Open AccessAntibodies against C1q in anti‐glomerular basement membrane nephritis
Author(s) -
COREMANS I. E. M.,
DAHA M. R.,
VOORT E. A. M.,
MUIZERT Y.,
HALMA C.,
BREEDVELD F. C.
Publication year - 1992
Publication title -
clinical & experimental immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.329
H-Index - 135
eISSN - 1365-2249
pISSN - 0009-9104
DOI - 10.1111/j.1365-2249.1992.tb02984.x
Subject(s) - nephritis , antibody , glomerular basement membrane , immunology , basement membrane , complement system , antigen , glomerulonephritis , medicine , immunoglobulin g , biology , pathology , kidney
SUMMARY The prevalence of antibodies against the collagen‐like region of the subcomponent of the first component of complement, Clq, was investigated in 11 patients with anti‐glomerular basement membrane (GBM) nephritis. Anti‐C1q antibodies (anti‐ClqAb) were detected in seven patients. IgG anti‐ClqAb were found in four and IgA anti‐ClqAb in five patients. During follow up of the patients a relationship was observed between the levels of IgG anti‐ClqAb and the levels of anti‐GBM antibodies (anti‐GBMAb). Gelfiltration experiments indicated that both IgG anti‐ClqAb as well as IgG anti‐GBMAb were monomeric and that binding also occurred with the F(ab′) 2 fragments of the antibodies. Although anti‐ClqAb and anti‐GBMAb are both directed against a collagen‐like structure, it was demonstrated by means of inhibition experiments that anti‐ClqAb and anti‐GBMAb are directed against different antigenic sites. Comparison of patients with anti‐GBM nephritis with and without anti‐ClqAb revealed that there were no differences in disease activity or disease severity. Therefore, the results of this study suggest that anti‐ClqAb do not play a direct pathogenetic role in anti‐GBM nephritis.