Diagnostic utility of biomarkers in diagnosis of early stages of neonatal sepsis in neonatal intensive care unit in Egypt

Background Neonatal sepsis is considered one of the major causes of morbidity and mortality in NICUs. To avoid unnecessary treatment of non-infected neonates, emergence of multidrug resistance organisms, prolonged hospitalization and a considerable economic burden, particularly in developing countries with poorly-equipped NICUs, an early, sensitive and specific laboratory test would be helpful to guide clinicians in neonatal units to decide whether or not to start antibiotics. Objective C-reactive protein (CRP), tumor necrosis factor-α (TNF), interleukin-6 (IL-6) and interleukin-1 (IL-1) were measured in an attempt to identify a set of tests which can confirm or refute the diagnosis of neonatal sepsis at an early stage before administration of antibiotics. Methods Assessment of serum levels of CRP, TNF-α, IL-6 and IL-1 was done using quantitative enzyme immunoassay sandwich technique in 116 neonates (36 newborns with clinically suspected sepsis, 48 newborns with culture-proven sepsis and 32 infection-free neonates). Results The cutoff levels for CRP at >12 mg/l had a sensitivity of 91% and specificity of 100%, for TNF-α at >113.2 ng/ml had a sensitivity of 83% and specificity of 100%, for IL-6 at >16.8 pg/ml had a sensitivity of 100% and specificity of 47%, and for IL-1 at >15 pg/ml had a sensitivity of 100% and specificity of 47% for the diagnosis of infection before antibiotics. Conclusion The area under ROC curve (AUC) of TNF and CRP in the diagnosis of sepsis was superior to determinations of IL-1 and IL-6. From our data analysis and based on our financial backgrounds, we can conclude that abnormal of CRP levels together with immature-to-total neutrophil ratio above 0.2 with or without elevated IL-1, IL-6 or TNF can be used as early markers of sepsis in neonates.