ANCA

Typically in patients with a positive ANA, a positive P-ANCA is a false positive.

Disease associations

• Granulomatosis with polyangiitis

  • 90% of GPa patients are ANCA positive

  • 80 to 90% have PR3-ANCA

• Microscopic polyangiitis

  • 90% of MPA are ANCA positive

• Renal-limited vasculitis

• Eosinophillic granulomatosis with polyangiitis (Churg Straus)

• Anti-GBM disease

• Drug induced ANCA-associated vasculitis

  • Hydralazine

  • Propylthiouracil

  • Minocycline

  • Cocaine

• Interstitial nephritis

• Non-vasculitic systemic rheumatic diseases

• Autoimmune gastrointestinal disorders

  • UC and Crohn’s

• Cystic fibrosis

• Infections

  • Bacterial endocarditis

  • COVID-19

  • TB, Leprosy, Malaria, IM, Aspergillosis

• IgA nephropathy

Reference:

• Clinical spectrum ANCA - Up To Date