acute: develops suddenly and rapidly worsens

alkylating agent: anti-cancer drug (eg, chlorambucil) that prevents cell division, sometimes combined with other drugs in chemotherapy

antibody: protein that targets foreign substances in the body which are destroyed by the immune system

autoimmune hemolytic anemia: rare condition where antibodies destroy red blood cells

B cell: type of lymphocyte that makes antibodies attack germs (bacteria)

chemotherapy: anti-cancer drug that fights cancer, usually by interfering with cell division

chronic: slowly developing and long lasting

chronic lymphocytic leukemia (CLL): slowly progressing cancer of the blood that affects lymphocytes

FLUDARA® (fludarabine phosphate): anti-cancer drug that is used for the treatment of alkylating-agent– refractory B-cell chronic lymphocytic leukemia

granulocyte: white blood cell that helps destroy harmful germs

hemoglobin: part of the red blood cell that carries oxygen

hemolytic anemia: rare condition that destroys red blood cells and results in fewer than normal red blood cells

hematologic: related to blood and blood-forming tissues

immune system: natural defense system of the body, includes white blood cells that fight infection and cancer

interstitial pneumonitis: inflammation or swelling of the lungs that can occur during chemotherapy; sometimes referred to as interstitial pneumonia; usually responds to steroid treatment

intravenously: method of giving a drug directly into the blood through a vein

leukemia: disease in which the body makes or builds up too many white blood cells that don't work properly

leukocyte: another name for white blood cell; leukocytes help protect your body against infections

lymphocyte: type of white blood cell; lymphocytes include B and T cells

lymphocytic leukemia: condition that involves diseased lymphocytes

malaise: feeling of being sick

monocyte: white blood cell that breaks down and removes damaged or dead blood cells and germs

myelosuppression: condition in the bone marrow that results in fewer platelets, red blood cells, and white blood cells

neutrophil: type of white blood cell that protects the body from infection

peripheral blood count: same as blood count (ie, the number of white or red blood cells in a volume of blood)

platelet: blood cell that helps control bleeding and forms clots

refractory: disease no longer responds to treatment; resistant

relapse: when a disease returns

remission: when a patient responds to treatment and the body appears to return to normal

T cell: type of lymphocyte that mainly attacks viruses

tumor lysis syndrome: condition that develops when many leukemia cells are destroyed at once