title: Retrospective analysis of factors predicting end-stage renal failure or death in patients with microscopic polyangiitis with mainly renal involvement.
abstract: BACKGROUND
  The aim of this study was to identify risk factors for end-stage renal failure (ESRF) or death in Japanese patients with microscopic polyangiitis (MPA) with renal involvement.
  
  
  METHODS
  From 54 consecutive patients with systemic vasculitis based on Watt's algorithm, we retrospectively analyzed 39 MPA patients with renal involvement, including 19 (48.7 %) with renal-limited vasculitis.
  
  
  RESULTS
  Thirty-three of 39 patients (84.6 %) demonstrated rapidly progressive glomerulonephritis, and 13 (33.3 %) developed ESRF; 8 of 13 required dialysis within 1 week. Thirteen (33.3 %) died during follow-up of more than 12 months, and 7 died during the first 6 months, mainly because of opportunistic infections. Overall survival at 6 and 12 months was 79.5 and 71.1 %, respectively. Serum creatinine levels did not differ significantly between survivors and non-survivors (P = 0.092). The mean Birmingham Vasculitis Activity Score, version 3 (BVAS v.3), was 16.2 ± 6.5, with a renal subscore of over 12 points in 82.1 %, and BVAS v.3 was marginally higher in non-survivors than survivors (P = 0.045). An age- and sex-adjusted Cox proportional hazards analysis demonstrated that neither the serum creatinine level (P = 0.277) nor BVAS v.3 (P = 0.188) at initial diagnosis was a risk factor for overall survival. The baseline serum creatinine cutoff value for discriminating between ESRF and non-ESRF was 4.6 mg/dl, with a sensitivity and specificity of 92.3 and 84.6 %, respectively.
  
  
  CONCLUSIONS
  Survival rates do not relate to ESRF in MPA patients with mainly renal involvement. Although patients with ESRF required regular hemodialysis, longer survival can be achieved.
authors.affiliation: Division of Nephrology and Rheumatology, Department of Internal Medicine, Aichi Medical University School of Medicine, Nagakute, Aichi, 480-1195, Japan.
authors.forename: Hirohisa
authors.initials: H
authors.lastname: Kawai
authors.forename: Shogo
authors.initials: S
authors.lastname: Banno
authors.forename: Shogo
authors.initials: S
authors.lastname: Kikuchi
authors.forename: Nahoko
authors.initials: N
authors.lastname: Nishimura
authors.forename: Hironobu
authors.initials: H
authors.lastname: Nobata
authors.forename: Yukihiro
authors.initials: Y
authors.lastname: Kimura
authors.forename: Yumiko
authors.initials: Y
authors.lastname: Takezawa
authors.forename: Mari
authors.initials: M
authors.lastname: Ogawa
authors.forename: Keisuke
authors.initials: K
authors.lastname: Suzuki
authors.forename: Wataru
authors.initials: W
authors.lastname: Kitagawa
authors.forename: Naoto
authors.initials: N
authors.lastname: Miura
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Imai
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D007564:Japan / Q000453:epidemiology; D007676:Kidney Failure, Chronic / Q000453:epidemiology* / Q000209:etiology / Q000628:therapy; D008297:Male; D055953:Microscopic Polyangiitis / Q000150:complications / Q000401:mortality* / Q000628:therapy; D008875:Middle Aged; D012189:Retrospective Studies