Neutrophil Cytoplasmic Antibodies
Also known as: ANCA; MPO/PR3; c-ANCA; p-ANCA
Please note that all ANCA requests are screened in the Laboratory to ensure that testing is restricted to those patients whose presenting features suggest a high pre-test probability of small vessel vasculitis. ANCA 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
IgG antibodies directed against neutrophil enzymes systems are useful in the diagnosis and management of systemic necrotising vasculitis.
The main systemic necrotising vasculitides that are associated with a positive ANCA pattern are Granulomatous Polyangitis (GPA/Wegener's Granulomatosis), Microscopic Polyarteritis, Rapidly Progressive Glomerulonephritis and Churg-Strauss Syndrome.
Two major forms of pattern are seen: the cytoplasmic ANCA (cANCA) usually associated with autoantibodies against anti-proteinase 3, and the perinuclear (pANCA) pattern generally associated with myeloperoxidase auto-antibodies.
Note 'false positives' may occur in diseases which may mimic systemic vasculitis e.g. infective endocarditis, tuberculosis, non-Hodgkin's lymphoma, acquired immune deficiency syndrome.
P-ANCA (of anti-MPO specificity) are found in up to 50% of patients with microscopic polyarteritis and pauci-immune glomerulonephritis, in addition to rheumatoid arthritis, SLE and ulcerative colitis
Samples from known ANCA positive patients are tested for MPO or PR3 antibody levels, as appropriate. New ANCA positives are analysed for ANCA specificity and levelsagainst both MPO and PR3.
Specimen requirements
Serum or plasma - 1ml
Cost
Price on application
Laboratory turnaround time
4 days
Laboratory method
Indirect Immunofluorescnce
Reference range/units
ANCA
Positive or Negative with pattern and titre
MPO Antibody Levels
>5.0 IU/ml = Positive
3.5-5 IU/ml = Equivocal
<3.5 IU/ml = Negative
PR3Antibody Levels
>3.0IU/ml = Positive
2-3.0 IU/ml = Equivocal
<2.0 IU/ml = Negative
Associated tests
MPO/PR3
Shipping and storage
UK and Ireland
Ambient temperature and first class post. Hays DX users please enquire via email below.
International
Ambient temperature if courier will deliver within 72 hours otherwise consider refrigerated transport. Freezing is not a requirement.
Ensure delivery Monday to Friday 07:00 - 17:30.
Further information and contact details
For further information, email immunology.office@nhs.net