Atypical Lymphocytes

Lymphocytes are a type of white blood cell (leukocyte) involved in the immune response. Atypical lymphocytes are generally lymphocytes that have been activated to respond to a viral infection or sometimes a bacterial or parasitic infection.

A few atypical lymphocytes are probably of little clinical significance. A large number of atypical lymphocytes are often found in viral infections like mononucleosis, cytomegalovirus infections and hepatitis B. Toxoplasmosis, certain bacterial infections, medications, stress and autoimmune diseases can also be accompanied by a larger number of atypical lymphocytes.