C-ANCA
c-ANCAs, or PR3-ANCA, or antineutrophil cytoplasmic antibodies, are a type of autoantibody, an antibody produced by the body that acts against one of its own proteins. These antibodies show a diffusely granular, cytoplasmic staining pattern under microscopy. This pattern results from binding of ANCAs to antigen targets throughout the neutrophil cytoplasm, the most common protein target being proteinase 3. For example, PR3 is the most common antigen target of ANCA in patients with granulomatosis with polyangiitis. In active granulomatosis with polyangiitis, c-ANCA is found over 90% of the time. Other antigens may also occasionally result in a c-ANCA pattern.
