Recurrent Pneumococcal Infections in a Patient with Lack of Specific IgG and IgM Pneumococcal Antibodies and Deficiency of Serum IgA, IgG2 and IgG4

Disseminated pneumococcal infections in a young woman are described. Serum from the patient showed reduced opsonic capacity for pneumococci and absence of pneumococcal anticapsular IgG and IgM antibodies even after pneumococcal immunization. Total serum IgG level was normal, but IgG2, IgG4, and IgA were deficient. The possible location of pneumococcal IgG antibodies in the IgG2 subclass is discussed as well as the existence of serious antibody deficiencies in patients with normal total IgG levels.