A Brief Introduction to Monocyte

Monocytes are derived from hematopoietic stem cells in the bone marrow and develop in the bone marrow. When they enter the blood from the bone marrow is still immature cells. Compared with other blood cells, monocytes contain more non-specific lipase, and has a stronger phagocytosis. Monocytes stay in the blood 2-3 days to migrate to the surrounding tissue, the cell volume continues to increase, the diameter of up to 50-80μm, cells contained lysosomal particles and mitochondria also increased the number of mature cells . Monocyte fixed in tissues are called macrophages, and they are often present in large numbers in organs such as lymph nodes, alveolar walls, bone marrow, liver and spleen. Activated monocytes and macrophages can produce and release a variety of cytotoxic, interferon and interleukin, participate in the body defense mechanism, but also produce some can promote the growth of endothelial cells and smooth muscle cells factor. Monocyte in the surrounding inflammation can carry out cell division, and surrounded by foreign bodies.

The structure and characteristics of monocytes

Monocytes are an important part of the body's defense system. It is through phagocytosis and antibody production and other ways to resist and destroy the invading pathogenic microorganisms.

Phagocytosis is one of the oldest and most basic defenses of organisms. For the object to be eliminated without specificity, in immunology called non-specific immune function. Neutrophils and monocyte phagocytosis strong eosinophils, although the migration is strong, but the phagocytosis is weak.

Monocytes can penetrate the endothelium of the capillaries, exudate from the blood vessels, and travel through the interstitial space. They swallow the invading bacteria, viruses, parasites and other pathogens and some necrotic tissue fragments. It is generally believed that monocytes can accumulate at the foreign body and swallow it because of monocyte chemotaxis. Due to bacterial or dead cells produced by chemical stimulation, induced monocyte migration to the place. Tissue inflammation produces an active polypeptide, is also induced by mononuclear cell migration of one of the substances.

Neutrophils granules for the lysosomes, containing a variety of hydrolases, can digest their intake of pathogens or other foreign body. Generally a white blood cell treatment of 5 to 25 bacteria, itself will die. Death of white blood cell groups and bacterial decomposition products constitute pus. Monocyte generated by the bone marrow, in the blood only to live 3 to 4 days, that is, into the liver, spleen, lung and lymph tissue into macrophages. Into macrophages, the volume increases, lysosomes increased, phagocytic and digestive capacity is also enhanced. But its phagocytic object is mainly into the cells of the pathogens, such as viruses, malaria parasites and bacteria. Macrophages are also involved in the activation of lymphocyte-specific immune function. In addition, it also has to identify and kill tumor cells, clear the role of aging and damaged cells.

Monocyte: about 3%, large volume, abundant cytoplasm, dyed blue-gray, the nucleus often kidney-shaped or horseshoe-shaped cells of different shapes, round, polygonal. Automatic counting method for men 0.003-1.3×109/L, women 0.002-1.1×109/L.

Related use of monocytes

Monocyte can phagocytosis of foreign body antibodies, in the body damage cure, anti-pathogen invasion and immune disease plays an important role. Inflammation of the body or other diseases can cause a change in the percentage of the total number of monocyte, so check the mononuclear cell count as an important method of diagnosis. In the body's protection, immunity and trauma healing process play a synergistic effect. Although they are a class of cell components in the blood, but their function to play, more reflected in the circulatory organs outside the pipeline. In function, they are closely related to many cellular components in these organs and tissues, such as macrophages, mast cells, fibroblasts and so on.

Monocyte in clinical cases

Infectious mononucleosis is an acute mononuclear-macrophage system. The course of a proliferative disease is often self-limiting. Clinical manifestations of irregular fever, swollen lymph nodes, sore throat, peripheral blood monocyte increased significantly, and the emergence of abnormal lymphocyte heterophile agglutination test positive serum can be measured anti-EB virus antibodies. In young and adult patients with primary EBV infection about half of the performance of infectious mononucleosis syndrome. Burkittis lymphoma in African children (BL and nasopharyngeal carcinoma only occurred in patients who had been infected with EB virus, and in BL and nasopharyngeal cancer cells with EB virus DNA and virus-determined nuclear antigen so that the EB The virus may be an important risk factor for BL and nasopharyngeal carcinoma.

Acute granulocyte, monocytic leukemia (referred to as acute granuloma, ANUL-M5). Bone marrow or (and) peripheral blood granulocyte and monocytic two-line cells, or "acute granuloma" of the original cells both granular and mononuclear morphological features. If the original granulocyte and promyelocytic proliferation, the original single andmonocyte should be more than 20%; such as the original mononuclear cell hyperplasia, the original particles and promyelocytic cells should be more than 20%.

Clinically, the "acute grain single" performance has the following characteristics:

(1) gingival hyperplasia, swelling, bleeding, ulcers, necrosis and other more common;

(2) nasal infiltration, nasal congestion, olfactory loss, hard palate ulcers, throat edema caused by asphyxia;

(3) skin leukemia lesions more common, can be expressed as diffuse rash, hard nodules, lumps, pustular, bullous or exfoliative dermatitis;

(4) intestinal wall infiltration, ulcers, gastrointestinal disorders and other relatively easy to see;

(5) renal failure, proteinuria more common, and monocytes and granulocytes rich lysozyme - easy to form lysozyme hemolytic and lysozyme urine related;

(6) joint pain and swelling are relatively common;

(7) in the treatment of acute granuloma and acute single effect than other acute non-lymphocytic leukemia is poor.