A study to observe quantitative levels of C- Reactive Protein in Cerebrospinal uid in patients with Meningitis as an add-on routine investigation- a case-control study

Introduction: C-reactive protein (CRP) is a member of the class of acute phase reactants as its level rises dramatically during inflammatory processes occurring in the body. Measuring and charting CRP values can prove useful in determining the disease progress. Aim: To estimate the CRP level in Cerebrospinal fluid (CSF) of patients with meningitis; and to evaluate whether CRP levels could be used to differentiate the various types of meningitis in adults. Materials and Methods: This study was a case-control study. 80 enrolled patients were subjected to a protocol that included detailed clinical history including duration of illness, symptoms and signs, history or any treatment history. Written informed consent was taken from the patients/guardian. Results: Meningitis was more common in the 18-30 years age group. Mean values of CSF CRP were- viral meningitis (2.70 mg/L) and pyogenic meningitis (91.13 mg/L) and control group (1.54 mg/L). CSF CRP can be used as a diagnostic tool to differentiate between pyogenic and viral meningitis as it is significantly raised in pyogenic meningitis in comparison to viral meningitis (p-value <0.0001). Conclusion: CRP in CSF is a valuable, rapid, bedside diagnostic test for differentiating between pyogenic and viral meningitis; with reasonably good sensitivity, specificity and positive predictive value. The absence of CRP in CSF rather than its presence is more important for the diagnosis of viral meningitis.


Introduction
The cerebrospinal fluid (CSF) is a clear, colourless, plasma-like fluid that circulates in the brain ventricles and the cranial and spinal subarachnoid spaces.The mean CSF volume is around 150 ml and it is renewed about four times every 24 hours.
Reduction of the CSF turnover rate during ageing leads to the accumulation of catabolites in the brain and CSF that are also observed in certain neurodegenerative diseases [1,2].The CSF space is a dynamic pressure system.CSF pressure determines intracranial pressure with physiological values ranging between 3 to 4 mmHg before the age of one year, and between 10 and 15 mmHg in adults.Apart from its function of hydromechanical protection of the central nervous system, CSF also

What does this study the
We recommend estimation of CRP in CSF of patients with meningitis when parameters are non conclusive to diagnose the subtype of meningitis, however its routine testing needs further evaluation with bigger sample size, utilizing accurate and precise quantitative assay for measuring CRP levels in CSF.
plays a prominent role in brain development and regulation of brain interstitial fluid homeostasis, which influences neuronal functioning [3].Meningitis is an inflammation of the meninges (the membranes surrounding the brain and spinal cord) and the cerebrospinal fluid (CSF) in the arachnoid space.It is most often caused by a tubercular, bacterial or viral infection.Bacterial meningitis remains a serious threat to global health accounting for an estimated annual 1,70,000 deaths worldwide.

Table 1 : Sex Distribution of Study Group
also for all controls.Specifics for collection and panels were CSF in 3 sterile test tubes, 2-4 ml each; Tube 1 for cellular, biochemical and direct smear examination; Tube 2 for CRP latex agglutination and Tube 3 for CSF culture.It was processed within 1 hour of collection or stored and processed within 24 hours.Kumar M. et al: A study to observe quantitative levels of C International Journal of Medical Research and Review 2021;9(4) CRP level was estimated by liquid phase immune precipitation assay with nephelometric endpoint detection.Fresh undiluted CSF was used.Turbid samples were centrifuged before assay.The normal value was taken below 6 mg/L.The study was approved by Institutional Ethical Committee and written informed consent was obtained from each patient/guardian and controls.Statistical analysis was done by SPSS version 12.0 for Window.Resultspresent study conducted on 80 patients with meningitis admitted in the Medicine ward of Hind Institute of Medical Sciences, Safedabad.Twenty age and sex-matched individuals in which clinical diagnosis was other than meningitis were taken as the control group.64subjectswere present in Study Group A (Viral Meningitis).The maximum number of subjects were in the age group 18-30 yrs with 32 patients (50%) being males and 32(50%) were females.The mean age of patients in Group A was 26.38 yrs.Group B (Pyogenic Meningitis) included 16 subjects.Themeanage of this study group was 22.38 yrs, 12(75%) were males and 4(25%) were females.A maximum number of the subjects were in the age group 18-30 yrs.Among the 20 subjects in the control group, 11(55%) were male and 9(45%) were female.The mean age was 28.95 years.(Table1).

Table 3 : Comparison of CSF CRP in group A and B
The mean value of CSF CRP in the cases of the pyogenic group is 91.13 mg/L which is statistically significantly raised than that in the viral group (mean value 2.70 mg/L) (p value<0.0001).

et al: A study to observe quantitative levels of C International Journal of Medical Research and Review 2021;9(4)
CRP is the fastest rising acute phase reactant and is secreted in increased amounts within 6 hours of an acute inflammatory stimulus.CSF CRP can be used as a diagnostic tool to differentiate between pyogenic and viral meningitis.This study establishes the credibility of CRP as a diagnostic tool in ATT, the CSF often becomes sterile.Biochemistry may be altered and pleocytosis persists though the nature of the cells changes.It poses a difficult problem in the differential diagnosis from bacterial and viral meningitis.In such circumstances the estimation of CSF CRP concentration provides a new dimension to the specific diagnosis of meningitis.specificity and positive predictive value.The absence of CRP in CSF rather than its presence is more important for the diagnosis of viral meningitis.Maximum prediction of pyogenic meningitis can be made if the CSF -CRP test is positive.