Lymphocytopenia (LIM-fo-si-to-PE-ne-ah) is a disorder in which your blood doesn’t have enough white blood cells called lymphocytes (LIM-fo-sites).
These cells are made in the bone marrow along with other kinds of blood cells. Lymphocytes help protect your body from infection. Low numbers of lymphocytes can raise your risk of infection.
Lymphocytopenia also is called lymphopenia.
About 20 to 40 percent of all white blood cells are lymphocytes. A normal lymphocyte count for adults usually is between 1,000 and 4,800 lymphocytes per microliter of blood. For children, a normal lymphocyte count usually is between 3,000 and 9,500 lymphocytes per microliter of blood.
The term "lymphocytopenia" refers to a count of less than 1,000 lymphocytes per microliter of blood in adults, or less than 3,000 lymphocytes per microliter of blood in children.
The three types of lymphocytes are B lymphocytes, T lymphocytes, and natural killer cells. All of these cells help protect the body from infection. Most people who have lymphocytopenia have low numbers of T lymphocytes. Sometimes they also have low numbers of the other types of lymphocytes.
Certain factors can cause a low lymphocyte count, such as:
Many diseases, conditions, and factors can cause the above problems that lead to lymphocytopenia. These causes can be acquired or inherited.
"Acquired" means you aren't born with the condition, but you develop it. One of the most common acquired causes of lymphocytopenia is AIDS.
"Inherited" means your parents passed the gene for the condition on to you. Inherited causes include DiGeorge anomaly, Wiskott-Aldrich syndrome, severe combined immunodeficiency syndrome, and ataxia-telangiectasia. These inherited conditions are rare.
Lymphocytopenia can range from mild to severe. The condition alone may not cause any signs, symptoms, or serious problems.
How long lymphocytopenia lasts depends on its cause. The treatment for this condition depends on its cause and severity. Mild lymphocytopenia may not require treatment. If an underlying condition is successfully treated, lymphocytopenia will likely improve.
If lymphocytopenia causes serious infections, you may need medicines or other treatments.
The NHLBI updates Health Topics articles on a biennial cycle based on a thorough review of research findings and new literature. The articles also are updated as needed if important new research is published. The date on each Health Topics article reflects when the content was originally posted or last revised.