MIR-126 and MIR-146A: Could they be two promising new markers for diagnosis of hypoxic ischemic encephalopathy?

Objective: The aim of this study was to evaluate the expression levels of miR-126 and miR-146a in newborns diagnosed with hypoxic-ischemic encephalopathy (HIE) and to investigate their potential use as diagnostic and prognostic biomarkers. Materials and Methods: The study included 45 newborns diagnosed with hypoxic-ischemic encephalopathy (HIE) for whom therapeutic hypothermia was planned, and 32 healthy term newborns serving as the control group. Prior to initiation of therapy, an additional 2 mL of venous blood was collected into EDTA tubes in both groups. Total RNA was isolated from peripheral blood samples, and the expression levels of miR-126 and miR-146a were quantified using real-time polymerase chain reaction (RT-PCR). Demographic, obstetric, clinical, and laboratory variables were obtained from medical records and the hospital electronic database. Statistical analyses were performed using IBM SPSS Statistics version 25.0, and a p-value <0.05 was considered statistically significant. Results: Although the raw CT values of both miR-126 and miR-146a differed significantly between the patient and control groups, ΔCT, ΔΔCT, and fold-change analyses did not show statistically significant differences. Correlation analyses revealed that miR-146a levels were significantly associated with clinical severity markers, including lactate levels and Apgar scores. miR-126 showed only a weak but significant positive correlation with the 5th-minute Apgar score. Conclusion: The stronger associations of miR-146a with hypoxic burden and clinical deterioration suggest that it may serve as a promising biomarker for assessing the severity of hypoxic-ischemic encephalopathy (HIE). miR-126, on the other hand, appears to reflect clinical stabilization and recovery processes, indicating its potential role as a complementary response marker. However, these findings require validation in larger, prospective studies with serial measurements to clarify the diagnostic and prognostic utility of these microRNAs in HIE.