As nouns the difference between lymphocyte and lymphopenia

is that lymphocyte is (cytology|immunology) a type of white blood cell or leukocyte that is divided into two principal groups and a null group; b-lymphocytes, which produce antibodies in the humoral immune response, t-lymphocytes, which participate in the cell-mediated immune response and the null group, which contains natural killer cells, cytotoxic cells that participate in the innate immune response while lymphopenia is (medicine) the condition of having an abnormally reduced number of lymphocytes in the blood.