HYPERSENSITIVITY - 3 Type III(immune complex reactions-antigen-antibody complexes are deposited in organs and cause inflammatory damage Complement

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HYPERSENSITIVITY (ALLERGY) 2. Type II (cytotoxic reactions)—these are mediated by IgG or IgM antibodies and complement.  This type of reaction is directed toward cells, which are lysed or damaged in other ways.      a. Blood groups—“wrong” type blood cells given in a transfusion are an example of this type  of reaction.       b. Drug-induced cytotoxic reactions—drug molecules coat a blood cell or a platelet and the  combination becomes antigenic, resulting in destruction of the cell or platelet. Complement  proteins are involved.                                Platelets attacked—thrombocytopenic purpura                               White blood cells attacked—agranuloctosis                                Red blood cells attacked—hemolytic anemia
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Unformatted text preview: 3. Type III (immune complex) reactions---antigen-antibody complexes are deposited in organs and cause inflammatory damage. Complement becomes activated and this plus attraction and release of enzymes from neutrophils results in damage or destruction of the cells in the area. Glomerulonephritis is an example. 4. Type IV (cell-mediated) reactions—also called delayed hypersensitivity reactions. T cells are involved in this type instead of antibodies. T cells become activated, release destructive cytokines, and attract macrophages to the area. Cytotoxic T cells may also appear. This results in damage to cells in the affected area. Contact dermatitis and poison ivy are examples. The skin test for tuberculosis is based on this type of reaction....
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This note was uploaded on 01/23/2012 for the course MCB MCB2010 taught by Professor Smith during the Fall '09 term at Broward College.

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