Lymphocytes Blood Test (B-Lymphocytes) – Assess Adaptive Immunity
B-Lymphocytes are a type of white blood cell that plays a central role in the adaptive immune system. They produce antibodies and coordinate long-term immune responses. Lymphocytes are produced in the bone marrow and circulate in the blood, lymph, and body tissues. Measuring their levels helps evaluate chronic infections, immunodeficiency, autoimmune disease, and blood cancers.
Why Test Lymphocytes Blood Test?
Measuring lymphocyte levels is useful for evaluating long-term infections, suspected immunodeficiencies, chronic inflammation, autoimmune diseases, or blood cancers such as leukemia or lymphoma. The test is often included in an extended blood panel to provide a complete immune profile.
What Do High Lymphocytes Blood Test Levels Mean?
Elevated lymphocytes (lymphocytosis) may suggest an active immune response. Possible causes include viral infections (mononucleosis, hepatitis, influenza), chronic infections (tuberculosis), autoimmune diseases, lymphatic blood cancers (leukemia, lymphoma), and long-term inflammation.
What Do Low Lymphocytes Blood Test Levels Mean?
Low lymphocytes (lymphocytopenia) may indicate immune suppression. Common causes include viral infections (HIV, measles), autoimmune diseases, kidney or liver disease, malnutrition, chemotherapy, corticosteroid treatment, and bone marrow disorders.
Symptoms to Watch For
- Recurrent or long-term infections
- Fever without obvious cause
- Swollen lymph nodes
- Persistent fatigue
- Unexplained weight loss
- Night sweats
Who Should Get Tested?
- People with recurrent or chronic infections
- Those with swollen lymph nodes or unexplained fever
- Patients with suspected autoimmune disease or cancer
- Anyone after immunosuppressive treatment
- Individuals with persistent fatigue or weight loss
How to Prepare for Your Test
No special preparation is needed. Bring valid ID to your appointment.
Frequently Asked Questions
What is a normal lymphocyte count?
Can a viral infection raise lymphocytes?
What is the difference between T-cells and B-cells?
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Wellth Team
Wellth
Our content is written and reviewed by Wellth, and fact-checked against peer-reviewed research and current Swedish clinical guidelines.
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The information on this page is provided for informational purposes only and does not constitute professional medical advice, diagnosis, or treatment. Wellth provides health information and testing services but is not a substitute for clinical care. Always consult a qualified healthcare provider if you have questions about a medical condition. If you are experiencing severe or urgent symptoms, contact your doctor or call 1177 Vårdguiden. Blood test results should be interpreted by a qualified healthcare professional in the context of your complete medical history.