title: Differences between myeloperoxidase-specific and -nonspecific P-ANCA-associated renal disease.
abstract: BACKGROUND
  Anti-neutrophil cytoplasmic antibodies (ANCA) are classified into perinuclear (P)-ANCA and cytoplasmic-ANCA by an indirect immunofluorescence (IIF) test with ethanol-fixed neutrophils. Circulating P-ANCA with specificity for myeloperoxidase (MPO) are frequently found in patients with pauci-immune necrotizing glomerulonephritis. P-ANCA without a specificity for MPO are also found in a minority of patients with this form of glomerulonephritis, but their clinicopathological features remain poorly delineated.
  
  
  METHODS
  The clinical data, the renal pathology, and the outcome were compared between 48 patients with MPO-specific P-ANCA-associated glomerulonephritis (MPO-specific group) and five patients with MPO-nonspecific P-ANCA-associated glomerulonephritis (MPO-nonspecific group). In the MPO-nonspecific group, antibodies against bactericidal/permeability-increasing protein were detected in one patient, but the other known antibodies that can produce a P-ANCA pattern on the IIF test were not detected in the remaining patients. All patients in the two groups were treated with steroids with or without cyclophosphamide.
  
  
  RESULTS
  There were no remarkable differences in the degree of hematuria and serum levels of C-reactive protein and creatinine between the two groups. In contrast, proteinuria levels and the rate of glomerular crescent formation were higher in the MPO-nonspecific group than in the MPO-specific group. While the patient survival rate was similar between the two groups, the renal survival rate was lower in the MPO-nonspecific group.
  
  
  CONCLUSIONS
  This pilot analysis suggests that there are clinicopathological differences between patients with MPO-specific and -nonspecific P-ANCA-associated pauci-immune necrotizing glomerulonephritis. Renal lesions appear to be more active in patients with MPO-nonspecific P-ANCA than in patients with MPO-specific P-ANCA.
authors: Third Department of Internal Medicine, Akita University School of Medicine, Akita, Japan.
authors: Hiroshi
authors: H
authors: Ohtani
authors: Hideki
authors: H
authors: Wakui
authors: Atsushi
authors: A
authors: Komatsuda
authors: Konstantin A
authors: KA
authors: Chyzh
authors: Takashi
authors: T
authors: Hatakeyama
authors: Rie
authors: R
authors: Masai
authors: Shin
authors: S
authors: Okuyama
authors: Masaru
authors: M
authors: Togashi
authors: Ken-ichi
authors: K
authors: Sawada
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D019268:Antibodies, Antineutrophil Cytoplasmic / Q000032:analysis*; D000918:Antibody Specificity; D001706:Biopsy; D005260:Female; D006801:Humans; D007668:Kidney / Q000201:enzymology / Q000276:immunology / Q000473:pathology*; D007674:Kidney Diseases / Q000201:enzymology / Q000276:immunology / Q000401:mortality / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D009195:Peroxidase; D016019:Survival Analysis
chemical_list: D019268:Antibodies, Antineutrophil Cytoplasmic; D009195:Peroxidase