Necrotizing enterocolitis in preterm infants: state of the intestinal barrier, features of vitamin D metabolism and their regulation

The priority of the national health policy is to preserve the life and a high level of quality of life for every premature baby. The clinical focus is on children born with ELBW. Among this category of children, NEC makes the main contribution to the structure of infant mortality. Based on the analysis of the literature, the authors conclude that the study of cell markers that characterize different depths of damage to enterocytes allows: to assess the likelihood of developing NEC in infants with ELMT; conduct early diagnosis of NEC; rule out NEC in neonates with similar symptoms; predict the course of NEC; propose and substantiate personalized approaches to correcting the low supply of 25(OH)D; to analyze the influence of candidate genes on the implementation of NEC, its outcomes, and 25(OH)D metabolism. To assess damage at the level of the enterocyte, the authors selected the intestinal fraction of fatty acid binding protein (I-FABP) for literature analysis. To determine the depth of damage to intercellular junctions of the intestine - the expression of transmembrane (claudin-2, claudin-3, claudin-4, occludin) and cytoplasmic (zonulin) tight junction proteins. Analysis of the results of studies on the expression of fecal calprotectin, lipocalin-2 (LCN2) and eosinophilic neurotoxin, showing the activity of local inflammation, was carried out in order to assess both the risk of NEC and its course. Intestinal damage is associated with impaired 25(OH)D metabolism, and metabolic bone disease in preterm infants with damage to the intestinal barrier up to NEC is recorded ten times more often at the stage of nursing in the NICU. A huge number of studies have shown a decrease in survival, an increase in the risk of severe complications against the background of a low supply of 25(OH)D in the preterm population. The authors analyze the relationship between 25(OH)D availability, taking into account the influence of exogenous and endogenous factors, the nature of damage to the intestinal wall and the implementation of NEC, and focus on the existing preventive and therapeutic approaches to prescribing various doses of vitamin D in preterm infants with NEC.