Immunopathogenesis of Vasculitides in cellular & subcellular aspect
17 till 20 April 2014، Tehran - Iran
Presentation Type: Speech
Vasculitis is a term for a group of almost rare Inflammatory diseases of the blood vessels which finally causes changes in the walls of arteries, capillaries and veins, including thickening, weakening, narrowing and scarring. Although the etiology and pathogenesis of vasculitides remains somehow obscure and may vary between different forms of the disease, however it is thought to be an autoimmune disease in which the lymphocytes react against self antigens on, in, near to or far from the sites of inflammation of vessels. Most vasculitides are attributed to humoral or cellular immune-mediated injuries induced by any of several mechanisms of major hypersensitivity reactions, including direct autoantibody binding, either to vessel wall structures (eg endothelium or basement membrane antigens) or to neutrophil components when vasculitis is associated with ANCA; immune-complex deposition over or in the vicinity of vasculatures; and T-cell-mediated reaction via DTH. Genetic factors that influence the responsiveness of T cells, antigen-presenting cells (APCs) and other effector cells of the immune apparatus appear to be important in this set of diseases, as are involved in other autoimmune disorders. Adhesion molecules and pro- and anti-inflammatory cytokines in form of both quantitative and qualitative abnormalities have been reported to mediate the pathologic immune responses. The real trigger of these immune reactions, besides the genetic factors, are yet unknown. Some cases of vasculitis are caused by reactions to drugs. Also, some chronic infections (eg by HCV or HBV) can cause vasculitis. Vasculitis can be a part of other rheumatic diseases like systemic lupus erythematosus, rheumatoid arthritis and Sjögren’s syndrome. Vasculitis can result in poor blood flow to tissues throughout the body, such as the lungs, nerves and skin, etc. Thus, vasculitis has a wide range of signs and symptoms according to the organ(s) in - volved and attacked by the immune system. Hence, vasculitis can be mild or disabling, or even lead to death. For example, vasculitis of the kidneys may produce no symptoms at first but is still a serious problem and can only be detected through intensive laboratory tests. Vasculitis affects persons of both sexes and all ages. A few forms of vasculitis affect certain groups of people. For instance, Kawasaki disease occurs only in children. IgA Vasculitis (Henoch-Schönlein) is much more common in children than adults. Since the disease is resulted from the evasion and malfunction of the immune system, the usual remedy is the suppression of the adaptive system commonly by use of corticosteroids or other immunosuppressive (mainly made from monoclonal antibodies) or immunomodulatory (eg Intra Venous Immmune Globuline) drugs. All these modalities show this immune vascular disease is principally treated by re-regulation of the immune disturbances.