Lymphocytes

Lymphocytes - the main cellular element of the immune system - are formed in the bone marrow, actively function in the lymphoid tissue. The main function of lymphocytes is to recognize the alien Ag and participate in the immunological response of the body. Reference values ​​of lymphocytes in the blood are given in Table.[Titz N., 1997].In children up to 4-6 years in the total number of leukocytes, lymphocytes predominate, that is, they have absolute lymphocytosis, after 6 years there is a "cross" and neutrophils predominate in the total number of leukocytes.

Lymphocytes are actively involved in the pathogenesis of immunodeficient conditions, infectious, allergic, lymphoproliferative, oncological diseases, transplantation conflicts, and autoimmune processes. With the listed processes, the amount of

lymphocytes in the blood can change significantly. As a result of an adequate response to antigenic stimulation, the number of lymphocytes increases - lymphocytosis, with an inadequate response, the number of lymphocytes can decrease - lymphopenia.

Table Reference values ​​for absolute and relative lymphocytes in the blood

Table Reference values ​​for the absolute and relative lymphocyte count in the blood

Absolute lymphocytosis: the absolute number of lymphocytes in the blood exceeds 4х109 / l in adults, 9x109 / l in young children and 8x109 / l inof older children. In clinical practice, leukemoid reactions of the lymph type are observed when the blood picture resembles that of acute or chronic leukemia. Lakemoid reactions of the lymphatic type most often develop with infectious mononucleosis, but sometimes also are possible with tuberculosis, syphilis, brucellosis. The blood picture in acute infectious mononucleosis is characterized by high leukocytosis due to lymphocytes. Lymphocytes in infectious mononucleosis acquire morphological diversity. A large number of atypical lymphocytes, characterized by dysplasia of the nucleus and an increase in the cytoplasm and acquiring a similarity to monocytes, appear in the blood.

Absolute lymphopenia - the number of lymphocytes in the blood of less than 1x109 / l - occurs with some acute infections and diseases. Lymphopenia is typical for the initial stage of the infectious-toxic process, which is associated with the migration of lymphocytes from the blood in the tissue to the foci of inflammation. The main causes leading to a change in the lymphocyte count in the blood are reflected in the table.

Table Diseases and conditions accompanied by changes in the lymphocyte content

Table Diseases and conditions accompanied by changes in the lymphocyte content of

Normally, the number of CD16 lymphocytes in the blood in adults is 6-26%.

CD16-lymphocytes are effector cells responsible for antitumor, antiviral and transplantation immunity. NK cells are a separate population of lymphocytes, they differ from T and B lymphocytes both in origin and in functional properties and surface receptors( in humans there are 2 subpopulations - CD16 and CD56).They have spontaneous cytotoxic activity against various tumor cells, cells infected with viruses and some normal cells, providing the first level of protection against tumors and intracellular infections before the incorporation of specific immune mechanisms. Unlike other cytotoxic cells, NK cells mediate cytotoxic reactions without presensitization and without limitations on the expression of Ar classes I or II of the main histocompatibility complex on target cells. High cytotoxicity and the way

to produce many cytokines - the main properties of CD ^ -lymphocytes. Reducing the number of CD16 lymphocytes leads to the development of cancer and weighting of the course of viral infections, autoimmune diseases, an increase - to the crisis of rejection of transplanted organs in recipients. Diseases and conditions leading to a change in the number of CD16-lymphocytes in the blood are presented in the table.

Table Diseases and conditions that lead to a change in the number of CD16-lymphocytes in the blood

Table Diseases and conditions that lead to a change in the number of CD16-lymphocytes in the blood

Normally, the number of CD56-lymphocytes in the blood in adults is 9-19%.

CD56-lymphocytes are cells-effectors of cellular immunity, responsible for antiviral, antitumor and transplantation immunity. Reducing the number of CD56-lymphocytes leads to the development of cancer and weighting of the course of viral infections. Diseases and conditions leading to a change in the number of CD56-lymphocytes in the blood are presented in the table.

Table Diseases and conditions that lead to a change in the number of CB56-lymphocytes in the blood

Table Diseases and conditions leading to a change in the number of CB56-lymphocytes in the blood

The magnitude of spontaneous blast transformation of lymphocytes in adults is normal - up to 10%.

Spontaneous blast transformation of lymphocytes - the ability of lymphocytes to transform without stimulation. The test is performed to evaluate the functional activity of T lymphocytes. The change in the test indices in one direction or the other indicates a violation of the functional activity of T-lymphocytes. The test is used to comprehensively assess the patient's immune status. Diseases and conditions at which spontaneous blast transformation of lymphocytes change are presented in Table.

Table Diseases and conditions in which the spontaneous blast transformation of lymphocytes changes

Table Diseases and conditions at which spontaneous blast transformation of lymphocytes changes

The values ​​of stimulatedreactions of blastic transformation of lymphocytes in adults are normal: with PHA - 44-72%, with ConA - 40-75%.

The functional activity of T and B lymphocytes is judged by the reaction of blast transformation of lymphocytes with the use of mitogens - PHA, ConA, latex, lipopolysaccharides, etc.

The stimulated blast transformation of lymphocytes with mitogens( PHA, ConA) characterizes the functional ability of T lymphocytes to transformand reproduction under the influence of Ar, allergens and mytogenes. Under the influence of mitogens, T cells turn into blasts and divide in response to Ar, which has got into the body, that is, in response to mitogens there is an increase in the number of T cells. The functional activity of B-lymphocytes is judged by blast transformation in response to stimulation with lipopolysaccharide, and on mitogen stimulation of latex - on cooperative processes between T and B lymphocytes. Proliferative response of lymphocytes to Ar gives an idea of ​​the severity of specific sensitization of the body. The states and diseases that lead to its change are similar to changes in blast transformation of lymphocytes without stimulation. The test is used for a comprehensive assessment of the patient's immune status.