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15 Cards in this Set
- Front
- Back
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criteria for an antigen to become immunogenic
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foreignness to the host
adequate size adequate chemical complexity being present in sufficient quantity |
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IgG
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most abundant class of immunoglobulins
accounting for most of the protective activity against infections smallest selective transport allows IgG to cross the placenta (think gravid) |
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IgM
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largest of the immunoglobulins
1st responder during the initial or primary exposure to antigen found in the serum 7-10 days post exposure characteristic J chain |
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IgA
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found in blood and secretions (like breast milk)
dominant immunoglobulin of the secretory system characteristic J chain |
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IgE
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normally in low concentrations in the circulation
mediator for allergic responses defends against parasitic infections |
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IgD
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found in low concentrations in the blood
primary function is antigen receptor on the surface of early B cells |
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How age affects the immune system
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immune function decreases with age
T cell function drops although numbers remain the same delayed hypersensitivity decreases T cell mediated responses to infection decreased T cell activity circulation autoantibodies and immune complexes increase making them more susceptible to autoimmune diseases |
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Type I hypersensitivity reaction
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mediated by IgE and the products of tissue mast cells
Allergic reactions & anaphylaxis Histamine is most potent mediator @ H1 receptors - contracts bronchial smooth muscles, causing bronchial constriction; increases vascular permeability, causing edema; causes vasodilation, increasing blood flow to the area @H2 receptors - increased gastric secretions & a decrease of histamine released from mast cells and basophils Immediate onset ex. seasonal allergic rhinitis |
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5 mechanisms of Type II hypersensitivity reaction
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1. cell destroyed by antibody and complement ex. autoimmune hemolytic anemia
2. antibody causes cell destruction via phagocytosis by macrophages ex. antibodies against platelet-specific antigens cause their removal by phagocytosis in the spleen 3. toxic products produced by neutrophils 4. antibody-dependent cell-mediated cytotoxicity (ADCC) - involves NK cells. The antibody on the target cell is recognized by the NK cell, which releases toxic substances that destroy the cell that has the antigen 5. Does not destroy the cell, but causes it to malfunction. ex. Graves Disease: autoantibody binds to and activates thyroid-stimulating hormone (TSH) receptors which make the thyroid produce more T4 overriding the normal feedback loop telling the thyroid to cease T4 production. |
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Type II hypersensitivity reaction
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has 5 mechanisms
involves IgG & IgM immediate onset ex. autoimmune thrombocytopenic purpura, Graves disease, autoimmune hemolytic anemia, graft rejections, transfusion reactions, myasthenia gravis |
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Type III hypersensitivity reaction
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Type III: immune complex mediated
caused by antigen-antibody complexes that are formed in the circulation and deposited in vessel walls or extravascular tissues not tissue specific harmful effects are caused by complement activation immediate onset ex. systemic lupus erythematosus, serum sickness, Raynaud phenomenon, glomerulonephritis, rheumatic heart disease |
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Type IV hypersensitivity reaction
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cell mediated delayed hypersensitivity
Does not involve antibody mediated by T-cells delayed onset ex. contact sensitivity to poison ivy & metals, TB skin test, graft rejections |
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Atopy
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a genetic predisposition toward the development of immediate hypersensitivity reactions against common environmental antigens (atopic allergy), most commonly manifested as allergic rhinitis but also as bronchial asthma, atopic dermatitis, or food allergy.
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Systemic lupus erythmatosus
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involves both type II & type III hypersensitivity
occurs more often in women, particularly Black women genetic predisposition no cure, treatment is palliative |
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Clinical manifestations of Lupus
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MD-SOAP-N-HAIR
1 Malar rash (facial rash confined to the cheeks) 2 Discoid rash (raised patches, scaling) 3 Serositis (pleurisy, pericarditis) 4 Oral ulcers 5 ANA + (presence of antinuclear antibody) 6 Photosensitivity 7 Neurologic disorders (seizures or psychosis) 8 Hematologic disorders (hemolytic anemia, leukocytopenia, lymphopenia, or thrombocytopenia) 9 Arthritis (nonerosive, of at least 2 peripheral joints) 10 Immune Disorders 11 Renal disorders |
