Thesis (M.Sc.) - Cairo University - Faculty of Medicine - Department of Pediatrics

Background: Mannose-binding lectin (MBL) is a component of innate immunity and particularly important in neonates in whom adaptive immunity is not yet completely developed. MBL deficiency and MBL gene polymorphism are associated with an opsonization defect and have been associated with recurrent infections. Objective: The aim of our study was to determine whether serum MBL levels and genotypes of MBL2 gene could serve as markers for predicting neonatal sepsis in neonatal intensive care (NICU). Patients and Methods: This case- control study was conducted on 95 neonates classified into 2 groups: 64 neonates had neonatal sepsis diagnosis as septic group and 31 neonates who had no sepsis according to clinical and laboratory findings as control group. Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP) was used for genetic analysis of MBL gene (rs1800450) and (rs1800451) SNPs. ELISA technique was used for measuring MBL serum concentration. Results: The combined polymorphic genotypes (AB and BB) at codon 54 had higher frequency than wild genotype (AA) (53.2% vs 46.9%) respectively in septic group and higher frequency of BB genotype was observed in septic group than non-septic group (14.1% vs 12.9%) while, at codon 57 the polymorphic genotype (AC) was more frequent in septic than non-septic group (28.1% vs 19.4%) respectively. Also, the deficient group (those with MBL level {u2264}0.7og/ml) had higher incidence of sepsis than the non-deficient group (51.6% vs 48.4%) respectively, yet these differences did not reach statistical significance. Conclusion: Low MBL levels and presence of B and C alleles of MBL exon 1gene might be associated with neonatal sepsis

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