Effective & Trusted Medications Guide

Historically considered to be one of the four major types of leukemia, chronic lymphocytic leukemia now is grouped together with small lymphocytic lymphoma as a cancer of the lymphocytes, the infection-fighting white blood cells that circulate throughout the body. Like all cancers, CLL/SLL is characterized by the unrestrained accumulation of abnormal cells. In this cancer, the disease starts in the lymphocytes.

In people with CLL/SLL, the lymphocytes don’t mature properly. These faulty cells do not die normally but instead accumulate in the bone marrow, bloodstream, and organs of the body. The buildup of abnormal lymphocytes not only interferes with the function of the immune system but also disrupts the production of other blood cells and the functions of vital organs, including the spleen. As a result, a person becomes more at risk of developing infections, anemia, and other cancers, including skin cancer and more serious cancers of the lymphocytes.

Over 15,000 new cases of CLL/SLL are expected to be diagnosed in the United States this year. The disease is typically diagnosed in adults in their mid-60s and is rarely found in people under the age of 40. Men are nearly twice as likely to develop this disease as women. CLL/SLL is more common in Caucasians and Afro-Americans and rarely diagnosed in people with ancestors from China, Japan, and other parts of Southeast Asia.

The outlook for a person diagnosed with CLL/SLL varies widely. For 2 out of 3 patients, the disease either remains stable for many years or progresses very slowly. These patients can delay treatment for several years or may never need treatment at all. In the remaining third of patients, the disease progresses quickly and brings about debilitating symptoms. For these patients, treatment is critical to slow down the disease and prolong their life. Approximately 4,500 people in the United States are expected to die this year from CLL/SLL. A thorough evaluation by a doctor who specializes in blood disorders and is experienced with CLL/SLL is vital to ensure that life-sustaining treatment is started when needed.

Need-to-know anatomy: blood

Blood consists of three types of blood cells suspended in plasma. Plasma is a watery liquid that contains proteins, hormones, minerals, vitamins, and antibodies. The different types of blood cells—red blood cells, platelets, and white blood cells—are produced in the bone marrow.

Red blood cells, or erythrocytes, account for 35 to 50 percent of the blood volume. Red blood cells are filled with hemoglobin, which enables them to deliver oxygen to the tissues of the body. When blood circulates through the lungs, the hemoglobin releases carbon dioxide and picks up oxygen. The oxygen-rich cells then circulate in the body, where they deliver oxygen to tissues in exchange for carbon dioxide before cycling back to the lungs. If the red blood cell volume falls below 35 percent, the cells can no longer meet the body’s demand for oxygen, and anemia can develop. Anemia can cause shortness of breath, fatigue, and pale skin.

Platelets, also known as thrombocytes, are small cells that help control blood loss. Platelets adhere to and repair damaged blood vessels as well as clump together, or clot, to control bleeding. A healthy body has about 150 billion to 450 billion platelets per liter of blood, depending upon the laboratory performing the analysis. When the platelet count drops considerably below this level, a person may bruise more easily, bleed longer, and have nosebleeds or bleeding gums. If the count falls as low as 10 billion platelets per liter, dangerous bleeding may develop.

White blood cells, or leukocytes, are the warriors of the immune system. Unlike red blood cells or platelets, white blood cells are able to enter the tissues of the body in order to fight infections caused by fungi, bacteria, viruses, and cancer. Changes in the white blood cell count can indicate infection, development of leukemia, or other conditions. The five main types of white blood cells are lymphocytes, neutrophils, eosinophils, basophils, and monocytes. White blood cell counts can range from about 3.5 billion to 10.5 billion cells per liter.

The rate at which cells are produced in the bone marrow is regulated similarly to the way heat is controlled in a house. As the temperature drops in a house, the thermostat calls for heat. When the temperature reaches the thermostat’s set point, the thermostat turns off the furnace. In the body, there are many different triggers for the bone marrow to produce blood cells. For example, an infection is a common trigger for the production of white blood cells. Once the infection is under control, the rate of white blood cell production drops off until it returns to normal.

Need-to-know anatomy: lymphatic system

Lymphocytes, a type of white blood cells, are the building blocks of the immune system. A healthy body can have up to 3 billion lymphocytes per liter of blood. These white blood cells can be divided into three main types: B cells, T cells, and natural killer cells. Lymphocytic cancer develops most often in the B cells, less frequently in the T cells, and rarely in the natural killer cells.

The largest concentrations of lymphocytes are found in the bone marrow—where they are made—followed by the lymph nodes, spleen, tonsils and adenoids, the digestive and respiratory systems, and the thymus. After maturing in the bone marrow, lymphocytes travel to the lymph nodes, where the B lymphocytes undergo further development to refine their ability to find and fight foreign substances. Then the lymphocytes return to the bone marrow, ready to be sent out on patrol. When a lymphocyte encounters an infection or abnormal cell, it will destroy the fungus, bacterium, virus, or cancer cell that is causing the disease.

Lymphocytes travel in the bloodstream and in a network of small vessels called the lymphatic system. These vessels carry lymph, an opalescent fluid that seeps from the tissues of the body. Lymph contains white blood cells, germs and other foreign substances, and a few red blood cells. The lymphatic system filters lymph through the lymph nodes, where the germs and other foreign substances collect before the lymph is discharged into the bloodstream.