title: Prophylaxis against Neisseria meningitidis infections and antibody responses in patients with deficiency of the sixth component of complement.
abstract: Forty South African patients with homozygous deficiency of the sixth component of complement (C6) have been identified in an area where group B meningococcal meningitis is endemic; 22 of the 24 proband cases presented with recurrent meningococcal meningitis. In a 2- to 4-year prospective study, patients with recurrent infections who received monthly prophylactic long-acting penicillin were significantly protected from subsequent neisserial infection compared with those who did not receive penicillin (P = .02, Fisher's exact test). Heterogeneous susceptibility to neisserial infection was confirmed by following C6-deficient patients who presented with one or no Neisseria meningitidis infections. These patients, on no prophylaxis, had significantly fewer infections (P = .004) than did patients who presented with recurrent disease. Functional C6 activity was restored by transfusion of fresh frozen plasma in a C6-deficient patient resistant to conventional antibiotic treatment. Antibody levels to the serotype 2 outer membrane proteins were significantly elevated in C6-deficient patients compared with control groups (P = .001).
authors.affiliation: Department of Clinical Science and Immunology, University of Cape Town Medical School, Observatory, South Africa.
authors.forename: P C
authors.initials: PC
authors.lastname: Potter
authors.forename: C E
authors.initials: CE
authors.lastname: Frasch
authors.forename: W J
authors.initials: WJ
authors.lastname: van der Sande
authors.forename: R C
authors.initials: RC
authors.lastname: Cooper
authors.forename: Y
authors.initials: Y
authors.lastname: Patel
authors.forename: A
authors.initials: A
authors.lastname: Orren
mesh_terms: D000907:Antibodies, Bacterial / Q000096:biosynthesis*; D001425:Bacterial Outer Membrane Proteins / Q000276:immunology; D002648:Child; D002675:Child, Preschool; D003183:Complement C6 / Q000172:deficiency*; D004198:Disease Susceptibility; D005500:Follow-Up Studies; D006801:Humans; D007223:Infant; D008585:Meningitis, Meningococcal / Q000517:prevention & control*; D009345:Neisseria meningitidis / Q000276:immunology*; D010400:Penicillin G / Q000627:therapeutic use*; D010401:Penicillin G Benzathine / Q000627:therapeutic use*; D011446:Prospective Studies; D012008:Recurrence
chemical_list: D000907:Antibodies, Bacterial; D001425:Bacterial Outer Membrane Proteins; D003183:Complement C6; D010400:Penicillin G; D010401:Penicillin G Benzathine