Lymphocytes "Lymphs" (Percent)

What is lymphocytosis?

A high lymphocyte count (= Lymphocytosis) means having a higher-than-normal amount of lymphocytes in your blood. 

What are Lymphocytes?

Lymphocytes are a type of white blood cell. 

What do Lymphocytes do?

They play an essential role in your immune system, helping your body fight infections.

Why do I have lymphocytosis?

Lymphocytosis often results from your immune system fighting off an infection or other disease. White blood cells called lymphocytes increase with these conditions. 

Having a temporarily high lymphocyte count usually means that your body is working as it should to protect you from germs that make you sick. Less often, lymphocytosis is a sign of a more serious condition.

What specifically can cause lymphocytosis?

A spike in your lymphocytes typically means that these white blood cells are springing into action to rid your body of an invader that can make you sick. Sometimes a serious condition, like cancers that affect your blood or lymphatic system, may cause elevated lymphocyte levels.

Many medical conditions can cause lymphocytosis. Here are a few:

Infections:

Lymphocytosis often results from viral infections. Bacteria and parasites can also cause infection, resulting in a high lymphocyte count. Infectious causes of lymphocytosis include:

→ Epstein-Barr virus (the virus that causes mononucleosis).

→ Cytomegalovirus (CMV).

→ Influenza (the flu).

→ Whooping cough.

→ Adenovirus.

→ Hepatitis.

→ Chickenpox or shingles.

→ Mumps.

→ Rubella.

→ HIV.

Cancer:

In some cases, lymphocytosis is one of the first signs of certain blood cancers (leukemia) or cancers of your lymphatic system (lymphoma). Cancers associated with lymphocytosis include:

→ Chronic lymphocytic leukemia.

→ Non-Hodgkin lymphoma.

→ Acute lymphoblastic leukemia.

→ Large granular lymphocyte leukemia.

Other causes:

→ Smoking.

→ Allergic reaction to medicine.

→ Stress related to a medical emergency.

→ Some autoimmune diseases.

→ Asplenia (removal of your spleen).

How common is lymphocytosis?

Lymphocytosis is very common, especially in people who have:

→ Had a recent infection (most commonly viral).

→ A medical condition that causes long-lasting inflammation, like rheumatoid arthritis.

→ A reaction to a new medication.

→ Severe medical illness, such as trauma.

→ Had their spleen removed.

→ Certain types of cancer, like leukemia or lymphoma.

Can lymphocytosis be prevented? 

Lymphocytosis is not preventable, but it can be treated by addressing what’s causing your temporary high lymphocyte count.

At what level do we talk about Lymphocytosis?

For adults, a high lymphocyte count means more than 3,100 lymphocytes in 1 microliter of blood.

Who is most at risk for getting lymphocytosis?

Anyone can have lymphocytosis.

What are the symptoms of lymphocytosis?

Lymphocytosis does not cause symptoms. However, you may experience symptoms from what is causing the spike in your white blood cell count. For instance, the lymph nodes in your neck may feel swollen due to an infection, which may be causing lymphocytosis. Depending on the cause, symptoms may range from no symptoms to severe.

Often, people learn of a high lymphocyte count incidentally after taking a blood test to check for other conditions.

How is lymphocytosis diagnosed?

Providers rely on your medical history, current symptoms, medication list, and a physical exam to help determine what is causing lymphocytosis. They may ask questions about your habits and lifestyle to see if you are at high-risk for certain infections, such as sexually transmitted infections (STIs). They may perform a blood test to check your lymphocyte count.

If your levels are high, your provider may retest later to see if the spike is temporary. If your levels remain high and your provider is unsure why, they may order additional tests. You may be referred to a blood specialist called a hematologist for a diagnosis.

What tests will be done to diagnose lymphocytosis?

Your provider may order a blood test called a complete blood count (CBC) with a differential. This test shows if you have a higher-than-normal amount of lymphocytes. They may order a flow cytometry test to see if the lymphocytes are clonal (seen in cancers like chronic lymphocytic leukemia). Testing may also include a bone marrow biopsy to help determine the root cause of lymphocytosis.

How is lymphocytosis treated?

Lymphocytosis treatment involves resolving what is causing the high lymphocyte count. If your body is producing white blood cells to fight a germ, you may not need treatment. In time, your immune system can usually take care of the issue. If the spike in white blood cells is a sign of cancer, you can discuss treatment options with your provider.

Receiving treatment for the underlying cause can help restore your lymphocyte levels to normal.

What complications are associated with lymphocytosis?

In some cases, lymphocytosis is one of the first signs of certain blood cancers, including chronic lymphocytic leukemia (CLL), the most common type of leukemia in adults. Further tests are usually necessary to rule out other medical conditions and make a firm diagnosis of the cause of lymphocytosis.

What is the outcome after treatment of lymphocytosis?

Lymphocytosis usually goes away after treatment for the condition or disease that caused your body to produce extra white blood cells.

Can lymphocytosis be prevented?

Lymphocytosis is not preventable. You can reduce your risk by taking steps to keep from getting sick:

→ Avoid physical contact with people who have a contagious bug.

→ Do not share personal items with people who are sick.

→ Wash your hands frequently and thoroughly with soap and water.

→ Disinfect surfaces and commonly used items that may carry germs.

When should I be concerned about high lymphocytes?

Contact your provider if you have a persistent infection or experience chronic (ongoing) symptoms or symptoms that get worse over time. Your doctor can determine if you have lymphocytosis during a complete medical examination.

