The c-ANCA pattern produces a granular cytoplasmic pattern with interlobular accentuation on ethanol fixed neutrophils. c-ANCA patterns are associated with necrotizing segmental glomerulonephritis and GPA ^3,4.

The p-ANCA pattern produces perinuclear staining with or without nuclear extension. The p-ANCA pattern is commonly detected in patients with MPA and about 40% of patients with Eosinophilic Granulomatosis with Polyangiitis (EGPA)^4,5.

The p-ANCA pattern produces perinuclear staining with or without nuclear extension. The p-ANCA pattern is commonly detected in patients with MPA and about 40% of patients with Eosinophilic Granulomatosis with Polyangiitis (EGPA)^4,5.

Anti-PR3 antibodies are primarily associated with GPA and to a lesser extent, found in MPA (10%) and EPGA^3,7. However, anti-PR3 antibodies can also be seen in connective tissue disease, IBD, some infections, malignancy, and as a reaction to drugs⁴. Therefore, results should be interpreted with care in light of the clinical findings and workup⁶.

Anti-MPO antibodies are primarily associated with MPA and to a lesser extent, found in GPA (6%) and EGPA^3,7. However, anti-MPO antibodies can also be seen in connective tissue disease, IBD, some infections, malignancy, and as a reaction to drugs. Therefore, results should be interpreted with care in light of the clinical findings and workup⁶.

Anti-MPO antibodies are primarily associated with MPA and to a lesser extent, found in GPA (6%) and EGPA³. However, anti-MPO antibodies can also be seen in connective tissue disease, IBD, some infections, malignancy, and as a reaction to drugs. Therefore, results should be interpreted with care in light of the clinical findings and workup⁶.