HYPERSENSITIVITY RXN Micro LE2 Flashcards
Which type of hypersensitivity involves IgE antibodies reacting to allergens?
a) Type I
b) Type II
c) Type III
d) Type IV
a) Type I
Rationale: Type I hypersensitivity, also known as immediate/anaphylactic hypersensitivity, involves IgE antibodies reacting to allergens, binding to mast cells and eosinophils via the Fc receptor.
Which cell undergoes degranulation upon subsequent exposure to the allergen in Type I hypersensitivity?
a) T-cells
b) Neutrophils
c) Mast cells
d) B-cells
c) Mast cells
Rationale: In Type I hypersensitivity, upon subsequent exposure to the allergen, fixed IgE becomes cross-linked, causing mast cells to undergo degranulation.
Histamine primarily contributes to which effect during an allergic reaction?
a) Platelet aggregation
b) Vasodilation
c) Antibody production
d) Phagocytosis
b) Vasodilation
Rationale: Histamine is the primary mediator for Type 1 reactions and causes vasodilation, increased capillary permeability, and smooth muscle contraction.
Which drug can be used to counteract the effects of histamine during an allergic reaction?
a) Ibuprofen
b) Epinephrine
c) Antihistamine
d) Insulin
c) Antihistamine
Rationale: Antihistamine drugs can block histamine receptor sites, thereby counteracting the effects of histamine during an allergic reaction.
Which substance promotes platelet aggregation during Type I hypersensitivity reactions?
a) Histamine
b) Prostaglandin
c) Thromboxane
d) Epinephrine
c) Thromboxane
Rationale: Thromboxanes, during Type I hypersensitivity reactions, promote platelet aggregation.
Which type of hypersensitivity is most prevalent?
a) Type I
b) Type II
c) Type III
d) Type IV
a) Type I
Rationale: Type I hypersensitivity is mentioned as the most prevalent type of allergy.
What is the main goal of treatment for Type I hypersensitivity reactions?
a) Stimulate immune response
b) Increase antibody production
c) Counteract the mediators’ effects
d) Promote mast cell degranulation
c) Counteract the mediators’ effects
Rationale: The main goal of treatment for Type I hypersensitivity reactions is to counteract the effects of mediators like histamine.
Which is NOT a treatment for Type I hypersensitivity reactions?
a) Epinephrine
b) Antihistamines
c) Corticosteroids
d) Vitamin C
d) Vitamin C
Rationale: The treatments for Type I hypersensitivity reactions include epinephrine, antihistamines, and corticosteroids. Vitamin C is not mentioned as a treatment.
What is the genetic predisposition towards certain allergic reactions called?
a) Hypoactivity
b) Atrophy
c) Atopy
d) Anaphylaxis
c) Atopy
Rationale: Atopy refers to the strong genetic predisposition towards certain allergic reactions.
Which allergic reaction is characterized by high IgE levels?
a) Atopy
b) Anaphylaxis
c) Eczema
d) Urticaria
a) Atopy
Rationale: Atopy is associated with elevated IgE levels and a genetic predisposition towards certain allergies.
Which is a symptom of atopy?
a) Bronchospasm
b) Hay fever
c) Thrombocytopenia
d) Anemia
b) Hay fever
Rationale: Hay fever is one of the symptoms of atopy, along with other allergic reactions like asthma, eczema, and urticaria.
Which pathway does prostaglandin originate from?
a) Arachidonic acid via the lipoxygenase pathway
b) Arachidonic acid via the cyclooxygenase pathway
c) Glycolysis
d) Krebs cycle
b) Arachidonic acid via the cyclooxygenase pathway
Rationale: Prostaglandin is derived from arachidonic acid via the cyclooxygenase pathway.
How are most allergens in Type I hypersensitivity identified?
a) Blood tests
b) MRI scans
c) Skin tests
d) Urine tests
c) Skin tests
Rationale: Allergens causing Type I hypersensitivity reactions are often identified using skin tests, such as injection, patch, or scratch tests.
Which cell contains histamine in a preformed state?
a) Neutrophils
b) Lymphocytes
c) Platelets
d) Monocytes
c) Platelets
Rationale: Histamine exists in a preformed state in platelets as well as in the granules of mast cells and eosinophils.
Which secondary mediator is involved in Type I hypersensitivity reactions?
a) Hemoglobin
b) Insulin
c) IL-4
d) Progesterone
c) IL-4
Rationale: Alongside cytokines like TNF-a, IL-4 acts as a secondary mediator in Type I hypersensitivity reactions.
Which type of hypersensitivity involves cell surface antigens reacting with antibodies?
a) Type I
b) Type II
c) Type III
d) Type IV
b) Type II
Rationale: Type II hypersensitivity, also known as antibody-mediated hypersensitivity, involves cell surface antigens reacting with antibodies.
Which antibody is primarily involved in binding to cell surface antigens in Type II hypersensitivity?
a) IgA
b) IgE
c) IgG
d) IgM
c) IgG
Rationale: In Type II hypersensitivity, IgG antibodies play a significant role by binding to cell surface antigens.
What can the interaction of antibodies with cell surface antigens in Type II hypersensitivity activate?
a) Phagocytosis
b) Complement system
c) Natural killer cells
d) B-cell proliferation
b) Complement system
Rationale: In Type II hypersensitivity, the interaction of antibodies with cell surface antigens can activate the complement system, potentially leading to complement-mediated lysis.
Which drug, when bound to red blood cell surfaces, can trigger antibody formation leading to hemolysis?
a) Aspirin
b) Ibuprofen
c) Penicillin
d) Metformin
c) Penicillin
Rationale: Penicillin can bind to proteins on red blood cell surfaces, triggering the formation of antibodies that can lead to hemolysis.
Which pathogen induces antibodies that cross-react with red cell antigens, causing hemolytic anemia?
a) Escherichia coli
b) Staphylococcus aureus
c) Mycoplasma pneumoniae
d) Salmonella typhi
c) Mycoplasma pneumoniae
Rationale: Mycoplasma pneumoniae can induce antibodies that cross-react with red cell antigens, resulting in hemolytic anemia.
In Rheumatic Fever, antibodies against which bacteria cross-react with cardiac tissue?
a) Group A streptococci
b) Group B streptococci
c) Group C streptococci
d) Group D streptococci
a) Group A streptococci
Rationale: In Rheumatic Fever, antibodies generated against group A streptococci cross-react with cardiac tissue, potentially causing damage.
In which syndrome are antibodies formed against the basement membranes of the kidney and lung?
a) Sjögren’s Syndrome
b) Goodpasture’s Syndrome
c) Guillain-Barré Syndrome
d) Turner Syndrome
b) Goodpasture’s Syndrome
Rationale: In Goodpasture’s Syndrome, antibodies target the basement membranes of both the kidney and lung, potentially causing severe damage.
In Graves’ Disease, an autoantibody binds to which receptor leading to hyperthyroidism?
a) Insulin receptor
b) Adrenaline receptor
c) Thyroid-stimulating hormone (TSH) receptor
d) Growth hormone receptor
c) Thyroid-stimulating hormone (TSH) receptor
Rationale: In Graves’ Disease, an autoantibody binds to the TSH receptor, which results in the stimulation of the thyroid and consequently, hyperthyroidism.
What is the primary result of complement-mediated lysis in Type II hypersensitivity?
a) Vasodilation
b) Antibody formation
c) Cell death
d) Inflammation
c) Cell death
Rationale: Complement-mediated lysis, which can occur in Type II hypersensitivity, leads to the destruction or death of cells.