Synonyms

   ANCA (Wegener's)

Clinical Significance

   It is useful for evaluating patients suspected of having antineutrophil cytoplasmic antibody-associated vasculitis (granulomatosis with polyangiitis and microscopic polyangiitis, and eosinophilic granulomatosis with polyangiitis).

Specimen

   Serum

Stability

   Refrigerated (preferred) : 21 days

   Frozen : 21 days

Reference Range

   pANCA Negative

   cANCA Negative

Interpretation

   Positive results for antineutrophil cytoplasmic antibodies (ANCA) demonstrate two main patterns namely, cytoplasmic and perinuclear in a compendium of small vessel vasculitis collectively referred to as ANCA-associated vasculitis (AAV) that includes granulomatosis with polyangiitis, microscopic polyangiitis, eosinophilic granulomatosis with polyangiitis. Negative ANCA results do not rule out a diagnosis of AAV or irritable bowel disease.

Limitation

   Current recommendations suggest that testing for antineutrophil cytoplasmic antibodies (ANCA) by indirect immunofluorescence assay should not be relied upon exclusively to establish the diagnosis of granulomatosis with polyangiitis (GPA), microscopic polyangiitis, or eosinophilic granulomatosis with polyangiitis. All positive ANCA results must be confirmed using solid-phase immunoassays using proteinase 3-ANCA for cytoplasmic ANCA (cANCA) and myeloperoxidase-ANCA for perinuclear ANCA.