[Interleukin-6, procalcitonin, C-reactive protein and the immature to total neutrophil ratio (I/T) in the diagnosis of early-onset sepsis in low birth weight neonates].

OBJECTIVE: To determine the influence of early-onset neonatal sepsis on interleukin-6 (IL-6) and procalcitonin (PCT) levels in cord blood. To evaluate the significance of usually used infection markers--C-reactive protein (CRP) and immature to total neutrophil ratio (I/T)--and new markers (PCT, IL-6) for the diagnosis of early-onset neonatal sepsis.

DESIGN: Prospective clinical study.

SETTING: Institute for the Care of Mother and Child, Prague.

METHODS: The serum levels of IL-6 and PCT were measured in cord blood in 37 low birht weight infants less than 35 week of gestation born in our institute. IL-6 and PCT levels were further evaluated together with CRP and I/T in neonatal blood within 2 hours after delivery. Neonatal sepsis within the first 72 hours of life was monitored.

RESULTS: Differences in mean values of CRP, I/T, IL-6, and PCT between "sepsis proven" and "sepsis not proven" groups were not statistically significant. Only the difference between groups in cord blood PCT was of borderline significance (p = 0.06, higher in "sepsis proven" group). Fisher test showed significant dependence on sepsis in cord blood PCT only (cut-off point 0.4 ng/ml, p < or = 0.05). Other parameters did not show significant dependence on sepsis. Sensitivity for early onset sepsis above 50% was found in cord blood PCT only (sensitivity 60%, specificity 85.2%). PCT predictive accuracy for sepsis expressed as AUC value was 0.74 +/- 0.06.

CONCLUSION: The only relatively sensitive marker and moderate predictor of early-onset sepsis in premature low birthweight infant was in our study cord blood PCT.