Low Serum Mannose Binding Lectin (MBL) Levels and -221 YX Genotype of MBL2 Gene Are Susceptible to Neonatal Sepsis in the Chinese Han Population

Background: The diagnosis of neonatal sepsis remains a challenge as the condition lacks early clinical signs and reliable biomarkers. Objectives: The aim of our study was to determine whether serum mannose binding lectin (MBL) levels and genotypes of MBL2 gene could be used as markers for predicting neonatal sepsis in the Chinese Han population. Methods: This prospective study was hospital-based in design. 48 neonates with clinical signs and symptoms of septicemia (study group), and 96 infants with no infection (control) were included. All the neonates are Chinese Han descent. MBL2 promoter polymorphisms at positions -550, -221 and +4 were analyzed by direct sequencing, and serum MBL levels were estimated by enzyme-linked immunesorbent assay. Results: Frequencies of genotype -221 YX were significantly higher in the study group (45.8%) compared with the control group (15.60%; P = 0.00009). The median serum MBL level was found to be significantly lower in infants who had the -221YX genotype (214.54 ng/mL) compared with those who had the -221YY genotype (597.85 ng/mL; P < 0.0001). Additionally, the median of serum MBL was significantly lower in infants with septicemia (289.65 ng/mL) than in controls (597.75 ng/mL; P = 0.041). According to ROC analysis, the cutoff value of MBL concentration ≤ 384.60 (ng/mL) had a sensitivity of 0.806 and a specificity of 0.777 for predicting sepsis. Conclusions: This study suggested that serum MBL and the -221 YX genotype of the MBL2 gene might be predisposed factors for sepsis in the Chinese Han population.