What does a low Lymphocyte count mean?

A low lymphocyte count is known as Lymphocytopenia (or lymphopenia) and it occurs when the lymphocyte count in your blood is lower than usual (below the laboratories reference ranges).

Severe and chronic low counts:

Severe or chronic low counts can indicate a possible infection or other illness and should be investigated by your doctor.

Low levels of T cells or too few NK cells can lead to uncontrolled viral, fungal, and parasitic infections. B-cell lymphocytopenia can lead to an increase in harmful and different types of infections.

What causes a low Lymphocyte count?

Lymphocytopenia (or lymphopenia) may be a sign of an underlying illness, condition, or another factor. Causes are usually acquired, which means that you develop rather than inherit them.

Autoimmune disorders:

Autoimmune disorders occur if the immune system is in overdrive and incorrectly attacks the body’s cells and tissues. 

These can include: lupus, myasthenia gravis, rheumatoid arthritis.

Certain immunosuppressant medications used to treat autoimmune disorders may cause lymphocytopenia.

Cancer and treatments for cancer:

Lymphoma (such as Hodgkin’s lymphoma), Kaposi sarcoma, and leukemia are among the most common cancers that can cause low lymphocyte levels.

The following cancer treatments may also result in lymphocytopenia:

→ chemotherapy

→ radiation therapy

Diseases that affect the blood and bone marrow:

These conditions can cause low lymphocyte levels:

→ aplastic anemia

→ lymphoproliferative disorders

Infections:

Viral, bacterial, parasitic, and fungal infections are common causes of lymphocytopenia. Any type of infection may cause your lymphocyte count to fall. For example:

→ HIV

→ histoplasmosis

→ influenza

→ malaria

→ viral hepatitis

→ tuberculosis

→ typhoid fever

Sepsis:

Lymphocytopenia may be a sign of sepsis or acute bacteremia. 

Inherited causes:

Inherited or congenital causes of lymphocytopenia are rare. Some of these are:

→ ataxia-telangiectasia

→ DiGeorge syndrome

→ severe combined immunodeficiency

→ Wiskott-Aldrich syndrome

Nutritional causes:

Malnutrition or undernutrition is a common global cause of lymphocytopenia. This occurs when the body lacks protein and other nutrients necessary to produce lymphocytes.

An eating disorder, such as anorexia nervosa, may lead to reduced-production lymphocytopenia.

Gastrointestinal conditions:

Conditions that damage the gut wall can affect the body’s absorption of nutrients and may lead to lymphocytopenia in some cases. These are generally referred to as protein-losing enteropathy and include:

→ amyloidosis

→ celiac disease

→ inflammatory bowel disease, such as Crohn’s disease or ulcerative colitis

→ regional enteritis

→ zinc deficiency

Specific medications:

In addition to cancer treatments, several drugs can reduce lymphocytes. Medication-induced lymphocytopenia ranges from minor to severe.

The following medications may lower your lymphocyte level:

- azathioprine (Imuran, Azasan)

- carbamazepine (Tegretol, Epitol)

- cimetidine (Tagamet)

- corticosteroids

- dimethyl fumarate (Tecfidera)

- imidazoles

- interferons

- methotrexate (Trexall, Rasuvo)

- opioids

- certain bisphosphonate therapy for osteoporosis

Kidney disease:

Kidney disease, particularly late stage chronic disease, can reduce the number of T cells in the blood, but lymphocytopenia can also occur in acute kidney injury.

Trauma and surgery:

Trauma from an injury or acute emergency such as cardiac failure can lower lymphocyte counts. Undergoing surgeries such as cardiac bypass can also cause lymphocytopenia.

Other causes:

Other causes of lymphocytopenia include stress and alcohol misuse.

Additionally, there is a rare condition known as idiopathic CD4-positive lymphocytopenia, in which the cause is unknown.

What are potential treatment options?

Treatment depends on the cause and treating the underlying factor usually resolves lymphocytopenia. You may also require therapy to prevent infections or other complications due to a compromised immune system.

If a medication is causing low counts, your doctor may stop or change the medication. Drug-related lymphocytopenia usually clears up after a person stops taking the drug.

Prevention:

You may not be able to fully prevent lymphocytopenia, but you can help boost your immune system and protect yourself against infections. Follow a healthy diet plan, get plenty of rest, and avoid germs as your body recovers its lymphocyte levels.

- Eat a nutrient-rich diet to feel better and more energized. Your doctor or nutritionist can help you choose whole foods that are right for you and are packed with protein and healing minerals and vitamins.

- Wash your hands thoroughly with warm, soapy water several times a day to help prevent illness. Use a hand sanitizer if you’re out and avoid crowded areas.

- Stay away from animals or ask someone else to clean up after pets.

- Be very careful or avoid activities that may cause cuts, scrapes, or even nicks on your skin.

- Ask friends and family members to delay visiting you if they’re not feeling well.

Additional notes:

Lymphocytopenia is a common diagnosis from a complete blood count test. Some people may have values slightly less than the usual range without any reason. Low counts are also common in older adults with no concerning symptoms.

This condition may reflect illness, recent surgery, or drug therapy and is usually reversible. Your doctor will look over your current and previous medical history to see if the lymphocytopenia is a new condition. Most cases resolve spontaneously without medical care.

If you receive a diagnosis of acute lymphocytopenia, your doctor will carefully monitor your levels with follow-up blood tests. You may need further tests and treatment to address the main cause. This may involve specialist referrals, blood tests, imaging, or a bone marrow biopsy.