title: Membranous nephropathy in Japan: analysis of the Japan Renal Biopsy Registry (J-RBR).
abstract: Membranous nephropathy (MN) is one of the most common causes of nephrotic syndrome in adults. The J-RBR/J-KDR registry developed by the Japanese Society of Nephrology provides nationwide cohort data for epidemiological studies of MN. MN was present in 36.8% of 1,203 primary nephrotic syndrome patients in Japan. In addition, 633 (77.9%) out of 813 MN patients were referred to as "idiopathic," whereas 22.1% were classified as "secondary" and involved conditions such as systemic lupus erythematosus, drug exposure, infections, cancer, and various collagen diseases. The mean age of the MN patients was 62.2 (2-88) years old, their mean eGFR was 76.7 (7.6-154.6) ml/min/1.73 m(2), and 63.3% had hypertension at the time of renal biopsy. On the basis of these findings, half of Japanese idiopathic MN patients have risk factors (age >60, male, or lower eGFR) for end-stage renal failure, and 10% belong to the high-risk group (daily proteinuria of over 8.0 g). Further studies with high-grade evidence should resolve the natural history and therapeutic problems of idiopathic MN in elderly Japanese.
authors.affiliation: Division of Nephrology, Kanazawa Medical University School of Medicine, 1-1 Daigaku, Uchinada, Ishikawa 920-0293, Japan. h-yoko@kanazawa-med.ac.jp
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Yokoyama
authors.forename: Takashi
authors.initials: T
authors.lastname: Taguchi
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Sugiyama
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Sato
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001706:Biopsy; D001938:Brazil / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D005260:Female; D005919:Glomerular Filtration Rate / Q000502:physiology; D015433:Glomerulonephritis, Membranous / Q000453:epidemiology* / Q000473:pathology* / Q000503:physiopathology; D006801:Humans; D007564:Japan / Q000453:epidemiology; D007668:Kidney / Q000473:pathology* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D009404:Nephrotic Syndrome / Q000453:epidemiology / Q000473:pathology / Q000503:physiopathology; D012042:Registries; D056910:Republic of Korea / Q000453:epidemiology; D014481:United States / Q000453:epidemiology; D055815:Young Adult