A low level of lymphocytes indicates that insufficient white blood cells are being made, cells are being destroyed, cells are caught in the lymph nodes or spleen, or any combination of these, according to the National Heart, Lung, and Blood Institute. This condition, lymphocytopenia, is either inherited or acquired.
Certain rare genetic disorders, such as severe combined immunodeficiency syndrome, DiGeorge anomaly and Wiskott-Aldrich syndrome, cause low levels of lymphocytes, NHLBI explains. However, this problem usually develops during a person's life. Certain diseases and disorders, including AIDS, viral hepatitis, tuberculosis, typhoid fever, lupus, blood cancer, Hodgkin's disease and aplastic anemia, lower the white blood cell count. Lymphocytopenia also occurs as the result of steroid treatment, radiation and chemo therapy.