Prevention of pneumococcal infection in a patient with normal immunoglobulin levels but impaired polysaccharide antibody production

Background: Patients with normal immunoglobulin levels may have an impaired response to immunization with pneumococcal vaccine and increased susceptibility to infection with encapsulated organisms. In children, but not adults, immunoglobulin replacement has been shown to be effective in reducing the infection rate. Objective: To reduce the incidence of infection in an adult with impaired response to pneumococcal vaccine but normal serum IgG levels. Methods: Intravenous IgG, 350 mg/kg, was given every 4 weeks. Results: The patient, who was hospitalized 3 times in 3 years with respiratory tract infections and who had documented infection with Streptococcus pneumoniae and Haemophilus influenzae, did not require antibiotic therapy for more than 15 months while undergoing intravenous immunoglobulin replacement therapy. Conclusion: Adults with impaired response to vaccination with polyvalent pneumococcal vaccine and normal IgG levels may benefit from replacement therapy.