79 Mannose Binding Lectin (MBL) Yy Genotype is Associated with An Increased Risk of Necrotizing Enterocolitis(NEC) in Preterm Neonates in NICU

Abstract

Background: MBL initiates complement activation and could have a role in the pathogenesis of ischemia-reperfusion pathologies, such as NEC. We investigated the association between MBL2 genotype, the development of NEC and the MBL expression on specimens of bowel tissue in a cohort of preterm neonates in NICU. Material and methods: We determined the MBL2 genotype in 118 preterm neonates admitted in NICU. The exon 1 SNPs 52,54, 57 and SNPs -550 and - 221 of the promoter region of the MBL2 gene were also determined. Immunoistochemical analysis was performed on 16 bowel bioptic paraffin-embedded specimens, collected during surgery in neonates with NEC. Clinical cases and summary results:21/118 neonates developed NEC. The analysis of the polymorphisisms in the promoter region at -221(variant X/Y) showed that the frequency of the YY genotype was 85.7% in the neonates with NEC and 53.6% in the controls(p=0.013). Adjusting for gestational age, the association between YY genotype and the development of NEC was still significant(OR=5.02;p=0.015). MBL was highly expressed in anastomotic healthy tissue, in enterocytes and istiocytes. No MBL staining was detectable in the necrotic bowel tissue. Neonates MBL low and deficient producer showed negligible or weak staining for MBL. Conclusions: YY genotype of the promoter of the MBL2 gene appeared to increase the risk of developing NEC. The epithelial localization of MBL in the bowel is consistent with a role for MBL in developing full-thickness necrosis during NEC.