RT Journal Article SR Electronic T1 Evidence of a Functional B-Cell Immunodeficiency in Adults Who Experience Serogroup C Meningococcal Disease JF Clinical and Vaccine Immunology JO Clin Vaccine Immunol FD American Society for Microbiology SP 692 OP 698 DO 10.1128/CVI.00485-08 VO 16 IS 5 A1 Foster, Rachel A. A1 Carlring, Jennifer A1 McKendrick, Michael W. A1 Lees, Andrew A1 Borrow, Ray A1 Read, Robert C. A1 Heath, Andrew W. YR 2009 UL http://cvi.asm.org/content/16/5/692.abstract AB After adolescence, the incidence of meningococcal disease decreases with age as a result of the cumulative immunizing effect of repeated nasopharyngeal colonization. Nevertheless, some adults succumb to meningococcal disease, so we hypothesized that this is due to a subtle functional immunological defect. Peripheral blood lymphocytes derived from survivors of serogroup C meningococcal disease and from age- and sex-matched controls were incubated with a polyclonal B-cell activator containing anti-immunoglobulin D (α-δ-dex) employed to mimic antigen-specific stimuli encountered during immune responses to bacterial polysaccharides, with and without T-cell activation (using anti-CD3/anti-CD28). Subsequent proliferation and activation of T and B lymphocytes were measured. In patients, T-cell responses to polyclonal stimuli and the delivery of T-cell help to B cells were unimpaired. Levels of B-cell proliferation in response to α-δ-dex stimulation alone were low in all samples but were significantly lower in patients than in controls, and these differences were more pronounced with the addition of T-cell help. The data are consistent with the presence of a subtle immunodeficiency in adults who have exhibited susceptibility to meningococcal disease. This defect is manifested as an impaired B-cell response to T-cell-independent type 2 antigens analogous to bacterial capsular polysaccharide.