Which of the following is not a mechanism for the development of autoimmune disorders?
a. cross-reaction of antibodies formed against foreign antigens (haptens) bound with self-antigens
b. mutation followed by the appearance of membrane proteins not previously present
c. exposure of previously "hidden" self-antigens to the adaptive immune system during trauma
d. a second exposure to an allergen

d. a second exposure to an allergen

Explanation:

An autoimmune disease is a condition that occurs when the immune system attacks and destroys healthy body tissues by mistake.

Normally, white blood cells (leukocytes), produced in the bone marrow and found in the blood, help to protect the body against invasive and harmful substances known as antigens. Examples are viruses, bacteria, toxins, cancer cells, etc. Leukocytes are a fundamental part of the immune system, whose main function is to produce antibodies that keep the human body protected from the action of these antigens by destroying them.

In the case of autoimmune diseases, the immune system cannot distinguish antigens from healthy body tissues and ends up attacking and destroying normal body cells.

The causes of autoimmune diseases are not yet known, although there are many mechanisms that trigger these diseases. However, we can confirm that these diseases are not caused by a second exposure to an allergen, which is a substance that can induce a hypersensitivity reaction in some people.