Inflammatory markers in cord blood or maternal serum for early detection of neonatal sepsis-a systemic review and meta-analysis

OBJECTIVE: To perform a quantitative review of the evidence on the diagnostic value of inflammatory markers in maternal serum or umbilical cord blood for the diagnosis of early-onset neonatal sepsis (EONS). STUDY DESIGN: We searched multiple databases for studies published through March 2013 that evaluated the diagnostic performance of procalcitonin (PCT), C-reactive protein (CRP) and interleukin-6 (IL-6), and leukocyte count (white blood cell, WBC) in either umbilical cord blood or maternal serum for diagnosis of EONS. We summarized test performance characteristics with the use of forest plots, hierarchical summary receiver operating characteristic curves and bivariate random effects models. RESULT: Our search identified 3874 citations, of which 15 studies evaluating 2178 episodes of suspected neonatal infection were included for analysis. IL-6 in cord blood with a pooled-positive likelihood ratio (LR+) of 9.47 (95% confidence interval: 3.86 to 23.3), PCT in cord blood with a LR+ of 5.72 (1.56 to 21.0) and IL-6 in maternal serum with a LR+ of 5.47 (2.10 to 14.2) can be qualified as a valid rule-in test. IL-6 in cord blood with a LR - of 0.10 (0.05 to 0.21) and PCT in cord blood with a LR - of 0.20 (0.12-0.37) can be qualified as a useful rule-out test. Either CRP or WBC was inadequate for diagnosis of EONS. CONCLUSION: For cord blood sample, IL-6 or PCT can be used as reliable rule-in and rule-out tool. For maternal serum, only IL-6 appeared to be sufficient for rule-in diagnosis. An interventional study may be needed to answer whether the addition of these tests will improve the outcome of patients with EONS.