title: Increasing frequency of idiopathic membranous nephropathy in primary glomerular disease: a 10-year renal biopsy study from a single Chinese nephrology centre.
abstract: OBJECTIVE
  To investigate the changing of idiopathic membranous nephropathy (iMN) in China.
  
  
  METHODS
  This study retrospectively analyzed renal disease spectrum of 6049 patients who underwent renal biopsy at Peking University First Hospital from January 2003 to December 2012. The patients were grouped into two periods at a 5-year interval: 2003-2007 (period 1) and 2008-2012 (period 2).
  
  
  RESULTS
  Among 6049 renal biopsied patients, 3831 (63.3%) patients were diagnosed as primary glomerular disease (PGD). The proportion of nephrotic syndrome (NS) in PGD was significantly higher in period 2 than that in period 1 (1016/2214 [55.0%] vs 682/1617 [42.2%], P = 0.022). The proportion of iMN in PGD increased from 16.8% (217/1617) in period 1 to 29.35% (646/2214) in period 2 in all groups of age (P < 0.001). There was no significant difference of clinical characteristics including age, gender, hypertension, serum cholesterol and proteinuria between the two periods (P > 0.05). However, in young patients with iMN (14-44 years old), the percentage of renal histopathology stage I and stage II of iMN in PGDs was significantly higher in period 2 than that in period 1 (101/1240 [8.15%] vs 210/1340 [15.7%], P < 0.001).
  
  
  CONCLUSIONS
  Our study suggests that the frequency of iMN in PGD in our referral diagnostic centre has doubled over the past 10 years. The increase of adult iMN is mainly due to the increase of early stages of iMN in young patients.
authors.affiliation: Renal Division, Department of Medicine, Peking University First Hospital, Beijing, China.|Institute of Nephrology, Peking University, Beijing, China.|Key Laboratory of Renal Disease, Ministry of Health of China, Beijing, China.|Key Laboratory of CKD Prevention and Treatment, Ministry of Education of China, Beijing, China.|Renal Division, Department of Medicine, The First College of Clinical Medical Science, China Three Gorges University, Yichang, China.
authors.forename: Ping
authors.initials: P
authors.lastname: Zhu
authors.affiliation: Renal Division, Department of Medicine, Peking University First Hospital, Beijing, China.|Institute of Nephrology, Peking University, Beijing, China.|Key Laboratory of Renal Disease, Ministry of Health of China, Beijing, China.|Key Laboratory of CKD Prevention and Treatment, Ministry of Education of China, Beijing, China.
authors.forename: Fu-de
authors.initials: FD
authors.lastname: Zhou
authors.affiliation: Renal Division, Department of Medicine, Peking University First Hospital, Beijing, China.|Institute of Nephrology, Peking University, Beijing, China.|Key Laboratory of Renal Disease, Ministry of Health of China, Beijing, China.|Key Laboratory of CKD Prevention and Treatment, Ministry of Education of China, Beijing, China.
authors.forename: Su-Xia
authors.initials: SX
authors.lastname: Wang
authors.affiliation: Renal Division, Department of Medicine, Peking University First Hospital, Beijing, China.|Institute of Nephrology, Peking University, Beijing, China.|Key Laboratory of Renal Disease, Ministry of Health of China, Beijing, China.|Key Laboratory of CKD Prevention and Treatment, Ministry of Education of China, Beijing, China.|Peking-Tsinghua Center for Life Sciences, Beijing, China.
authors.forename: Ming-Hui
authors.initials: MH
authors.lastname: Zhao
authors.affiliation: Renal Division, Department of Medicine, Peking University First Hospital, Beijing, China.|Institute of Nephrology, Peking University, Beijing, China.|Key Laboratory of Renal Disease, Ministry of Health of China, Beijing, China.|Key Laboratory of CKD Prevention and Treatment, Ministry of Education of China, Beijing, China.
authors.forename: Hai-Yan
authors.initials: HY
authors.lastname: Wang
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D001706:Biopsy; D002681:China / Q000453:epidemiology; D015897:Comorbidity; D005260:Female; D015433:Glomerulonephritis, Membranous / Q000453:epidemiology* / Q000473:pathology; D006785:Hospitals, University; D006801:Humans; D007678:Kidney Glomerulus / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D009404:Nephrotic Syndrome / Q000453:epidemiology* / Q000473:pathology; D012189:Retrospective Studies; D012720:Severity of Illness Index; D017678:Sex Distribution; D013997:Time Factors; D055815:Young Adult
keywords: idiopathic membranous nephropathy; nephrotic syndrome; primary glomerular disease; renal histopathology