Therapeutic intervention of clinical sepsis with intravenous immunoglobulin, white blood cells and antibiotics.

Antibiotics are the mainstay of therapy for acute bacterial infections. However, recent studies have suggested that adjunctive therapy designed to augment host immunity, might reduce morbidity and mortality. Many bacterial pathogens such as Haemophilus influenzae, Streptococcus pneumoniae and Group B streptococcus are encapsulated and require opsonic antibody to promote efficient phagocytosis and killing by neutrophils. Children with bacterial sepsis may be deficient in both of these components of immunity. This is a particularly serious problem in premature babies who may not receive protective amounts of antibodies from their mothers, since most antibody crosses the placenta in the last 4-6 weeks of pregnancy. Septic infants may also deplete their neutrophil reserves and develop neutropenia during infection. Since efficient clearance of encapsulated bacteria require both neutrophils and antibody, these babies are at high risk for treatment failure even with appropriate antibiotic therapy. Several studies have analyzed the role of neutrophil transfusions and immunoglobulin therapy in septic infants. However, relatively few patients have been prospectively evaluated in controlled studies. In addition, the logistical problems related to rapidly collecting neutrophils for therapy of bacterial sepsis are considerable and have decreased the usefulness of this approach. The availability of intravenous immunoglobulin (IVIG) has made the use of immunoglobulin feasible even in rapidly progressing bacterial sepsis. Animal studies have demonstrated the potential usefulness of IVIG and studies in septic babies strongly suggest that IVIG as an adjunct to antibiotics might improve mortality in septic neonates. Further research is needed to improve the logistics of obtaining neutrophils and to improve the availability of pathogen-specific immunoglobulin preparations.