Diagnostic value of immature myeloid information in early-onset bacterial infection in term and preterm neonates

Abstract

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/µL (38-8 759) vs. 289/µL (6-3 126); Term: 1 268/µL (48-14 035) vs. 856/µL (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/µL 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.