Umbilical cord blood procalcitonin as an early predictor of early-onset neonatal sepsis in premature neonates: a comparative study versus C-reactive protein

ABSTRACT

This study aimed to compare the efficacy of umbilical cord blood levels of procalcitonin [PCT] and C-reactive protein [CRP] as early predictors of early-onset sepsis [within 72 hours since delivery] in premature neonate admitted to NICU. The study included 88 preterm neonates with mean gestational age of 33.8 +/- 3; range 29-38 weeks and mean birth weight of 1955 +/- 234; range 1480-2350 gm with a mean 5-min Apgar score was 7.7 +/- 1.1; 7 neonates were small-for-gestational age and 23 neonates required resuscitation at birth. Neonates were categorized according to the presence of sepsis into two groups Infected neonates had clinical manifestations of sepsis and positive blood culture and Non-infected neonates showed no clinical manifestations and had negative blood culture at 72 hours since delivery. Two blood samples were obtained umbilical cord blood samples obtained at time of admission to NICU for estimation of serum CRP and plasma PCT and a venous blood sample was obtained either at time of development of clinical signs of sepsis or at 72 hours since delivery in non-infected groups for blood culture and complete blood count [CBC] to assure the clinical diagnosis of infected cases. Sixty neonates [68.2%] developed clinical signs of sepsis and proved by blood culture to be infected. The mean levels of CRP and PCT estimated in umbilical blood sample obtained at time of admission to NICU were significantly higher [p<0.05] in infected compared non-infected neonates. Calculation of diagnostic validity characters of each cutoff point defined plasma PCT cutoff at >0.6 ng/ml as the appropriate value for exclusion of neonatal sepsis with 100% sensitivity and negative predictive value [NPV] and specificity rate of 93% and accuracy of diagnosis with rate of 97.7%. Comparison of the diagnostic validity characters of umbilical cord plasma PCT [at cutoff point of >0.6 ng/ml] and umbilical cord serum CRP [at cutoff point of >10 mg/l] as an early predictor of development of neonatal sepsis showed a significant difference in favor of plasma PCT, [X2= 3.19, p<0.01]. It could be concluded that estimation of plasma PCT in umbilical cord blood of preterm neonates could be used as an early specific and sensitive predictor for the possibility of development of early-onset neonatal sepsis at NICU and plasma PCT level at cutoff point of >0.6 ng/ ml is appropriate for identification of neonates at risk of developing sepsis with 100% sensitivity and negative predictive value