C-reactive protein and Lactate dehydrogenase in serum and cerebrospinal fluid in rapid and early diagnsis of childhood meningitis

Objective Bacterial meningitis is still a life threatening epidemiological problem especially in many developing countries; considering its dire consequences, its prompt and accurate diagnosis has become a priority for clinicians. Because of the various limitations of conventionally used laboratory techniques, we evaluated and compared the diagnostic utility of C-reactive protein and lactate dehydrogenase in serum and cerebrospinal fluid in the diagnosis of bacterial meningitis and its effectivity in distinguishing it from aseptic meningitis. Material and Methods A total of 125 pediatric cases, aged between 1 month and 12 years, including patients with bacterial meningitis (n=45), aseptic meningitis (n=42) and a control group (n=38), were retrospectively analyzed on the basis of data from the initial clinical examinations. Cultures, smears and other common serum and CSF indices were compared with serum and CSF CRP levels and LDH activity. Results Compared with each of the other variables, there were significant differences in the mean values of serum-CRP, CSF-glucose, CSF-LDH and CSF/serum LDH ratio between the bacterial and aseptic meningitis groups (p<0.001). Of all the tests applied, the highest sensitivity (95%) and negative predictive value (95%) belonged to CSF-LDH activity and the most specific (100%) test with the highest positive predictive value (100%) was CSF-CRP titration as well as smear and culture. Combination of CSF-CRP serum-CRP, and CSF-LDH yielded the highest sensitivity (100%) and negative predictive value but the combined application of CSF-LDH and CSF-CRP proved to be the most specific and efficient. Conclusion In the presence of a normal CRP titration and low glucose level in CSF, bacterial meningitis is excluded, whereas elevated level of CSF-LDH activity is a valid confirmatory predictor of BM. In addition, combination of these three tests with serum CRP is far more effective than the separate determination of any of these parameters.