Diagnostic Value of Immature Myeloid Information in Early-onset Bacterial Infection in Term and Preterm Neonates

Background: For quick detection of neonatal early-onset bacterial infection (EOBI) pro-inflammatory cytokines like Interleukin-6 (IL-6) and Interleukin-8 (IL-8) in combiantion with C-reactive Protein (CRP) have been used. Automated determination of immature myeloid information (IMI) seems to be an additional useful tool in the diagnosis of NBI. Objective: To compare the diagnostic value of IMI, I/T-Ratio, plasma IL-6 and IL-8 levels and CRP in term and preterm neonates at time of clinical suspicion of EOBI. Patients and Methods: 31 preterm and 123 term neonates with clinical and serological signs of EOBI were analysed. 91 preterm and 159 term neonates with risk factors but without proven EOBI served as non-infected controls. Results: Neonates with EOBI showed significantly elevated IMI levels at time of first clinical suspicion of EOBI (Preterm: 1 028/mu L (38-8 759) vs. 289/mu L (6-3 126); Term: 1 268/mu L (48-14 035) vs. 856/mu L (19-5 735); p < 0.05 respectively). I/T-Ratio, IL-6, IL-8 and CRP values were significantly higher in preterm and term neonates with EOBI (p < 0.05). Sensitivity of IMI at a cut-off level of 650/mu L was 84.2 % [95 %-CI: 74.0-91.6 %] in preterm and 65.4 % [95 %-CI: 56.8-73.3 %] in term infants. Specificity was 66.7 % [95 %-CI: 47.1-82.7 %] and 53.9 % [95 %-CI: 43.8-63.7 %], respectively. Combination of different infection parameters improved sensitivity up to 93.5 % and specificity up to 98.9 %. Conclusion: The diagnostic value of IMI in diagnosing EOBI in preterm and term neonates is not comparable to IL-6, IL-8 and CRP. Combination of IMI-Channel with IL-6, IL-8 or CRP improves their sensitivity, specificity and predictive value.