Evaluation of Immature Neutrophil Ratio and Calprotectin Level for the Diagnosis of Neonatal Sepsis

Background: Sepsis is defined as a systematic inflammatory reaction against infection. Despite the recent advances in medical and pediatric sciences, sepsis remains a significant life-threatening health issue. The main problem associated with this disorder is the nonspecific and non-discriminative symptoms of noninfectious diseases. The present study aimed to introduce diagnostic parameters of high sensitivity and specificity for neonatal sepsis.Methods: This case-control study was conducted in Mashhad, Iran during 2013-2015. Subjects included 40 septic neonates with confirmed diagnosis by a subspecialist of pediatrics and 40 neonates without clinical and laboratory findings of sepsis as the control group. Blood samples were collected from all the infants. In addition, differential white blood cell count of peripheral blood smear was performed, and immature/total neutrophil ratio (I/T) was calculated for all the PBS slides. Plasma calprotectin levels were also determined using the sandwich ELISA method.Results: Mean plasma concentration of calprotectin was 33190±23760 and 18980±13410 ng/ml in the septic and control groups, respectively. Moreover, mean I/T was 0.61±0.22 and 0.51±0.26 in the septic and control groups, respectively. The obtained results indicated that calprotectin levels and I/T were significantly higher in the septic group compared to the control group (P<0.05). Conclusion: According to the results, nucleated red blood cell count and calprotectin levels were the most specific parameters for the definite diagnosis of neonatal sepsis, while neutrophils had the highest sensitivity in this regard.