Perinatal asphyxia is a significant health problem with an incidence of 1 to 8 per 1,000 live births and can lead to serious morbidity and mortality during the neonatal period. One of its most severe consequences is hypoxic-ischemic encephalopathy (HIE), a condition that causes irreversible damage to the newborn brain due to hypoxia and ischemia. HIE is one of the leading causes of long-term neurological sequelae. Therapeutic hypothermia initiated within the first six hours after birth has been shown to significantly reduce both mortality and neurodevelopmental impairments associated with HIE. However, biomarkers that can reliably predict individual treatment response or objectively demonstrate the severity of brain injury at an early stage remain limited.
Neurofilament light chain (NfL) is a protein found within the cytoskeletal structure of myelinated axons. When axonal injury occurs, NfL is released into the interstitial space and subsequently enters the cerebrospinal fluid and systemic circulation, where it can be measured. Increased NfL levels have been identified in a variety of neurological conditions, including neurodegenerative disorders and traumatic brain injury. Recent findings show that both cerebrospinal fluid and serum/plasma NfL levels are elevated in newborns diagnosed with HIE, supporting its potential role as a biochemical marker of axonal injury.
The primary aim of this study is to investigate the time-dependent changes in serum NfL levels in newborns diagnosed with HIE and undergoing therapeutic hypothermia, and to evaluate the relationship between these changes, clinical findings, and neuroimaging results. For this purpose, serum NfL levels were measured at four specific time points: within the first six hours after birth (preferably cord blood), upon reaching the target cooling temperature (approximately 12-24 hours), during the rewarming phase (72-96 hours), and on the day of magnetic resonance imaging (preferably day seven). The results are expected to provide insights into the prognostic utility of NfL in HIE and contribute to determining the optimal timing for clinical sampling.
The secondary objective of the study is to compare NfL levels of newborns diagnosed with HIE to those of a control group without HIE, thereby identifying potential cut-off values that may help distinguish between affected and unaffected infants.
Newborns with a gestational age ≥36 weeks (term)
Diagnosis of hypoxic ischemic encephalopathy (HIE) based on clinical and/or laboratory findings
Diagnosis of stage I, stage II, or stage III HIE according to the Sarnat staging system
Therapeutic hypothermia (TH) treatment initiated within the first 6 hours after birth
Major congenital malformation or genetic syndrome (e.g., Trisomy 21, congenital heart disease)
Newborns with suspected sepsis, metabolic disease, or other systemic disease
Premature infants with a gestational age <36 weeks
Therapeutic hypothermia treatment not started on time or inadequately administered
Mustafa Gürkan
Lead sponsor
Kırıkkale University
Sponsor institution