(D) Bacterial vasculitis # ANTI-NEUTROPHIL CYTOPLASMIC ANTIBODIES (ANCA) are antibodies directed against certain proteins in cytoplasm of neutrophils. It is of two types:(i) Cytoplasmic (c) ANCA: Refers antibodies against proteinase-3 in azurophilic granules. It is found in - weger's granulomatosis(ii) Perinuclear (p) ANCA: Refers antibodies against myeloperoxidase (major target), elastase, cathepsin G, Lactoferin, Lysozyme.# ANCA is found in: PAN, Microscopic polyangitis, Churg-Strauss syndrome, Crescentic GN, Good-pasture's syndrome Non vascular causes like rheumatic and non-rheumatic autoimmune diseases, IBD, drugs, endocarditis, bacterial infections in patient of cystic fibrosis, primary sclerosing cholangitis etc.> 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 arid focal necrotizing 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.