title: Incidence and outcome of pauci-immune rapidly progressive glomerulonephritis in Wessex, UK: a 10-year retrospective study.
abstract: BACKGROUND
  The Wessex Renal Unit serves a large stable population (2.5 million). Pauci-immune rapidly progressive glomerulonephritis (RPGN) is a frequent cause of acute renal failure requiring admission to our unit ( approximately 8%). At a population level, little is known of the epidemiology and outcome of RPGN.
  
  
  METHODS
  Between 1 April 1986 and 31 March 1996, 141 cases of biopsy proven pauci-immune RPGN were seen in the Wessex region. The records of 128 patients were reviewed. Median (range) follow-up was 1.8 (0.9-9.64) years from diagnosis.
  
  
  RESULTS
  The incidence of 4 per million was stable throughout the period. No clustering was seen. The diagnosis was made (median, 25th, 75th centile) 78.5 (45, 166) days after symptom onset. Co-morbidity (mostly hypertension) was seen in 47% of patients. Other organs affected were lungs 63%, nose/sinuses 50%, joints 42%, muscle 33%, skin 22% and nervous system 14%. Anti-neutrophil cytoplasmic antibody (ANCA) was positive in 73%; cytoplasmic ANCA 34%, peri-nuclear ANCA 26% and undifferentiated 14%. Twenty-seven per cent tested ANCA negative. The differences between the groups were small; time to diagnosis was shorter in the ANCA negative (-ve) group (P=0.02) and there were more airway symptoms in the ANCA positive (+ve) group (P:<0.05). All biopsies demonstrated a necrotizing process; crescents were seen in 96% involving (mean+/-SD) 54+/-26% of the glomeruli. Creatinine concentration (mean+/-SD) at diagnosis was 806+/-540 micromol/l. Treatment followed established immunosuppressive regimens. Initial dialysis was required by 59%, 36% needing long-term dialysis. At 1 year 68% were alive. The need for dialysis (P=0.0004) and age (P=0. 004) were poor prognostic markers. Ten per cent were transplanted, graft survival was 90% at 1 year, no recurrence was seen.
  
  
  CONCLUSIONS
  This study, looking at a large cohort, has established the incidence and outcome of ANCA +ve and ANCA -ve RPGN in a defined stable population. It stresses the similarities between ANCA +ve and ANCA -ve cases and supports the notion that pauci-immune RPGN is part of a continuum of vasculitic illness. In this series transplantation is a safe option.
authors.affiliation: Wessex Renal and Transplant Unit, Portsmouth, UK.
authors.forename: N
authors.initials: N
authors.lastname: Hedger
authors.forename: J
authors.initials: J
authors.lastname: Stevens
authors.forename: N
authors.initials: N
authors.lastname: Drey
authors.forename: S
authors.initials: S
authors.lastname: Walker
authors.forename: P
authors.initials: P
authors.lastname: Roderick
mesh_terms: D017677:Age Distribution; D000368:Aged; D019268:Antibodies, Antineutrophil Cytoplasmic / Q000378:metabolism; D000936:Antigen-Antibody Complex / Q000032:analysis*; D015331:Cohort Studies; D018450:Disease Progression; D005260:Female; D005921:Glomerulonephritis / Q000453:epidemiology* / Q000276:immunology* / Q000503:physiopathology / Q000628:therapy; D006801:Humans; D015994:Incidence; D016030:Kidney Transplantation; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012189:Retrospective Studies; D016019:Survival Analysis; D013997:Time Factors; D014018:Tissue Distribution; D016896:Treatment Outcome; D006113:United Kingdom
chemical_list: D019268:Antibodies, Antineutrophil Cytoplasmic; D000936:Antigen-Antibody Complex