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13.6.1. Autoimmunity


The term autoimmunity refers to an error of the body's immune system to recognize its cells and tissues as its own, producing antibodies as if they were foreign to the body. Autoimmunity is a self-destructive process that causes slow but progressive autoimmune diseases.

When lymphocytes are maturing, some are not able to distinguish antigens that come from the outside (heteroantigens) from their own molecules (autoantigens). Normally, these abnormal lymphocytes or autoreactive lymphocytes are eliminated, but it can happen that they reach the blood circulation and reach some organs, developing autoimmune processes.

The production of autoreactive lymphocytes is due to some of the following reasons:

  • There are some changes in the autoantigens that prevent the immune system from recognizing them as its own.
  • Some foreign antigens are very similar to autoantigens (molecular mimicry), so the body confuses them and reacts against them.
  • Some cells are not recognized as their own because they had not come into contact with lymphocytes.

Some of the best known autoimmune diseases are:




Multiple sclerosis

Brain and spinal cord

 Multiple and serious nervous disorders

 Lupus erythematosus

Virtually all fabrics

Generalized disorders (erythema or skin rashes)

Myasthenia gravis

Striated muscles

Severe muscle weakness

Juvenile diabetes

(Mellitus diabetes)


Immune-dependent diabetes

Questions that have come out in University entrance exams (Selectividad, EBAU, EvAU)

Basque Country, June 2018, option B, question 4.

The antibody (IgG);

d) What is an autoimmune disease, why does it occur and how is it combated? Give reasons for your answer and give an example. (0.5 points).

Aragon. June 2017, option A, question 5.

Define the following concepts related to the immune system: autoimmunity. (0.2 points)

September 2016, option A, question 4. (1 point)

b) What is an autoimmune disease? Is it the same as allergy? Reason for the answer. (0.5 points)

Aragon. September 2015, option B, question 5.

Define the following statements: (2 marks)

Autoimmunity (0.5 points)

Aragon. September 2014, option B, question 4 .

Define the following terms referring to immunity: (2 points)

Autoimmune disease. (0.5 points)

Canary Islands, July 2019, option B, question 10.

An international team led by the CSIC identifies the function of the protein called p38, key in autoimmune diseases, the finding will favor the development of new drugs (Source

a. What is an autoimmune disease?

b. How is the cellular response and the humoral response of the immune system different?

c. What do you understand by immunodeficiency?

Extremadura, July 2021, question 10 b and c

Answer the following questions:

B. What is an autoimmune disease? (0.5 points)
C. Indicate 2 autoimmune diseases and indicate which organs or tissues
 it affects. (0.5 points)


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