title: Characteristics of nephritogenic IgA immune complexes.
abstract: Studies were undertaken to elucidate the characteristics of IgA immune complexes responsible for glomerular deposition and complement activation. Monomeric IgA antidinitrophenyl (DNP) and the antigen DNP-Ficoll tended to form small soluble complexes that circulated in the blood without localizing in glomeruli of experimental animals. In contrast, polymeric IgA formed intermediate and large-sized complexes that caused glomerular immune deposits. Although covalently cross-linked large-sized IgA oligomers deposited in the glomeruli, they failed to induce concomitant deposition of complement components. Only the presence of a complement-activating antigen endowed the glomerular IgA immune deposits with the ability to activate complement. Thus, the size of the IgA complexes plays a primary role in initiating glomerular localization, and the nature of the antigen causes a secondary phase of inflammation.
authors.affiliation: Department of Pathology, Rhode Island Hospital, Brown University Medical Program, Providence, RI 02903.
authors.forename: A
authors.initials: A
authors.lastname: Rifai
mesh_terms: D000818:Animals; D000936:Antigen-Antibody Complex / Q000276:immunology*; D003167:Complement Activation; D005260:Female; D005922:Glomerulonephritis, IGA / Q000276:immunology*; D007070:Immunoglobulin A / Q000276:immunology*; D007678:Kidney Glomerulus / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D011108:Polymers
chemical_list: D000936:Antigen-Antibody Complex; D007070:Immunoglobulin A; D011108:Polymers; C034639:polymeric IgA