Term
| Hypersensitivity type IV can be mediated via which immune reactants? |
|
Definition
| TH1 (macrophage activation), TH2 (eosinophil activation) and CTL cells (cytotoxicity) |
|
|
Term
| What are the enzyme contents of mast cells? |
|
Definition
| tryptase, chymase, cathespsin G, carboxypeptidase |
|
|
Term
| What are the "toxic mediators" of mast cells? |
|
Definition
| histamine and heparin (toxic to parasites) |
|
|
Term
| What are the cytokines found in mast cells and their functions? |
|
Definition
| TNF alpha (inflammation, cytokine production, activates endothelium), IL-4 and IL-13 (for TH2 cells), and IL-3, IL-5, and GM-CSF (promotes eosinophil production and activation) |
|
|
Term
| What chemokines are in mast cells? |
|
Definition
| CCL3 (chemotactic for monocytes, macrophages, and neutrophils) |
|
|
Term
| What lipid mediators are in mast cells? |
|
Definition
| leukotrienes C4, D4, and E4 (smooth muscle contraction, increase vascular permeability and mucus secretion) and platelet-activating factor (chemotactic for leukocytes, amplifies production of lipid mediators, activates neutrophils, eosinophils and platelets |
|
|
Term
| What is the effect of mast cell degranulation on the airways? GI tract? |
|
Definition
| decreased diameter and increaed mucus secretion; expulsion of GI tract contents |
|
|
Term
| What are the features of inhaled allergens that may promote the priming of TH2 cells that drive IgE responses? |
|
Definition
| proteins, proteases, low doses, low molecular weight, high solubility, high stability, contains peptides that bind to host MHC class II |
|
|
Term
| Mast cell degranulation causes the recruitment of ______ from blood to enter nasal passages with mucus. |
|
Definition
|
|
Term
| Allergic (acute) asthma is what type of hypersensitivity reaction? |
|
Definition
|
|
Term
| How is acute asthma attack different from allergic rhinitis? |
|
Definition
| acute asthma attack is more extensive and the inflamation never fully resolves |
|
|
Term
| Hives are due to what type of hypersensitivity? |
|
Definition
|
|
Term
| What is the medical term for hives and what is the mechanism behind them? |
|
Definition
| urticaria are due to the release of histmine that causes raised pruitic swellings |
|
|
Term
|
Definition
| more diffuse swelling in deeper tissue |
|
|
Term
| What is atopic dermatitis? |
|
Definition
| prolonged allergic response with similarities to respiratory allergic responses, frequently seen in families with history of asthma and allergic rhinitis, etiology unkown unlike asthma and rhinitis and can outgrow |
|
|
Term
| What type of hypersensitivity reaction is systemic anaphylaxis? |
|
Definition
|
|
Term
| How does Type I hypersensitivty take care of the "problem"? |
|
Definition
| physical expulsion of parasites from respiratory and GI tracts. Also, eosinophils become activated by cytokines and release enzymes and proteins toxic to parasites and host cells as well |
|
|
Term
| Which cell has more protective effects and less host damage, TH1 or TH2? |
|
Definition
|
|
Term
| Which T helper cell produces IL13 and what is it's function? |
|
Definition
TH2
induces epithelial cell repair and mucus |
|
|
Term
| TH2 recruits and activates eosinophils via... |
|
Definition
|
|
Term
| TH2 drives mast cell recruitment via... |
|
Definition
|
|
Term
| TH1 cells activate B cells via ______ to produce _______. |
|
Definition
INFgamma
IgG2a (complement fixing antibody that causes host damage) |
|
|
Term
| What is atopy? What causes it? |
|
Definition
| predisposition to make IgE to allergens from 50% genetics and 50% environment |
|
|
Term
| Genes for what molecules may contribute to atopy? |
|
Definition
| MHC class II, T cell receptor alph alocus, TIM gene family, IL-4, IL-4 receptor alpha chain, high-affinity IgE receptor beta chain, 5 lipoxygenase, beta 2 adrenergic receptor and ADAM 33 |
|
|
Term
| What is the hygiene hypothesis? |
|
Definition
| theory that attributes autoimmune diseases and allergies to widespread practice of hygiene, vaccination and antibiotic therapy |
|
|
Term
| Trichuris suis eggs can be used to treat.. |
|
Definition
|
|
Term
| How are trichuris suis ova manufactured? |
|
Definition
| you inoculate SPF pigs with TSO, harvest adults worms from pig uts, ultivate worms until egg release, harvest eggs and steralize them. Determine egg embryonation coefficient and adjust dose then label, package and distribute |
|
|
Term
| How can you be eventually desensitized to an allergen? |
|
Definition
| a graded dose of antigen causes switch from IgE to IgG4 which complexes with antigen but doesn't recruit effectors |
|
|
Term
| Type I hypersensitivity reaction requires a _______ antigen. |
|
Definition
|
|
Term
| The antigen in type II hypersentivity reaction must be either... |
|
Definition
| cell or matrix associated antigen OR a cell-surface receptor |
|
|
Term
| What type of hypersensitivity reaction is a penicillin allergy? |
|
Definition
| type II OR type III (serum sickness can be caused by an IgG response to penicillin bound to erythrocytes) |
