II. Indications

III. Mechanism

  1. Antibodies bind to cytoplasmic region of Neutrophils

IV. Labs

  1. Cytospin preparations of Neutrophils are permeabilized
  2. Binding of serum antibodies assessed as with ANA

V. 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)

VI. 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)
    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)

VII. 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]

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