title: IgG4-related tubulointerstitial nephritis with membranous nephropathy.
abstract: We describe a 67-year-old woman who presented with significant proteinuria and hematuria. Kidney biopsy showed immunoglobulin G4 (IgG4)-related tubulointerstitial nephritis (TIN) with concurrent membranous nephropathy. IgG4-related TIN is a recently described entity that presents with progressive decreased kidney function and is characterized by a plasma cell-rich infiltrate that is positive for IgG4. It is associated with patchy, often well-localized, tubular atrophy and interstitial fibrosis. Workup for circulating anti-phospholipase A(2) receptor antibodies was negative, suggesting that the membranous nephropathy was not "primary" and may be linked to the IgG4-related disease. The presence of significant proteinuria and hematuria in the setting of IgG4-related TIN should raise suspicion of a glomerular disease. It is important to correctly diagnose IgG4-related TIN and concurrent membranous nephropathy because the lesion responds well to steroid therapy.
authors.affiliation: Division of Nephrology and Hypertension, Department of Internal Medicine, Mayo Clinic, Rochester, MN, USA.
authors.forename: Fernando C
authors.initials: FC
authors.lastname: Fervenza
authors.forename: Gregory
authors.initials: G
authors.lastname: Downer
authors.forename: Laurence H
authors.initials: LH
authors.lastname: Beck
authors.forename: Sanjeev
authors.initials: S
authors.lastname: Sethi
mesh_terms: D000368:Aged; D005260:Female; D015433:Glomerulonephritis, Membranous / Q000150:complications* / Q000276:immunology*; D006801:Humans; D007074:Immunoglobulin G; D009395:Nephritis, Interstitial / Q000150:complications* / Q000276:immunology*
chemical_list: D007074:Immunoglobulin G