What Is Lymphocytopenia?

Lymphocytopenia (LIM-fo-si-to-PE-ne-ah) is a condition in which your blood has a low number of 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 increase your risk for infection.

Overview

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 count usually is between 3,000 and 9,500 lymphocytes per microliter of blood.

"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.

There are three types of lymphocytes: 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.

Several factors can cause a low lymphocyte count, such as:

• The body doesn't make enough lymphocytes.
• The body makes enough lymphocytes, but they are destroyed due to an abnormal condition.
• The lymphocytes get trapped in the spleen or lymph nodes. Lymphocytes normally pass through these organs into the blood.
• A combination of the above factors.

A number of 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.

Outlook

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 also depends on its cause and severity. Mild lymphocytopenia may not require treatment. If an underlying condition is successfully treated, lymphocytopenia will likely improve.

If you get serious infections due to lymphocytopenia, you may need medicines or other treatments.

February 2009