title: Membranous glomerulonephritis is a manifestation of IgG4-related disease.
abstract: IgG4-related disease (IgG4-RD) is a systemic immune-mediated disease that typically manifests as fibro-inflammatory masses that can affect nearly any organ system. Renal involvement by IgG4-RD usually takes the form of IgG4-related tubulointerstitial nephritis, but cases of membranous glomerulonephritis (MGN) have also been described. Here we present a series of 9 patients (mean age at diagnosis 58 years) with MGN associated with IgG4-RD. All patients showed MGN on biopsy, presented with proteinuria (mean 8.3 g/day), and most had elevated serum creatinine (mean 2.2 mg/dl). Seven patients had known extrarenal involvement by IgG4-RD, with 5 patients having concurrent IgG4-related tubulointerstitial nephritis. Immunohistochemical analysis for the phospholipase A2 receptor, a marker of primary MGN, was negative in all 8 biopsies so examined. Six of 7 patients with available follow-up (mean 39 months) were treated with immunosuppressive agents; one untreated patient developed end-stage renal disease and underwent transplantation, without recurrence at 12 years after transplant. All 6 treated patients showed decreased proteinuria (mean 1.2 g/day), and most showed decreased serum creatinine (mean 1.4 mg/dl). Thus, MGN should be included in the spectrum of IgG4-RD and should be suspected in proteinuric IgG4-RD patients. Conversely, patients with MGN and an appropriate clinical history should be evaluated for IgG4-RD.
authors.affiliation: Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota, USA.
authors.forename: Mariam P
authors.initials: MP
authors.lastname: Alexander
authors.forename: Christopher P
authors.initials: CP
authors.lastname: Larsen
authors.forename: Ian W
authors.initials: IW
authors.lastname: Gibson
authors.forename: Samih H
authors.initials: SH
authors.lastname: Nasr
authors.forename: Sanjeev
authors.initials: S
authors.lastname: Sethi
authors.forename: Mary E
authors.initials: ME
authors.lastname: Fidler
authors.forename: Yassaman
authors.initials: Y
authors.lastname: Raissian
authors.forename: Naoki
authors.initials: N
authors.lastname: Takahashi
authors.forename: Suresh
authors.initials: S
authors.lastname: Chari
authors.forename: Thomas C
authors.initials: TC
authors.lastname: Smyrk
authors.forename: Lynn D
authors.initials: LD
authors.lastname: Cornell
mesh_terms: D000328:Adult; D000368:Aged; D001323:Autoantibodies / Q000032:analysis; D005260:Female; D015433:Glomerulonephritis, Membranous / Q000188:drug therapy / Q000209:etiology* / Q000276:immunology / Q000473:pathology; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood / Q000276:immunology*; D016130:Immunophenotyping; D008297:Male; D008875:Middle Aged; D009395:Nephritis, Interstitial / Q000150:complications*; D054507:Receptors, Phospholipase A2 / Q000276:immunology
chemical_list: D001323:Autoantibodies; D007074:Immunoglobulin G; D054507:Receptors, Phospholipase A2