Overview

Lymphocytes are a type of white blood cell crucial for the immune system. Comprising T, B, and natural killer cells, they play key roles in defending the body against infections, viruses, and abnormal cells. Lymphocytes are produced in lymphoid tissues, such as the lymph nodes, and circulate throughout the bloodstream to combat pathogens.

Lymphocytes help fight cancer, harmful bacteria and foreign viruses by boosting your immune system. In simple words, there are a few types of white blood cells, and lymphocytes are one of them. The level of lymphocyte count differs, and it heavily depends upon the age, race, gender, and lifestyle of the person.

[caption id="attachment_23308" align="alignnone" width="1426"] Types of Lymphocytes[/caption]

Function of Lymphocytes

Lymphocytes contribute to your body's defence system, which is the immune system that helps protect you against antigens, cancers, and foreign viruses.

- Immune Response: Lymphocytes, specifically T and B cells, are key components of the adaptive immune system. They recognise and target specific pathogens, facilitating an immune response tailored to the invader.
- Cell-Mediated Immunity: T cells, including helper and cytotoxic T cells, contribute to cell-mediated immunity. They assist other immune cells and directly destroy infected or abnormal cells.
- Antibody Production: B cells produce antibodies, proteins that bind to and neutralise harmful substances such as viruses and bacteria.
- Memory Response: Memory B and T cells retain information about previously encountered pathogens. In subsequent infections, these memory cells mount a quicker and more effective immune response.
- Surveillance: Natural Killer (NK) cells, a type of lymphocyte, play a role in immune surveillance by identifying and destroying abnormal cells, such as cancer cells.

[caption id="attachment_23309" align="alignnone" width="1945"] Anatomy of Lymphocytes[/caption]

Anatomy of Lymphocytes

The type of white cells that come under the category of Lymphocytes are typically produced in the bone marrow. When the cells mature, they get released into the bloodstream. You can find mature lymphocytes in every part of the lymphatic system and your blood. There is a chance that some of the cells might travel to your thymus gland. The cells that go into the thymus gland are called T cells. The other cells which travel to your organs and nodes are called B cells.

You can't see lymphocytes because they are microscopic, even though they are a little larger than the red blood cells. You can find a big nucleus at each of the lymphocyte centres. The nucleus itself has a centre that is dark purple. Each cell is also surrounded by a purplish fluid that is jelly-like. These are called cytoplasm.

Levels of Lymphocytes

The Normal Range Of Lymphocytes

As lymphocytes vary due to age, sex, lifestyle, race, and many more factors, giving everyone the same number of lymphocytes as the normal range is hard. However, an estimate can be made about the normal count range of lymphocytes. In adults, you can find that in every 1 microlitre of blood, there are 1000 - 4800 lymphocytes. For children, every microlitre of blood holds 3000 to 9500 lymphocytes. Almost 20 to 40% of human white blood cells are lymphocytes.

What Does a High Lymphocyte Count Mean?

When one has more than the normal range of lymphocytes in their body, they get lymphocytosis. The most likely causes behind someone getting lymphocytosis are some kind of illness or infection. However, some other serious conditions can be the underlying cause of lymphocytosis. These include —

- AIDS and HIV
- Syphilis
- Hepatitis
- Mononucleosis
- Hypothyroidism or Underactive thyroid
- Tuberculosis
- Various infections such as cytomegalovirus, whooping cough, toxoplasmosis
- Leukaemia or Lymphoma, such as blood cancer.

What Does A Low Lymphocyte Count Mean?

When a person has a low level of lymphocytes, they develop a condition called lymphopenia or lymphocytopenia. Some mild infections and the flu are the most likely cause of lymphopenia. However, just like lymphocytosis, lymphopenia can be caused by some serious underlying illness or condition, which are —

- Treatments which include chemotherapy and radiation
- Typhoid fever or Tuberculosis
- HIV and AIDs
- Lupus-like autoimmune diseases
- Viral hepatitis
- Some blood diseases such as Hodgkin’s disease

Other than these, some rare genetic conditions can also cause lymphopenia. These are ataxia telangiectasia, SCID or severe combined immunodeficiency, Wiskott-Aldrich syndrome, and DiGeorge Syndrome.

When to Consult a Doctor

You can also get in touch with the expert Hematology doctors at Narayana Healthcare based in your city to get immediate attention and medical support during injuries, health disorders or any other health concern.

Conclusion

Lymphocytes are a part of your immune system, and they help you fight infections and diseases. During the regular blood test, you can check your lymphocyte count at your healthcare provider's office. If you see your lymphocyte count being high or lower than normal, it might raise anxiousness in you about what that means.

In most cases, when the body is fighting against infection, the lymphocyte count may differ from the normal range. However, if you believe you have reasons to be worried, it's always better to get advice from your healthcare provider for any underlying cause.

Reference Links

- https://my.clevelandclinic.org/health/body/23342-lymphocytes
- https://www.medicalnewstoday.com/articles/320987