|
|
Term
| How does penicillin cause an allergic reaction? |
|
Definition
| penicillin modifies proteins on human erythrocytes to create foreign epitopes. The RBC is coated with C3b. Macrophage eats RBCs and then presents peptides from penicillin protein conjugates and activates specific CD4 T cells to become TH2 cells. B cells are activated by penicillin antigen on RBCs and then are stimulated to make IgG against penicillin |
|
|
Term
| Transfusion reactions are due to what type of hypersensitivity? |
|
Definition
| type II hypersensitivity reactions |
|
|
Term
| How does the Ig:antigen ration change over the course of an infection? |
|
Definition
| at first there are few Ig creating small immune complexes that don't fix complement and are not cleared from the blood. Then Ig=antigen and large immune complexes are formed and cleared. Lastly there is too much Ig and too little antigen forming medium sized immune complexes that fix complement and are cleared from circulation. |
|
|
Term
| Examples of type III hypersensitivity are... |
|
Definition
| arthus reaction and serum sickness |
|
|
Term
| What's another name for atopic dermatitis? |
|
Definition
|
|
Term
| How does helminth infection help prevent allergies? |
|
Definition
| triggers production of nonspecific IgE that competes with antigen-specific IgE for a spot on mast cells, basophils and activated eosinophils. Also, T cell responses are generally suppressed in chronic parasitic infections |
|
|
Term
| What type of hypersensitivity reaction is caused by antibodies specific for altered components of human cells? |
|
Definition
|
|
Term
| Which hypersensitivity reactions are caused by immune complexes formed from IgG and soluble antigens? |
|
Definition
|
|
Term
| How do immune complexes cause type III hypersensitivity reactions? |
|
Definition
| small immune complexes are less efficient at fixing complement and deposit in blood vessel walls. As they accumulate they fix complements and intiate tissue damaging inflammatory reactions through their interactions with the Fc receptors and complement receptors on circulating leukocytes and mast cells. They also produce C3a and C5a through complement activation. |
|
|
Term
| What are the manifestations of type III hypersensitivity reactions and what causes those manifestations? |
|
Definition
| C3a causes mast cells to release histamine, causing urticaria and C5a recruits inflamatory cells into the tissue. Platelets accumulate around the site of immune-complex deposition and the clots that they form cause the blood vessels to burst, producing hemorrhage in the skin |
|
|
Term
| A type III hypersensitivity reaction can be induced by injecting antigen subcutaneously in people who... |
|
Definition
| have made igG against a soluble protein |
|
|
Term
| What is an arthus reaction? |
|
Definition
| when you inject antigen subcutaneously and waiting for signs of erythema and induration which are evidence that antibodies are made against that antigen |
|
|
Term
| Serum sickness is caused by what type of hypersensitivity? |
|
Definition
|
|
Term
| Intravenous high doses of antigen cause serum sickness which manifests as... |
|
Definition
| vasculitits, nephritis and arthritis |
|
|
Term
|
Definition
| a type III hypersensitivity reaction in which inhaled antigens such as hay dust and mold spores cause formation and deposition of mass amounts of immune complexes in the lung causing inflammatory response and dyspnea |
|
|
Term
| Contact dermatitis, tuberculin reaction, chronic asthma, and chronic allergic rhinitis are all examples of what type of hypersensitivity reaction? |
|
Definition
|
|
Term
| Delayed type ypersensitvity reaction are aka |
|
Definition
| type IV hypersensitivity response |
|
|
Term
| Why does type IV hypersensitivty reaction need so much more antigen to elicit a respones? |
|
Definition
| because it uses T cells instead of antibodies as mediators |
|
|
Term
| T/F The tuberculin skin test is a type of arthus reaction. |
|
Definition
| false, tuberculin skin test is type IV and arthus reaction is type III |
|
|
Term
| What type of hypersensitivity reaction does poison ivy cause? |
|
Definition
| type IV (pentadecacatechol covalently binds to extracellular and intracellular proteins) |
|
|
Term
| Why type of hypersensitivity is celiac's disease? What is the antigen? |
|
Definition
| type IV; gliadin (gluten) |
|
|
Term
| What processing must occur to gluten fragments before CD4 naive T cells will respond to the presented fragment? |
|
Definition
| transglutaminase deaminates gluten fragments |
|
|
Term
| What HLA is associated with celiacs? |
|
Definition
|
|
Term
|
Definition
| stevens-johnsons syndrome which is a bad reaction to a drug. FIrst two weeks present as fevers, aches and a cough then sloughing off of epidermis from dermis forming severe blisters |
|
|
Term
|
Definition
| toxic epidermal necrolysis. Same thing as SJS only more than 30% of the skin is affected |
|
|
Term
| What is the leading cause of SJS and TEN/ |
|
Definition
| carbamazepine (also, allopurinol and abacavir) |
|
|
