Term
| what is a hypersensitivity reaction? |
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Definition
| State of heightened reactivity to a foreign or self antigen |
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Term
| what is a hypersensitivity disease? |
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Definition
| (Chronic) inflammatory disease that is initiated by a hypersensitivity reaction |
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Term
| which type of hypersensitivity reaction is mediated by T cells? |
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Definition
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Term
| how do you classify a hypersensitivity reaction? |
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Definition
| they are based on the underlying immunological mechanism of the reaction |
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Term
| Hemolytic anemia, blood transfusion reactions, rheumatic fever, graves disease and Myasthenia Gravis are all part of which class of hypersensitivity reactions/diseases? |
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Definition
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Term
| how does hemolytic anemia come about? |
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Definition
| side effect of Penicillin, it changes RBC cell surface and makes the body thinks it foreign. This activates their complement-mediated phagocytosis. |
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Term
| what is the underlying principle of hemolysis in blood transfusion reactions? |
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Definition
| ABO blood group antigens have structural similarities to common bacterial antigens. |
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Term
| what is the underlying principle of hemolysis in blood transfusion reactions? |
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Definition
| ABO blood group antigens have structural similarities to common bacterial antigens. |
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Term
| how does rheumatic fever develop? |
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Definition
| antibodies against streptococcus (from strep throat) can cross react with antibodies in the heart and/or joints, leading to myocarditis or arthritis |
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Term
| in Graves' Disease and Myasthenia gravis, what is the underlying cause of the disease? |
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Definition
| Graves' Disease: the antibodies react against the Thyroid Stimulating Hormone Receptor found on throid cells. Myasthenia Gravis: antibody against Ach receptor at the neuromuscular junction |
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Term
| what are common mechanisms of type II hypersensitivity reactions? |
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Definition
| mediated by antibodies against tissue antigens. (2:14PM slide 13) |
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Term
| Systemic Lupus Erythematosus (SLE) and Serum Sickness are what type of hypersensitivity diseases? |
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Definition
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Term
| how do type III reactions take place? |
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Definition
| immune complexes (soluble antigens + IgG), are deposited in blood vessels and lead to inflammation. Systemic in nature. |
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Term
| why arent immune complexes cleared from the blood vessels? |
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Definition
| they are too small, so do not fix complement and are not cleared from circulation. |
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Term
| what are antibodies attacking in SLE (systemic lupus erythmatosus)? |
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Definition
| DNA. the IgG-antigen deposits itself in vital organs (kidney glomeruli, joints, heart, SKIN) |
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Term
| what happens in serum sickness? |
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Definition
| large amounts of immune complexes and a complement-mediated inflammation ensues. |
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Term
| what are some treatments for Type II and III diseases? |
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Definition
| 1) corticosteroids, 2) Anti-CD20 mAb, and 3) Anti-CD40L mAb. |
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Term
| What do Anti-CD20 mAb and Anti-CD40L mAb do? |
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Definition
| they deplete B cells and inhibition of T cell help, respectively |
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Term
| Type IV hypersensitivity reactions take how long to occur? |
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Definition
| 1-3 days after antigen contact. Known as Delayed-type hypersensitivity (DTH) |
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Term
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Definition
| CD4+ T cells in specific response to antigen. tissue injury then ensues from recruited macrophages and neutrophils |
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Term
| what test is done to determine immunity to M. tuberculosis? |
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Definition
| tuberculin skin test. PPD test. |
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Term
| Contact hypersensitivity normally occurs from which plant? |
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Definition
| poison ivy. Type IV hypersensitivity disease |
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Term
| what happens in Celiac disease? |
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Definition
| CD4+ T cells respond to Gluten-derived antigens. Causes inflammation, then atrophy of intestinal villi, leading to malabsorption and diarrhea. |
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Term
| how does Multiple Sclerosis occur? |
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Definition
| mediated by CD4+ T cells that respond to myelin antigen surrounding peripheral neurons. |
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Term
| what takes place in Type 1 Diabetes? |
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Definition
| CD4 T cells respond to pancreatic antigens and destroy the alpha cells leading to an insulin deficiency. |
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Term
| What are some therapies for T cell-mediated hypersensitivity reactions? |
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Definition
| 1) corticosteroids, 2) Cyclosporine A (inhibits T cell activation), and 3) block inflammatory cytokines to reduce inflammation. |
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Term
| what is characteristic of Type II hypersensitivity reactions? |
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Definition
| IgG and IgM antibodies present |
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Term
| what is characteristic of Type III hypersensitivity reactions? |
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Definition
| Immune Complex deposition |
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Term
| what is characteristic of Type IV hypersensitivity reactions? |
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Definition
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