Anti Neutrophil Cytoplasmic Antibodies (ANCA)
Department of Immunology
Notes
- Association with systemic vasculitis: including granulomatosis with polyangiitis (Wegener's granulomatosis), microscopic polyarteritis, eosinophilic granulomatosis with polyangiitis (Churg Strauss), and necrotising or crescentic glomerulonephritis.
- The main antigen for c-ANCA is proteinase-3 (PR3), while for p-ANCA is myeloperoxidase (MPO).
- Positive PR3 has a specificity for granulomatosis with polyangiitis of >80%. Less often seen in microscopic polyangiitis and eosinophilic granulomatosis with polyangiitis.
- Positive MPO is seen in 50% with microscopic polyarteritis, pauci-immune glomerulonephritis, but also in some patients with rheumatoid arthritis and SLE.
- MPO & PR3 quantitation performed in house. New patients will also be referred to Immunology NBT for immunofluorescence testing.
- Requesting should be confined to patients presenting with:
- Chronic necrotising large airways disease
- Cavitating pulmonary nodules
- Subglottic stenosis
- Pulmonary-renal syndrome
- Rapidly progressive glomerulonephritis
- Cutaneous vasculitis accompanied by systemic symptoms
- Mononeuritis multiplex
Sample Requirements
Clotted Blood (No patient preparation required)
Adult
5ml Gold-top SST tube or 3.5ml Rust-top gel tube (Trust users only)
Paediatric
Time limit for add-on
3 days
Turnaround Times
- Urgent: 24 hours
- Routine: 7 days
Information:
Updated: September 2025