Question

Define hypersensitivity. List three types of hypersensitivity reactions. For each, note whether antibodies or T cells are involved and provide two examples.

Answer 1

Hypersensitivity refers to maladaptive immune responses towards harmless foreign substances or self antigens. The three types of hypersensitivity reactions are type I, type II, and type III.

Step-by-step explanation:

Hypersensitivity refers to maladaptive immune responses towards harmless foreign substances or self antigens. There are three types of hypersensitivity reactions:

1. Type I hypersensitivity: In this type, antibodies (specifically, IgE) are involved. Examples include allergies to pollen, pet dander, and food allergies (such as peanuts or shellfish).
2. Type II hypersensitivity: Antibodies (IgG and/or IgM) are involved in this type of hypersensitivity. Examples include hemolytic transfusion reactions and hemolytic disease of the newborn.
3. Type III hypersensitivity: Antibodies (IgG, IgM, and occasionally IgA) are involved in this type. Examples include systemic lupus erythematosus (SLE) and rheumatoid arthritis.