Lymphocytopenia, or lymphopenia, is the condition of having an abnormally low level of lymphocytes in the blood. … In T lymphocytopenia, there are too few T lymphocytes, but normal numbers of other lymphocytes. … The most common cause of temporary lymphocytopenia is a recent infection, such as the common cold.
Alemtuzumab, an anti-CD52 monoclonal antibody, causes lymphocytopenia by eliminating CD52-positive cells. … The described patient acquired a R. equi infection during alemtuzumab-induced lymphocytopenia. … Alemtuzumab causes lysis of these cells by binding to CD52, resulting in lymphocytopenia, which can persist for up to 320 days after treatment ( 5 ).