Autoantibodies Against Factor B and Factor H Without Pathogenic Effects in a Patient with Immune Complex-Mediated Membranoproliferative Glomerulonephritis
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Le résumé fourni par la source
Background: Membranoproliferative glomerulonephritis (MPGN) is an umbrella term for chronic disorders affecting the glomeruli. MPGN is often accompanied by the presence of autoantibodies against complement components. However, the actual pathogenic effects of such autoantibodies, if any, are rarely studied. In this work, we investigated the role of anti-complement autoantibodies in an IC-MPGN patient. Methods: The presence of autoantibodies, their binding site, isotype, and titer were analyzed in ELISA. Antibody–antigen complexes were detected in the patient’s serum using Western blot. Autoantibodies were studied in functional assays to analyze their effects on C3 convertase, complement deposition, cofactor activity, C3b binding, and hemolysis. Results: We identified autoantibodies against factor B (FB) and factor H (FH) in the patient’s serum. Both FB-, and FH-autoantibodies were of IgG2, IgG3, IgG4, and IgGκ, IgGλ isotypes. FB-autoantibodies bound to the Ba and the enzymatically active Bb part of FB. FH-autoantibodies bound to the N- and C-termini of FH and cross-reacted with FHL-1 and FHR-1 proteins. In vivo formed complexes of the autoantibodies with both FB and FH were detected in the IgG fraction isolated from the serum. The autoantibodies did not influence solid-phase C3 convertase assembly and its FH-mediated decay. The free autoantibodies had no effect on complement deposition and on FH cofactor activity but slightly reduced C3b binding to FH. The IgG fraction of the patient dose-dependently inhibited complement-mediated rabbit red blood cell lysis, and the free autoantibodies decreased the solid phase C3 convertase activity. Conclusions: This case highlights that FB- and FH-autoantibodies are not necessarily pathogenic in IC-MPGN.
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Le contrôle bibliographique ouvert
DOI retrouvé dans Crossref DOI retrouvé ; titre concordant.
- Titre Crossref
- Autoantibodies Against Factor B and Factor H Without Pathogenic Effects in a Patient with Immune Complex-Mediated Membranoproliferative Glomerulonephritis
- Date Crossref
- 06/03/2025
- Éditeur
- MDPI AG
- Type
- journal-article
Ce recoupement confirme des métadonnées liées au DOI. Il ne confirme ni la méthode ni les conclusions de l’étude, et il ne compte pas comme une seconde source scientifique indépendante.
Où se fait cette recherche
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Eötvös Loránd University Department of Immunology pays non établi dans la noticeUniversité ou école supérieure
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Hungarian Research Network pays non établi dans la noticeInstitution
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Semmelweis University Department of Internal Medicine and Hematology pays non établi dans la noticeUniversité ou école supérieure
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Innsbruck Medical University pays non établi dans la noticeUniversité ou école supérieure
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Universität Innsbruck pays non établi dans la noticeUniversité ou école supérieure
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HUN-REN-ELTE Complement Research Group pays non établi dans la noticeInstitution
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Medical University of Innsbruck Department of Internal Medicine IV pays non établi dans la noticeUniversité ou école supérieure
Department of Immunology — Eötvös Loránd University, Hungarian Research Network et Department of Internal Medicine and Hematology — Semmelweis University, avec 4 autres affiliations.
Une affiliation ne permet pas de déduire la nationalité d’un auteur.