title: Picking transplant glomerulopathy out of the CAN: evidence from a clinico-pathological evaluation.
abstract: BACKGROUND
  Since the term chronic allograft nephropathy (CAN) was removed from the Banff scheme in 2005, transplant glomerulopathy (TG) has been regarded as a clinicopathological entity that is one of the major causes of graft loss. To assess the distinction between CAN and TG, we performed a comprehensive evaluation comparing TG with traditional CAN.
  
  
  METHODS
  We compared the clinicopathological features of 43 cases of TG with 43 matched cases of non-TG CAN (non-TG group) after renal transplantation. TG was diagnosed by light microscopy based on the double contours of the glomerular basement membranes, and the Banff 97 classification system was used to score TG severity (cg0-3).
  
  
  RESULTS
  Compared to the control group, we found a significantly higher incidence of positivity for human leukocyte antigen class-I and II antibodies, a higher incidence of hepatitis C virus (HCV) infection, and poorer graft survival in TG patients. Clinically, TG was associated with a higher prevalence of proteinuria, hematuria, anaemia and hypoalbuminemia. Histologically, TG strongly correlated with antibody related microcirculatory injuries, including glomerulitis, peritubular capillaritis and peritubular capillary (PTC) C4d deposition. Interestingly, the TG patients showed a significantly higher incidence of IgA deposition than the control patients. C4d-positive TG was correlated with higher TG and PTC scores, and PTC C4d deposition was correlated with a more rapid progression to graft dysfunction. TG accompanied by HCV infection was associated with heavier proteinuria, higher TG and C4d scores, and poorer graft survival.
  
  
  CONCLUSIONS
  TG presents clinicopathological features that are distinct from non-TG cases and leads to poorer outcomes. PTC C4d deposition is related to a more rapid progression to graft loss, suggesting ongoing antibody reactivity. HCV-positive TG is a more severe sub-entity, that requires further investigation.
authors.affiliation: Research Institute of Nephrology, Jinling Hospital, Nanjing University School of Medicine, Nanjing, 210002, China.
authors.forename: Qiquan
authors.initials: Q
authors.lastname: Sun
authors.forename: Xianghua
authors.initials: X
authors.lastname: Huang
authors.forename: Song
authors.initials: S
authors.lastname: Jiang
authors.forename: Caihong
authors.initials: C
authors.lastname: Zeng
authors.forename: Zhihong
authors.initials: Z
authors.lastname: Liu
mesh_terms: D000328:Adult; D005260:Female; D005921:Glomerulonephritis / Q000188:drug therapy / Q000453:epidemiology / Q000473:pathology*; D006084:Graft Rejection / Q000453:epidemiology / Q000473:pathology / Q000517:prevention & control; D006085:Graft Survival / Q000187:drug effects / Q000502:physiology*; D006801:Humans; D007166:Immunosuppressive Agents / Q000494:pharmacology / Q000627:therapeutic use; D007678:Kidney Glomerulus / Q000473:pathology*; D016030:Kidney Transplantation / Q000009:adverse effects / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D051436:Renal Insufficiency, Chronic / Q000453:epidemiology / Q000473:pathology / Q000601:surgery; D014184:Transplantation, Homologous
chemical_list: D007166:Immunosuppressive Agents