Background/Aim Encephalopathy following severe neonatal asphyxia is one of the leading causes of morbidity and mortality in term neonates. Therapeutic hypothermia has been shown to improve outcomes in moderate and severe encephalopathy if administered within six hours of birth. Rapid diagnosis of at-risk infants is therefore crucial. To-date, no effective early diagnostic biomarker has been established in blood, urine or CSF. Biomarkers in placental biopsies have been largely overlooked due to the perceived difficulty in obtaining and processing viable samples soon after birth. Our aim was to establish the feasibility of using placental biopsies for biomarker analysis in neonatal encephalopathy(NE).
Methods Placental biopsies were collected following elective caesarean sections(controls), stored according to 4 different protocols and snap frozen at 5 different time points after delivery. Immunohistochemical staining, total RNA and protein concentrations were used to analyse tissue degradation over time. Biopsies from infants with NA were also collected in a pilot study and our biopsy methodology applied. Potential biomarker expression levels were then determined using enzyme immune assays.
Results Our timeline study from 4 control placentas revealed that gene and protein expression results together with immunohistochemical findings showed limited deterioration on tissue viability up to 90 minutes after delivery. In 10 asphyxia placentas the expression profiles of four specific biomarkers(Activin-A, sFlt-1, IL-6 and MMP-9) revealed changes in protein expression between asphyxia and control cases.
Conclusion Placental biopsies collected at up to 90 minutes after delivery show stable gene and protein expression and may provide useful early biomarkers in NE.