title: Demonstration of circulating group B streptococcal immune complexes in neonates with meningitis.
abstract: Group B streptococci are the major cause of sepsis and fatal shock in neonates in the United States. Although a number of clinical features have been associated with enhanced severity of disease, the role of soluble immune complex formation in group B streptococcal infection has not been evaluated. We determined the frequency with which circulating immune complexes occurred in 16 infants with nonfatal type III, group B streptococcal meningitis, using an immunoglobulin-specific C1q enzyme immunoassay. Ten healthy, age-matched infants served as a control group. Elevated levels of immunoglobulin M (IgM)-containing immune complexes were present in the sera of four (25%) patients with group B streptococcal meningitis. Group B antigen was detected in precipitated IgM immune complexes from each of these four infants by competitive enzyme-linked immunosorbent assay. In addition, IgG-containing immune complexes were present in 56% of sick and 60% of control infants. Group B antigen was demonstrated in the serum of a sick neonate containing only IgG immune complexes but not in controls. Our findings indicate that a subset of infants with type III, group B streptococcal meningitis develop IgM immune complexes containing group B-specific antigen, and these may persist for up to 3 months in some patients.
authors: Department of Pediatrics, Baylor College of Medicine, Houston, Texas.
authors: J G
authors: JG
authors: Vallejo
authors: C J
authors: CJ
authors: Baker
authors: M S
authors: MS
authors: Edwards
mesh_terms: D000907:Antibodies, Bacterial / Q000097:blood*; D000936:Antigen-Antibody Complex / Q000097:blood*; D000942:Antigens, Bacterial / Q000097:blood*; D006801:Humans; D007075:Immunoglobulin M / Q000097:blood / Q000276:immunology; D007231:Infant, Newborn; D016920:Meningitis, Bacterial / Q000097:blood / Q000276:immunology* / Q000382:microbiology; D013290:Streptococcal Infections / Q000097:blood / Q000276:immunology* / Q000382:microbiology; D013292:Streptococcus agalactiae / Q000276:immunology*
chemical_list: D000907:Antibodies, Bacterial; D000936:Antigen-Antibody Complex; D000942:Antigens, Bacterial; D007075:Immunoglobulin M