The cells of the human immune system - lymphocytes - belong to the leukocyte group of white agranulocytes and create the conditions for the formation of humoral and cellular immunity. Humoral immunity produces antibodies, while cellular immunity provides contact with victim cells. Also, lymphocytes play the role of observers for other blood cells and, if necessary, regulate their activity.
Lymphocytes and lymphoblasts
Lymphocytes are the dominant cellular elements of the entire immune system in the human body, which enter the bloodstream from the bone marrow and then actively function in the lymphoid tissue. If there are elevated lymphocytes in the blood, the reasons for this require immediate clarification, and first of all it is necessary to do a general laboratory analysis. In adult blood, lymphocytes account for 20 - 35 percent of the total number of white cells. Some of them (about 2%) are in free circulation in the peripheral blood circulation, and 98% are in the tissues. According to their morphological characteristics, lymphocytes are divided into two categories: large granular (NK cells, immunoblasts, lymphoblasts) and small (T cells and B cells). All of these cells are active, and lymphoblasts are involved in immune processes much less frequently. If an increased content of lymphocytes in the blood is noted, this means that negative changes have occurred in the body, a hidden focus of infection or local inflammation has arisen.
Lymphocyte groups
B cells detect antigens, foreign structures that penetrate the body. At the same time, they produce protein molecules that neutralize harmful agents. T cells destroy antigens, supporting immunity in the active phase, preventing its weakening. Elevated lymphocytes in the blood, a person may not know the causes of this phenomenon, are detected using a blood test. NK lymphocytes control the quality of cells throughout the body. At the same time, they destroy cells that do not meet the standards, for example, cancer cells. T-lymphocytes account for 70-80% of the total, B-cells are in the ratio of 15-20%, and NK lymphocytes are the smallest, their content does not exceed 5-10%. If there are elevated lymphocytes in the blood, the reasons for this may be different, but in any case, this is a signal that not everything is safe in the body.
Pathogenesis
Lymphocytes, together with their molecular components, help to carry out the pathogenesis of immunodeficiency, infectious, oncological and allergic diseases, transplant conflicts and, importantly, autoimmune diseases. During functioning, an increase in the level of lymphocytes and the appearance of lymphocytosis is possible, this occurs with an adequate response to antigenic activity. If there is an increased number of lymphocytes, this means the beginning of the fight of cells with antigens. But there may also come a decrease in the level, in the case of an inadequate response to stimulation of antigens, and then lymphopenia occurs.
Lymphocyte morphology
In clinical practice, leukemoid reactions of the lymphatic type are found in which a picture appears with signs of chronic or acute leukemia. Such reactions occur with infectious mononucleosis, tuberculosis, syphilis and brucellosis. Infectious mononucleosis - the result of a viral infection most often occurring in children, is characterized by a high level of leukocytosis due to lymphocytes, which in the course of the disease acquire new qualities of morphological diversity. Blood is enriched with atypical lymphocytes, with signs of nuclear dysplasia and an increase in cytoplasm. In any case, when elevated lymphocytes in the blood are diagnosed, the causes will be found and possibly eliminated.