Chronic lymphocytic leukemia (CLL) affects cells that become lymphocytes. Monitoring the number of lymphocytes in the blood is important for many aspects of this form of cancer.
A healthy adult usually has lymphocyte counts
| Normal range | lymphocyte count between 1,000 and 4,800 μl |
|---|---|
| CLL | B-cell count of at least 5,000 μl |
The bone marrow produces lymphocytes. They are present in the lymphoid tissue such as the thymus, spleen, and lymph nodes and they circulate in the blood.
This article discusses how CLL affects the levels of these cells and what that might mean for a person’s outlook.
Not all individuals with CLL have symptoms. In some cases, the disease progresses slowly before symptoms develop. Therefore, doctors partly base the diagnosis of CLL on the level of lymphocytes in the blood.
There are two main types of lymphocytes: B cells and T cells. Both types of lymphocytes are part of the immune system and help the body fight viruses, bacteria, and other pathogens.
B-cell CLL affects the B cells and is the
Another rare form of cancer related to CLL that can develop as a result of uncontrollable B-cell growth is known as B-cell prolymphocytic leukemia. It typically occurs as a transformation or evolution of B-cell CLL.
T-cell prolymphocytic leukemia is another related, rare form of cancer that has a higher prevalence among males and older adults.
A normal lymphocyte range for adults is anywhere between
When someone develops CLL, they have a higher level of lymphocytes. However, these cells do not work as they should, so they do not fight infection properly.
If a person’s blood tests show an abnormally high lymphocyte count, they should consult a doctor. Depending on the underlying cause of the increased count, additional symptoms may occur.
For example, if high lymphocytes occur due to leukemia, the person may experience:
- recurrent infections
- shortness of breath
- fatigue
- chills
- night sweats
Although a high lymphocyte count can indicate CLL, it can also occur due to other conditions. In some cases, abnormally high lymphocyte levels can develop as a typical part of the body’s response to an infection. For instance, a viral infection, such as the flu, may lead to increased lymphocytes.
Increased counts can also sometimes develop due to an inflammatory condition, such as Crohn’s disease. In addition, high lymphocytes can also indicate other types of cancer, including multiple myeloma.
Although a lymphocyte level of at least 5,000 B cells helps doctors make a diagnosis, it does not appear to determine a person’s outlook.
Instead, researchers use staging systems for this purpose. A standard staging system for CLL is the
All stages include lymphocytosis. They also include the following:
- Rai stage 0: No spleen, liver, or lymph node enlargement. Platelet and red blood cell counts near normal.
- Rai stage 1: Enlarged lymph nodes, but liver and spleen not enlarged. Platelet and red blood cell counts near normal.
- Rai stage 2: Enlarged spleen and possibly enlarged lymph nodes and liver. Platelet and red blood cell counts near normal.
- Rai stage 3: Possibly enlarged liver, lymph nodes, or spleen. Red blood cell count is low, but platelet count is close to normal.
- Rai stage 4: Enlarged lymph nodes, liver, or spleen. Low platelet count, and red blood cell count may also be low.
CLL often progresses slowly. In many cases, the cancer is not curable, but treatment helps keep the symptoms at bay and slows the progression of the disease.
Not all people with CLL start treatment immediately after diagnosis. One factor in determining when to start treatment is the level of lymphocytes.
Research from 2017 shows that a
The presence of symptoms of leukemia also indicates the need for treatment to start.
Doctors determine lymphocyte counts through a B- and T-cell screen. This test involves a blood draw to measure the level of lymphocytes.
A lymphocyte count is part of a complete blood count, which measures red blood cells and platelets, as well as white blood cells. Doctors often order a complete blood count to help diagnose various illnesses and infections.
After finding an abnormally high lymphocyte level, a doctor may order a peripheral blood smear. This test looks at the maturity and form of the blood cells, providing the doctor with more information on the cause of high lymphocytes.
If the doctor suspects cancer, they may order a bone marrow biopsy. This involves removing a small amount of bone marrow, often from the hip bone, and sending it to a laboratory for analysis. The size, shape, and other traits of the cells help doctors determine a diagnosis.
The outlook for people with CLL often depends on the stage.
According to the
The 5-year relative survival rate for people with CLL is
It is important to note that survival rate statistics vary depending on a person’s stage at diagnosis and treatment options. A doctor can talk with a person about their individual outlook.
The number of lymphocytes, a type of white blood cell, increases with certain types of cancers. Therefore, a lymphocyte count of at least 5,000 B cells per μl of blood indicates the possibility of chronic lymphocytic leukemia (CLL).
However, increased lymphocytes also occur with other conditions, such as infections and inflammatory diseases.
Not everyone with CLL will require immediate treatment, but when lymphocyte levels increase quickly, this may indicate an advanced stage of cancer and the need for prompt treatment.