110 of 126
Our book introduces four syndromes that fall into this category. Before outlining these syndromes, I’ll recap the relevant general information:
Vasculitis: inflammation of the vessel wall
Can result from:
Immune complex deposition
Cell-mediated immune reactions against the vessel wall
Immune complexes activate complement cascade Æ get release of chemoattractants and anaphylatoxins Æ get increased vascular permeability Æ neutrophils come to the vessel wall Æ neutrophils injure the vessel with their lysosomal contents and toxic oxygen-derived free radicals.
2. Cell-mediated immune reactions: T cells bind vascular antigens Æ release lymphokines Æ attract additional lymphocytes and macrophages to the vessel wall.
Giant cell arteritis
Thromboangiitis obliterans (Buerger’s disease)
Arteries Commonly Affected
small to medium size (esp. renal, coronary, hepatic, skel musc)
aorta and its branches
medium to large size (esp. cranial, aortic arch & branches)
small size (esp. distal arteries of extremities)
PMNs, acute fibrinoid necrosis, aneurismal dilatation
Granulomatous arteritis w/ fibrosis; significant luminal narrowing
lymphocytes, intimal fibrosis, granuloma formation
inflammation and thrombosis without necrosis
These inflammatory processes can cause end-organ ischemia because of either vascular necrosis or local thrombosis.
Most Vasculitic Syndromes do not have known causes…they’re distinguished from each other by pattern of vessels involved and histologic characteristics.
Table of Vasculitic Syndromes (modified from p.336):
Now, for outlines of these syndromes…