CSF Lactate - An Independent and Reliable Biomarker among the CSF Parameters to Differentiate Bacterial Meningitis from Aseptic Meningitis

The objective of this study was to compare the mean values of CSF parameters (lactate, protein, sugar, ADA) and thereby distinguish between cases of bacterial and non-bacterial meningitis. A cross sectional study was conducted in which 60 adult patients were included and CSF parameters (differential counts, protein, sugar, ADA, lactate) were analyzed in 22 patients of bacterial meningitis and 38 patients of aseptic meningitis. Data were analyzed using SPSS version 21.0. Analytical statistics were represented using Chi-square test for the comparison of categorical variables. The mean values were compared using independent t- test. Among the other CSF parameters, the mean value of CSF lactate and CSF sugars were found to have significant difference (p-value 0.01) in bacterial and non-bacterial meningitis. However other parameters including CSF protein and CSF ADA did not show significant difference between bacterial meningitis including TBM and non-bacterial meningitis. This study concluded that CSF lactate is an important, independent and reliable biomarker with a cut off value of 3mmol/L, to differentiate bacterial meningitis including TBM from nonbacterial meningitis. TBM and viral meningitis are difficult to differentiate due to their similar clinical features and lab parameters. In such cases, CSF lactate can be taken as a reliable differentiating marker. CSF lactate can be used when CSF gram stain and cultures are inconclusive and time consuming. Thus, helps in initiating early treatment and achieving better outcomes.