What can be the cause if the lymphocytes are reduced?
Lymphocytopenia often occurs as a result of therapy and is not considered pathological in this context: this is particularly common in treatment with corticoids, especially cortisone, and in the administration of antilymphocyte globulin. Both are used specifically to suppress inflammatory reactions. Other forms of therapy that can cause a lymphocyte deficiency are radiotherapy and chemotherapy, both of which are used to treat cancer, but can also affect rapidly dividing body cells, such as the precursors of blood cells.
This phenomenon has also been observed with the drug ganciclovir, which is mainly used for the treatment of cytomegalovirus (CMV, Human Herpesvirus 5, HH5). During treatment with long-wave UV light (UVA), the natural substance psoralen is often administered due to its photosensitizing effect, which can also have a reducing effect on the leukocyte count. A further possible reason for lymphocytopenia is a low-protein malnutrition or continuous stress, which can permanently increase the cortisol level (see cortisone therapy).
In addition, there are also clinical pictures with organic causes such as Cushing’s disease, which stimulates the adrenal medulla to produce more cortisol due to a malfunction of the pituitary gland (adenohypophysis). Certain autoimmune diseases such as rheumatoid arthritis, systemic lupus erythematosus (butterfly lichen) and exudative (gastero) enteropathy (Gordon’s syndrome) can also lead to lymphopenia. Uraemia is a condition in which substances accumulate in the blood due to kidney dysfunction and are discharged via the urine in healthy individuals.
In addition to a number of other symptoms, this leads to a reduced leukocyte function. Since an infection with the HI-Virus (Human Immunodeficiency Virus, which triggers AIDS) attacks and destroys the T-helper cells in particular, a sharp drop in the number of lymphocytes is to be expected. In addition, there are also congenital causes, which mostly concern the development of the lymphocytes (lymphocytopoiesis) and are triggered by mutations in the genes for certain enzymes.
These include adenosine deaminase deficiency and purine nucleoside phosphorylase deficiency, as well as the Wiskott-Aldrich syndrome, which primarily affects the thrombocytes (blood platelets) due to the disturbed formation of the cell skeleton. In addition, in certain Hodgkin lymphomas (Hodgkin’s disease, lymphogranulomatosis, lymphogranuloma) and individual non-Hodgkin lymphomas, i.e. cancer of the entire lymphatic system, the development of the lymphocytes can be disturbed and their number reduced as a result. or HIVThe everyday terms cold and flu-like infection stand for a number of different, mild diseases of the respiratory tract, which are mostly caused by viruses, but occasionally also by bacteria.
It is typical for bacterial infections that the total number of leukocytes increases (=leukocytosis), which usually also affects the lymphocytes. With viral infections, the total number of leukocytes is rather decreased (=leukopenia), which is often due to the fact that the immune system does not keep up with the production of defence cells, but certain viruses can also directly inhibit the immune system. However, it is characteristic that the number of lymphocytes remains stable or even increases, as they are particularly well suited to fight viral infections and therefore prefer to develop from the common stem cells.
The HI virus (human immunodeficiency virus) attacks cells that possess a specific surface protein, CD4 (cluster of differentiation). These are primarily the T-helper cells, which are destroyed by the reproduction of the virus, resulting in a drastic reduction in the number of lymphocytes (lymphopenia). The loss of functional T-helper cells exceeds the number of infected cells, so that indirect inhibition mechanisms must also play a role, which for example affect the maturation of lymphocytes.In addition, macrophages (giant eating cells) are also attacked, but these do not belong to the lymphocytes and only a comparatively small number of them die.
In the very first phase about 1-4 weeks after infection (primary infection), patients often show cold-like symptoms for about a week. However, the number of leukocytes usually increases slightly, while the number of lymphocytes decreases. This is often followed by a symptom-free period during which the number of lymphocytes decreases only very slowly, remains stable or even normalizes. This condition can last for several years and often goes unnoticed until it finally develops into AIDS if left untreated.
