Immunodeficiencies

The immunodeficiencies are a group of disorders characterized by a defect in the immune system activity, the function of the immune system defending the individual against foreign agents, usually infectious in nature. Therefore, the main consequence of immunodeficiencies is an increase in the frequency and severity of infections.

Immunodeficiencies are classified into two large groups:

1. Primary Immunodeficiencies (PID): They have a genetic basis and usually affect a single component of the immune system. They generally manifest in childhood, although some may go unnoticed into adulthood.
2. Secondary or acquired immunodeficiencies (IDS): produced by causes external to the body, such as infectious, physical, chemical agents, drugs or nutritional defects. They can appear in anyone and affect more than one component of the immune system.

Primary immunodeficiencies

It was in the mid-twentieth century when the first Primary Immunodeficiency (PID) was diagnosed and many more have been described later, which has also led to an advance in new diagnostic and treatment techniques. Better knowledge of the functioning of the immune system has also greatly facilitated the classification of these diseases, which until then was merely descriptive.

In turn, Primary Immunodeficiencies (PID) can be classified into:

1. Humoral immunodeficiencies: the defect consists of a decrease in some of the immunoglobulin fractions (or antibodies). They are characterized by an increased susceptibility to bacterial infections.
2. Cellular immunodeficiencies: in this case cellular immunity is affected. Infections caused by bacteria, viruses, fungi and other microorganisms are increasing.
3. Mixed immunodeficiencies: in this case there is both a humoral and a cellular deficit. Those affected often die at an early age.
4. Non-specific immunodeficiencies: they affect neutrophils, both in their quantity and in their functioning. There are other cases in which there is a deficit of the complement.

Secondary immunodeficiencies

Secondary immunodeficiencies are much more common than primary ones. Its causes are very varied and include:

Infections; the best known example is the Acquired Immune Deficiency Syndrome ( AIDS ) produced by the Human Immunodeficiency virus (HIV) infection, but other infections can also cause immunodeficiency, generally less severe and limited in time (malaria, measles).

Medicines; immunodeficiency can be a consequence of its own therapeutic effect, as is the case with immunosuppressive drugs that are prescribed to decrease the immune response in cases of transplantation or autoimmune diseases. In other cases it may be an unexpected adverse effect of a drug prescribed for other indications. In developed countries, taking medications is the most common cause of immunodeficiency.

Physical agents: among them the most destructive are radiation, both those administered for therapeutic purposes (in the treatment of tumors) and those suffered accidentally (accidents in nuclear power plants)

Malnutrition: severe nutritional deficits can also cause immunodeficiency, since an adequate supply of proteins is necessary for the proper functioning of the immune system. This protein deficit is the most frequent cause of immunodeficiencies in underdeveloped countries.

Treatment

In the treatment of immunodeficiencies, the administration of drugs that eliminate the infectious agent is very important. This can be done preventively (before the infection occurs) or curatively (when the infection has already been contracted).

Other treatments are aimed at making up for the deficit in the immune system. Examples of these would be the periodic administration of immunoglobulins in cases of antibody deficiencies, the administration of substances that stimulate the formation of leukocytes or bone marrow transplantation if the affectation is cellular.