title: Absence of glomerular IgG4 deposition in patients with membranous nephropathy may indicate malignancy.
abstract: BACKGROUND
  The renal pathological manifestations of malignancy-associated membranous nephropathy (M-MN) and idiopathic membranous nephropathy (I-MN) are similar. It has been suggested that glomerular IgG4 deposition may play an important role in the pathogenesis of I-MN. In the present study, we compared the IgG subclass of immune complex deposition, clinical data and pathological data of patients with M-MN and I-MN.
  
  
  METHODS
  Eight patients with M-MN and 42 patients with I-MN diagnosed between 1997 and 2009 in our hospital were enrolled. The clinical and pathological data were retrospectively collected, and glomerular IgG subclass deposition was detected by immunohistochemistry.
  
  
  RESULTS
  Patients with M-MN were older (P = 0.003), with lower serum albumin (P = 0.034) and higher serum C-reactive protein (CRP) level (P = 0.003) than patients with I-MN. The majority of patients with M-MN had earlier pathological stages (P = 0.003) and less IgG deposition in glomeruli (P = 0.029). Absence of IgG4 deposition in glomeruli was notably observed in patients with M-MN (7/8 in M-MN versus 6/42 in I-MN, P < 0.001) and it was an independent predictor for occurrence of malignancy (hazard ratio 0.065, 95% confidence intervals 0.007-0.571, P = 0.014).
  
  
  CONCLUSIONS
  Absence of glomerular IgG4 deposition, together with older age, severe hypoalbuminemia and high serum CRP level could be useful clues to differentiate M-MN from I-MN.
authors: Renal Division, Department of Medicine, Peking University First Hospital, Institute of Nephrology, Peking University, Key Laboratory of Renal Disease, Ministry of Health of China, Beijing, China.
authors: Zhen
authors: Z
authors: Qu
authors: Gang
authors: G
authors: Liu
authors: Jun
authors: J
authors: Li
authors: Li-hua
authors: LH
authors: Wu
authors: Ying
authors: Y
authors: Tan
authors: Xin
authors: X
authors: Zheng
authors: Jie
authors: J
authors: Ao
authors: Ming-hui
authors: MH
authors: Zhao
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D001706:Biopsy; D002097:C-Reactive Protein / Q000378:metabolism; D003937:Diagnosis, Differential; D005260:Female; D015433:Glomerulonephritis, Membranous / Q000175:diagnosis* / Q000276:immunology* / Q000473:pathology; D006801:Humans; D007074:Immunoglobulin G / Q000378:metabolism*; D007668:Kidney; D007678:Kidney Glomerulus / Q000276:immunology* / Q000473:pathology; D007680:Kidney Neoplasms / Q000175:diagnosis* / Q000276:immunology* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D012709:Serum Albumin / Q000378:metabolism
chemical_list: D007074:Immunoglobulin G; D012709:Serum Albumin; D002097:C-Reactive Protein