Evaluation of urinary S100B protein level and lactate/creatinine ratio for early diagnosis and prognostic prediction of neonatal hypoxic-ischemic encephalopathy.

BACKGROUND: Early identification and prevention of hypoxic-ischemic encephalopathy (HIE) in newborns may reduce neonatal mortality and neurological dysfunction. OBJECTIVE: To analyze the diagnostic and prognostic values of urinary S100B level and lactate/creatinine ratio in newborns with HIE. METHODS: Seventy-eight full-term newborns with HIE and 25 normal newborns were enrolled. The Neonatal Behavioral Neurological Assessment (NBNA) and Developmental Screening Test were scored. The concentration of urinary S100B protein was determined using the S100B enzyme-linked immunosorbent assay and the levels of urinary lactate and creatinine were measured with the enzyme colorimetric method. RESULTS: Urinary S100B level on days 1-3 after birth and lactate/creatinine ratio on day 1 were significantly higher in newborns with HIE than those in the control group. Both indexes were positively correlated with the clinical grading of HIE. A cutoff value for the S100B level of 0.47 microg/l on day 3 after birth had a sensitivity of 90% and specificity of 92% for prediction of HIE. A lactate/creatinine ratio of more than 0.55 on day 1 showed the highest sensitivity (92%) and specificity (90%). A combination of both indexes improved the sensitivity and specificity to 99 and 97%, respectively. A negative correlation of both lactate/creatinine ratio on day 1 and S100B level on days 1-3 after birth with the NBNA score was identified on days 3, 7 and 14 after birth. The Developmental Screening Test score of 36 newborns with HIE within 6 months after birth showed that 65% of infants with moderate and high HIE had an abnormal developmental quotient. CONCLUSION: These data suggest that early measurement of both S100B level and lactate/creatinine ratio in the urine of newborns with HIE is a practical convenient and sensitive way to improve diagnosis on the third day of life and prognostic prediction of HIE.

[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.