title: Reanalysis of membranoproliferative glomerulonephritis patients according to the new classification: a multicenter study.
abstract: BACKGROUND
  All types of membranoproliferative glomerulonephritis (MPGN) are progressive diseases with poor prognoses. Recently, a newly proposed classification of these diseases separated them into immune complex- and complement-mediated diseases. We investigated the frequency of C3 glomerulonephritis among previously diagnosed MPGN patients.
  
  
  METHODS
  We conducted a retrospective study of patients diagnosed with MPGN at three tertiary care institutions between 2001 and 2010. We investigated the incidence of complement-mediated disease among patients diagnosed with MPGN. Progressive renal dysfunction was defined as a 50% reduction in the glomerular filtration rate or the need for renal replacement therapy.
  
  
  RESULTS
  Among the 3,294 renal biopsy patients, 77 (2.3%) were diagnosed with MPGN; 31 cases were excluded, of which seven were diagnosed with systemic lupus nephritis, and the others were not followed for a minimum of 12 months after biopsy. Based on the new classification, complement-mediated MPGN was diagnosed in two patients (4.3%); only one patient developed progressive renal dysfunction. Among the immune complex-mediated MPGN patients, 17 patients developed progressive renal dysfunction. Serum albumin and creatinine levels at the time of MPGN diagnosis were risk factors of renal deterioration, after adjusting for low C3 levels and nephrotic syndrome.
  
  
  CONCLUSIONS
  Complement-mediated glomerulonephritis was present in 4.3% of patients previously diagnosed with MPGN.
authors.affiliation: Department of Internal Medicine, Soonchunhyang University Seoul Hospital, Seoul, Korea.
authors.forename: Sung Ae
authors.initials: SA
authors.lastname: Woo
authors.affiliation: Department of Internal Medicine, Soonchunhyang University Bucheon Hospital, Bucheon, Korea.
authors.forename: Hye
authors.initials: H
authors.lastname: Young Ju
authors.affiliation: Department of Internal Medicine, Soonchunhyang University Seoul Hospital, Seoul, Korea.
authors.forename: Soon
authors.initials: S
authors.lastname: Hyo Kwon
authors.affiliation: Department of Pathology, Soonchunhyang University Cheonan Hospital, Cheonan, Korea.
authors.forename: Ji-Hye
authors.initials: JH
authors.lastname: Lee
authors.affiliation: Department of Internal Medicine, Soonchunhyang University Bucheon Hospital, Bucheon, Korea.
authors.forename: Soo
authors.initials: S
authors.lastname: Jeong Choi
authors.affiliation: Department of Internal Medicine, Soonchunhyang University Seoul Hospital, Seoul, Korea.
authors.forename: Dong
authors.initials: D
authors.lastname: Cheol Han
authors.affiliation: Department of Internal Medicine, Soonchunhyang University Bucheon Hospital, Bucheon, Korea.
authors.forename: Seung
authors.initials: S
authors.lastname: Duk Hwang
authors.affiliation: Department of Internal Medicine, Soonchunhyang University Cheonan Hospital, Cheonan, Korea.
authors.forename: Sae-Yong
authors.initials: SY
authors.lastname: Hong
authors.affiliation: Department of Pathology, Soonchunhyang University Seoul Hospital, Seoul, Korea.
authors.forename: So-Young
authors.initials: SY
authors.lastname: Jin
authors.affiliation: Department of Pathology, Soonchunhyang University Seoul Hospital, Seoul, Korea.
authors.forename: Hyo-Wook
authors.initials: HW
authors.lastname: Gil
keywords: Complement C3; Incidence; Membranous glomerulonephritis