Lymphocytosis Explained: Causes, Symptoms, and Treatments

What is Lymphocytosis (High Lymphocyte Count)?

Our bodies respond to infections or diseases by activating white blood cells known as lymphocytes. When the count of these cells significantly increases in your bloodstream, we refer to this condition as Lymphocytosis, or high lymphocyte count. It's essential to understand that lymphocytes play a critical role in your immune system, protecting you from harmful infections. Therefore, a temporary increase in lymphocyte count is usually a sign that your body is functioning correctly to ward off harmful germs. However, in some rare cases, Lymphocytosis could be indicative of more severe conditions. For adults, a high lymphocyte count typically means more than 4,000 lymphocytes per microlitre of blood.

How Common is Lymphocytosis?

Lymphocytosis isn't an uncommon occurrence. It frequently presents itself among people who have:

• Recently overcome an infection (usually viral)
• Medical conditions causing long-lasting inflammation, like rheumatoid arthritis
• Newly administered medication
• Experienced severe medical illnesses such as trauma
• Undergone spleen removal
• Certain types of cancer, like leukaemia or lymphoma

What Causes Lymphocytosis?

Infections

A high lymphocyte count often suggests that your body is battling an infection or inflammatory condition. These white blood cells work tirelessly to eliminate any foreign threats that might make you ill.

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

Sometimes, Lymphocytosis could be an early sign of certain blood cancers (like leukaemia) or cancers affecting your lymphatic system (like lymphoma).

Examples of cancers associated with Lymphocytosis are:

• Chronic lymphocytic leukaemia
• Non-Hodgkin lymphoma
• Acute lymphoblastic leukaemia
• Large granular lymphocytic leukaemia

Other Causes

There are also non-infectious factors that may contribute to a high lymphocyte count.

These include:

• Smoking
• Allergic reaction to medication
• Stress related to a medical emergency
• Certain autoimmune diseases
• Asplenia (removal of your spleen)

What are the Symptoms of Lymphocytosis?

Lymphocytosis usually doesn’t cause any symptoms on its own. However, the underlying issue that raises your white blood cell count might lead to symptoms. For example, if you have an infection, you could notice swollen lymph nodes in your neck. Symptoms can vary from mild to severe, depending on the cause. Many people only discover they have a high lymphocyte count during blood tests for other conditions.

How is Lymphocytosis Diagnosed?

Healthcare providers assess lymphocytosis by reviewing your medical history, current symptoms, medications, and conducting a physical exam. They may also ask about your lifestyle and habits to evaluate your risk for specific infections, including sexually transmitted infections (STIs). A key component of the diagnosis is a blood test to measure your lymphocyte count.

What Tests Will Be Done to Diagnose Lymphocytosis?

After identifying a high lymphocyte count, your healthcare provider may order a complete blood count (CBC) with differential. This test helps confirm whether your lymphocyte levels are elevated. Depending on the findings, further tests like flow cytometry may be necessary to determine if the lymphocytes are clonal, which can suggest conditions such as chronic lymphocytic leukaemia. In certain situations, a bone marrow biopsy might also be required to investigate the underlying cause of lymphocytosis.

How is Lymphocytosis Treated?

The treatment for Lymphocytosis involves addressing the underlying cause, resulting in a high lymphocyte count. If your body is producing more white blood cells to combat an infection, you may not need treatment, as your immune system usually takes care of the issue. However, if the surge in white blood cells indicates cancer, you will need to discuss treatment options with your healthcare provider.

What Complications are Associated with Lymphocytosis?

In some cases, Lymphocytosis can be an early indicator of certain blood cancers. Chronic lymphocytic leukaemia (CLL), the most common form of leukaemia in adults, can often present with Lymphocytosis. Further testing is needed to rule out other medical conditions and confirm the cause of Lymphocytosis.

Can Lymphocytosis be Prevented?

Although lymphocytosis cannot be prevented, you can lower your risk of illness by taking certain precautions:

• Avoid physical contact with people carrying contagious diseases
• Refrain from sharing personal items with those who are sick
• Wash hands frequently and thoroughly using soap and water
• Regularly disinfect surfaces and items that may carry germs

What is the Outcome After Treatment of Lymphocytosis?

Typically, Lymphocytosis resolves after treating the condition or disease causing your body to produce extra white blood cells.

When Should I be Concerned About Lymphocytes?

Reach out to your healthcare provider if you have a persistent infection, chronic (ongoing) symptoms or symptoms that worsen over time. A complete medical examination can help determine if you have Lymphocytosis.

Does Lymphocytosis Lead to Leukaemia?

While it can, this is rare. Sometimes monoclonal B-cell Lymphocytosis (MBL) progresses to a specific leukaemia known as chronic lymphocytic leukaemia (CLL). With MBL, you have higher-than-normal amounts of clonal B-cells in your blood.

Conclusion

Lymphocytosis, or a high lymphocyte count, is often a sign of your body's hard work in fighting off infection or disease. However, if lymphocyte counts remain high for an extended period, it is vital to consult with healthcare professionals for further tests and possible treatments. At Metropolis Healthcare, we provide accurate pathology testing and health check-up services right at your doorstep. To learn more about our services and how we can assist you with your health journey, do visit the Metropolis Healthcare website today.