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.

What Causes Lymphocytopenia?

In general, lymphocytopenia (a low lymphocyte count) occurs because:

• The body doesn't make enough lymphocytes.
• The body makes enough lymphocytes, but they are destroyed due to an abnormal condition.
• The lymphocytes get stuck in the spleen or lymph nodes.

A combination of these factors also may cause a low lymphocyte count.

A number of diseases, conditions, and factors can cause the problems that lead to a low lymphocyte count. These conditions can be inherited (passed from parents to children), or they can develop at any age.

Exactly how each disease, condition, or factor affects your lymphocyte count isn't known. Sometimes, people have low lymphocyte counts with no underlying cause.

Acquired Causes

A number of acquired diseases, conditions, and factors can cause lymphocytopenia. Examples include:

• Infectious diseases, such as AIDS, viral hepatitis, tuberculosis, and typhoid fever
• Autoimmune disorders, such as lupus
• Steroid therapy
• Blood cancer and other blood diseases, such as Hodgkin's disease and aplastic anemia
• Radiation and chemotherapy (treatments for cancer)

Inherited Causes

Certain inherited diseases and conditions can lead to lymphocytopenia. Examples include DiGeorge anomaly, Wiskott-Aldrich syndrome, severe combined immunodeficiency syndrome, and ataxia-telangiectasia. These inherited conditions are rare.

Who Is At Risk for Lymphocytopenia?

People at highest risk for lymphocytopenia are affected by one of the diseases, conditions, or factors that can lead to a low lymphocyte count. This includes people who have:

• AIDS or other infectious diseases
• Autoimmune disorders
• Blood cancers or other blood diseases
• Certain inherited diseases or conditions

People at highest risk also include those who have had steroid therapy or radiation or chemotherapy (treatments for cancer). For more information, see "What Causes Lymphocytopenia?"

What Are the Signs and Symptoms of Lymphocytopenia?

Lymphocytopenia alone may not cause any signs or symptoms. The condition usually is found when a person is tested for other diseases or conditions, such as AIDS.

If you have unusual infections, repeat infections, and/or infections that won't go away, your doctor may suspect that you have lymphocytopenia. Fever is the most common symptom linked to infections.

How Is Lymphocytopenia Diagnosed?

Your doctor will diagnose lymphocytopenia based on your medical history, a physical exam, and the results from tests.

Lymphocytopenia alone may not cause any signs or symptoms. As a result, the condition often is diagnosed during testing for other diseases or conditions.

Specialists Involved

Your primary care doctor may notice that you have unusual infections, repeat infections, and/or infections that won't go away. These may be signs of lymphocytopenia. Your primary care doctor may refer you to an infectious disease specialist to find out what's causing the infections.

You also may see a hematologist (blood disease specialist) or an immunologist (immune disorders specialist). Blood diseases and immune disorders can cause lymphocytopenia.

Medical History

To learn about your medical history and your risk for a low lymphocyte count, your doctor may ask:

• About your risk for AIDS, including questions about blood transfusions, sexual partners, intravenous (IV) drug use, and exposure to infectious blood or bodily fluids at work
• Whether you've ever received radiation or chemotherapy (treatments for cancer)
• Whether you've ever been diagnosed with a blood disease or immune disorder, or whether you have a family history of such illnesses

Physical Exam

Your doctor will do a physical exam to look for signs of infection, such as fever. He or she may check your abdomen for signs of an enlarged spleen and your neck for signs of enlarged lymph nodes.

Your doctor also will look for signs and symptoms of diseases and conditions that can affect your lymphocyte count, such as AIDS and blood cancers.

Diagnostic Tests

Your doctor may order one or more of the following tests to help diagnose a low lymphocyte count.

Complete Blood Count With Differential

A complete blood count (CBC) measures many different parts of your blood. It checks the number of red blood cells, white blood cells, and platelets in your blood. The CBC shows whether you have a low number of white blood cells.

Lymphocytes account for 20 to 40 percent of all white blood cells. Although a CBC will show an overall low white blood cell count, it won't show whether the number of lymphocytes is low.

You may need a more detailed test, called a CBC with differential, to see whether you have a low lymphocyte count. This test shows whether you have low levels of different types of white blood cells, such as lymphocytes. The results of this test can help your doctor diagnose lymphocytopenia.

Flow Cytometry

This test looks at many types of blood cells. It's even more detailed than a CBC with differential.

Flow cytometry can measure the levels of the different types of lymphocytes—T cells, B cells, and natural killer cells. This can help diagnose the underlying cause of lymphocytopenia. Some underlying conditions cause low levels of T cells. Others may cause low levels of B cells or natural killer cells.

Tests for Underlying Conditions

A number of diseases and conditions can cause lymphocytopenia. Thus, your doctor will want to find out what's causing the condition. You may be tested for HIV/AIDS, tuberculosis, blood diseases, and immune disorders.

Tests for these underlying conditions might include blood tests, bone marrow tests, and lymph node tests.

Lymph nodes are part of the immune system. They're found in many places in your body. During a physical exam, your doctor may find that certain lymph nodes are swollen. In lymphocytopenia, the lymph nodes may hold on to too many lymphocytes and not release them into the bloodstream.

To test a lymph node, you may need to have it removed. This involves a minor surgical procedure.

How Is Lymphocytopenia Treated?

