Protein S100B in umbilical cord blood as a potential biomarker of hypoxic-ischemic encephalopathy in asphyxiated newborns

Background: Neonatal hypoxic ischemic encephalopathy (HIE) is a devastating condition resulting from a sustained lack of oxygen during birth. The interest in identifying a relevant biomarker of HIE has thrown into limelight the role of protein S100B as a clinical diagnostic marker of hypoxic brain damage in neonates. Aims: To evaluate the diagnostic value of protein S100B, measured in umbilical cord blood immediately after birth, as a useful biomarker in the diagnosis of HIE Sarnat stages II-III as well as a marker for long-term mortality and morbidity. Study design: Protein S100B was analyzed in cord blood sampled at birth from 13 newborns later diagnosed with stage II-III HIE and compared with 21 healthy controls. S100B concentrations were related to cord artery pH, amplitude-integrated electroencephalography (aEEG), stage of HIE, and death/sequelae up to an age of 6 years. Both parametric and non-parametric statistics were used with a two-sided P < 0.05 considered significant. Results: The difference in S100B concentration was marginally statistically significant between HIE cases and controls (P = 0.056). Cord blood acidosis (P = 0.046), aEEG pattern severity (P = 0.030), HIE severity (P = 0.027), and condition at 6-year follow-up (healthy/permanent sequelae/death; P = 0.027) were all related to an increase in S100B concentration. Conclusions: Protein S100B in neonates suffering from HIE stages appeared elevated in umbilical cord blood at birth. The S100B concentrations were positively associated to the severity of disease and the risk of suffering from neurodevelopmental sequelae and even death.