Low serum levels of mannose binding lectin are a risk factor for neonatal sepsis

Mannose binding lectin (MBL) is a soluble pattern recognition receptor of innate immunity that binds a wide range of pathogens and exerts opsonic effects. We investigated the association between serum MBL levels and development of sepsis in infants admitted to neonatal intensive care units (NICUs). Serum MBL levels on admission were measured by enzyme-linked immunosorbent assay (ELISA) in 206 neonates consecutively admitted to an NICU of whom 138 did not develop hospital-acquired sepsis and 68 did. Of these 68, 40 had confirmed sepsis with positive blood cultures. 19 clinically suspected sepsis, with negative blood cultures, and nine had clinically suspected sepsis with blood culture yielding coagulase-negative staphylococci (CoNS). Serum MBL levels on admission were significantly lower in infants with sepsis [0.45 mu g/mL; interquartile range (IQR) 0.09-1.68], particularly in those with confirmed sepsis (0.17 mu g/mL; IQR 0.05-0.96), compared with infants without sepsis (1.45 mu g/mL; IQR 0.43-3.52), and infants with CoNS-positive blood culture (1.70 mu g/mL: IQR 0.85-3.60). After adjusting for duration of exposure gestational age (GA) and birth weight (BW), the association of low MBL levels with development of sepsis was maintained [odds ratio (OR) = 0.52; 95% confidence interval (CI): 0.36-0.75]. The measurement of serum MBL levels on admission in NICU may help to identify neonates at higher risk of developing sepsis.