What is a potential consequence if negative selection fails?

What is a potential consequence if negative selection fails?

• A. Autoimmunity
• B. Increased immunity
• C. Normal immune function
• D. Improved tolerance

Answer: (A)

When negative selection in the immune system fails, it can lead to a condition known as autoimmunity. Negative selection is a crucial process that occurs during the development of T cells in the thymus gland. During this process, T cells that strongly recognize self-antigens are eliminated. This mechanism is essential for preventing the immune system from attacking the body's own tissues, which could lead to autoimmune diseases.

If this process is disrupted or ineffective, autoreactive T cells may escape into the peripheral circulation and can mistakenly target and destroy healthy cells, tissues, and organs in the body. This misdirected immune response can result in autoimmune disorders such as rheumatoid arthritis, lupus, or type 1 diabetes, where the immune system erroneously recognizes self-components as foreign. Thus, the failure of negative selection directly correlates to the risk and occurrence of autoimmunity in individuals.