Monocytosis


Monocytosis is an increase in the number of monocytes circulating in the blood. Monocytes are white blood cells that give rise to macrophages and dendritic cells in the immune system.
In humans, monocytosis occurs when there is a sustained rise in monocyte counts greater than 800/mm3 to 1000/mm3.
Monocytosis has sometimes been called mononucleosis, but that name is usually reserved specifically for infectious mononucleosis. Infectious mononucleosis does not present as monocytosis. The cell type increased in infectious mononucleosis is the lymphocyte population, as infectious mononucleosis is a viral infection caused by the Epstein-Barr virus.

Causes

Monocytosis often occurs during chronic inflammation. Diseases that produce such a chronic inflammatory state:
During these stages of extreme inflammation, monocytosis can damage tissues because it increases the activation of the immune response and prevents the inflammation from subsiding which is seen in cases where sepsis occurs.

Diagnosis