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/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.