title: Myeloperoxidase-antineutrophil cytoplasmic antibody-associated crescentic glomerulonephritis in autosomal dominant polycystic kidney disease.
abstract: BACKGROUND
  Autosomal dominant polycystic kidney disease (ADPKD) is an inherited disorder that is characterized by the development of cysts in the kidneys and other organs. Urinary protein excretion is usually less than 1 g/day, and ADPKD is rarely associated with nephrotic syndrome or rapidly progressive glomerulonephritis (RPGN). To date, myeloperoxidase (MPO)-antineutrophil cytoplasmic antibody (ANCA)-associated crescentic glomerulonephritis (CrGN) has not been reported in a patient with ADPKD.
  
  
  METHODS
  We report two cases of MPO-ANCA positive ADPKD. A 60-year-old Japanese woman (case 1) and a 54-year-old Japanese woman (case 2) presented with RPGN featuring severe proteinuria and microscopic hematuria. In both patients percutaneous needle biopsy of the kidney revealed MPO-ANCA-associated CrGN with a paucity of glomerular immunoglobulin staining. Each patient received intravenous methylprednisolone for 3 days, followed by oral prednisolone. Case 1 showed gradual improvement and has not progressed to end-stage renal disease (ESRD), but case 2 developed ESRD requiring hemodialysis within one month despite treatment.
  
  
  CONCLUSIONS
  These are the first two reported cases of MPO-ANCA-associated CrGN in patients with ADPKD. Our experience suggests that serial measurement of the ANCA titer and renal biopsy should be considered for accurate diagnosis and appropriate treatment of ADPKD patients who present with proteinuria, hematuria, and rapid decline of renal function.
authors.forename: Keiichi
authors.initials: K
authors.lastname: Sumida
authors.forename: Yoshifumi
authors.initials: Y
authors.lastname: Ubara
authors.forename: Junichi
authors.initials: J
authors.lastname: Hoshino
authors.forename: Noriko
authors.initials: N
authors.lastname: Hayami
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Suwabe
authors.forename: Rikako
authors.initials: R
authors.lastname: Hiramatsu
authors.forename: Eiko
authors.initials: E
authors.lastname: Hasegawa
authors.forename: Masayuki
authors.initials: M
authors.lastname: Yamanouchi
authors.forename: Naoki
authors.initials: N
authors.lastname: Sawa
authors.forename: Kenmei
authors.initials: K
authors.lastname: Takaichi
authors.forename: Kenichi
authors.initials: K
authors.lastname: Ohashi
mesh_terms: D019268:Antibodies, Antineutrophil Cytoplasmic / Q000097:blood*; D005260:Female; D005921:Glomerulonephritis / Q000097:blood* / Q000150:complications / Q000175:diagnosis*; D006801:Humans; D008875:Middle Aged; D009195:Peroxidase / Q000097:blood*; D016891:Polycystic Kidney, Autosomal Dominant / Q000097:blood* / Q000150:complications / Q000175:diagnosis*
chemical_list: D019268:Antibodies, Antineutrophil Cytoplasmic; D009195:Peroxidase