Mononucleosis is characterized by an abnormal increase in which type of blood cell?

Mononucleosis is characterized by an abnormal increase in mononuclear leukocytes, specifically atypical lymphocytes. This viral infection, often caused by the Epstein-Barr virus, leads to a proliferation of these white blood cells, which are crucial for the immune response. The presence of these atypical lymphocytes is a key indicator when diagnosing mononucleosis, as they can be identified in blood tests.

While red blood cells, platelets, and eosinophils play important roles in various bodily functions, they do not typically show an increase in cases of mononucleosis. Red blood cells are involved in oxygen transport, platelets play a key role in blood clotting, and eosinophils are associated with allergic reactions and parasitic infections. None of these blood components are the primary characteristic affected during mononucleosis, further highlighting the significance of the abnormal increase in mononuclear leukocytes in this condition.