ORGENTEC Autoimmunity Blog

Covering Autoimmune Diseases

Anti-neutrophil cytoplasmic antibodies (ANCA)

Anti-neutrophil cytoplasmic antibodies (ANCA) are a group of autoantibodies, mainly of the IgG class, directed against the cytoplasm of neutrophil granulocytes and monocytes. They can be detected in special types of primary systemic vasculitis.

There are three primary diseases that are consistently associated with ANCA: Granulomatosis with polyangiitis (GPA, “Wegener’s granulomatosis”), microscopic polyangiitis, and Churg-Strauss syndrome. The autoantibodies are assumed to be involved in the generation and/or progression of lesions and clinical signs. Therefore, theses diseases are also called ANCA-associated autoimmune vasculitides.

Based on the pattern of staining on ethanol-fixed neutrophiles and according to the main target, ANCA are classified into two main classes, cANCA and pANCA. ANCA titres are generally measured using enzyme-linked immunosorbant assay (ELISA) and indirect immunofluorescence assays (IFA).

cANCA, also referred to as cytoplasmic/classical antineutrophil cytoplasmic antibodies, demonstrate a diffusely granular staining pattern in indirect immunofluorescence assays (IFA). The target antigen is most commonly proteinase 3 (PR3). cANCA are associated with granulomatosis with polyangiitis (GPA), fomerly known as “Wegener’s granulomatosis”.

pANCA, also called peri-nuclear/protoplasmic-staining antineutrophil cytoplasmic antibodies, show a perinuclear staining pattern in IFA. Most commonly pANCA target myeloperoxidase (MPO). Classically, pANCA is associated with Churg-Strauss syndrome, microscopic polyangiitis, and focal necrotising and crescentic glomerulonephritis.

As a third distinct ANCA, the so called xANCA may be seen in many disease processes. Most commonly, the xANCA pattern is found in chronic inflammatory bowel disease. Moreover, in recent years ANCA targeted against other autoantigens have been identified (e.g. elastase, cathepsin G, GBM, lysozyme, BPI, just to mention a few).

Patients with a number of other diseases, such as ulcerative colitis and ankylosing spondylitis, will commonly have ANCA as well. However in these cases there is no associated vasculitis, and the ANCA are thought to be incidental or epiphenomena rather than part of the disease itself.

 

ANCA tests offered by ORGENTEC Diagnostika

ELISA/Alegria®:

ANCAcombi (ORG 530)
ANCAscreen (ORG 589, ORG 289)
Anti-BPI (ORG 523, ORG 223)
Anti-Cathepsin G (ORG 525, ORG 225)
Anti-Elastase (ORG 524, ORG 224)
Anti-GBM (ORG 550, ORG 250)
Anti-Lactoferrin (ORG 527, ORG 227)
Anti-Lysozyme (ORG 526, ORG 226)
Anti-MPO (ORG 519, ORG 219)
Anti-PR3 (cANCA) (ORG 518, ORG 218)
Anti-PR3 hs (high sensitive)® (ORG 618, ORG 318)

Immunoblot:

ANCA-3-Line (ORG 789)

 

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