Effect of intravenous gammaglobulin therapy in IgG2 deficient and IgG2 sufficient children with recurrent infections and poor response to immunization with Hemophilus influenzae type b capsular polysaccharide antigen.

Nine children with recurrent sinopulmonary infections and normal IgG levels failed to improve after a 12-month period of prophylactic antibiotic therapy with trimethoprim-sulfamethoxazole. Five of these children had selective deficiency of IgG2 subclass, while the other four did not, but all nine children had a poor response to immunization with Hemophilus influenzae type b (Hib) capsular polysaccharide. Following the institution of intravenous immunoglobulin (IVIG) therapy, there was a significant decrease in the episodes of sinusitis and otitis media in all patients. Intravenous immunoglobulin therapy resulted in a significant increase in total serum IgG, IgG2, and IgG anti-Hib antibody levels. Discontinuation of IVIG therapy was followed by the return of recurrent infections. This preliminary study demonstrates that IVIG replacement therapy in children with recurrent infections and selective antibody deficiency is associated with a significant reduction in the frequency of sinopulmonary infections.