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Antineutrophil Cytoplasmic Antibody

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Antineutrophil Cytoplasmic Antibody, Antineutrophil Cytoplasmic Antibodies, ANCA, Proteinase 3-ANCA, PR3-ANCA, Myeloperoxidase-ANCA, MPO-ANCA

  • See Also
  1. Antinuclear Antibody
  2. Small Vessel Vasculitis
  • Indications
  1. Small Vessel Vasculitis
  2. Granulomatosis with Polyangiitis (previously known as Wegener's Granulomatosis) suspected (cANCA)
  • Mechanism
  1. Antibodies bind to cytoplasmic region of Neutrophils
  • Labs
  1. Cytospin preparations of Neutrophils are permeabilized
  2. Binding of serum antibodies assessed as with ANA
  • Labs
  • Interpretation
  1. C-ANCA (Cytoplasmic: PR3-ANCA)
    1. Classic, Diffuse, fine granular cytoplasmic staining
    2. Antibodies directed to Proteinase-3 Antigen (PR3)
  2. P-ANCA (Peri-nuclear: MPO-ANCA)
    1. Perinuclear pattern
    2. Antibodies to Myeloperoxidase (MPO)
  • Associated Conditions
  1. C-ANCA or PR3-ANCA
    1. Granulomatosis with Polyangiitis (Very Strongly associated)
      1. Positive in 75-98% of patients with Wegener's
      2. Sensitivity drops to 30% during remission
    2. Crescentic Glomerulonephritis (moderately associated)
    3. Polyarteritis Nodosa (Weakly associated)
  2. P-ANCA or MPO-ANCA
    1. Crescentic Glomerulonephritis (Strongly associated)
    2. Polyarteritis Nodosa (Moderately associated)
    3. Churg-StraussVasculitis (Moderately associated)
    4. Granulomatosis with Polyangiitis (Weakly associated)
    5. Henoch-Schonlein Purpura (Possibly associated)
    6. Temporal Arteritis (Possibly associated)
  • References
  1. Gladman in Klippel (1997) Rheumatic Diseases p. 255-6
  2. Peng in Ruddy (2001) Kelley's Rheumatology, p. 161-72
  3. Callegari (1995) Postgrad Med, 97(4):65-74 [PubMed]
  4. Lane (2002) Am Fam Physician 65(6):1073-80 [PubMed]