title: Primary membranoproliferative glomerulonephritis on the decline: decreased rate from the 1970s to the 2000s in Japan.
abstract: BACKGROUND
  A prolonged change in the rate of primary membranoproliferative glomerulonephritis (MPGN) was identified using a Japanese database of renal biopsies.
  
  
  METHODS
  We retrospectively investigated 6,369 renal biopsies that were performed between 1976 and 2009. Primary MPGN patients were selected, and the clinical and pathological findings were examined. We also statistically analyzed the changing rate of the onset of primary MPGN according to each decade.
  
  
  RESULTS
  Seventy-nine cases with primary MPGN (1.2 % of total biopsies) were diagnosed. The age of the patients ranged from 6-79 years (average 34.6 years). There were 24 children and 55 adults, including 37 male and 42 female patients. Thirty-six cases of primary MPGN (45.6 %) showed nephrotic syndrome-8 childhood and 28 adult cases. In the pathological classification of 44 samples using electron microscopy, 29 cases were MPGN type I, 1 case was MPGN type II, and 14 cases were MPGN type III. The secular change of the rate of primary MPGN onset showed a statistically significant reduction from the 1970s to the 2000s. The rate of primary MPGN onset in the child population also significantly decreased, but not in the adult population. Among the clinical parameters, disease severity and prognosis remained unchanged. Regarding treatment in recent years, steroid pulse therapy became more available but the administration of warfarin and anti-platelet drugs significantly decreased.
  
  
  CONCLUSIONS
  We concluded that the rate of total primary MPGN and that of pediatric patients with primary MPGN decreased.
authors.affiliation: Department of Nephrology, Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki, Japan.
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Kawamura
authors.forename: Joichi
authors.initials: J
authors.lastname: Usui
authors.forename: Koji
authors.initials: K
authors.lastname: Kaseda
authors.forename: Kenji
authors.initials: K
authors.lastname: Takada
authors.forename: Itaru
authors.initials: I
authors.lastname: Ebihara
authors.forename: Takashi
authors.initials: T
authors.lastname: Ishizu
authors.forename: Tadashi
authors.initials: T
authors.lastname: Iitsuka
authors.forename: Kentaro
authors.initials: K
authors.lastname: Sakai
authors.forename: Katsumi
authors.initials: K
authors.lastname: Takemura
authors.forename: Masaki
authors.initials: M
authors.lastname: Kobayashi
authors.forename: Akio
authors.initials: A
authors.lastname: Koyama
authors.forename: Katsuyoshi
authors.initials: K
authors.lastname: Kanemoto
authors.forename: Ryo
authors.initials: R
authors.lastname: Sumazaki
authors.forename: Noriko
authors.initials: N
authors.lastname: Uesugi
authors.forename: Masayuki
authors.initials: M
authors.lastname: Noguchi
authors.forename: Michio
authors.initials: M
authors.lastname: Nagata
authors.forename: Machi
authors.initials: M
authors.lastname: Suka
authors.forename: Kunihiro
authors.initials: K
authors.lastname: Yamagata
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D017668:Age of Onset; D000368:Aged; D001706:Biopsy; D002648:Child; D016208:Databases, Factual; D005260:Female; D015432:Glomerulonephritis, Membranoproliferative / Q000453:epidemiology* / Q000473:pathology; D006801:Humans; D007564:Japan / Q000453:epidemiology; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D009404:Nephrotic Syndrome / Q000453:epidemiology / Q000473:pathology; D011379:Prognosis; D012042:Registries; D016896:Treatment Outcome; D055815:Young Adult