If you have mild lymphocytopenia with no underlying cause, you may not need any treatment. The condition may improve on its own.

If you have unusual infections, repeat infections, and/or infections that won't go away due to lymphocytopenia, you'll need treatment for the infections.

If you have a disease or condition that's causing lymphocytopenia, your doctor will prescribe treatment for that illness. Treating the underlying problem will help treat the lymphocytopenia.

Treatment for Infections

Low levels of lymphocytes make it harder for your body to fight infections. You may get infections caused by viruses, fungi, parasites, or bacteria.

Treatment for the infections will depend on their causes. You also may need treatment after an infection is gone to help prevent future infections.

Children who have serious bacterial infections that keep coming back may get a medicine called immune globulin. This medicine helps boost their immune systems and fight the infections.

Treatment for Underlying Diseases or Conditions

A number of diseases and conditions can cause lymphocytopenia. Examples include infectious diseases, such as AIDS; blood diseases, such as aplastic anemia; and inherited diseases, such as Wiskott-Aldrich syndrome.

Your treatment will depend on your underlying disease or condition.

Emerging Treatments

Researchers are looking at ways to increase lymphocyte production in people who have lymphocytopenia with serious underlying conditions.

For example, some studies are looking into blood and marrow stem cell transplants. Conditions that cause the body to not make enough blood cells, including lymphocytes, may cause lymphocytopenia. A blood or marrow stem cell transplant may help treat or cure some of these conditions.

Other studies are looking at medicines and other substances that can help the body make more lymphocytes.

Talk to your doctor about whether a clinical study might benefit you.

How Can Lymphocytopenia Be Prevented?

You can't prevent lymphocytopenia that's due to an inherited cause. However, you can take steps to control the condition. Follow your treatment plan and take all medicines as your doctor advises.

You may be able to lower your risk for acquired lymphocytopenia by lowering your risk for the conditions that cause it. For more information about acquired causes of the condition, see "What Causes Lymphocytopenia?"

Living With Lymphocytopenia

If you have mild lymphocytopenia with no underlying condition, you may not need treatment. The lymphocytopenia may improve on its own.

If an underlying condition is causing your lymphocytopenia, you'll need treatment for that condition. You'll also need treatment for infections if your body is unable to fight them due to lymphocytopenia.

Treating and Preventing Infections

The main risk of lymphocytopenia is getting unusual infections, repeat infections, and/or infections that won't go away. If you have lymphocytopenia, you may get treatment to prevent infections or to treat infections you already have.

You also can take other steps to prevent infections. For example:

• Stay away from people who are sick, and avoid large crowds of people.
• Avoid certain kinds of foods that can expose you to bacteria, such as uncooked foods.
• Wash your hands often.
• Brush and floss your teeth and get regular dental care to reduce the risk of infection in your mouth and throat.
• Ask your doctor whether you should get a yearly flu shot and the pneumonia vaccine.

It's important to know the signs of infection, such as fever. Call your doctor right away if you think you have an infection.

Living With Underlying Conditions

If you have a disease or condition that causes lymphocytopenia, you need to get treatment for that condition.

You'll probably have regular tests to see how the treatment is working. For example, you may have blood tests to check the level of lymphocytes in your blood.

If the treatments for the underlying condition are working, the level of lymphocytes in your blood may go up.

Physical Activity

Talk to your doctor about what types and amounts of physical activity are right for you. You may want to avoid activities that could result in injuries or increase your risk for infections.

Key Points

• Lymphocytopenia is a condition in which your blood has a low number of white blood cells called lymphocytes.
• Lymphocytes help protect your body from infection. When your blood has a low number of lymphocytes, you have an increased risk for infection.
• 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.
• 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 is lower than normal.
• In general, a low lymphocyte count develops for one or more of these reasons:
  • The body doesn't make enough lymphocytes.
  • The body makes enough lymphocytes, but they are destroyed due to an abnormal condition.
  • The lymphocytes get stuck in the spleen or lymph nodes.
• A number of diseases, conditions, and factors can cause the problems that lead to lymphocytopenia. These conditions can be inherited or acquired. The inherited conditions are rare. A common acquired cause of lymphocytopenia is AIDS.
• Lymphocytopenia alone may not cause any signs or symptoms. The condition usually is found when a person is tested for other diseases or conditions, such as AIDS. If you have unusual infections, repeat infections, and/or infections that won’t go away, your doctor may suspect that you have lymphocytopenia.
• Your doctor will diagnose lymphocytopenia based on your medical history, a physical exam, and tests results.
• Treatment for lymphocytopenia depends on its cause and severity. Mild lymphocytopenia with no underlying cause may not require treatment. If you have unusual infections, repeat infections, and/or infections that won't go away due to lymphocytopenia, you'll need treatment for the infections.
• You can't prevent lymphocytopenia that's due to an inherited cause. You may be able to lower your risk for acquired lymphocytopenia by lowering your risk for the conditions that cause it.
• The main risk of lymphocytopenia is infections. If you have lymphocytopenia, take steps to prevent infections and report any signs of infection to your doctor right away. Fever is the most common sign of infection.

Links to Other Information About Lymphocytopenia

Non-NHLBI Resources

• Lymphocytopenia (MedlinePlus)

Clinical Trials

• Current Research (ClinicalTrials.gov)
• NHLBI Pediatric Clinical Trials