Serum C-reactive protein in the differential diagnosis of childhood meningitis

Background: Although determination of serum C-reactive protein (CRP) is con sidered one of the most useful tests for differentiating between bacterial and aseptic meningitis, its diagnostic accuracy in comparison with other la boratory parameters is yet to be further evaluated. Methods: A total of 192 pediatric cases, aged between 2 months and 14 years , comprising patients with bacterial meningitis (n=66) and aseptic meningit is (n=126), were retrospectively analyzed on the basis of data from the ini tial examination. The area under the best fit binormal curve of the receive r operating characteristics (Az) for CRP was determined and compared with t hat for several other analytic parameters, including white blood cell count and erythrocyte sedimentation rate of peripheral blood, standard cerebrosp inal fluid analysis variables and the combination test (probability of acut e bacterial meningitis (pABM)) derived from Hoen's model. Results: Compared with each of the other variables, the Az for serum CRP (0 .97+/-0.02) was found to be significantly greater (P <0.01) for all except pABM (0.99+/-0.01; P >0.05). False-negative cases among the CRP test result s were found to have been examined too early. Conclusions: The diagnostic accuracy of a single CRP determination was foun d to be equivalent to that of the most effective combination test. Patients with meningitis in whom serum CRP values are determined at least 12 h afte r the onset of fever and are <2 mg/dL are far less likely to have bacterial meningitis.