Lymphocyte count is the absolute value of lymphocytes. A low lymphocyte count is a decrease in the absolute value of peripheral blood lymphocytes. Normal reference value of lymphocytes: adults (0.8-4) × 10*9/L. Lymphocyte count is influenced by both physiological and pathological factors. Low absolute lymphocyte count is commonly due to the following causes: treatment with alkylating agents (cyclophosphamide, etc.) can cause a significant decrease in leukocytes, accompanied by a significant decrease in lymphocytes, which can persist for several years after stopping treatment; recovery from influenza; radiation therapy can destroy lymphocytes, with each low-dose radiation therapy having a stronger destructive effect than two high-dose radiation therapies per week; immune diseases such as systemic lupus erythematosus , rheumatoid arthritis, mixed connective tissue disease, and polymyositis, are reduced due to the production of anti-lymphocyte antibodies by antibodies, resulting in the destruction of lymphocytes, and the degree of reduction correlates with the titer of the antibodies; early lymphocytopenia in tuberculosis, in which CD4+ cells are significantly reduced, and lymphocytes may return to normal if treatment is effective; various types of congenital immunodeficiency such as severe combined immunodeficiency Various types of congenital immunodeficiencies such as severe combined immunodeficiency, ataxia capillaris, malnutrition or zinc deficiency can cause lymphopenia to varying degrees. Certain drugs can also cause lymphocytopenia, such as menadione, nitrogen mustard phenylbutyrate, cortisone, epinephrine, lithium, nicotinic acid, and steroids.
It can be seen that there are many causes of low lymphocyte count, but the specific causes need to be combined with clinical symptoms and other relevant laboratory tests.