Introduction Autophagy is a crucial cellular degradation pathway that maintains homeostasis during stress. Preterm infants are exposed to significant oxidative and metabolic stress during the perinatal transition. This study aimed to evaluate the levels of autophagy markers (Beclin-1, LC3B-I and LC3B-II) in the umbilical cord blood of preterm infants and investigate their association with neonatal morbidities and mortality. Material and methods This prospective multicentre cohort study included 60 preterm infants. Umbilical cord blood samples were analysed for Beclin-1, LC3B-I and LC3B-II levels using Western blot. The LC3B-I/LC3B-II ratio was calculated as an indicator of autophagic flux. The relationship between these markers and major neonatal outcomes (respiratory distress syndrome (RDS), intraventricular haemorrhage (IVH), haemodynamically significant patent ductus arteriosus (hsPDA), early neonatal sepsis (ENS) and mortality) was evaluated using Mann-Whitney U tests and multivariable logistic regression adjusted for gestational age. Results A significant positive correlation was observed between gestational age and Beclin-1 levels (r=0.406, p=0.005). In subgroup analyses, non-survivors exhibited significantly lower median Beclin-1 levels (0.45 vs 0.92, p=0.047) and a depressed LC3B-I/LC3B-II ratio (0.48 vs 1.90, p=0.018) compared with survivors. Similarly, infants with IVH had significantly lower LC3B-I levels (0.07 vs 0.65, p=0.011). However, in multivariable logistic regression analyses adjusted for gestational age, the independent statistical significance of these markers was attenuated, suggesting that the observed autophagic impairment is closely linked to gestational immaturity. No significant associations were found for RDS, hsPDA or ENS. Discussion This study identifies lower cord blood Beclin-1 levels and an altered LC3B ratio as potential markers of vulnerability in preterm infants, particularly for mortality and IVH. The findings suggest that autophagic capacity at birth is developmentally regulated, with more immature infants displaying compromised autophagy initiation.
Armağan et al. (Fri,) studied this question.