The absolute lymphocytes count is part of a complete blood count (CBC). An absolute lymphocytes count tells you the number of cells as an absolute number instead of as a percentage. Multiply your total number of white blood cells by the percentage of your white blood cells that are lymphocytes to get your absolute lymphocytes count. The absolute Lymphocyte Count test is performed on a sample of blood to measure the level of Absolute Lymphocyte Count in the blood. Lymphocytes are one of the several different types of white blood cells. White blood cells are an important part of your immune system. They help your body fight antigens, like bacteria, viruses and other toxins that make you sick. If you have a weak immune system, it means that there are not enough white cells in your bloodstream. The test is performed to detect Infectious Mononucleosis, Leukemia, Lymphoma, and tuberculosis.