Copeptin as an inflammatory marker in diagnosis and prognosis of neonatal sepsis

Background Copeptin is an immediate biomarker of individual stress response; many life-threatening diseases are causing a high elevation of its concentration in plasma, such as myocardial infarction and cardiovascular shock. Moreover, copeptin is a promising marker in sepsis. We aimed to evaluate copeptin as a diagnostic and prognostic marker in neonatal sepsis for the early initiation of appropriate therapy and the prediction of mortality. A prospective case-control study involved 237 neonates (165 cases had neonatal sepsis, and 72 served as controls). Cases were admitted to the neonatal intensive care unit (NICU) and followed up for symptoms and signs of sepsis confirmed by laboratory data: complete blood count (CBC), c-reactive protein (CRP), and cultures. Serum copeptin level by the enzyme-linked immunosorbent assay (ELISA) was measured for all included neonates. We observed that the copeptin level was significantly higher in cases than control (3.51 ± 1.4, 1.61 ± 0.51 pmol/liter, respectively). The cut-off value of copeptin at which we can discriminate between cases and controls was above 2.065 pmol/liter. Among cases, copeptin was higher in early-onset sepsis (EOS) than late-onset sepsis (LOS) neonates, and there was a significant correlation between its level and all the following: age at admission, birth weight, gestational age, history of perinatal asphyxia, maternal chorioamnionitis, and premature rupture of membrane (PROM). Also, copeptin was strongly associated with CRP level and the poor prognosis of patients. Copeptin can predict the death of cases at a cut-off value above 2.995 pmol/liter. Conclusion Serum copeptin level can be used as a diagnostic and prognostic marker in neonatal sepsis.