title: Membranous-like glomerulopathy with masked IgG kappa deposits.
abstract: The diagnostic classification of glomerulonephritis is determined by the interplay of changes seen using light, immunofluorescence, and electron microscopy of the renal biopsy. Routine direct immunofluorescence on fresh tissue is currently considered the gold standard for the detection and characterization of immune deposits. We recently found a peculiar form of glomerular immune complex deposition in which masked deposits required an antigen-retrieval step to be visualized. Over a 2-year period, 14 cases were characterized by numerous, large subepithelial deposits visualized by electron microscopy and C3-predominant staining by routine immunofluorescence on fresh tissue with weak to negative immunoglobulin staining. Repeat immunofluorescence after digestion of the formalin-fixed paraffin-embedded tissue with pronase elicited strong IgG-κ staining restricted within the deposits. The patients were often young with a mean age of 26 years and commonly had clinical evidence of vague autoimmune phenomenon. The clinicopathologic findings in this unusual form of glomerulopathy do not fit neatly into any currently existing diagnostic category. We have termed this unique form of glomerulopathy membranous-like glomerulopathy with masked IgG-κ deposits.
authors.affiliation: Nephropath, Little Rock, Arkansas, USA.
authors.forename: Christopher P
authors.initials: CP
authors.lastname: Larsen
authors.affiliation: Nephropath, Little Rock, Arkansas, USA.
authors.forename: Josephine M
authors.initials: JM
authors.lastname: Ambuzs
authors.affiliation: Nephropath, Little Rock, Arkansas, USA.
authors.forename: Stephen M
authors.initials: SM
authors.lastname: Bonsib
authors.affiliation: Nephropath, Little Rock, Arkansas, USA.
authors.forename: Christie L
authors.initials: CL
authors.lastname: Boils
authors.affiliation: Nephropath, Little Rock, Arkansas, USA.
authors.forename: L Nicholas
authors.initials: LN
authors.lastname: Cossey
authors.affiliation: Nephropath, Little Rock, Arkansas, USA.
authors.forename: Nidia C
authors.initials: NC
authors.lastname: Messias
authors.affiliation: Nephropath, Little Rock, Arkansas, USA.
authors.forename: Fred G
authors.initials: FG
authors.lastname: Silva
authors.affiliation: Nephropath, Little Rock, Arkansas, USA.
authors.forename: Yihan H
authors.initials: YH
authors.lastname: Wang
authors.affiliation: University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA.
authors.forename: Neriman
authors.initials: N
authors.lastname: Gokden
authors.affiliation: Nephropath, Little Rock, Arkansas, USA.
authors.forename: Patrick D
authors.initials: PD
authors.lastname: Walker
mesh_terms: D000293:Adolescent; D000328:Adult; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000627:therapeutic use; D000936:Antigen-Antibody Complex / Q000378:metabolism; D003937:Diagnosis, Differential; D005260:Female; D015433:Glomerulonephritis, Membranous / Q000145:classification / Q000175:diagnosis* / Q000276:immunology*; D006801:Humans; D007074:Immunoglobulin G / Q000378:metabolism*; D007145:Immunoglobulin kappa-Chains / Q000378:metabolism*; D007166:Immunosuppressive Agents / Q000627:therapeutic use; D008297:Male; D046529:Microscopy, Electron, Transmission; D008856:Microscopy, Fluorescence; D008875:Middle Aged; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D000806:Angiotensin-Converting Enzyme Inhibitors; D000936:Antigen-Antibody Complex; D007074:Immunoglobulin G; D007145:Immunoglobulin kappa-Chains; D007166:Immunosuppressive Agents