Monocytes
Monocytes are formed in the red bone marrow from monoblasts. After exiting the bone marrow, where unlike granulocytes they do not form a marrow reserve, monocytes circulate in the blood from 36 to 104 hours, and then go into tissues.7h106 monocytes leave the blood in the tissue for 1 h. In tissues, monocytes differentiate into organo- and tissue-specific macrophages. The extravascular pool of monocytes is 25 times greater than the circulating one.
The system of mononuclear phagocytes unites various types of cells involved in the protective reactions of the body. Macrophages play an important role in the processes of phagocytosis. They remove from the body dying cells, remnants of destroyed cells, denatured protein, bacteria and Arg-AT complexes. Macrophages are involved in the regulation of hematopoiesis, immune response, hemostasis, lipid and iron metabolism. The reference values of the monocyte content in the blood are given in Table.[Titz N., 1997].
Table Reference values for the absolute and relative content of monocytes in the blood
Table Reference values for the absolute and relative content of monocytes in the blood
Monocytosis - an increase in the number of monocytes in the blood more than 0.8x109 / l - accompanies a number of diseases( Table).With tuberculosis, the appearance of monocytosis is considered a proof of the active spread of the tuberculosis process. An important indicator is the ratio of the absolute number of monocytes to lymphocytes, which is normally 0.3-1.0.This ratio is more than 1 in the active phase of the disease and decreases with recovery, which is used to assess the course of tuberculosis.
Table Diseases and conditions in which monocytosis is possible
Table Diseases and conditions in which monocytosis is possible
In infectious endocarditis, sluggish sepsis, significant monocytosis is possible, which is often observed in the absence of leukocytosis. Relative or absolute monocytosis is noted in 50% of patients with systemic vasculitis. Short-term monocytosis can develop in patients with acute infections during convalescence.
Monocytopenia - a decrease in the number of monocytes less than 0,09х109 / l. Reduction of the number of monocytes in the blood is observed with hematopoiesis hypoplasia.