Lymphocytes

Lymphocytes are one of the five white blood cells. Each white blood cell has a specific function but works together to fight illnesses and diseases. Your white blood cells are important to your immune system’s function.

These cells help the body fights antigens, such as viruses, bacteria and other toxins that cause sickness. A weakened immune system means you do not have enough white blood cells in your bloodstream.

How do lymphocytes work?

Lymphocyte production in the body takes place in your bone marrow. Most lymphocytes move through the lymphatic system, and some enter your bloodstream. The lymphatic system consists of a group of organs and tissues, such as lymph nodes, tonsils and the spleen, which protect the body from infection.

Around 25% of the produced lymphocytes remain in the bone marrow to form B cells, while the remaining 75% enter the thymus to become T cells.

Different kinds of T and B cells are available. They include:

• The memory cells that have been in the body long enough to recognise past infections and take action quickly if reinfection occurs with an antigen
• The effector cells, which are activated by antigens to fight an active infection

The B and T lymphocytes work together to fight infection

What are the roles of B and T cells?

The B cells recognise antigens and form plasma cells that produce antibodies to fight off the infection.

Three T cell types are available, each with a specific function. They include:

• Cytotoxic T cells

  These cells are also known as killer T cells. They destroy the cells in the body infected with antigens, foreign cells like transplanted organs and cancer cells.

• Helper T cells

  They help direct the immune system’s response to B cells and other T cells.

• Regulatory T cells

  They suppress the immune system to ensure their response is in check. Besides preventing autoimmune disease, regulatory T cells prevent other white blood cells from fighting perceived or real antigens.

  Perceived antigens are substances such as normal flora, bacteria in the gastrointestinal tract and allergens. Allergens are substances that cause allergic reactions like mould, pet dander and pollen.

B and T cell screening

If you experience an infection or blood disorder symptoms, your overall lymphocyte count will be abnormal. In this case, the doctor may order a B and T screen. This blood test checks the number of lymphocytes in your bloodstream. An elevated or low lymphocyte count may indicate an illness.

You will have your blood drawn at the lab or doctor’s office for this test, and the blood analysis will be in the lab. Your healthcare provider will receive the test result and explain its implications.

A few factors can affect your blood test result, so ensure you inform your doctor if you:

• Have HIV
• Had surgery
• Had radiation therapy
• Had a recent infection
• Had chemotherapy
• Had steroid therapy

What do the test results mean?

Different laboratories have varying ways of measuring their blood test results. These results vary depending on the following:

• Gender
• Age
• Living in high altitude
• Heritage

The table below gives the approximate ranges for adults.

Causes of low lymphocyte counts 

Lymphocytopenia or low lymphocyte count often occurs for the following reasons.

• Your lymphocytes are getting destroyed
• Your lymphocytes are trapped in the lymph nodes or spleen
• Your body is not producing sufficient lymphocytes

A low lymphocyte count may occur from several diseases and conditions. They include mild infections or the flu, which aren’t serious for most people, but lymphocytopenia increases your risk of infection.

Other conditions that may cause a low lymphocyte count include:

• Influenza
• HIV and Aids
• Undernutrition
• Certain drugs, including chemotherapy drugs
• Some cancers, including lymphoma, lymphocytic anaemia and Hodgkin’s disease
• Autoimmune conditions like lupus
• Steroid use
• Some inherited disorders, such as DiGeorge syndrome and Wiskott-Aldrich syndrome

Causes of high lymphocyte counts

An elevated lymphocyte count or lymphocytosis is common during an infection. High lymphocyte levels that remain for a prolonged period may indicate a more serious disease or illness, such as:

• Toxoplasmosis
• Hepatitis
• Tuberculosis
• Adenovirus
• Viral infections, including mononucleosis, mumps and measles
• Influenza
• Vasculitis
• Brucellosis
• Cytomegalovirus
• Acute lymphocytic leukaemia

Questions to ask your doctor

Asking your doctor the following questions if they order, a B and T cell screening is necessary.

• Why do I need this test?
• Is the test for a specific condition?
• When will my result be available?
• Do I need any special preparation for this test?
• Who will give me the result and explain it?
• If my test result is abnormal, what will be my next steps?
• If my test result is normal, what will be my next steps?
• What self-care tips are necessary while waiting for for my result?

You can visit our Clinic at Suite E, 117a Harley St, Marylebone, London W1G 6AT if you need B and T cell screening tests. Our healthcare professionals can perform a lymphocyte blood test. Call us today on 02071830244 for more information on our tests or to schedule an appointment for your B and T cell test.