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© Dirk Biddle
The vasculitides may be separated into primary vasculitis conditions and secondary vasculitis conditions. Primary vasculitides have been described as having “no cause” or as arising “out of the blue”, but these terms are misleading. Causal elements and mechanisms have been postulated and found for some primary vasculitides. Primary vasculitides are probably best considered as vasculitis conditions that are diseases in their own right, with no defined preceding or accompanying disease. Secondary vasculitides are vasculitis conditions secondary to, or associated with, an underlying disease process. Secondary vasculitis is also the term employed when the underlying cause is a neoplasia, drug, or other toxin.
Primary vasculitides are inclusive of systemic vasculitides, simply meaning the vasculitis condition may express itself practically anywhere in the body, also of the term idiopathic vasculitis, a vasculitis arising from an unknown cause (as distinct from having “no cause”). Cutaneous vasculitis, another commonly used term, is a vasculitis condition relating to or affecting the skin. This type of vasculitis may manifest in both primary and secondary vasculitides, or as a vasculitis condition in its own right.
Primary vasculitides include: Behcet’s disease, Buerger’s disease, Central Nervous System (CNS) Vasculitis, Churg-Strauss syndrome, Cryoglobulinemia, Cutaneous leukocytoclastic angiitis, Giant cell (Temporal) arteritis, Henoch-Schönlein purpura, Kawasaki disease, Microscopic polyangiitis, Polyarteritis nodosa, Polymyalgia rheumatica, Takayasu’s arteritis, and Wegener’s granulomatosis (this list is considered exhaustive and exclusive).
Secondary vasculitides may include: Chronic venous insufficiency, Drug-induced vasculitis, Rheumatoid vasculitis and Urticarial vasculitis. Or be noted in association with: Cogan's syndrome, Relapsing polychondritis, Scleroderma, Serum sickness, Sjögren's syndrome and Systemic lupus erythematosus (to name just a few of the most commonly recognised).
Other common classificatory terms utilised in reference to both primary and secondary vasculitides include: Necrotising vasculitis, meaning a vasculitis causing the death of living tissues; Granulomatous vasculitis, a vasculitis causing a mass or nodule of chronically inflamed tissue, characterised by a large number of cells of various types (macrophages, lymphocytes, fibroblasts, giant cells, some degrading and some repairing the tissues; Leukocytoclastic vasculitis, a cutaneous acute vasculitis characterised clinically by palpable purpura, especially of the legs, and histologicallyby exudation of the neutrophilsand sometimes fibrinaround dermal venules, with nuclear dustand extravasationof red cells; may be limited to the skin or involve other tissues as in Henoch-Schönlein purpura; Lymphocytic vasculitis, a vasculitis mediated by the cells originating in lymphoidtissues such as the thymusor specific types bone marrow (eg; B-cells, T-cells) and Eosinophilic vasculitis, a vasculitis mediated by leucocytes(white blood cells) that stain brightly purple with eosin dyes (eg;eosinophils, neutrophils ). Fuller definitions of these vasculitis terms can be found later in this article.
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a)Neoplasia1. The process of tumour formation.2. A tumorous condition of the body. (M+)",
b)MacrophagesA phagocytic tissue cell of the mononuclear phagocyte system that may be fixed or freely motile, is derived from a monocyte, and functions in the protection of the body against infection and noxious substances. (M+)",
c)Lymphocytes White cell of the blood that are derived from stem cells of the lymphoid series. Two main classes are recognised, T- and B- lymphocytes, the latter responsible (when activated) for production of antibody, the former subdivided into subsets (helper, suppressor, cytotoxic T-cells) and responsible both for cell-mediated immunity and for stimulating B-cells. (OMD)",
d) Fibroblast Resident cell of connective tissue, mesodermally derived, that secretes fibrillar procollagen, fibronectin and collagenase. (OMD)",
e) Giant CellsA cell of large size, often with many nuclei. They are multinucleated masses produced by the fusion of many cells.They are often associated with viral infections. In AIDS, they are induced when the envelope glycoprotein of HIV binds to the CD4 antigen of uninfected neighboring T4 cells. The resulting syncytium leads to cell death and thus may account for the cytopathic effect of the virus.",
f) CutaneousOf, relating to, or affecting the skin. (M+)",
g) PurpuraA small haemorrhage (up to about 1 cm in diameter) in the skin, mucous membrane or serosal surface, which may be caused by various factors, including blood disorders, vascular abnormalities and trauma. (OMD) Thus palpable purpura - purpura that are able to be 'palpated' or felt. Small haemorrhages are classified according to size as petechiae (very small), purpura (up to 1 cm) and ecchymoses (larger). The massive accumulation of blood within a tissue is called a haematoma.(OMD)",
h) HistologyThe study of cells and tissue on the microscopic level",
i) NeutrophilA granulocyte that is the chief phagocytic white blood cell. ",
j) FibrinThe insoluble protein formed from fibrinogen by the proteolytic action of thrombin during normal clotting of blood. Fibrin forms the essential portion of the blood clot. (OMD)",
k) VenuleAny of the minute veins connecting the capillaries with the larger systemic veins. (M+)",
l) Nuclear DustFragments of cell nucleii. When a cell dies, its nucleus shrivels and becomes composed entirely of heterochromatin. Later the nucleus can break up into fragments ('nuclear dust') or even disappear",
m) ExtravasationA discharge or escape, as of blood, from a vessel into the tissues",
n) Red Blood Cells: Cell specialised for oxygen transport (erythrocyte, having a high concentration of >haemoglobin in the cytoplasm (and little else). Biconcave, anucleate discs, 7nm diameter in mammals, nucleus contracted and chromatin condensed in other vertebrates. (OMD)",
o) Lymphoid: 1 : of, relating to, or being tissue (as the lymph nodes or thymus) containing lymphocytes 2 : of, relating to, or resembling lymph. M+",
p) ThymusThe lymphoid organ in which T lymphocytes are educated, mature and multiply. It is composed of stroma (thymic epithelium) and lymphocytes, almost entirely of the T-cell lineage. In mammals the thymus is just anterior to the heart within the rib cage. The thymus tends to atrophy as the animal matures. OMD",
q) B-CellsA type of lymphocyte normally involved in the production of antibodies to combat infection. It is a precursor to a plasma cell. During infections, individual B-cell clones multiply and are transformed into plasma cells, which produce large amounts of antibodies against a particular antigen on a foreign microbe. This transformation occurs through interaction with the appropriate CD4 T helper cells. (OMD)",
r) T-CellsAny of several lymphocytes (as in helper T-cell) that differentiate in the thymus, possess highly specific cell-surface antigen receptors, and include some that control the initiation or suppression of cell-mediated and humoral immunity (such as by the regulation of T- and B-cell maturation and proliferation) and others that lyse antigen-bearing cells - called also T-lymphocyte. (M+)",
s) LeucocyteWhite Blood Cell(WBC) a cell which circulates in the blood and lymphatic system and harbours in the lymph glands and spleen. They are part of the immune system responsible for both directly (T-cells and macrophages) and indirectly B-cells producing antibodies) attacking foreign invaders of the body. They are colourless, lack haemoglobin, contain a nucleus, and include the lymphocytes, monocytes, neutrophils, eosinophils, and basophils. (OMD) ",
t) EosinophilA white blood cell or other granulocyte with cytoplasmic inclusions readily stained by eosin. (M+)",
u) NeutrophilA granulocyte that is the chief phagocytic white blood cell
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