What is the term for a deficiency in the number of circulating white blood cells?

Leukopenia specifically refers to a lower-than-normal count of white blood cells (WBCs) in the bloodstream. White blood cells play a crucial role in the immune system by defending the body against infections and diseases. When there is a deficiency in these cells, individuals may experience increased susceptibility to infections and may have diminished immune responses.

Thrombocytopenia indicates a reduced number of platelets in the blood, which affects clotting rather than the immune system. Leukoplakia is a condition characterized by white patches on mucous membranes and is not related to blood cell counts. Pancytopenia involves reductions in all three blood cell types: red blood cells, white blood cells, and platelets, but does not specifically address the deficiency of white blood cells alone as leukopenia does. Thus, leukopenia is the accurate term for a deficiency in circulating white blood cells.