Letters to the Editor
Indian Pediatrics 2004; 41:1073-1074
CSFC-Reactive Protein Estimation for Bedside Diagnosis of Pyogenic Meningitis
One hundred children suffering from meningitis and other neurological disorders admitted over a period of one year were studied. The patients admitted with suspicion of meningitis that later proved to be having either tubercular or pyogenic meningitis were included in the study group. Control group consisted of patients with febrile convulsions, acute respiratory tract infection with menin-gismus and acute flaccid paralysis. A qualita-tive slide test utilizing latex agglutination method was used. The minimum concen-tration of C-reactive protein that can be detected by this kit is 1.2 mg/dL. Observations were tested statistically by the Chi-square test and Student ‘t’ test, and for sensitivity, speci-ficity and predictive value of cerebrospinal fluid C-reactive protein in different types of meningitides.
We found that C-reactive protein test was able to detect 80% cases of pyogenic meningitis and 15% cases of tubercular meningitis and was negative in all controls. The positive predictive value of the test for pyogenic and tubercular meningitis was 100%. Similarly, negative cerebrospinal fluid C-reactive protein test was 100% specific for absence of pyogenic and tubercular meningitis. Cerebrospinal fluid culture showed growth in 16 cases (52%) with pyognic meningitis (Table I).
TABLE I Diagnostic Utility of C-Reactive Protein (CRP) Test in Cerebrospinal Fluid.
This test appears to be promising in view of its rapidity, simplicity and relative low cost(3,4). The present study was planned to verify this contention and evaluate its relative importance amongst conventional diagnostic methods. In this study, 80% cases of pyogenic meningitis revealed a positive latex agglutination test for C-reactive protein, there was a striking absence of any positive case in the non-meningitis group.
Our findings show that estimates of C-reactive protein in cerebrophinal fluid is a valuable, rapid, beside diagnostic test for pyogenic meningitis with reasonably good sensitivity and 100% specificity and positive predictive value. Absence of C-reactive protein rather than its presence is more important for the diagnosis of tubercular meningitis(3-5). Maximum prediction of pyogenic meningitis can be made if the test is positive. Additionally this test virtually rules out the possibility of tubercular meningitis. However, recommending it for routine clinical application needs further evaluation utilizing accurate and precise quantitative assay for measuring C-reactive protein levels in the cerebrospinal fluid.
Department of Pediatrics,
Gajra Raja Medical College &
Associated Kamala Raja Hospital,
Gwalior (M.P.) 747 001, India.