Evaluation of high sensitivity C-reactive protein assay in cerebrospinal fluid on the Dimension RxL analyzer

Abstract

Introduction: Low sensitivity and specificity in traditional laboratory tests became insufficient for accurate diagnostics and initiation of proper treatment of patients infected with bacterial meningitis. High sensitivity C reactive protein (hsCRP) may be an appropriate supplement for rapid diagnosis of bacterial meningitis. The subject of our investigation was the determination of C- reactive protein in cerebrospinal fluid (CSF) during acute bacterial meningitis. Methods: HsCRP was analysed by a sensitive immunoturbidimetric assay using the Dimension RxL analyser (Siemens). Cerebrospinal fluid concentrations of C-reactive protein have been measured in 20 patients (age range,1 to 50 years) presenting with acute bacterial meningitis and also in a non-infected, non-inflamed control group (n=25). Results: The accuracy and precision of the method proved to be satisfactory. Repeatability of serial sampling for hsCRP described by coefficient of variation were CV=2.1-4.5%. This assay hsCRP in cerebrospinal fluid demonstrates adequate performance characteristics for routine clinical use. Elevated levels of CRP were found in 95% patients with bacterial meningitis. The mean CRP value in 25 uninfected control group was 0.25 mg/L (range 0.10-0.55). The mean CRP for patients with bacterial meningitis was 21.4 mg/L (range 0.40-100). Conclusions: A sensitive assay for CRP in CSF would be an useful adjunct to conventional investigation of acute infective meningitis.

Keywords

• High sensitivity C-reactive protein
• cerebrospinal fluid
• bacterial meningitis