Lymphocytosis is an increase in the content of lymphocytes above 4000 (or 40%) in 1 µl of blood. The cause is acute viral diseases, some chronic bacterial infections, malignant hematological diseases, etc. Clinical manifestations are determined by the nosology against which lymphocytosis developed. The level of lymphocytes is examined in venous or capillary blood when calculating the leukocyte formula of the general blood test. To correct lymphocytosis, a fight against the cause is carried out, i.e. treatment of the underlying disease.
There are no clear numerical criteria for separating lymphocytosis according to severity. Conditionally allocated moderate (up to 60%) and high lymphocytosis (more than 60%). The main cause of high lymphocytosis is considered to be malignant diseases of the hematopoietic and lymphatic tissue. Lymphocytosis, like other types of leukocytosis, is divided into:
The most striking example is physiological lymphocytosis in children under the age of 4-5 years. The reason for this phenomenon is associated with age-related changes in the immune system of the child. From the 7th day of life, children begin an active increase in the number of lymphocytes (up to 55-60%) and a fall in neutrophils (the first leukocyte crossover). Then, by the age of 4, lymphocytes return to the levels as in adults (up to 40%), while neutrophils, on the contrary, increase (second crossover). Pathological lymphocytosis in children should be considered more than 60%.
Separately, short-term lymphocytosis, not associated with any disease, is isolated. Among these causes of lymphocytosis:
Lymphocytes are the main "tool" of the immune system against viruses. They produce special antibodies (immunoglobulins) that bind to the virus and prevent it from entering the cells. Subsequently, the viral particles undergo phagocytosis. Another mechanism of antiviral immunity is the destruction of cells infected with viral DNA or RNA by triggering programmed cell death (apoptosis). Similarly, lymphocytes fight some bacteria, intracellular parasites (toxoplasma).
In addition to quantitative changes, viral infections are considered the cause of the appearance of atypical mononuclear cells (virocytes) - lymphocytes that have a different shape, an altered nucleus structure, and basophilic cytoplasm. In small quantities (less than 10%), they are present in any viral infections. A higher concentration of such cells (more than 10%) indicates infectious mononucleosis.
In adults, one of the common causes of lymphocytosis is bacterial infections with a chronic course, accompanied by the formation of specific epithelioid granulomas (tuberculosis, brucellosis, syphilis). Less commonly, the cause of lymphocytosis in adults is typhoid diseases (typhoid, typhus, paratyphoid). The only acute bacterial infection that causes lymphocytosis in children is whooping cough.
Basically, there is a slight lymphocytosis, and almost always relative, against the background of general leukopenia. In view of the chronic course of diseases, lymphocytosis can persist indefinitely (months, years), increasing during periods of exacerbation. In tuberculosis, lymphocytosis indicates a benign course and is considered a predictor of a favorable outcome.
Lymphocytosis: norm and pathology
Myeloproliferative and lymphoproliferative diseases are recognized as the most dangerous cause of lymphocytosis in adults and children. In such cases, lymphocytosis is due to the proliferation of tumor clones of lymphatic tissue or malignant transformation of hematopoietic cells in the bone marrow. In adults, chronic leukemia, non-Hodgkin's lymphomas (lymphosarcomas) are mainly observed. In children, lymphogranulomatosis (Hodgkin's lymphoma) is more common. Lymphocytosis reaches very high numbers (up to 70-90%).
The increase in lymphocytosis occurs gradually: the maximum value is reached after a few years, it decreases slowly, only under the influence of chemotherapy courses. A quick return to normal values is possible only with bone marrow transplantation. In addition to lymphocytosis, there are such signs as a simultaneous increase in eosinophils and basophils (basophilic-eosinophilic association), the presence of a large number of blasts, intermediate forms (prolymphocytes).
In some cases, diseases of the endocrine organs become the cause of lymphocytosis. The exact mechanism of this phenomenon has not yet been finally established. A moderate degree of lymphocytosis often develops simultaneously with an increase in the concentration of eosinophils. In adults, this picture is observed with acromegaly, thyrotoxicosis, adrenal insufficiency. In children, congenital dysfunction of the gonads is a common cause. Lymphocytosis quickly regresses after the appointment of hormone replacement therapy.
The level of lymphocytes is measured with a clinical blood test. In view of the fact that lymphocytosis has a fairly wide etiological spectrum, when it is detected, you should contact a generalist (therapist or pediatrician) so that, based on the patient's complaints, anamnestic data, physical examination, he prescribes an additional examination, which may include:
Leukocyte count
There are no direct ways to normalize the concentration of lymphocytes. To combat lymphocytosis, it is necessary to treat the underlying pathology that caused the increase in lymphocytes. Insignificant short-term lymphocytosis, which arose against the background of stress, taking medications, or during the period of recovery from a cold, does not require therapy. In the case of long-term lymphocytosis, both absolute and relative, it is necessary to consult a doctor.
For many viral infections (chicken pox, rubella, ARVI), etiotropic therapy has not been developed to date. For their treatment, pathogenetic and symptomatic methods are used - plentiful hot drink, antipyretic, anti-inflammatory drugs. With catarrhal syndrome, rinsing and irrigation of the throat with antiseptic solutions and sprays are prescribed. In the early days of influenza, the use of antiviral drugs (oseltamivir, rimantadine) is effective.
There is evidence of a decrease in the number of complications of infectious mononucleosis in adults by prescribing acyclovir, valciclovir. For bacterial infections, antibiotics are prescribed, for tuberculosis - a combination of anti-tuberculosis drugs. If the cause of lymphocytosis was a lymphoproliferative disease, then long-term repeated courses of chemotherapy are required. With the ineffectiveness of conservative treatment of chronic myeloid leukemia in adults, they resort to allogeneic bone marrow transplantation.
In some cases, the level of lymphocytes can be a guideline for predicting the development of the disease. For example, lymphocytosis in tuberculosis, both in children and adults, indicates a favorable course of the disease and a speedy recovery. Conversely, if the cause of an excessive increase in lymphocytes is malignant hematological diseases, this can indirectly indicate a high probability of death. However, first of all, it is necessary to focus on the underlying pathology and its severity. Therefore, any degree of lymphocytosis requires a thorough examination to establish the cause and timely therapy.