In:
Clinical and Vaccine Immunology, American Society for Microbiology, Vol. 12, No. 5 ( 2005-05), p. 586-592
Abstract:
The capsular polysaccharide of Neisseria meningitidis serogroup W135 is expressed in both O -acetyl-positive (OA + ) and O -acetyl-negative (OA − ) forms. This study investigates the impact of OA status (OA + versus OA − ) on serological measurements of anti-W135 immunoglobulin G (IgG) antibodies in immunized adults. W135-specific serum antibody assignments were made for 28 postimmunization sera from adults by enzyme-linked immunosorbent assay using the meningococcal standard reference serum CDC1992. The established IgG concentration in micrograms per milliliter ([IgG]μg/ml) for CDC1992 against OA + antigen (16.2 μg/ml) was used as a reference to assign a concentration of 10.13 μg/ml IgG against OA − antigen by cross-standardization. Overall, the IgG assignments for these sera were higher against OA + antigen (geometric mean concentration [GMC] = 7.16 μg/ml) than against OA − antigen (GMC = 2.84 μg/ml). However, seven sera showed higher specific [IgG]μg/ml values against the OA + antigen than against the OA − antigen. These sera were also distinguished by the inability of fluid-phase OA − antigen to compete for antibody binding to OA + solid-phase antigen. Although there was no overall difference in functional activity measured by complement-mediated serum bactericidal assay (SBA) against OA + and OA − target bacteria (geometric mean titers of 9,642 and 9,045, respectively), three serum specimens showed a large difference in SBA antibody titers against OA + versus OA − W135 target bacteria, which may reflect different epitope specificities for these sera. Our data indicate that, for some sera, the agreement in anti-OA + versus anti-OA − W135 IgG assignments is serum specific and does not reflect the functional (killing) activity in vitro.
Type of Medium:
Online Resource
ISSN:
1556-6811
,
1556-679X
DOI:
10.1128/CDLI.12.5.586-592.2005
Language:
English
Publisher:
American Society for Microbiology
Publication Date:
2005
detail.hit.zdb_id:
1496863-0
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