Hypersensitivity Reactions

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What is the significance of a pre-sensitized state of the host in hypersensitivity reactions?

It is a characteristic of type IV hypersensitivity reactions only.

It is a necessary condition for a hypersensitivity reaction to occur. (correct)

It is a necessary condition for a normal immune response.

It is a characteristic of type I hypersensitivity reactions only.

What is the time frame for the onset of a type I hypersensitivity reaction?

Within 1-2 weeks of exposure to the antigen.

Within 1-2 hours of exposure to the antigen.

Within 10-12 days of exposure to the antigen.

Within 15-30 minutes of exposure to the antigen. (correct)

What is the primary cellular component involved in type I hypersensitivity reactions?

B-cells

Mast cells or basophils (correct)

Neutrophils

T-cells

What is the name of the type of hypersensitivity reaction that involves skin, eyes, nasopharynx, bronchopulmonary tissues, and gastrointestinal tract?

Type I hypersensitivity Signup and view all the answers

What type of immunoglobulin is involved in mediating type I hypersensitivity reactions?

IgE Signup and view all the answers

What is the range of symptoms that can occur in a type I hypersensitivity reaction?

A range of symptoms from minor inconvenience to death Signup and view all the answers

What is the characteristic of hypersensitivity reactions?

They are excessive and undesirable reactions Signup and view all the answers

What type of cells are mainly found in a biopsy of the reaction site?

Mast cells and eosinophils Signup and view all the answers

What is the primary function of IgE in type-I hypersensitivity reactions?

Binding to mast cells and basophils Signup and view all the answers

Which of the following is NOT a common allergen?

Viral particles Signup and view all the answers

What is the preferred mechanism of therapeutic intervention for type-I hypersensitivity reactions?

Avoidance of the responsible allergen Signup and view all the answers

Which cytokines are produced by TH cells in individuals prone to type-I hypersensitivity?

IL-4, IL-5, and IL-13 Signup and view all the answers

What is the primary purpose of skin tests in diagnosing type-I hypersensitivity reactions?

To determine the individual's susceptibility to the allergen Signup and view all the answers

Which of the following cells secrete IL-4, IL-5, and IL-13 in individuals prone to type-I hypersensitivity?

TH cells Signup and view all the answers

What is the primary goal of hypo sensitization in treating allergies?

To stimulate the production of IgG blocking antibodies Signup and view all the answers

What type of hypersensitivity reaction is primarily mediated by IgM or IgG antibodies and complement?

Type II hypersensitivity Signup and view all the answers

What is the role of phagocytes and NK cells in Type II hypersensitivity?

They play a secondary role in the reaction Signup and view all the answers

What is the mechanism of action of anti-histamines in treating allergic symptoms?

They block histamine receptors Signup and view all the answers

What type of medications are used to provide short-term relief from bronchoconstriction in allergic reactions?

Bronchodilators Signup and view all the answers

What is the time frame of Type II hypersensitivity reactions?

Minutes to hours Signup and view all the answers

What type of antigens are typically involved in Type II hypersensitivity reactions?

Both endogenous and exogenous proteins Signup and view all the answers

What is the result of the combination of IgG or IgM with Ag on cell surface or tissue?

Lysis or inactivation of the target cell Signup and view all the answers

Which of the following is NOT a mechanism of destroying target cells?

Apoptosis Signup and view all the answers

What is the cause of Hemolytic Disease of the Newborn?

Maternal IgG Ab's crossing the placenta Signup and view all the answers

What is the result of mismatched blood types in blood transfusions?

Complement-mediated lysis Signup and view all the answers

Which autoimmune disease is characterized by Ab's produced vs thyroid hormone receptor?

Grave's Disease Signup and view all the answers

What is the mechanism of action of NK cells in ADCC?

Antibody-dependent cytotoxicity Signup and view all the answers

What is the result of immune adherence in phagocytosis?

Phagocytosis of target cells Signup and view all the answers

What is the characteristic of Hyperacute graft rejection?

Immediate immune response Signup and view all the answers

What is the consequence of Hemolytic Disease of the Newborn in severe cases?

Erythroblastosis fetalis Signup and view all the answers

Which of the following processes is responsible for the destruction of target cells through the action of NK cells?

Antibody-dependent cellular cytotoxicity Signup and view all the answers

What is the primary mechanism of Hemolytic Disease of the Newborn?

Maternal IgG Ab's crossing the placenta Signup and view all the answers

Which autoimmune disease is characterized by Ab's produced vs acetylcholine receptors?

Myasthenia Gravis Signup and view all the answers

What is the result of the activation of the complement system in Type II hypersensitivity?

Lysis of target cells Signup and view all the answers

Which of the following is an example of Type II hypersensitivity reactions?

Autoimmune hemolytic anemia Signup and view all the answers

What is the mechanism of action of IgG in blood transfusion reactions?

IgG-mediated complement activation Signup and view all the answers

Which of the following cells is responsible for phagocytosis of target cells?

Phagocytic cells Signup and view all the answers

What is the consequence of mismatched blood types in blood transfusions?

All of the above Signup and view all the answers

Which of the following autoimmune diseases is characterized by Ab's produced vs thyroid hormone receptor?