Lymphocytes
Also known as: lymphocyte count, lymphs
The white blood cells of adaptive immunity: B cells that make antibodies, T cells that direct the response and kill infected cells, and natural killer cells. The lymphocyte count rises in many viral infections and falls with steroids, HIV and some cancers.
- Also known as
- lymphocyte count, lymphs
- Units
- ×10⁹/L
- Measured by
- Full blood count
What it is and what it does
Lymphocytes circulate between blood, lymph nodes, the spleen and the tissues, and most of them are outside the bloodstream at any moment. In children the normal count is much higher than in adults. A high count is common in viral infections such as glandular fever and in whooping cough; a persistently high count in an older adult raises the question of chronic lymphocytic leukaemia. A low count is seen with corticosteroids, acute illness, HIV infection, some autoimmune diseases and after chemotherapy or radiotherapy.
Why it may be higher
- Viral infections (glandular fever, cytomegalovirus, hepatitis, many childhood viruses)
- Whooping cough, tuberculosis, brucellosis
- Chronic lymphocytic leukaemia and lymphoma
- Smoking; after removal of the spleen
Why it may be lower
- Corticosteroids and acute stress or illness
- HIV infection
- Chemotherapy, radiotherapy, immunosuppressants
- Lupus, kidney failure, severe sepsis, malnutrition
- Bone-marrow failure
A high or low value can be associated with several different situations. The result is interpreted with other results, symptoms, history and clinical findings.
What can affect the result
- Age: children run much higher counts
- A recent viral illness can leave the count changed for weeks
- Steroid dose timing