Question

Allergens are
A) Infectious and increased secretion of IgE
B) Non-infectious and increased secretion of IgE
C) Infectious and increased secretion of IgG
D) Non-infectious and increased secretion of IgM

Answer 1

Hint:-A healthy individual’s body can fight against or resist disease-causing agents and foreign particles. When the components of the immune system come across these pathogens or foreign particles, an immune response is triggered. The foreign particles are known as antigens. Substances that most people usually consume or are exposed to daily, could trigger an immune response in certain individuals. These substances are called allergens.

Complete Answer:-Certain individuals express an exaggerated immune response when the components of their immune system are activated. This is known as hypersensitivity. Hypersensitivity can be broadly classified into four types. Allergens (foreign particles/antigens) cause Type-one hypersensitivity. The presence of allergens in the body alarms the immune system and it increases the secretion of immunoglobulin E. These IgE antibodies bind to mast cells and basophils. Primary mediators (such as heparin) are released, once IgE binds to the mast cells and basophils. An inflammatory response is caused by these primary mediators. The individual’s body shows signs and symptoms such as inflammation, airways getting constricted, pain, sneezing, red skin, etc. The individual may also suffer from severe tissue damage and will require immediate medical intervention if his/her situation worsens. Allergens are not infectious agents. Allergies are not passed on to other people through close contact or by sharing body fluids.
IgM and IgG are never activated by allergens. When IgM/IgG antibodies get activated they could cause cell lysis. For example, the host’s immune system will not recognize transfused blood, if it does not match the recipient’s. This is an example of type-two hypersensitivity.
Type-three hypersensitivity is mediated by IgG antibodies.


The correct option is (B). Allergens are Non-infectious and they increase the secretion of IgE.

Note:- Allergy could be caused by anything. Hair of certain animals can cause an allergic reaction, a bee’s sting, or even pollen grains. Allergens can also be food (say nuts) or even medicines such as penicillin. The presence of any metal in a drug or exposure to any metal could cause allergic reactions. While allergies and allergens are not infectious, the allergic reactions towards a substance can be inherited. Such allergies are called atopic allergy.