Concentration of Serum Biomarkers of Brain Injury in Neonates With a Low Cord pH With or Without Mild Hypoxic-Ischemic Encephalopathy

Umbilical cord blood pTau217 and BD-tau are associated with markers of neonatal hypoxia: a prospective cohort study

Objective

Current methods for early detection of hypoxic-ischemic encephalopathy (HIE) are limited by lack of specificity, cost, and time constraints. Blood tau protein concentrations reflect neuropathology in adults. This study examines tau as a potential HIE biomarker in neonates by relating cord blood levels to short-term fetomaternal outcomes. We aimed to examine 1) association of BD-tau with non-reassuring fetal status; 2) correlations between cord blood tau and other hypoxia biomarkers; 3) associations between tau levels and risk factors for fetomaternal morbidity; 4) associations between tau levels and short-term fetomaternal outcome.

Methods

107 maternal participants were prospectively recruited at Royal Prince Alfred Hospital-a large Australian tertiary referral centre. Simoa analysis detected umbilical cord blood pTau217 and brain-derived (BD)-tau levels.

Results

Of 509 deliveries, cord blood was analysed in 107/110 recruited maternal participants. BD-tau correlated with non-reassuring fetal status (OR=3.0;95%CI=1.6- 5.7;p=0.001), though not when adjusting for mode of delivery and gestational age. BD-tau was higher in vaginal deliveries, and positively associated with pTau217, NfL, and lactate (p<0.001), and negatively associated with pH and base excess. pTau217 was higher in preterm neonates and was associated with neurofilament light chain (Spearman's rho=0.44,p<0.001). BD-tau and pTau217 were associated with maternal hypertension and placental abnormalities.

Conclusions

Cord blood BD-tau correlates with surrogate markers of fetal hypoxia, whilst pTau217 may represent a marker of neurodevelopment. Further studies could explore whether these findings translate to clinical use of tau as an HIE biomarker.

Funding

US National Institutes of Health (grant:R01AG063849-01).

NRBC concentrations over time in neonates with moderate to severe neonatal encephalopathy with and without sentinel events

OBJECTIVE

To study the serum concentrations of nucleated red blood cells (NRBC) over time in neonates with moderate to severe neonatal encephalopathy (NE).

STUDY DESIGN

A retrospective cohort study with subjects subdivided into three groups: definite sentinel events (n = 52), probable sentinel events (n = 20) and no history of sentinel events (n = 63). Peak absolute NRBC and NRBC/100 WBC were compared between groups and with MRI Injury score, cord and admission pH/base deficit.

RESULTS

Absolute NRBC peaked at 24.05 h after birth (CI: 15.30-32.79), 17.56 h after birth (CI: 7.35-27.77), and 39.81 h after birth (CI: 28.73-50.89) in each respective group. The peak in absolute NRBC correlated with the severity of injury in the grey matter in group 2 and white matter in groups 1 and 2. Higher peak absolute NRBC value correlated to a lower admission ABG pH.

CONCLUSION

NRBC peak at 24 h after birth in neonates with sentinel events.

MicroRNAs as biomarkers of brain injury in neonatal encephalopathy: an observational cohort study

Neonatal Encephalopathy (NE) is a major cause of lifelong disability and neurological complications in affected infants. Identifying novel diagnostic biomarkers in this population may assist in predicting MRI injury and differentiate neonates with NE from those with low-cord pH or healthy neonates and may help clinicians make real-time decisions. To compare the microRNA (miRNA) profiles between neonates with NE, healthy controls, and neonates with low cord pH. Moreover, miRNA concentrations were compared to brain injury severity in neonates with NE. This is a retrospective analysis of miRNA profiles from select samples in the biorepository and data registry at the University of Florida Health Gainesville. The Firefly miRNA assay was used to screen a total of 65 neurological miRNA targets in neonates with NE (n = 36), low cord pH (n = 18) and healthy controls (n = 37). Multivariate statistical techniques, including principal component analysis and orthogonal partial least squares discriminant analysis, and miRNA Enrichment Analysis and Annotation were used to identify miRNA markers and their pathobiological relevance. A set of 10 highly influential miRNAs were identified, which were significantly upregulated in the NE group compared to healthy controls. Of these, miR-323a-3p and mir-30e-5p displayed the highest fold change in expression levels. Moreover, miR-34c-5p, miR-491-5p, and miR-346 were significantly higher in the NE group compared to the low cord pH group. Furthermore, several miRNAs were identified that can differentiate between no/mild and moderate/severe injury in the NE group as measured by MRI. MiRNAs represent promising diagnostic and prognostic tools for improving the management of NE.

Correlation analysis between the amniotic fluid contamination and clinical grading of neonatal hypoxic-ischemic encephalopathy and biomarkers of brain damage

BACKGROUND

Amniotic fluid contamination (AFC) is a risk factor for neonatal hypoxic ischemic encephalopathy (HIE); however, the correlation between AFC level and the incidence and clinical grading of HIE, in addition to relevant biomarkers of brain damage, have not been assessed.

METHODS

This single-center observational study included 75 neonates with moderate-to-severe HIE. The neonates with HIE were divided into four subgroups according to the AFC level: normal amniotic fluid with HIE group (NAF-HIE), I°AFC with HIE group (I°AFC-HIE), II°AFC with HIE group (II°AFC-HIE), and III°AFC with HIE group (III°AFC-HIE). The control groups consisted of 35 healthy neonates. The clinical grading of neonatal HIE was performed according to the criteria of Sarnat and Sarnat. Serum tau protein and S100B were detected by enzyme-linked immunosorbent assay kits. Correlations of serum tau protein and S100B were evaluated using the Pearson correlation analysis.

RESULTS

(1) The incidence of neonatal HIE in the NAF-HIE group was 20 cases (26. 7%), I°AFC-HIE was 13 cases (17.3%), II°AFC-HIE was 10 cases (13.3%), and III°AFC-HIE was 32 cases (42. 7%). The incidence of moderate-to-severe HIE in the I°-III°AFC-HIE groups was 73.3% (55/75). (2) In 44 cases with severe HIE, 26 cases (59.1%) occurred in the III°AFC-HIE group, which had a significantly higher incidence of severe HIE than moderate HIE (p < 0.05). In NAF-HIE and I°AFC-HIE groups, the incidence of moderate HIE was 45.2% and 29.0%, respectively, which was higher than that of severe HIE (X2 = 9.2425, p < 0.05; X2 = 5.0472, p < 0.05, respectively). (3) Serum tau protein and S100B levels in the HIE groups were significantly higher than in the control group (all p < 0.05), and were significantly higher in the III°AFC-HIE group than in the NAF-HIE and I°AFC-HIE groups (all p < 0.05). (4) Serum tau protein and S100B levels in the severe HIE group were significantly higher in the moderate HIE group (all p < 0.05). (5) Serum tau protein and S100B levels were significantly positively correlated (r = 0.7703, p < 0.0001).

CONCLUSION

Among children with severe HIE, the incidence of III°AFC was higher, and the levels of serum tau protein and S100B were increased. AFC level might be associated with HIE grading.