Role of mannose-binding lectin in nosocomial sepsis in critically ill neonates.

We investigated the association of mannose-binding lectin (MBL) serum levels with nosocomial sepsis (NS), their changes overtime during infection, their relation with pathogens, with the MBL2 genotype and their relationship with mortality. In a prospective observational study, we included 365 critically ill neonates: 261 had no infection and 104 had at least 1 septic event. The median MBL serum concentration was significantly lower in infected than in noninfected neonates (p < 0.001). Low MBL levels on admission increased the risk of infection, independently from gestational age and invasive procedures. The median peak MBL level during infection was higher than the median level on admission (p < 0.001) and was correlated with it (r(2) = 0.83, p < 0.001). Moreover, MBL levels on admission were not associated with death (OR = 0.80, 95% CI = 0.56-1.14, p = 0.21). Similarly, no association was found between MBL peak levels during infection and death among infected neonates (OR = 1.10, 95% CI = 0.78-1.57, p = 0.57). In 127 neonates (42 infected) genotyped for exon-1 and -221 promoter MBL2 variants, we did not find significant difference in the frequencies of MBL2 genotypes between infected and noninfected neonates. Moreover, no association was found between MBL2 genotypes and death.