The normal values range from to x 109/L. An increase of monocytes is called monocytosis; a dercrease is called monocytopenia.
Monocytes may have a distinct migration ability. When they have emigrated to the tissue, they are referred to as macrophages. Monocytes take on an important role in acute and chronic infections. They actively phagocytize and are important components of cell-mediated immunity.
Monocytosis is associated with various chronic infections (e.g. tuberculosis, typhoid fever), chronic inflammatory and malignant diseases (e.g. M. Hodgkins). Monocytosis can likewise be found in acute myelomonocytic leukemia and acutemonocytic leukemia as well as in chronic myelomonocytic leukemia.
Monocytopenia is present in bone marrow failure, hairy cell leukemia and in steroid therapy.