Q Hypersensitivity Study online at https://quizlet.com/_7qzu6z 1. What is a characteris- An infiltrate composed of helper T cells and tic of a delayed hyper- macrophages sensitivity reaction? Type IV is driven by T cell immune responses, often CD4 T cells, which promote macrophage activation 2. A child disturbs a Systemic anaphylaxis. wasp's nest, is stung repeatedly, and goes The wasp venom, which contains multiple allergens into shock within (the main one is called antigen 5), cross-links IgE minutes, manifesting on the surface of mast cells and basophils causing as respiratory fail- rapid release of mast cell products including hista- ure and vascular col- mine, prostaglandins and leukotrienes inducing se- lapse. What is the most likely cause of vere rapid inflammation (type I). these symptoms? 3. Which major prob- lem is seen fol- lowing bone mar- row transplantation in immunocompro- mised patients? Potentially lethal graft-versus-host disease One potential issue is that the recipient has residual immune cells that react to the donated immune cells, the second more problematic issue is that immune cells present in the bone marrow of the donor react against the host's own cells (recognised as non-self), causing inflammation and tissue damage (GvHD) 4. A wheal and flare re- Type I. action is typical of sensitivity reaction? which type of hyper- Wheal (a common name for swelling) and flare (a common name for redness) are seen in multiple in- flammatory reactions but prototypic of rapid allergic, type I, inflammation. 5. A 77-year old man The antigen cross-links IgE on the mast cells and with enterococcal en- causes release of histamine docarditis needed to be treated with peni- The individual had a history of severe penicillin re- cillin G but had a his- actions, the most common of which is caused by tory of severe peni- a penicillin-specific IgE, type I, reaction. Thus when 1/15
Q Hypersensitivity Study online at https://quizlet.com/_7qzu6z cillin reactions. He was therefore test- ed using a dermal injection of penicil- loyl-polylysine as a test antigen. What is most likely to occur? injected, the analogue will cause a local release of histamine through the same mechanism. 6. A kidney biopsy tak- Patchy, irregular fluorescence of the glomerular base- en from a patient with acute glomeru- ment membrane. lonephritis is stained Why? As an immune-complex, type III, disease with fluorescein-con- glomerulonephritis results from deposition of free jugated anti-human floating immune complexes in the basement mem- lgG antibody. What is brane of the kidneys, and the generation of local in- in the biopsy? of the cellular make-up of the basement membrane, partly as immune complexes drive local sites of in- flammation, and partly due to availability of antigen. likely to be observed flammation. This process is uneven partly as a result 7. Hypersensitivity to both penicillin and hypersensitivity to poison ivy are initi- ated or mediated by what cells or mole- cules? Initiated by happens. Poison Ivy reactions are the most common form of type IV reaction, driven by Th1 cells and activated macrophages. Meaning they are not