title: Incidence and disease severity of anti-neutrophil cytoplasmic antibody-associated nephritis are higher than in lupus nephritis in Sweden.
abstract: OBJECTIVE
  The objectives of this study were to compare incidence rates, renal and patient survival between lupus nephritis (LN) and anti-neutrophil cytoplasmic antibody-associated nephritis (AAN) during a 12-year period in two geographically defined populations in Sweden.
  
  
  METHODS
  In the health care districts surrounding the Skåne University Hospital in Lund [mean population ≥18 years (1997-2008), 188 400] and the University Hospital in Linköping [mean population ≥18 years (1997-2008), 328 900] all patients with biopsy-proven LN and AAN during the period 1997-2008 were included in the study if they (i) were residing within the study areas at the time of onset of nephritis, (ii) had a clinical diagnosis of either SLE or ANCA-associated vasculitis (AAV) and (iii) experienced a first flare of biopsy-proven nephritis during the study period.
  
  
  RESULTS
  Eighty-two patients (Lund 44 + Linköping 38) with biopsy-proven AAN were identified and 27 patients with LN (Lund 13 + Linköping 14). The annual incidence rate per million inhabitants aged ≥18 years in both study areas was estimated to be 13.2 (95% CI 10.4-16.1) for AAN and 4.3 (95% CI 2.7-6.0) for LN, P < 0.001. The patients were followed until January 2013. During the follow-up time 38 patients died (AAN 36, LN 2; P = 0.001), and 20 patients went into end-stage renal disease (AAN 19 and LN 1), P = 0.020.
  
  
  CONCLUSIONS
  In Sweden, AAN was three times more common than LN, and the outcome was considerably worse. SLE is often diagnosed before the onset of nephritis leading to earlier treatment, while AAN is still often diagnosed at a later stage.
authors.affiliation: Department of Clinical Sciences, Section of Rheumatology, Lund University, Lund, Sweden Department of Renal Medicine, Vasculitis and Lupus Clinic, Addenbrooke's Hospital, Cambridge, UK.
authors.forename: Aladdin J
authors.initials: AJ
authors.lastname: Mohammad
authors.affiliation: Department of Nephrology, Linköping University, Linköping, Sweden Department of Medical and Health Sciences, Linköping University, Linköping, Sweden.
authors.forename: Maria
authors.initials: M
authors.lastname: Weiner
authors.affiliation: Department of Rheumatology/AIR, Linköping University, Linköping, Sweden Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden.
authors.forename: Christopher
authors.initials: C
authors.lastname: Sjöwall
authors.affiliation: Department of Laboratory Medicine Malmö, Clinical Pathology, Lund University, Malmö, Sweden.
authors.forename: Martin E
authors.initials: ME
authors.lastname: Johansson
authors.affiliation: Department of Clinical Sciences, Section of Rheumatology, Lund University, Lund, Sweden.
authors.forename: Anders A
authors.initials: AA
authors.lastname: Bengtsson
authors.affiliation: Department of Internal Medicine, Section of Rheumatology, Helsingborg Hospital, Helsingborg, Sweden.
authors.forename: Christina
authors.initials: C
authors.lastname: Ståhl-Hallengren
authors.affiliation: Department of Clinical Sciences, Section of Rheumatology, Lund University, Lund, Sweden.
authors.forename: Ola
authors.initials: O
authors.lastname: Nived
authors.affiliation: Department of Rheumatology/AIR, Linköping University, Linköping, Sweden Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden.
authors.forename: Per
authors.initials: P
authors.lastname: Eriksson
authors.affiliation: Department of Clinical Sciences, Section of Rheumatology, Lund University, Lund, Sweden.
authors.forename: Gunnar
authors.initials: G
authors.lastname: Sturfelt
authors.affiliation: Department of Nephrology, Linköping University, Linköping, Sweden Department of Medical and Health Sciences, Linköping University, Linköping, Sweden.
authors.forename: Mårten
authors.initials: M
authors.lastname: Segelmark
mesh_terms: D000328:Adult; D000368:Aged; D056648:Anti-Neutrophil Cytoplasmic Antibody-Associated Vasculitis / Q000150:complications / Q000453:epidemiology* / Q000401:mortality / Q000473:pathology; D019268:Antibodies, Antineutrophil Cytoplasmic / Q000097:blood; D005260:Female; D005921:Glomerulonephritis / Q000150:complications / Q000453:epidemiology* / Q000401:mortality / Q000473:pathology; D006801:Humans; D015994:Incidence; D007676:Kidney Failure, Chronic / Q000175:diagnosis / Q000453:epidemiology* / Q000209:etiology / Q000401:mortality; D008181:Lupus Nephritis / Q000150:complications / Q000453:epidemiology* / Q000401:mortality / Q000473:pathology; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012720:Severity of Illness Index; D015996:Survival Rate; D013548:Sweden / Q000453:epidemiology
chemical_list: D019268:Antibodies, Antineutrophil Cytoplasmic
keywords: ANCA; end-stage renal disease; incidence; lupus nephritis; systemic lupus erythematosus