In Graves disease (hyperthyroidism), autoantibodies bind to and activate receptors for thyroid-stimulating hormone (TSH) so that excessive T₄ (thyroxine) is secreted, causing clinical manifestations of an increased metabolism.This mechanism is an example of which type II hypersensitivity reaction?
A)Modulation
B)ADCC
C)Neutrophil-mediated damage
D)Complement-mediated lysis

Question

Quizplus · Accepted Answer

The antibody reacts with the receptors on the target cell surface and modulates the function of the receptor by preventing interactions with their normal ligands, replacing the ligand and inappropriately stimulating the receptor, or destroying the receptor. For example, in the hyperthyroidism (excessive thyroid activity) of Graves disease, autoantibody binds to and activates receptors for TSH (a pituitary hormone that controls the production of the hormone thyroxine by the thyroid).

In Graves Disease (Hyperthyroidism), Autoantibodies Bind to and Activate Receptors