title: Risk factors associated with relapse in Japanese patients with microscopic polyangiitis.
abstract: OBJECTIVE
  We retrospectively studied the risk factors associated with relapse during remission maintenance therapy for myeloperoxidase-antineutrophil cytoplasmic autoantibody (MPO-ANCA)-positive microscopic polyangiitis (MPA).
  
  
  METHODS
  Sixty-two patients diagnosed with MPA according to the European Medicines Agency classification algorithm during a 2-year period from January 1, 2005, to December 31, 2006, and who achieved remission after the first remission-induction therapy, were examined (registration no. UMIN000001785).
  
  
  RESULTS
  The patient group comprised 25 men and 37 women aged 70.0 ± 8.9 years. The mean observation period was 30.2 ± 15.9 months. The rate of relapse was 24.2% (15/62), and mean interval between remission and relapse was 16.9 ± 13.5 months. During maintenance therapy following remission, the risk of relapse increased when the reduction rate of prednisolone increased above 0.8 mg/month (OR 12.6, 95% CI 2.2-97.9). Proteinuria at the start of maintenance therapy (regression coefficient 1.991 ± 0.758, p < 0.05) and the change in red blood cell counts in urine during the period from the start of maintenance therapy to the final observation (regression coefficient 0.126 ± 0.040, p < 0.01) were identified as risk factors influencing the vasculitis damage index.
  
  
  CONCLUSIONS
  In Japan, relapse of MPO-ANCA-positive MPA may be associated with the reduction rate of oral prednisolone administration during maintenance therapy.
authors.affiliation: Division of Nephrology, Department of Laboratory Medicine, Kanazawa University, 13-1 Takara-machi, Kanazawa, 920-8641, Japan. twada@m-kanazawa.jp
authors.forename: Takashi
authors.initials: T
authors.lastname: Wada
authors.forename: Akinori
authors.initials: A
authors.lastname: Hara
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Arimura
authors.forename: Ken-Ei
authors.initials: KE
authors.lastname: Sada
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Makino
mesh_terms: D000368:Aged; D044466:Asian People; D003520:Cyclophosphamide / Q000627:therapeutic use*; D004305:Dose-Response Relationship, Drug; D004906:Erythrocyte Count; D005260:Female; D006801:Humans; D007166:Immunosuppressive Agents / Q000627:therapeutic use*; D015994:Incidence; D007564:Japan; D008297:Male; D055953:Microscopic Polyangiitis / Q000097:blood / Q000188:drug therapy* / Q000453:epidemiology*; D008875:Middle Aged; D011239:Prednisolone / Q000627:therapeutic use*; D012008:Recurrence; D012074:Remission Induction; D012189:Retrospective Studies; D012307:Risk Factors; D014657:Vasculitis / Q000453:epidemiology
chemical_list: D007166:Immunosuppressive Agents; D003520:Cyclophosphamide; D011239:Prednisolone