Lymphopenia

Lymphopenia is the condition in which there exists an abnormally low number of lymphocytes[?] in the blood.

Lymphopenia can be caused by various types of chemotherapy, such as with cytotoxic agents[?] or immunosuppresive drugs. Some malignancies in the bone marrow will also cause lymphopenia.

A decreased number of lymphocytes (notably T cells) is present in those with AIDS. People exposed to large doses of radiation, such as those involved with Chernobyl can also exhibit a lymphopenia.

Lymphopenia may be present as part of a pancytopenia[?], when all the blood cells are of decreased number. This can occur in marrow failure[?].