Test & Diagnostics 571

Lymphocyte percentage - Biomarker

2 min read

Simon Körösi

Reviewed by: Gustav Grippe

Why measure lymphocyte percentage?


Normal levels of lymphocytes suggest that your immune system is in balance, and that the immune system is not fighting off various infections nor handling chronic processes and conditions such as autoimmune disorders and leukemia.

Maintaining normal levels of lymphocytes is associated with a longer and healthier life.

Measuring lymphocyte percentage can consequently give you important information about your body’s immune system and overall health. It plays a vital role when measuring the complete blood count, and there are several reasons where measuring lymphocyte percentage is relevant, including:

Help in diagnosing and monitoring diseases affecting lymphocytes


Quantifying immune response


Monitoring and evaluating treatments affecting the immune system


Evaluating side effects of treatments


To measure biological age with the Levine clock

What is lymphocyte percent?


Lymphocytes are a type of white blood cells that plays a vital role in our immune system.

Lymphocyte percent refers to the percentage of white blood cells in the body that are lymphocytes.



What does a high lymphocyte percentage mean?


A high lymphocyte percentage, also known as lymphocytosis, generally means that the immune response is activated. To better understand exactly why it is activated, further investigation and testing may be necessary. In many cases, bacterial or viral infections are the underlying cause. The severity can differ, but the immune system will activate to fight off these invading pathogens. Sometimes, when the body misinterprets its own tissues or organs as hostile, the immune system will activate towards the presumed hostile target, causing an activation of the immune system towards the specific tissue. This is known as an autoimmune disorder, and can occur to almost any of the tissues in our bodies. Medications and treatments that cause damage to organs and tissues, such as radiation therapy, may also activate the immune system resulting in an increased lymphocyte percentage. In very rare cases, cancers affecting the lymphatic system such as leukemia and lymphoma can cause an increase in the lymphocyte percentage, but to even raise that suspicion, many more tests together with various symptoms will be deviation from the normal.



What does a low lymphocyte percent mean? 


A low lymphocyte percentage, also known as lymphocytopenia, implies that you have a lower amount of lymphocytes among your total amount of white blood cells. The common denominator and implication of a low lymphocyte percentage, is that the immune system is suppressed rather than overactive.This can be a result of various conditions, including malnutrition and severe stress. Viral infections targeting the immune system such as HIV and bone marrow disorders are rare but yet occurring reasons for low percentages, as is immunosuppressive medication.

Important note: A low lymphocyte percentage alone isn’t enough for diagnosing any specific condition. A divergent percentage will need further testing and investigation to determine the underlying cause.



What is a normal lymphocyte percentage?


Lymphocyte percentage is measured as part of a complete blood count test (CBC).
Normal lymphocyte percent range may vary due to factors including age and overall health, but in general falls between 20% and 40% of total white blood cells.