Antineutrophil Cytoplasmic Antibody (ANCA) Profile is a comprehensive test that detects autoantibodies associated with systemic vasculitides and inflammatory conditions. This test identifies three main ANCA patterns: cytoplasmic (c-ANCA), perinuclear (p-ANCA), and atypical p-ANCA, along with specific antibodies against proteinase 3 (PR3) and myeloperoxidase (MPO). The presence of anti-PR3 antibodies is highly specific for granulomatosis with polyangiitis (formerly Wegener's granulomatosis), while anti-MPO antibodies are associated with microscopic polyangiitis, eosinophilic granulomatosis with polyangiitis, and certain forms of glomerulonephritis. ANCA levels correlate with disease activity, making this test valuable for both initial diagnosis and monitoring treatment response. The test helps distinguish between different types of vasculitis and guides appropriate immunosuppressive therapy.