Prevention of hypogammaglobulinemia of prematurity with intravenous immune globulin.

: We evaluated the effect of 1 g/kg intravenous immune globulin (IGIV) on immunoglobulin levels and half-life, the dose and frequency of IGIV administration necessary to maintain IgG levels at greater than 400 mg/dL, and IGIV effect on immunoglobulin levels after discharge in infants less than or equal to 32 weeks' gestation and less than or equal to 1500 g. Fifteen infants received 31 infusions at IgG levels less than or equal to 400 mg/dL. Immunoglobulin levels were obtained 24 hours postinfusion, weekly during hospitalization, and monthly after discharge. Mean IgG postinfusion was 980 mg/dL. Mean IgG half-life was 18 days (range 7 to 41). Smaller infants with greater than or equal to 5% of blood volume removed per week experienced shorter immunoglobulin half-lives. IGIV caused increased IgG levels after discharge and did not delay endogenous production of IgG. We conclude that 1 g/kg IGIV given to infants less than or equal to 32 weeks' gestation and less than or equal to 1500 g every 1 to 6 weeks during hospitalization, depending on weight and blood volume removed, prevents hypogammaglobulinemia of prematurity.