Lymphocytopenia: why lymphocytes in the blood are lowered25.05.2022
Lymphocytes are a fairly large group of leukocytes – white blood cells that protect the body from foreign agents.
Lymphocytes are assigned extremely important functions in the immune system, such as protection against viral and bacterial infections through the production of antibodies, as well as the regulation of the entire immune system as a whole by activating it or, conversely, suppressing it.
There are two types of lymphocytes in the human body (modern studies, however, have already proven that there are more): T- and B-lymphocytes. They develop from a single precursor cell in the bone marrow, but mature in different places. Normally, the content of lymphocytes in the peripheral blood should be 40% of the total number of leukocytes in adults and 50% (according to some laboratories 60%) in children.
Lymphocytopenia is a decrease in the absolute number of lymphocytes less than 1.5 × 109 / l (according to some sources, less than 1 × 109 / l.)
Types of lymphocytopenia
Lymphocytopenia can be either congenital (hereditary) or acquired.
Primary (congenital) lymphocytopenias may result from stem cell abnormalities leading to ineffective lymphopoiesis, or from defects in the structure of the lymphocytes themselves leading to their premature destruction. This group of diseases includes severe immunodeficiencies, such as ataxia-telangiectasia (LouiBar syndrome), Wiskott-Aldrich syndrome, McKusick’s metaphyseal chondrodysplasia, and many other diseases.
They are usually detected already at an early age, since the child’s body is not able to resist infections. Hematologists and immunologists are engaged in the treatment of such patients.
Secondary (acquired) lymphocytopenia can develop for a number of reasons, which, for ease of perception, can be logically divided into groups:
1. Infectious diseases.
First of all, here it is necessary to mention HIV , which infects one of the varieties of T-lymphocytes in such a way that they become unable to perform their functions.
The most common cause of transient (temporary) lymphocytopenia are viral infections, as some viruses have the ability to infect lymphocytes. This includes measles, hepatitis , influenza, herpes viruses , Covid-19 .
Bacterial infections, such as tuberculosis , typhoid fever, bacterial pneumonia, etc., can also cause a decrease in the level of lymphocytes. In this case, usually a decrease in the number of lymphocytes indicates the depletion of the body’s reserve capacity and makes doctors wary.
2. Systemic autoimmune diseases ( systemic lupus erythematosus , rheumatoid arthritis, systemic vasculitis, dermatomyositis, etc.).
3. Lymphoproliferative diseases ( leukemias , lymphomas) in the later stages can give lymphocytopenia due to the depletion of the hematopoietic system and due to the replacement of normal cells by malignant ones.
4. The impact of drugs. First of all, we are talking about drugs that depress the immune system – these are glucocorticoid hormones and cytostatics, that is, exactly those drugs that are prescribed for autoimmune and oncological diseases, as well as in the treatment of severe allergies.
A slight lymphocytopenia can also be expected in a healthy person against the background of stress, prolonged high physical exertion, during periods of starvation or severe restriction of oneself in protein foods, however, in this situation, one has only to stop the impact of an unfavorable factor, as the level of lymphocytes quickly returns to normal.
In all other cases, when lymphocytopenia is detected in blood tests, further diagnostic measures are necessary.
If there are signs of an infectious disease, a bacteriological, virological and serological examination is carried out to make an accurate diagnosis. Treatment consists of prescribing antibiotics, antiviral and anti-inflammatory drugs.
In case of suspicion of oncohematological disease, the bone marrow and the material of the lymph nodes are examined. Treatment consists of courses of radiation, chemotherapy, and if it is ineffective, bone marrow transplantation.
Autoimmune pathologies are diagnosed by the presence of an increase in the level of proteins of the acute phase of inflammation and the presence of autoantibodies. Treatment consists in the appointment of hormones and cytostatics to suppress inflammation.
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