Chronic lymphocytic leukemia (CLL)

CLL mainly affects older adults and accounts for 16,000, one-third of all new cases of leukemia every year. The average age of diagnosis is 72 years. CLL is rare in those under 40 and extremely rare in children.

Lymphocytes evolve from immature stem cells, growing into T lymphocytes (T cells), B lymphocytes (B cells), or natural killer (NK) cells. Each of these plays a special role in the body’s immune defense.

In CLL, there are changes in the leukemic B cells that result in an over production of lymphocytes. In rare cases the T cells can be affected as well, resulting in T-cell prolymphocytic leukemia.

As the disease progresses leukemic lymphocytes can overcrowd the bone marrow preventing production of normal red and white blood cells and platelets. As the number of oxygen-carying red blood cells decline, patients may develop anemia, appearing pale, tired or short of breath. A decline in platelets that normally help the blood clot may lead to easy bruising or bleeding. A decline in white blood cells puts patients at increased risk for infections that can be life threatening.

CLL is usually a slowly progressive disease and can take a long time to cause any symptoms. However, in some patients CLL can be more aggressive and progress faster resulting in the need for immediate treatment.

Certain tests at the time of diagnosis can help predict the course of the disease and guide treatment recommendations.