters were recorded. <b>Results</b>: Median CSF PCT level was significantly higher in the meningitis group compared to non-meningitis: 0.93 (0.39-1.59) vs. 0.34 (0.195-0.74) ng/mL, <i>p</i> < 0.000001. Median CSF lactate level was significantly higher in the meningitis group compared to non-meningitis: 3.1 (2.27-3.96) vs. 1.78 (1.38-3.19) mmol/L, <i>p</i> < 0.001. At a cutoff of 0.35 ng/mL, CSF PCT had a sensitivity of 82% and specificity of 52% in the diagnosis of meningitis (AUC = 0.7). At a cutoff of 2.07 mmol/L, CSF lactate had a sensitivity of 84% and specificity of 60% in the diagnosis of meningitis (AUC = 0.701). <b>Conclusions</b>: Concentrations in CSF of PCT and lactate in neonates with meningitis are significantly higher than in the non-meningitis group. None of the biochemical indicators studied met the criteria for a marker for the diagnosis of meningitis as a single indicator.