CML Glossary ‘A’
*a-INT= alpha Interferon.
The preferred abbreviation is IFN-a
*ABL = a gene (named for a researcher whose last name was Abelson) on human chromosome # 9, involved in normal white blood cell replication. Abl only causes trouble when it leaves to join chromosome #22, creating the bcr-abl gene. (See bcr-abl)
*Absolute neutrophil count = the total number of neutrophil cells per microliter of blood. It is calculated by using the total white blood count (WBC) and the percentage of neutrophils shown on the laboratory “differential.”
*Accelerated phase = a phase of CML between chronic and blast phase. The actual definition of accelerated phase is somewhat variable and depends on whom you ask. Evidence of acceleration includes: recurrence of certain clinical findings such as night sweats, fatigue and an enlarged spleen; increased difficulty in controlling the blood cell counts; increases in certain cell types such as basophils, eosinophils, and especially blasts; and the appearance of new chromosomal abnormalities on cytogenetic analysis. Any one of these may (or may not) be cause for concern, but the appearance of two or more in combination makes the diagnosis of accelerated phase more likely. Untreated, the accelerated phase progresses to blast phase within a few months.
Additive = often used in discussion of combined drug efficacy: when the effect of two drugs is additive it means that their effect together is only equivalent to the sum of their individual effects. Compare this to a “synergistic” effect, where the result is greater than the sum of the parts.
* aGVHD = Acute Graft vs. Host Disease
ALL = Acute lymphocytic leukemia (not covered in this primer)
*ALLO-BMT= Allogeneic Bone Marrow Transplant
*Allogeneic (as in allogeneic stem cell transplant) = with respect to CML, this term is usually used in reference to stem cell or bone marrow transplantation. Allogeneic stem cells mean that they come from another person. “Allo” means other – as in another person. Compare to Autologous (see below).
ALT = alanine aminotransferase: a blood test used to detect liver inflammation (see AST)
AML = Acute myelocytic
(or myelogenous, or myeloid) leukemia (not covered in this primer)
*ANC = absolute neutrophil count
*Angiogenesis = creation or promotion of new blood vessels.
Tumor angiogenesis is an abnormal type of new blood vessel production stimulated by chemicals produced by cancer cells, which need extra supplies of oxygen and nutrients in order to keep growing. Angiogenesis inhibitor drugs are a new class of drugs targeted against this abnormal process, which block or slow tumor growth.
Antigen = a substance (often a protein) that induces an immune response (usually an antibody, or cell-mediated response).
Apoptosis = programmed cell death. Normal cells are programmed to die after a certain amount of time or a certain number of cell divisions. Cancerous cells lose this characteristic and go on living and dividing as long as they get the nutrition they need. Certain anti-leukemia drugs (in particular Gleevec, Sprycel, Tasigna, Bosulif, iClusig and interferon – with more drugs in trial) inhibit the cancer’s anti-apoptotic mechanisms – that is, they restore the cells’ ability to die and, therefore, help to eliminate the disease.
*Ara-C = Cytarabine (cytosine arabinoside) – a chemotherapy agent sometimes used in the treatment of CML.
ASH = American Society of Hematologists
Aspirate = to draw in by suction
AST = aspartate aminotransferase: a blood test used to detect liver inflammation (see ALT).
*Autologous = refers to getting tissue back from yourself (auto = self). In an autologous stem cell transplant, for example, one’s own marrow cells are harvested and the “good” ones separated from the “bad.” One’s own marrow is then destroyed (usually but not always – see non-myeloablative, below) with radiation and chemotherapy. Then the autologous cells are re-transfused. Neither graft rejection nor graft vs. host disease (see GVHD) is a significant problem with autologous transplants. The reason they are not done routinely is that 1) it is currently not possible to insure that ALL the leukemic cells have been eliminated from the autologous marrow, so there is a significant chance that leukemic cells are reintroduced; and 2) one’s own immune cells are not as effective as donor immune cells at suppressing the leukemic cells that might have been reinfused.
Avascular Necrosis (AVN) =
pathological bone death; a rare complication of interferon therapy, seen almost exclusively in patients whose platelet counts remain abnormally high despite treatment.
AVN = avascular necrosis.