Systemic vasculitis is a group of diseases in which vascular necrosis and inflammation are the main pathological changes, and all parts of the blood vessels of the body can be involved, including large and small arteries and veins, and the type of vessels involved. Size. Size. Location. The disease course and pathological characteristics vary. Most of the disease has systemic manifestations. Vasculitis can occur singly or as a clinical manifestation of a particular disease. It can be systemic in nature, causing dysfunction of multiple systemic organs, or it can be confined to a single organ. Its prognosis depends on the size of the involved vessels. The number and location. Many physicians have a detailed knowledge of their specialty, but sometimes lack a certain understanding of multisystem disease. When a patient presents with a rash, Raynaud’s phenomenon, arthralgia, urine protein or occult blood, and extremely increased sedimentation, the possibility of vasculitis should be considered. Tests such as ANCA and antinuclear antibodies are recommended. Spectrum of diseases associated with ANCA Disease name Fluorescent model Specific target antigen Wegener’s granulomatosis Microscopic polyangiitis Allergic granulomatous vasculitis Necrotizing crescentic glomerulonephritis (NCGN) Nodular polyarteritis Anti-glomerular basement membrane disease Systemic lupus erythematosus Rheumatoid arthritis Drug-resistant lupus Felty’s syndrome Ulcerative colitis Crohn’s disease Primary sclerosing cholangitis Primary biliary cirrhosis Autoimmune hepatitis (type I) Pulmonary cystic fibrosis Acute/chronic infections (HIV, bacterial, amoebic) c-ANCA, rarely p-ANCA c-ANCA, p-ANCA p-ANCA, rarely c-ANCA p-ANCA, rarely c-ANCA ANCA (low positive rate) p- ANCA p-ANCA p-ANCA,a-ANCA p-ANCA p-ANCA,a-ANCA p-ANCA,a-ANCA p-ANCA,a-ANCA p-ANCA,a-ANCA p-ANCA,a-ANCA p-ANCA,a-ANCA p-ANCA,a-ANCA p-ANCA,a-ANCA p-ANCA,a- ANCA PR3 (85%), MPO (10%) PR3 (45%), MPO (45%) PR3 (10%), MPO (60%) PR3 (25%), MPO (65%) PR3 (5%), MPO (15%) MPO (30%) CG, LF, HLE, MPO (rare) LF, MPO (rare) LF, HLE, CG, MPO (rare) LF, MPO (rare) LF, CG, LYS, other LF, CG, LYS, other LF, CG, other LF, CG, LYS, HLE, other LF, CG, LYS, HLE, other BPI (91%) PR3, MPO, BPI, other