Use of intravenous immune globulin in newborn infants.

Bacterial infections remain a major cause of morbidity and mortality in neonates. Intravenous immune globulin (IVIG) may enhance immunity to neonatal bacterial pathogens by facilitating opsonophagocytosis. In early-onset neonatal sepsis, antibody has improved survival when used therapeutically in combination with antibiotics. However, some IVIG lots may not contain sufficient pathogen-specific antibody to provide effective therapy. Antibody prophylaxis has not provided protection from late-onset (nosocomial) sepsis consistently. Failure of antibody prophylaxis may also be related to variable levels of opsonic antibodies to nosocomial bacteria in IVIG preparations. Staphylococci (particularly Staphylococcus epidermidis) have become a major cause of late-onset sepsis. IVIG preparations contain variable levels of antibody to S. epidermidis, with many lots having nearly undetectable anti-staphylococcal antibody titres. This absence of antibodies to staphylococci may explain why antibody prophylaxis of neonatal sepsis has not been consistently effective. In future studies, IVIG preparations or monoclonal antibodies that possess specific antibodies to key neonatal pathogens will be needed.