GENERAL HISTOLOGY

ENDOCRINE SYSTEM

THYROID FOLLICULAR CELL

Question [CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
Graves = autoantibodies to ____ leads to ____
A
TSH receptor, hyperthyroidism
B
TSH receptor, hypothyroidism
C
follicular cells, hyperthyroidism
D
follicular cells, hypothyroidism
Explanation: 

Detailed explanation-1: -The hyperthyroidism of Graves’ disease (GD) is caused by TSH-receptor (TSH-R) stimulating autoantibodies (TSAb), leading to overproduction of thyroid hormones. We present evidence for TSAb interaction with three distinct regions of the TSH-R, one in immediate vicinity of the carboxy terminal serpentine.

Detailed explanation-2: -Hyperthyroidism is the most common feature of Graves’ disease, affecting nearly all patients, and is caused by autoantibodies to the thyrotropin receptor (TRAb) that activate the receptor, thereby stimulating thyroid hormone synthesis and secretion as well as thyroid growth (causing a diffuse goiter).

Detailed explanation-3: -Thyrotropin receptor (TSHR) antibodies that stimulate the thyroid (TSAb) cause Graves’ hyperthyroidism and TSHR antibodies which block thyrotropin action (TBAb) are occasionally responsible for hypothyroidism. Unusual patients switch from TSAb to TBAb (or vice versa) with concomitant thyroid function changes.

Detailed explanation-4: -Graves’ disease happens when the immune system of an individual makes specialized proteins called antibodies, which circulate in the blood then attach to the thyroid gland at a place called the TSH receptor. These TSH receptor antibodies then stimulate the thyroid to make excess amounts of thyroid hormone.

Detailed explanation-5: -The antibody associated with Graves’ disease-thyrotropin receptor antibody (TRAb)-acts like the regulatory pituitary hormone. That means that TRAb overrides the normal regulation of the thyroid, causing an overproduction of thyroid hormones (hyperthyroidism).

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