30 Questions
What is the mechanism of cell lysis in Anti-GBM disease?
Complement-mediated lysis
Which autoimmune disease is driven by a Th2 response and involves hyperthyroidism?
Graves' Disease
What is the primary mechanism of RBC lysis in ABO blood group incompatibility?
Complement-mediated lysis
Which antibody-mediated reaction involves IgG binding to cell surface antigens and impairing cell functioning?
Antagonistic antibody-mediated cell dysfunction
What are the initial symptoms of Anti-GBM disease?
Fatigue, weakness, anemia
In Graves' Disease, which antibody binds to the TSHR and leads to hyperthyroidism?
Anti-TSHR IgG
What is the primary treatment for Anti-GBM disease?
Plasmapheresis + immunosuppressants
Which type of hypersensitivity reaction therapy involves daily plasma exchanges for a few weeks?
Plasmapheresis + immunosuppressants
What characterizes the involvement of mast cells in autoimmune diseases?
Histamine release and inflammation
What role do neutrophils and macrophages play in complement activation and frustrated phagocytosis?
Release nucleases and proteases for cell destruction
What is the percentage of the human population that generates a hypersensitivity response to an antigen called an allergen?
20%
Which of the following is NOT a type of antigen that can trigger hypersensitivity reactions?
Autoimmune antigens
Who placed pollen grains in the nose of patients in 1873 to observe rhinitis as part of immediate hypersensitivity experiments?
Charles Blackley
What type of response occurs when pollen extract is injected intradermally into patients with immediate hypersensitivity?
Wheal and flare
Which immunologist purified IgE from the serum of hay fever patients caused by ragweed exposure in 1967?
Kimishige Ishizaka
What is the consequence of mast cells expressing Fcε receptors with increased affinity for IgE in patients with allergies?
Increased mast cell activation
What type of cytokines are associated with Th2 differentiation in genetic predisposition for Type I hypersensitivity reactions?
'Th2' cytokines
Which component's influence leads to dendritic cells producing IL-4 and IL-13 for Th2 differentiation in Type I hypersensitivity reactions?
Basophils
What happens when allergen epitopes bind to MHC class II molecules in Type I hypersensitivity reactions?
Dendritic cells produce IL-4 and IL-13 for Th2 differentiation
In allergic individuals compared to nonallergic individuals, what is a significant difference regarding Fcε receptors on mast cells?
They have higher levels of Fcε receptors on mast cells.
Which cell type is responsible for producing allergen-specific IgE in the sensitization step of the immune response?
GC B cells
What is the primary role of histamine released during mast cell degranulation in allergic reactions?
Triggers nerve bundles to promote itch signal
Which molecule binds to high molecular weight kininogen to promote vasodilation, increased vascular permeability, and recruitment of neutrophils during mast cell degranulation?
Bradykinin
Which pathway is responsible for the synthesis of leukotrienes, which are 1000-fold more potent than histamine in allergic reactions?
LOX pathway
Which secondary mediator is known for recruiting monocytes/macrophages and increasing vascular permeability during allergic reactions?
VEGF
What is the primary mechanism of action of epinephrine in treating systemic anaphylaxis?
Stimulates cAMP production in mast cells
Which mediator acts much more rapidly than antihistamines in treating anaphylaxis?
Epinephrine
In Type II hypersensitivity reactions, what is the outcome when antibodies bind to cell surface receptors and block signaling through them?
"Antagonistic antibodies" are produced
"Frustrated phagocytosis", seen in cytotoxic hypersensitivity, occurs when:
"Tissue cells expressing the antigen" cannot be engulfed by immune cells
In Type I hypersensitivities, what is the primary role of IL-4 producing Th2 cells during sensitization?
Help in differentiation into plasma cells producing allergen-specific IgE
Learn about antigens, genetic predispositions, cytokines, antibody isotypes, and effector mechanisms of type I and II hypersensitivity reactions. Discover diseases associated with these reactions and understand the mechanisms of action of antihistamines, leukotriene modifying agents, and allergy injections.
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