Allergy, hypersensitivity Flashcards

Question

TNF-α

Answer 1

may contribute to shock in systemic anaphylaxis

Answer 2

acts as a chemotactic factor, attracting other cells

Answer 3

stimulates production and activation of myeloid cells, e.g., granulocytes

Answer 4

systemic or localized

Answer 5

Often initiated by an injected or gut-absorbed allergen, e.g., bee sting venom, penicillin, seafood, nuts * Severe symptoms

Answer 6

Pathology is limited to a specific tissue or organ * Includes allergic rhinitis (hay fever), allergic conjunctivitis, asthma, atopic dermatitis (eczema), atopic urticaria (hives), and food allergies * Symptoms result from release of mediators in immediate exposure area

Answer 7

a chronic lung disease affecting people of all ages. It is caused by inflammation and muscle tightening around the airways, which makes it harder to breathe. Symptoms can include coughing, wheezing, shortness of breath and chest tightness. These symptoms can be mild or severe and can come and go over time.

Answer 8

Skin barrier disruption might cause development of high IgE Results in food allergies and secondary infections

Answer 9

Food allergy initial sensitization takes place through the skin * Infants with eczema and children deficient in filaggrin support the hypothesis – Skin epithelial cells produce innate cytokines that affect DCs and induce allergen- specific TH2 cells, which trigger B-cell isotype switch to IgE – Circulating IgE Ab carried in blood to intestinal tissue – Intestinal epithelial, ILC2, TH2, and TH9 cells are activated by binding IgE to produce cytokines that recruit, support, activate mast cells and basophils – Mediators released that cause symptoms of food allergies

Answer 10

Repeated low-dose exposures may induce a TREG cell increase and their cytokines * May also induce TH1 and TREG cells where TH1 cytokines induce competitive IgG subtypes switching from IgE to IgG4 * TREG cytokines downregulate TH2 response inhibiting recruitment of basophils and eosinophils * Oral immunotherapy consists of feeding children increasing amounts of the food allergen(s) * Anti-IgE antibodies that bind and inhibit the allergen-specific IgE from binding to mast cell FcεR molecules

Answer 11

refers to an antibody-mediated immune reaction in which antibodies (IgG or IgM) are directed against cellular or extracellular matrix antigens, resulting in cellular destruction, functional loss, or damage to tissues. Damage can occur through multiple mechanisms.

Answer 12

nvolve Ab-mediated destruction of cells by non-IgE Ab * Blood group Ag are carbohydrates – Adults possess antibodies to the blood type they do NOT have – If they receive a transfusion of the “wrong” type of blood, their antibodies will quickly attach to the donor blood cells and trigger complement proteins » The degraded RBC components can build to toxic levels

Answer 13

is a blood disorder that occurs when the blood types of a mother and baby are incompatible. HDN is relatively uncommon in the United States due to advances in early detection and treatment, limiting it to approximately 4,000 cases a year.

Answer 14

an abnormal immune response is mediated by the formation of antigen-antibody aggregates called "immune complexes."[1] They can precipitate in various tissues such as skin, joints, vessels, or glomeruli and trigger the classical complement pathway.

Answer 15

If immune complexes aren’t cleared effectively, they may deposit in tissues * May trigger release of inflammatory mediators and vasoactive mediators – Proteases released may damage connective tissues – Clots may form as complexes activate platelets * Symptoms include fever, rashes, joint pain, lymph node enlargement, and proteinuria – Vasculitis if in blood vessel – Glomerulonephritis if in kidney – Arthritis if in joints

Answer 16

An autoantigen is usually a normal protein or complex of proteins (and sometimes DNA or RNA) that is recognized by the immune system of patients suffering from a specific autoimmune disease.

Answer 17

an acute, localized inflammatory response that typically occurs after vaccination. It is classified as a type III hypersensitivity reaction, which is when antigen-antibody clusters, also known as immune complexes, are formed due to an abnormal immune system response.

Answer 18

Hypersensitivity pneumonitis is an immune system disorder in which your lungs become inflamed as an allergic reaction to inhaled microorganisms, plant and animal proteins or chemicals.

Answer 19

Cell-mediated response Purely cell mediated rather than Ab mediated Initiated by T cells Requires a delay for the reaction to develop Characterized by recruitment of macrophages at inflammation site

Answer 20

The Type IV hypersensitivity (also called delayed-type hypersensitivity, DTH) involves T cell–antigen interactions that cause activation and cytokine secretion (Figure 8.4). This type of hypersensitivity requires sensitized lymphocytes that respond 24–48 h after exposure to soluble antigen.

Answer 21

Initial exposure triggers production of a T-cell response * Often of the CD4+ TH1 subset * Takes 1–2 weeks of time

Answer 22

Second exposure induces production of TH1 inflammatory cytokines * These recruit and help activate macrophages – A prolonged activation of macrophages leads to granuloma formation

Answer 23

A prolonged inability to clear Ag can result in formation of destructive multinucleate giant cell and granulomas

Answer 24

– Sensitization can occur if a reactive chemical compound binds to skin proteins * Modified proteins are then presented to T cells * Could be induced by cosmetics, pharmaceuticals, industrial chemicals, metal ions, poison ivy, poison oak – Can cause strong cell-mediated responses against skin cells, inducing blisterlike lesions and rashes

Answer 25

* Food protein α-gliadin – Wheatgluten – Oat gluten – Barley gluten * Infiltration lamina propria * CD4 T-cells, plasma cells, macrophages

Allergy, hypersensitivity Flashcards

(49 cards)