Renal disease in the elderly and the very elderly Japanese: analysis of the Japan Renal Biopsy Registry (J-RBR).
OBJECTIVE
Data regarding renal disease in the elderly (age ≥65 years old) and very elderly (age ≥80 years old) Japanese are extremely limited. The aim of this study was to examine the causes of renal disease and their clinical presentations in elderly patients who underwent renal biopsy.


METHODS
From July 2007 to November 2011, all of the elderly native renal biopsy patients who had been registered in the Japan Renal Biopsy Registry (J-RBR; 2802 including 1596 males and 1206 females) were identified. Their data were compared with a control group of 7416 patients who ranged in age from 20 to 64 years old and were registered on the J-RBR over the same period. In addition, the clinical and pathological classifications of 276 very elderly patients were also analyzed.


RESULTS
The indications for biopsy were nephrotic syndrome (NS) in 36.2 and 50.7 % of the elderly and the very elderly patients, chronic nephritic syndrome in 31.8 and 17.4 %, and acute kidney injury including rapidly progressive glomerulonephritis in 18.6 and 22.5 %, respectively. Primary glomerular disease was the most frequent diagnosis, followed by MPO-ANCA-positive nephritis, IgA nephropathy (IgAN), and diabetic nephropathy. In primary GN including IgAN, membranous nephropathy (MN) was the most frequent histological type, followed by IgAN and minor glomerular abnormalities. A comparison with the control group showed that MN, MPO-ANCA-positive nephritis, and amyloid nephropathy were more common in the elderly (P < 0.001), and IgAN was less common (P < 0.001). As for nephrotic syndrome in the elderly, MN was the most common histological type, followed by minimal change NS, diabetic nephropathy, amyloid nephropathy, and focal segmental glomerulosclerosis. There was a significant discrepancy between the urinary protein/creatinine ratio and daily proteinuria after the 7th decade of life.


CONCLUSIONS
Renal biopsy is a valuable diagnostic tool, even in elderly and very elderly Japanese patients. In the future, modified clinical guidelines for elderly renal disease should be developed.
Division of Nephrology, Kanazawa Medical University School of Medicine, 1-1 Daigaku, Uchinada, Ishikawa 920-0293, Japan. hyokoyama-npr@umin.ac.jp
Hitoshi
H
Yokoyama
Hitoshi
H
Sugiyama
Hiroshi
H
Sato
Takashi
T
Taguchi
Michio
M
Nagata
Seiichi
S
Matsuo
Hirofumi
H
Makino
Tsuyoshi
T
Watanabe
Takao
T
Saito
Yutaka
Y
Kiyohara
Shinichi
S
Nishi
Hiroyuki
H
Iida
Kunio
K
Morozumi
Atsushi
A
Fukatsu
Tamaki
T
Sasaki
Kazuhiko
K
Tsuruya
Yukimasa
Y
Kohda
Makoto
M
Higuchi
Hideyasu
H
Kiyomoto
Shin
S
Goto
Motoshi
M
Hattori
Hiroshi
H
Hataya
Shoji
S
Kagami
Norishige
N
Yoshikawa
Yuichiro
Y
Fukasawa
Yoshihiko
Y
Ueda
Hiroshi
H
Kitamura
Akira
A
Shimizu
Kazumasa
K
Oka
Naoki
N
Nakagawa
Takafumi
T
Ito
Shunya
S
Uchida
Kengo
K
Furuichi
Izaya
I
Nakaya
Satoshi
S
Umemura
Keiju
K
Hiromura
Mitsuhiro
M
Yoshimura
Nobuhito
N
Hirawa
Takashi
T
Shigematsu
Masafumi
M
Fukagawa
Makoto
M
Hiramatsu
Yoshio
Y
Terada
Osamu
O
Uemura
Tetsuya
T
Kawata
Akira
A
Matsunaga
Aki
A
Kuroki
Yasukiyo
Y
Mori
Koji
K
Mitsuiki
Haruyoshi
H
Yoshida
D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D001706:Biopsy; D005260:Female; D005921:Glomerulonephritis / Q000453:epidemiology / Q000473:pathology; D005922:Glomerulonephritis, IGA / Q000453:epidemiology / Q000473:pathology; D006801:Humans; D015994:Incidence; D007564:Japan / Q000453:epidemiology; D007668:Kidney / Q000473:pathology*; D007674:Kidney Diseases / Q000453:epidemiology* / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D009404:Nephrotic Syndrome / Q000453:epidemiology / Q000473:pathology; D012042:Registries