Serum Level and Genetic Polymorphism of Mannose-Binding Lectin in Infants with Neonatal Sepsis at Zagazig University Hospitals.

Immature immune system in neonates is considered a risk factor for neonatal infections and sepsis. Mannose-binding lectin (MBL) is one of the innate immune system components that could recognize a wide variety of pathogens and initiate an immune response against them. Objectives of this study were to assess the correlation between serum level of MBL and MBL2 gene polymorphism and incidence of neonatal sepsis. Isolation of bacteria from neonatal blood culture was carried out by conventional methods then, serum level of MBL was measured by ELISA and MBL2 gene polymorphism was determined by PCR-RFLP. Out of 50 neonates with sepsis enrolled in this study, 44 (88%) neonates had MBL deficiency and 6 (12%) had normal serum level with a very high statistically significant difference (P=0.00001). Genotype BB was more frequent in neonatal sepsis (56%) followed by genotype AB (32%) then genotype AA (12%) and it was more prevalent in preterm (63.2%) than in full term (33.3%) with a high statistically significant difference (P=0.001). Patients with BB genotype had the lowest MBL level in serum compared to other genotypes with a very high significant difference (P=0.001). In conclusion, low serum level of MBL and genotype BB might be significantly associated with development of sepsis among neonates.