Monocytosis
In medicine, monocytosis is an increase in the number of monocytes , a fraction of white blood cells ( leukocytes ), in the blood . It is a subtype of leukocytosis .
Monocytes come from the bone marrow . In contrast to granulocytes , however, these cells are not stored in the bone marrow. If necessary, they are released into the blood as immature monocytes or their precursor cells ( monoblasts , promonocytes ) and differentiate in inflammation foci to macrophages , epithelioid cells or multinucleated giant cells. The number of monocytes circulating in the blood is usually relatively small.
Monocytosis occurs with chronic inflammation , with processes with increased phagocytosis and with necrosis . Mild monocytosis can also be triggered as an unspecific “ stress response ” by high levels of glucocorticoids .
Certain diseases in the blood can also lead to changes in the cell morphology of the monocytes. Thus vacuoles occur with phagocytosed material. These can be, for example, red blood cells ( erythrocytes ) in immune-mediated hemolytic anemia , fungi such as in systemic histoplasmosis, or protozoa such as in leishmaniasis . It should be noted that fresh blood is more suitable for examination for such changes, since if stored in EDTA for a longer period of time, phagocytosis of other white or red blood cells can take place even after they have been taken.
