MPO-ANCA associated crescentic glomerulonephritis with numerous immune complexes: case report.
BACKGROUND
Antineutrophil cytoplasmic antibody (ANCA)-associated crescentic glomerulonephritis (CGN) is a major cause of rapidly progressive glomerulonephritis (RPGN). ANCA-associated CGN is generally classified into pauci-immune RPGN, in which there are few or no immune complexes.


METHODS
A 78-year-old man presented with RPGN after a 7-year course of chronic proteinuria and hematuria with stable renal function. A blood examination showed a high titer of myeloperoxidase (MPO)-ANCA. A renal biopsy showed crescentic glomerulonephritis with abundant subepithelial, intramenbranous and subendothelial deposits by electron microscopy, leading to the diagnosis of ANCA-associated CGN superimposed on type 3 membranoproliferative glomerulonephritis (MPGN).


CONCLUSIONS
This case is unique in that type 3 MPGN and MPO-ANCA-associated CGN coexisted, and no similar case has been reported to date. Because ANCA-associated CGN has a predilection for elderly individuals and primary type 3 MPGN is rarely seen in this age group, coincidental existence appears less likely. This case may confer valuable information regarding the link between immune complex and ANCA-associated CGN.
Department of Internal Medicine, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan. morizanr@da2.so-net.ne.jp
Ryuji
R
Morizane
Konosuke
K
Konishi
Akinori
A
Hashiguchi
Hirobumi
H
Tokuyama
Shu
S
Wakino
Hiroshi
H
Kawabe
Matsuhiko
M
Hayashi
Koichi
K
Hayashi
Hiroshi
H
Itoh
D000368:Aged; D019268:Antibodies, Antineutrophil Cytoplasmic / Q000276:immunology*; D003937:Diagnosis, Differential; D005921:Glomerulonephritis / Q000175:diagnosis* / Q000276:immunology*; D006801:Humans; D007105:Immune Complex Diseases / Q000175:diagnosis* / Q000276:immunology*; D008297:Male; D009195:Peroxidase / Q000276:immunology*
D019268:Antibodies, Antineutrophil Cytoplasmic; D009195:Peroxidase