What is Lymphocytosis?
Lymphocytosis, also known as a high lymphocyte count, is an increase in the number of lymphocytes in your blood. Lymphocytes are a type of white blood cell crucial for fighting off infections and diseases. A temporary rise in lymphocyte count is common following an infection; however, a persistently high count may indicate a more serious underlying condition.
Lymphocytes are a vital component of the immune system. They are produced in the bone marrow and are found in the blood and lymph tissue. The two main types are B lymphocytes and T lymphocytes, each playing a unique role in immune responses.
Lymphocytosis is diagnosed when the absolute lymphocyte count (ALC) exceeds the normal range. In adults, this is generally defined as more than 4000 lymphocytes per microliter of blood. Source: StatPearls - NCBI Bookshelf
Causes of Lymphocytosis
A high lymphocyte count can stem from various factors, both benign and serious:
- Viral or bacterial infections: The body's natural response to infection often includes a temporary increase in lymphocytes. Source: Mayo Clinic This is often harmless and resolves once the infection clears. Examples include pertussis (whooping cough) and infectious mononucleosis. Source: ScienceDirect Topics
- Autoimmune diseases: Conditions where the immune system mistakenly attacks the body's own tissues can lead to elevated lymphocyte counts.
- Certain cancers: Some types of leukemia and lymphoma are characterized by an overproduction of lymphocytes. Source: Osmosis
- Medications: Some drugs can affect lymphocyte production.
- Other systemic disorders: Conditions affecting the entire body can sometimes manifest as lymphocytosis.
Symptoms of Lymphocytosis
Lymphocytosis itself often has no noticeable symptoms. Symptoms experienced are usually related to the underlying cause. For example, fever might be a symptom if the lymphocytosis is due to an infection. Source: PatientPower Swollen lymph nodes can also be a symptom. Source: Medical News Today
Diagnosis and Treatment
Diagnosis involves a complete blood count (CBC) to measure the lymphocyte count. Further investigations may be necessary depending on the results and any associated symptoms to determine the underlying cause. Treatment focuses on addressing the root cause, which may include antibiotics for infections, medication for autoimmune disorders, or cancer therapies.
