White Cell Indices and C-reactive protein: Predictors of Meningitis in Neonatal Sepsis?

Background Objective: To evaluate the utility of specific cut-off values for C- reactive protein (CRP) and immature-to-total neutrophil ratio (I/T) as screening tests for meningitis in culture negative early onset sepsis (EOS). Materials and Methods: Retrospective chart review of 97 newborns with culture negative sepsis who had lumbar puncture performed as part of the sepsis evaluation in a level IIIB NICU at an academic medical center serving a predominantly minority population. Meningitis was defined as either a positive cerebrospinal fluid (CSF) culture or CSF WBC count ≥30/mm. The outcome measures were the sensitivity, specificity and predictive values of CRP >40 mg/L and I/T ratio >0.3 for diagnosing meningitis in newborns with EOS. Results: The sensitivity, specificity and positive predictive value of I/T ratio >0.3, CRP >40 mg/L or a combination of these two either at 12 or 24 hours of life were very poor. However, CRP >40 mg/L alone or in combination with I/T ratio >0.3 at both 12 and 24 hours of life had negative predictive values of 85-90%. Conclusion: CRP >40 mg/L and/or I/T ratio >0.3 have poor sensitivity, specificity and predictive values as screening tests for meningitis in culture negative early onset sepsis.