title: Renal histopathology and clinical course in 94 patients with Wegener's granulomatosis.
abstract: BACKGROUND
  The main purpose of this study was to examine histopathological changes seen in renal biopsies from patients with Wegener's granulomatosis (WG) with varying degrees of renal involvement and to study possible correlations between the morphological variables and the severity of the disease.
  
  
  METHODS
  Ninety-four patients with WG and active renal disease were included in this retrospective study. All patients had a percutaneous renal biopsy taken on their first admission to the hospital and 14 patients had a second biopsy. The patients were followed for a median of 42.5 months (range 0.5-184).
  
  
  RESULTS
  Segmental necrotizing glomerulonephritis and extracapillary proliferation were present in 85.1 and 91.5% respectively. Of seven patients (7.4%) with normal serum creatinine and urinary protein excretion <0.5 g/day, all had crescents and six had segmental glomerular necrosis. Serum creatinine at biopsy correlated significantly with the percentage of glomeruli with crescents (rho=0.52, P=0.0004), with necrosis (rho=0.36, P=0.002) and with the percentage of normal glomeruli (rho=-0.55, P=0.0003). On a multivariate analysis, only the percentage of normal glomeruli was significantly associated with renal function and development of end-stage renal disease. In 14 second biopsies after a mean of 41.2 (+/-26) months, chronicity scores had increased significantly in 13 biopsies in spite of full immunosuppressive treatment.
  
  
  CONCLUSIONS
  Although renal biopsy is of value in defining renal involvement in WG, it is of limited help in the early stage of the disease in predicting renal outcome for the individual patient. A follow-up biopsy can be useful in revealing the degree of activity and chronicity and hence be of importance for the choice of further therapy.
authors.affiliation: Department of Medicine, University Hospital of Trondheim, Olav Kyrres gate 17, N-7006 Trondheim, Norway.
authors.forename: K
authors.initials: K
authors.lastname: Aasarød
authors.forename: L
authors.initials: L
authors.lastname: Bostad
authors.forename: J
authors.initials: J
authors.lastname: Hammerstrøm
authors.forename: S
authors.initials: S
authors.lastname: Jørstad
authors.forename: B M
authors.initials: BM
authors.lastname: Iversen
mesh_terms: D000328:Adult; D000368:Aged; D003404:Creatinine / Q000097:blood; D005260:Female; D005921:Glomerulonephritis / Q000209:etiology / Q000473:pathology; D014890:Granulomatosis with Polyangiitis / Q000150:complications / Q000473:pathology*; D006801:Humans; D007668:Kidney / Q000473:pathology* / Q000503:physiopathology; D007678:Kidney Glomerulus / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009336:Necrosis; D012189:Retrospective Studies; D012720:Severity of Illness Index
chemical_list: D003404:Creatinine