[Urinary S100B protein and lactate/creatinine ratio measurements: a tool for the early identification of neonatal hypoxic-ischemic encephalopathy].

Objective: To investigate the value of urinary S100B protein and lactate/creatinine ratio determination in early identification of neonatal hypoxic-ischemic encephalopathy (HIE).

Methods: The levels of urinary S100B protein and urinary lactate/creatinine ratio were detected in 58 full-term newborn infants with HIE on the first, second and third day after birth. The severity of clinical manifestations, including the degree of encephalopathy, was assessed within 7 days after birth. Twenty five normal neonates were enrolled into the control groups.

Results: (1) The urinary S100B level of HIE neonates was significantly higher in samples collected throughout the monitoring period than those of the normal control groups (all P < 0.001). The urinary lactate/creatinine ratio of the HIE neonates was also significantly higher than that of normal control groups within the first day (P < 0.001). (2) A significantly positive correlation was found between the level of urinary S100B protein within three days and the urinary lactate/creatinine ratio within the first day and between the level of urinary S100B protein within three days and clinical degree (P < 0.05). (3) When S100B concentration was 0.47 microg/L and urinary lactate/creatinine ratio was 0.55, the sensitivity and specificity of detecting the third day urinary S100B alone, were respectively 90.4%, 91.9%. Detecting it associated with the first day urinary lactate/creatinine ratio could increase the sensitivity and specificity (respectively 98.8% and 97.4%) for predicting development of HIE.

Conclusion: On the basis of clinical manifestations of asphyxic neonatals, detecting the level of urinary S100B within three days and the first day urinary lactate/creatinine ratio may be of important value in early diagnosis and grading of HIE.