Vascular adhesion protein-1 expression is reduced in the intestines of infants with necrotizing enterocolitis: an observational research study

BACKGROUND: Necrotizing enterocolitis (NEC) is an inflammatory bowel disease in preterm neonates with high morbidity and mortality. The only treatment available is supportive with broad-spectrum antibiotics and gastrointestinal rest. Better understanding of the pathogenesis is crucial for the development of new therapies. Vascular adhesion protein-1 (VAP-1), expressed in human blood vessels and lymphatic, plays a crucial role in the pathogenesis of inflammatory diseases in adults. The aim of the study was to investigate the VAP-1 expression in the intestines of infants affected by NEC. METHODS: Intestinal tissues from 42 preterm infants with NEC were examined with immunohistochemical staining using antibodies against VAP-1 and semi-automated digital image analysis was performed to determine tissue protein expression of VAP-1 in blood vessels located in the submucosa. Intestinal tissue from 26 neonates that underwent laparotomy and ileostomy due to other intestinal surgical conditions served as controls. Clinical data and protein expression were compared between the NEC-group and Controls. RESULTS: Mean gestational age was lower in NEC infants compared to controls, 26.6 ± 3.0 gestational weeks versus 36.5 ± 4.0 (p < 0.001) but without any significant difference in median postnatal age at surgery; for NEC 8 (5–27) days and for controls 3 (1–36) days (p = 0.6). Low VAP-1 correlated with increased risk for developing NEC in the logistic regression (p < 0.001). Multiple linear regression showed that both gestational age and NEC were independent predictors of VAP-1 expression. CONCLUSION: VAP-1 may play a role in the pathogenesis of NEC. Diminished expression of VAP-1 independent of maturation could indicate arrested vascular development in infants suffering from NEC. Further studies are needed to elucidate the role of VAP-1 in NEC. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12887-022-03681-9.