title: The kinetics of glomerular deposition of nephritogenic IgA.
abstract: Whether IgA nephropathy is attributable to mesangial IgA is unclear as there is no correlation between intensity of deposits and extent of glomerular injury and no clear mechanism explaining how these mesangial deposits induce hematuria and subsequent proteinuria. This hinders the development of a specific therapy. Thus, precise events during deposition still remain clinical challenge to clarify. Since no study assessed induction of IgA nephropathy by nephritogenic IgA, we analyzed sequential events involving nephritogenic IgA from IgA nephropathy-prone mice by real-time imaging systems. Immunofluorescence and electron microscopy showed that serum IgA from susceptible mice had strong affinity to mesangial, subepithelial, and subendothelial lesions, with effacement/actin aggregation in podocytes and arcade formation in endothelial cells. The deposits disappeared 24-h after single IgA injection. The data were supported by a fluorescence molecular tomography system and real-time and 3D in vivo imaging. In vivo imaging showed that IgA from the susceptible mice began depositing along the glomerular capillary from 1 min and accumulated until 2-h on the first stick in a focal and segmental manner. The findings indicate that glomerular IgA depositions in IgAN may be expressed under the balance between deposition and clearance. Since nephritogenic IgA showed mesangial as well as focal and segmental deposition along the capillary with acute cellular activation, all glomerular cellular elements are a plausible target for injury such as hematuria.
authors.affiliation: Division of Nephrology, Department of Internal Medicine, Juntendo University School of Medicine, Tokyo, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Yamaji
authors.affiliation: Division of Nephrology, Department of Internal Medicine, Juntendo University School of Medicine, Tokyo, Japan.
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Suzuki
authors.affiliation: Division of Nephrology, Department of Internal Medicine, Juntendo University School of Medicine, Tokyo, Japan.
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Suzuki
authors.affiliation: Division of Nephrology, Department of Internal Medicine, Juntendo University School of Medicine, Tokyo, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Satake
authors.affiliation: Division of Nephrology, Department of Internal Medicine, Juntendo University School of Medicine, Tokyo, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Horikoshi
authors.affiliation: Department of Microbiology, University of Alabama at Birmingham, Birmingham, Alabama, United States of America.
authors.forename: Jan
authors.initials: J
authors.lastname: Novak
authors.affiliation: Division of Nephrology, Department of Internal Medicine, Juntendo University School of Medicine, Tokyo, Japan.
authors.forename: Yasuhiko
authors.initials: Y
authors.lastname: Tomino
mesh_terms: D000818:Animals; D016026:Bone Marrow Transplantation; D005260:Female; D005455:Fluorescent Antibody Technique / Q000379:methods; D005920:Glomerular Mesangium / Q000276:immunology* / Q000473:pathology; D005922:Glomerulonephritis, IGA / Q000276:immunology* / Q000473:pathology* / Q000628:therapy; D006801:Humans; D007070:Immunoglobulin A / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D008854:Microscopy, Electron / Q000379:methods; D011507:Proteinuria / Q000276:immunology / Q000473:pathology
chemical_list: D007070:Immunoglobulin A