Immunology: Immune Responses Flashcards
(364 cards)
Which 3 cytokines secreted by macrophages may contribute to the development of fever and sepsis?
Interleukin-1, interleukin-6, tumor necrosis factor-α
What is the definition of an anergic state?
It is an inactive state in which an immune cell cannot become activated when exposed to a specific antigen
How does Epstein-Barr virus invade B cells to cause infectious mononucleosis?
EBV binds to CD21on the surface of B cells (must be 21 to drink Beer in a Barr)
Myasthenia gravis, Graves disease, and pemphigus vulgaris are examples of what type II hypersensitivity mechanism?
Cellular dysfunction, in which the opsonized cells do not function normally but are not completely destroyed
A patient is diagnosed with a hereditary deficiency of the enzyme involved in the regeneration of NADPH from NADP+. Which enzyme is deficient?
Glucose-6-phosphate dehydrogenase (G6PD)
What steps in antibody generation are antigen independent or antigen dependent?
Generation of antibody diversity is antigen independent; generation of antibody specificity is antigen dependent
When a cell is opsonized (coated) by antibodies in a type II hypersensitivity reaction, what are the cell’s 2 potential fates?
Phagocytosis and/or complement system activation or destruction by natural killer cells (antibody-dependent cellular cytotoxicity)
Iron is an essential nutrient for microbes. What protein found in secretory fluids and neutrophils counteracts microbes via iron chelation?
Lactoferrin
What does a live attenuated vaccine contain?
A microorganism that has been modified to lose its pathogenicity (though it retains the capacity for transient growth within the host)
What lab findings are associated with hyper-IgE syndrome (Job syndrome)?
Increased IgE levels and eosinophilia
What is the pathophysiology of leukocyte adhesion deficiency type 1?
Lack of LFA-1 integrin (CD18) on phagocytes → impaired migration and chemotaxis
Type IV hypersensitivity reactions can occur by 2 mechanisms. Describe the inflammatory reaction mechanism
Effector CD4+ T cells detect antigen and release cytokines that induce inflammation
A patient experiences severe graft dysfunction within minutes of kidney transplantation. What is the correct treatment?
Removal of the graft (the appropriate treatment for a patient with hyperacute rejection, which occurs within minutes of transplantation)
The Arthus reaction is what type of hypersensitivity reaction?
Type III
How is the lectin pathway of the complement system activated?
Mannose or other sugars found on microbial surface
Name the 2 autoantibodies associated with pernicious anemia.
Antiparietal cell and anti-intrinsic factor autoantibodies
What is the main drawback associated with toxoid vaccines?
They stimulate the production of antitoxin levels that decrease with time (requiring subsequent boosters)
An hour after blood transfusion, a patient reports fever, dyspnea, flank pain, and jaundice. What is the diagnosis?
Acute hemolytic transfusion reaction (type II hypersensitivity); antibodies to donor RBC surface antigens cause extravascular hemolysis
Describe the mechanism by which type II hypersensitivity causes inflammation.
Binding of antibodies to cell surfaces leads to complement system activation and Fc receptor–mediated inflammation
A patient with IgA deficiency develops wheezing, hypotension, and respiratory arrest after receiving a blood transfusion. What is the most likely cause?
Type I hypersensitivity reaction to IgA in donor blood; patients with IgA deficiency must receive blood products that do not contain IgA
A patient with cancer appears thin with prominent temporal muscle wasting. Which cytokine is known to promote this process?
Tumor necrosis factor-α (promotes cachexia in malignancy)
Mast cells play a major role in immediate, type I hypersensitivity. Which antibody isotype facilitates this phenomenon?
IgE (cross-links when exposed to an allergen and mediates the release of inflammatory mediators)
Which type of cells produce and secrete interferons?
Virally infected cells (interferons interfere with viruses)
What are the 5 major adverse effects shared by interferons when used in pharmacotherapy?
Myopathy, neutropenia, flu-like symptoms, depression, and autoimmune reactions (interferon-induced autoimmunity)