title: Meningococcal meningitis in a women with inherited deficiency of the ninth component of complement.
abstract: A 17-year-old woman presented with acute pyogenic meningitis; Neisseria meningitidis group C was isolated from blood on culture. Complement assays demonstrated a hemolytic complement titer of 12 u/ml; individual components were normal except for C9, which was absent by both functional and antigenic analysis. Family studies were consistent with a familial C9 deficiency, autosomal co-dominant inheritance. This is the first report of the association of C9 deficiency and disseminated neisserial infection; whether this complement deficiency predisposes to the neisserial infection remains to be established.
mesh_terms: D000293:Adolescent; D000328:Adult; D000907:Antibodies, Bacterial / Q000276:immunology; D001666:Binding Sites, Antibody; D002648:Child; D003186:Complement C9 / Q000172:deficiency* / Q000235:genetics; D003171:Complement Pathway, Classical; D005260:Female; D006461:Hemolysis; D006801:Humans; D008297:Male; D008585:Meningitis, Meningococcal / Q000209:etiology / Q000235:genetics / Q000276:immunology*; D008875:Middle Aged
chemical_list: D000907:Antibodies, Bacterial; D003186:Complement C9