ANATOMY

Detailed explanation-1: -Failure or breakdown of immunological tolerance results in autoimmunity and autoimmune diseases. Such events are related to both genetic and environmental factors, the latter being mainly represented by infections.

Detailed explanation-2: -The ability to discriminate between self and nonself antigens is vital to the functioning of the immune system as a specific defense against invading microorganisms. Failure of the immune system to “tolerate” self tissues can result in pathological autoimmune states leading to debilitating illness and sometimes death.

Detailed explanation-3: -Other environmental initiators of autoimmunity that break tolerance can act like infections by causing tissue damage, such as sunlight in lupus erythematosus, or alter a host molecule sufficiently that it becomes immunogenic, as in chemical-or drug-induced autoimmune syndromes.

Detailed explanation-4: -Self-tolerance errors result in autoimmune disorders such as celiac disease, type-1 diabetes, inflammatory bowel disease (IBD), multiple sclerosis to name a few. Self-tolerance mechanisms also provide barriers to therapeutic interventions.

Detailed explanation-5: -Autoimmune disease occurs when a specific adaptive immune response is mounted against self antigens. The normal consequence of an adaptive immune response against a foreign antigen is the clearance of the antigen from the body.