c-ANCA

Cytoplasmic Anti-Neutrophil Cytoplasmic Antibodies (c-ANCA) display a cytoplasmic staining pattern on neutrophils via IIF. This pattern is highly specific for antibodies against Proteinase 3 (PR3), which are strongly associated with Granulomatosis with Polyangiitis (GPA, formerly Wegener's granulomatosis). A positive c-ANCA pattern usually prompts testing for specific PR3 antibodies.