Chronic Lymphocytic Leukemia - The Leukemia & Lymphoma Society

HLA. The abbreviation for “human leukocyte-associated antigen(s).” These antigens
are proteins on the surface of most tissue cells, and they give an individual his or
her unique tissue type. HLA factors are inherited from mother and father, and
the greatest chance of having the same HLA type is between siblings. On average,
one in four siblings is expected to share the same HLA type. The testing for HLA
factors is referred to as “tissue typing.” There are six major groups of HLA: A, B,
C, D, Dr, and Dq. These proteins on the cell surface act as antigens when donated
(transplanted) to another individual, the recipient. If the antigens on the donor cells
are identical (as in identical twins) or very similar (as in HLA-matched siblings), the
transplant (donated stem cells) is more likely to survive (engraft) in the recipient.
In addition, the recipient’s body cells are less likely to be attacked by the donated
immune cells (a result called “graft-versus-host disease”).
Immunoglobulin Heavy Chain Variable Region (IgHv) Gene Status. A
marker that can distinguish between CLL subtypes (unmutated IgHv and mutated
IgHv). People with CLL with unmutated IgHv gene status may have a more
progressive form of the disease.
Immunophenotyping. A method that uses the reaction of antibodies with cell
antigens to determine a specific type of cell in a sample of blood cells, marrow cells
or lymph node cells. The antibodies react with specific antigens on the cell. A tag is
attached to an antibody so that it can be detected. The tag can be identified by the
laboratory equipment used for the test. As cells carrying their array of antigens are
tagged with specific antibodies, they can be identified.
Indwelling Catheter. See Central Line.
Karyotype. The systematic arrangement, using images, of the 46 chromosomes in
the human cell in 22 matched pairs (maternal and paternal member of each pair)
by length from longest to shortest and other features, with the sex chromosomes
shown as a separate pair (either XX or XY). These 22 pairs are referred to as
“autosomes.” See Fluorescent In Situ Hybridization.
Leukocytes. See White Cells.
Leukopenia. A decrease below normal in the concentration of blood leukocytes
(white cells).
Lymphadenopathy. Enlargement of lymph nodes.
Lymphatic System. The system comprising the lymph nodes, the thymus gland
(in the first several decades of life), the lymphatic channels, the lymphatic tissue of
the marrow, the gastrointestinal tract, the skin and the spleen, along with the T, B
and Natural Killer (NK) lymphocytes contained in those sites.
Chronic Lymphocytic Leukemia I page 35