Membranous glomerulonephritis in a patient with anti-u1 ribonucleoprotein (RNP) antibody-positive mixed connective tissue disease: A case report

Naoya Toriu; Junichi Hoshino; Eiko Hasegawa; Keiichi Sumida; Tatsuya Suwabe; Junichi Inenaga; Masahiro Kawada; Toshiharu Ueno; Koichi Kikuchi; Noriko Hayami; Akinari Sekine; Rikako Hiramatsu; Masayuki Yamanouchi; Naoki Sawa; Kenmei Takaichi; Kenichi Ohashi; Noriko Uesugi; Takeshi Fujii; Motoko Yanagita; Yoshifumi Ubara

Human Pathology: Case Reports (Mar 2018)

Membranous glomerulonephritis in a patient with anti-u1 ribonucleoprotein (RNP) antibody-positive mixed connective tissue disease: A case report

Naoya Toriu,
Junichi Hoshino,
Eiko Hasegawa,
Keiichi Sumida,
Tatsuya Suwabe,
Junichi Inenaga,
Masahiro Kawada,
Toshiharu Ueno,
Koichi Kikuchi,
Noriko Hayami,
Akinari Sekine,
Rikako Hiramatsu,
Masayuki Yamanouchi,
Naoki Sawa,
Kenmei Takaichi,
Kenichi Ohashi,
Noriko Uesugi,
Takeshi Fujii,
Motoko Yanagita,
Yoshifumi Ubara

Affiliations

Naoya Toriu: Nephrology Center, Toranomon Hospital, Tokyo, Japan; Corresponding authors at: Nephrology Center, Toranomon Hospital Kajigaya, 1-3-1, Takatsu, Kawasaki, Kanagawa 212-0015, Japan.
Junichi Hoshino: Nephrology Center, Toranomon Hospital, Tokyo, Japan
Eiko Hasegawa: Nephrology Center, Toranomon Hospital, Tokyo, Japan
Keiichi Sumida: Nephrology Center, Toranomon Hospital, Tokyo, Japan
Tatsuya Suwabe: Nephrology Center, Toranomon Hospital, Tokyo, Japan
Junichi Inenaga: Nephrology Center, Toranomon Hospital, Tokyo, Japan
Masahiro Kawada: Nephrology Center, Toranomon Hospital, Tokyo, Japan
Toshiharu Ueno: Nephrology Center, Toranomon Hospital, Tokyo, Japan
Koichi Kikuchi: Nephrology Center, Toranomon Hospital, Tokyo, Japan
Noriko Hayami: Nephrology Center, Toranomon Hospital, Tokyo, Japan
Akinari Sekine: Nephrology Center, Toranomon Hospital, Tokyo, Japan
Rikako Hiramatsu: Nephrology Center, Toranomon Hospital, Tokyo, Japan
Masayuki Yamanouchi: Nephrology Center, Toranomon Hospital, Tokyo, Japan
Naoki Sawa: Nephrology Center, Toranomon Hospital, Tokyo, Japan
Kenmei Takaichi: Nephrology Center, Toranomon Hospital, Tokyo, Japan
Kenichi Ohashi: Department of Pathology, Toranomon Hospital, Tokyo, Japan; Department of Reumatology, Yokohama City Hospital, Kanagawa, Japan
Noriko Uesugi: Department of Kidney and Vascular Pathology, Faculty of Medicine, University of Tsukuba, Japan
Takeshi Fujii: Department of Pathology, Toranomon Hospital, Tokyo, Japan
Motoko Yanagita: Department of Nephrology, Kyoto University Graduate School of Medicine, Japan
Yoshifumi Ubara: Nephrology Center, Toranomon Hospital, Tokyo, Japan; Corresponding authors at: Nephrology Center, Toranomon Hospital Kajigaya, 1-3-1, Takatsu, Kawasaki, Kanagawa 212-0015, Japan.

Journal volume & issue: Vol. 11
pp. 43 – 46

Abstract

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We report a 33-year-old Japanese man diagnosed with mixed connective tissue disease (MCTD) who developed nephrotic proteinuria. Both speckled antinuclear antibody (ANA) and anti-U1 ribonucleoprotein (RNP) antibody were positive, but anti-double-stranded DNA (dsDNA) antibody and anti-Smith (Sm) antibody were negative, while complement levels were normal. Renal biopsy revealed membranous glomerulonephritis (MGN) with diffuse thickening of the glomerular basement membrane (GBM) plus spike and bubble formation. Immunofluorescence demonstrated granular deposits of IgG and C3 along the GBM. Analysis of IgG subclasses showed predominant deposition of IgG1 and IgG4, unlike typical lupus nephritis in which there is predominant deposition of IgG1, IgG2, IgG3, and C1q. Electron microscopy identified numerous large electron-dense deposits (EDD) of various types in the subepithelial region of the GBM, but there were no EDD localized in the mesangium or subendothelium. Based on these findings, MGN was considered to be closely related to MCTD in this patient. Keywords: Membranous glomerulonephritis, Mixed connective tissue disease

Published in Human Pathology: Case Reports

ISSN: 2214-3300 (Online)
Publisher: Elsevier
Country of publisher: United States
LCC subjects: Medicine: Pathology
Website: http://www.journals.elsevier.com/human-pathology-case-reports/

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