Study of the Role of Cerebrospinal Fluid C-reactive Protein and Adenosine Deaminase to differentiate Various Types of Meningitis.

OBJECTIVE

(1) To study cerebrospinal fluid (CSF) adenosine deaminase (ADA) and CSF C-reactive protein (CRP) levels in the differentiation of viral, pyogenic, and tuberculous meningitis (TBM). (2) To estimate the borderline levels of CRP in CSF in viral, pyogenic, and TBM.

METHODS

A prospective and cross-sectional study was conducted at the Department of Medicine, SRN Hospital, Prayagraj, Uttar Pradesh, India, between August 2016 and September 2018. In this study, a total of 100 patients with meningitis were included applying specific inclusion and exclusion criteria after proper ethical approval.

RESULTS

Out of 100 patients, 61 were TBM, 31 were pyogenic meningitis, and eight were viral meningitis (VM). CSF CRP level was significantly increased in pyogenic meningitis (1.05 ± 0.36 mg/dL) compared to nonpyogenic meningitis [TBM (0.42 ± 0.13 mg/dL) and VM (0.37 ± 0.09 mg/dL)]. At the cut-off level of CRP in CSF > 0.6 mg/dL, its diagnostic sensitivity in pyogenic meningitis was 93.55% and specificity 94.20%. While CSF ADA levels were higher in the TBM group (13.32 ± 3.21 U/L) compared to the other two groups [pyogenic meningitis (6.15 ± 1.27 U/L) and VM (4.86 ± 0.88 U/L)]. At a cut-off, CSF ADA level of >10 U/L, its diagnostic sensitivity for TBM was 91.67% and specificity 90%.

CONCLUSION

Cerebrospinal fluid (CSF) CRP levels were found to be raised in pyogenic meningitis, and CSF ADA was found to be elevated in TBM. While both ADA level and CRP level in CSF are found low in VM.