Vaccination responses to capsular polysaccharides of Neisseria meningitidis and Haemophilus influenzae type b in two C2-deficient sisters: alternative pathway-mediated bacterial killing and evidence for a novel type of blocking IgG

摘要: Meningitis caused by Neisseria meningitidis serogroup W-135 was diagnosed in a 14-year-old girl with history of neonatal septicemia and meningitis group B streptococci type III. C2 deficiency I found the patient her healthy sister. Both sisters were vaccinated tetravalent meningococcal vaccine conjugate Haemophilus influenzae b vaccine. Three main points emerged from analysis. First, vaccination resulted serum bactericidal responses demonstrating anticapsular antibody-mediated recruitment alternative pathway. Second, addition to prevaccination sera produced activity absence antibodies, which suggested that action antibodies subcapsular antigens detected might strictly depend on classical A third point concerned previously unrecognized blocking activity. Thus, postvaccination sister contained IgG inhibited killing C2-deficient serum, deposition C3 enzyme-linked immunosorbent assay plates coated purified polysaccharide. Our findings be serogroup-specific dependent early pathway components. Retained opsonic probably supported immunity despite The demonstration functional pathway-mediated defense should encourage further trial capsular vaccines states.