Rheumatoid Arthritis Support

There are three primary diseases that are consistently associated with ANCA: Wegener's granulomatosis, microscopic polyangiitis, and glomerulonephritis. The antibodies are assumed to be involved in the generation and/or progression of lesions and clinical signs.

Classically, c-ANCA is associated with Wegener’s granulomatosis; p-ANCA is associated with microscopic polyangiitis and focal necrotising and crescentic glomerulonephritis. However, in recent years ANCA targeted against other autoantigens have been identified.

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. Churg-Strauss syndrome is associated with p-ANCA directed against MPO.

It is unclear what the role of ANCA may be in these diseases – they may be markers of disease or may play some part in the pathogenic process. It has been shown that in Wegener's granulomatosis there is positive correlation between ANCA titre and disease activity and ''in vitro'' studies have shown that ANCA cause activation of primed neutrophils and react with endothelial cells expressing PR3. ANCA may act by causing release of lytic enzymes from the white blood cells, causing inflammation of the blood vessel wall (vasculitis). ANCA associated vasculitides usually present with features of a small-vessel vasculitis.


Adapted from the Wikipedia article Anti-neutrophil cytoplasmic antibody, under the G. N. U. Free Documentation License. Please also see http://en.wikipedia.org/wiki