Mannose-binding lectin deficiency in preterm neonates

Background: Mannose-binding lectin (MBL) is a collagenous protein that plays a role in innate immunity. MBL deficiency is associated with an opsonization defect and has been associated with recurrent infections, especially in immunocompromised individuals. Neonates are considered to be immunocompromised because adaptive immunity has not yet been developed. Objective: This study was done to evaluate the levels of MBL in premature neonates and to determine the relation between MBL deficiency and development of sepsis. Methods: This case- control study was conducted on 64 neonates classified into 2 groups; 39 preterm neonates with gestational age (G.A) <36 weeks and 25 healthy full term neonates. Measurement of mannose-binding lectin (MBL) serum level was done on the first day of life using ELISA technique. Results: Mean MBL plasma level was found to be lower in preterm than full term neonates, yet this difference did not reach statistical significance. There was a negative correlation albeit an insignificant one, between MBL level and GA. The deficient group (those with MBL level ≤0.7μg/ml) had higher incidence of sepsis, albeit an insignificant one, than the non deficient group. A highly significant positive correlation was demonstrated between MBL plasma level in neonatal and umbilical cord blood samples. Conclusion: Premature neonates have low MBL serum levels which could be measured in either their venous or umbilical cord blood efficiently. Further studies are needed to investigate the relationship between MBL deficiency and neonatal sepsis and whether measuring MBL levels might be used to identify which neonates are prone to infections. Keywords: Mannose binding lectin, neonates, preterm, sepsis Egypt J Pediatr Allergy Immunol 2010;8(2):75-80