Chronic lymphocytic leukemia

Medical quality assurance by Dr. Albrecht Nonnenmacher, MD at February 27, 2016
StartDiseasesChronic lymphocytic leukemia

A type of leukemia, chronic lymphocytic leukemia (CLL) is generally a slow-growing cancer which begins in the lymphocytes in the bone marrow and extends into the blood.


Definition & Facts

Chronic lymphocytic leukemia affects the white blood cells, lymphocytes, and bone marrow. Lymphocytes are important to the body and the immune system. They determine how the immune system will respond to infections and foreign substances present in the body. Chronic lymphocytic leukemia tends to progress slowly over many years.

The lymphocyte becomes affected when it begins to function abnormally. Once affected it only partially matures and never reaches full maturity. The modified cells carry out some of the normal functions in fighting against infections. The infected cells multiply over time, ultimately blocking out healthy blood cells; this reduction in healthy cells can lead to infections including anemia and excessive bleeding due to the interference of normal blood cell production in the bone marrow.

The leukemic infected cells travel through the bloodstream to other areas of the body, such as the lymph nodes, liver, and spleen. The functions of these organs become compromised. Ninety-five percent of CLL cases start in the B lymphocyte (B cells).

The American Cancer Society estimates around 14,600 people are diagnosed each year in the United States. Chronic lymphocytic leukemia is the most common type of leukemia in adults and accounts for one-third of all cases. This type of leukemia does not affect children.

Symptoms 8 Complaints

In the early stages of the disease there are no noticeable symptoms but as the condition progresses symptoms can develop including:

Many people with the disease do not exhibit any symptoms, with 50 out of every 100 cases diagnosed when an individual has a routine blood test for another reason. The symptoms are mild at beginning and become progressively worse over the course of the condition. Due to the symptoms experienced many sufferers feel as if they have the flu.


The cause of Leukemia is unknown, but there are some factors which increase the likelihood of getting the disease. Chronic lymphocytic leukemia can run in families, and be inherited in a genetic mutation in the DNA of blood-producing cells. Individuals from a European, American and Australian origin are the most commonly affected by the condition. It also affects those with light skin more often than dark skinned people. It is unknown why it affects certain ethnic backgrounds more than others.

Exposure to environmental toxicants such as certain herbicides and insecticides are linked to an increased risk of developing the disease. Research in the condition shows that having another medical condition increases the risk of developing CLL. The conditions include shingles, sinusitis, pneumonia, chronic osteoarthritis and prostatitis - an inflamed prostate.

These conditions can also occur as a result of a weakened immune system from the decreased numbers of white blood cells present in the body. Diseases such as HIV or taking a medication that lowers the immune system can also increase the risk of developing CLL.

Men are twice as likely to develop CLL than women. The risk of developing the disease increases with age. People diagnosed with CLL are at risk of developing a more aggressive form of cancer or another cancer such as melanoma.

Diagnoses & Tests

There are several tests for diagnosing the disease, but most cases are diagnosed when an individual is checked for other health reasons. An individual suspected of having leukemia is referred to a hematologist, a doctor who specializes in conditions affecting the blood. The blood sample will be taken and sent to a laboratory for a complete blood count.

An abnormally high number of white blood cells suggests the individual may have chronic lymphocytic leukemia. Chest X-rays are often used to see if there are any changes in the tissues and organs of the individual. A physical examination is carried out to check the size of the spleen. A bone marrow biopsy, where a small sample of bone marrow is taken and examined for cancerous cells.

Treatment & Therapy

Treatment of CLL depends on the stage of the condition when diagnosed. Chronic lymphocytic leukemia often develops very slowly. Some people do not experience symptoms for a long time and may not need treatment for many years but for others, particularly those with certain genetic abnormalities, the condition may progress much faster.

Chemotherapy is used to treat the disease, but it can weaken the immune system, and infections may develop. Antibiotics can be prescribed to help prevent infections. Rituximab is a monoclonal antibody that is genetically engineered in a laboratory and is injected into the body. Rituximab works by attaching to a protein found on the surface of the lymphocytes. The immune system then targets and destroys the lymphocytes.

Alemtuzumab is similar to rituximab and is prescribed if the leukemia stops responding to chemotherapy. Ofatumumab is a monoclonal antibody that works in the same way as rituximab and alemtuzumab. It is prescribed to patients who have relapsed after receiving alemtuzumab, or to those who are not healthy enough to receive other medications. Bone marrow transplant or stem cell transplants are sometimes used to treat chronic lymphocytic leukemia. This intensive treatment aims to eliminate the chronic disease.

Prevention & Prophylaxis

Many types of cancer can be prevented by lifestyle changes to avoid certain risk factors, but there are very few known risk factors for CLL, and these cannot be avoided. However, once diagnosed the patient should take precautions to avoid infections.

Get an influenza vaccine, wash hands frequently and maintain a healthy diet. Patients should also reduce their risk of a second cancer by adapting their current lifestyle by stopping smoking, drinking in moderation, wearing sunscreen and exercising daily.