Absolute lymphocytosis:

The presence of more than 15,000 lymphocytes in a cubic millimetre of blood.

Acute:

Sudden onset of disease symptoms.

Acute lymphocytic leukemia (ALL):

The most common type of leukemia in young children. This disease also affects adults; especially those age 65 and older. ALL is characterized by the unrestrained production of immature lymphoblasts and has three subgroups, L1 to L3.

Acute myeloid leukemia (AML):

AML occurs in both adults and children. This type of leukemia is also known as acute myelogenous leukemia and acute nonlymphocytic leukemia (ANLL). AML is characterized by a massive proliferation of mature and immature, abnormal granulocytes. There are eight subgroups of AML which are designated M0 to M7.

Adenopathy:

Swelling or morbid enlargement of the lymph nodes.

Alkylating agents:

Anticancer drugs that can damage DNA of cells, leading to cell death.

Allogeneic bone marrow transplantation:

A procedure in which a patient receives bone marrow from a compatible, though not genetically identical donor.

Alopecia:

Loss of hair, be it on the head or all over the body. Alopecia can be caused by certain chemotherapy drugs.

Anecdotal:

A single case report not yet substantiated by clinical trials or studies using large numbers of people.

Anemia:

A below-normal number of red blood cells.

Angiogenesis:

Development of blood vessels.

Anthracyclines:

Drugs used in leukemia therapy to prevent cell division by disrupting the DNA. Drugs of this type include, daunorubicin, doxorubicin (adriamycin), epirubicin, and idarubicin.

Antibodies:

Proteins produced by certain white blood cells in response to the presence of foreign substances (antigens). Each antibody can bind to only one specific antigen. The purpose of this binding is to help destroy that antigen.

Antigen:

Any substance that the body regards as foreign. When introduced into the body, an antigen causes the immune system to produce a corresponding antibody to fight it.

Antimicrobial therapy:

Treatment to kill micro-organisms (such as bacteria or fungi) or to suppress their growth.

Apheresis:

Removal of blood from the body using specialized equipment and single-use tubing in order to extract various blood cell types such as, platelets, white blood cells, stem cells, etc. After these cells are extracted, the remaining blood is returned to the body.

Aplasia:

Failure of the bone marrow to produce blood cells. Usually this condition affects all types of blood cells, which is called aplastic anemia.

Aplastic anemia:

A form of anemia that occurs when the bone marrow fails to produce adequate numbers of blood cells.

Apoptosis:

Programmed cell death. If apoptosis is affected, the cell will not die, causing a malignant or cancerous condition.

Aspirate:

To remove material from a body cavity by suction through a needle. Also refers to material that is removed this way.

Asymptomatic:

Without symptoms.

Autoimmune disease:

Diseases caused by an individual's immune system producing antibodies against tissues of its own body.

Autologous bone marrow transplantation:

A procedure in which bone marrow that has been removed from the patient is given back to the patient. The marrow may be purged in the laboratory in an effort to eliminate contamination with leukemia cells. This procedure may be carried out up to the age of 55 - 60 years.

Axillary lymph node:

A lymph node found in the armpit (axilla).