Below are some useful common terms that you may find in lab reports, hear your oncologist use, or read in medical articles about Waldenstrom’s macroglobulinemia. More terms are available in the glossaries of the IWMF Medical Tests and Questions & Answers booklets.
The National Cancer Institute of the U.S. National Institutes of Health maintains an expansive on-line dictionary of cancer terms at www.cancer.gov/dictionary
Alkylating agent: A chemotherapeutic agent such as chlorambucil (Leukeran), cyclophosphamide (Cytoxan), or melphalan (Alkeran) which blocks cell division.
Allogeneic: Derived from different individuals of the same species.
Amyloidosis: A group of conditions of diverse etiologies characterized by the accumulation of insoluble fiber-like proteins (amyloid) in various organs and tissues of the body such that vital function is compromised. The associated disease states may be inflammatory, hereditary, or cancerous, and the deposition can be local, generalized, or systemic. Amyloidosis in WM is usually caused by fragments of light chains and affects predominantly the kidneys and heart.
Anemia: A condition in which the number of red cells or the amount of hemoglobin in the blood is abnormally low.
Antibody: Also called immunoglobulin. A protein made by B-cells and plasma cells in response to an antigen. Each antibody can bind to only one specific antigen, with the purpose of helping to destroy the antigen. Antibodies are divided into five basic classes (IgM, IgG, IgA, IgE, IgD) on the basis of structure and biologic activity.
Antigen: Any foreign molecule which reacts with preformed antibody and the specific receptors on T-cells and B-cells; also used loosely to describe materials used for immunization.
Autoantibody: An antibody directed against a self-antigen, i.e. against a normal tissue constituent. The IgM antibody which causes peripheral neuropathy is considered an autoantibody.
Autologous: Derived from the same individual, “self”.
B-cell/B-lymphocyte: A type of lymphocyte that matures in the bone marrow; B-cells carry immunoglobulin (antibody) on their cell surfaces and are precursors of antibody-forming terminally differentiated plasma cells. WM is a disorder of the B-cells.
Basophil: A white blood cell whose granules stain blue with specific basic dyes; involved in the release of histamine and serotonin when stimulated, usually in an allergic reaction.
Bence-Jones proteins:Abnormal two-unit (dimers) complexes of immunoglobulin (antibody) light chains found in the urine of some patients, particularly those with multiple myeloma and WM.
Beta-2-microglobulin: Cell membrane associated protein that is specifically elevated in inflammation, renal disease, AIDS, and in some cancers, including WM, CLL and multiple myeloma. Urine levels of beta-2-microglobulin can be affected by kidney disease.
Bone marrow: Spongy tissue occupying the hollow central cavity of bones that is the site of blood cell formation (hematopoiesis). Following puberty, the marrow located in the spine, ribs, breastbone, hip, shoulders, and skull is most active in blood cell formation. In the adult, the bones of the hands, feet, legs and arms do not contain marrow in which blood cells are made; in these sites, the marrow is filled with fat cells.
CD markers: Cell surface molecules that are identifiable with monoclonal antibodies (such as CD20 and rituximab) and may be used to differentiate cell populations.
Cold agglutinin disease: An autoimmune hemolytic anemia caused by autoantibodies that bind to red blood cells at the lower temperatures found in the capillaries of the skin and subcutaneous tissues, causing red blood cell destruction (hemolysis). The IgM antibodies are monoclonal in origin and are seen in certain patients with WM and other diseases.
Cryoglobulinemia: Clinical disease characterized by cryoglobulins in the serum; often associated with immune complex antigen-antibody deposits in the kidneys and other tissues. Three types of cryoglobulinemia have been described: Type I (monoclonal cryoglobulinemia); Type II (mixed cryoglobulinemia) was first noted in WM, and can be seen as well in auto-immune disorders; Type III (mixed polyclonal-polyclonal cryoglobulinemia) can be seen with auto-immune diseases, infections, and other medical diseases.
Cryoglobulins: Abnormal proteins detected in the laboratory by chilling serum to below 32 degrees Celsius where they become insoluble. At a normal body temperature of 37 degrees Celsius, cryoglobulins are soluble. Serum specimens from patients must be kept warm until testing.
Eosinophil: A white blood cell whose granules stain red with acidic dyes; particularly involved in reactions against parasitic worms and in some hypersensitivity reactions involving IgE.
Erythrocyte: Also called a red blood cell. Erythrocytes contain hemoglobin, which binds oxygen as the erythrocytes circulate through the lung and releases it to the tissues of the body. Erythrocytes make up a little less than half the volume of blood in healthy individuals.
Erythropoietin: A hormone produced mainly by the kidneys that is required for the normal production of red blood cells (RBCs). Released into the bloodstream in response to decreased levels of oxygen in the blood (as in anemia), erythropoietin (EPO) interacts with the EPO receptor on red blood cell progenitors to increase production of RBCs. Epoetin alfa (Epogen, Procrit) and darbepoetin alfa (Aranesp) are laboratory-made forms of the human hormone EPO that can be used to treat anemia.
Graft vs. host disease: A reaction of white blood cells in transplanted tissue (the graft) against the tissues of the recipient (the host).
Heavy chains: The larger of the two types of chains that comprise a normal immunoglobulin (antibody) molecule.
Hematocrit: A measure of red blood cells as a percentage of whole blood.
Hematopoiesis: The process of blood formation.
Hematopoietic stem cell (HSC): The single common ancestor to all the functional cells found in the blood and immune cells. The stem cells represent less than 0.01% of bone marrow cells in adults and give rise to a larger, intermediately differentiated population of progenitor cells. These progenitor cells in turn divide and differentiate further through several stages into mature cells responsible for specific tasks. The stem cells are also able to recreate themselves through self-renewal: this potential for unlimited life span and future proliferation is their most important defining property.
Hemoglobin: The protein inside red blood cells that binds to oxygen in the lungs and carries it to the tissues.
Hyperviscosity: Excessive blood thickness.
IgM: A specific immunoglobulin (antibody), an excess of which characterizes WM.
Immunity: The condition of being immune; the protection against infectious disease conferred either by the immune response generated from vaccination, from previous infection, or from transfer of immune substances from another person or animal.
Immunoglobulin: See antibody.
Indolent: Slow growing.
Inflammation: A localized protective response elicited by injury or destruction of tissues, which serves to destroy, dilute, or wall off both the injurious agent and the injured tissue. It is characterized in its acute form by the classical signs of pain, heat, redness, swelling, and loss of function in the affected area.
Interferon (IFN): Any of a family of immune regulatory proteins produced by T-cells and other cells in response to DNA, viruses, antigens, and other substances usually associated with infected or malignant cells. Interferons increase the bacteriocidal, viricidal, and tumoricidal activities of macrophages.
Leukemia: A progressive, malignant disease of the blood-forming organs, characterized by distorted proliferation and development of white blood cells and their precursors in the blood and bone marrow.
Leukocyte: Any type of white blood cell, including lymphocytes, neutrophils, basophils, eosinophils, and monocytes.
Light chains: The smaller of the two types of chains that comprise a normal immunoglobulin or antibody molecule. They are either of the kappa or lambda type and combine with any of the heavy chain types. Light chains can also be found as two-unit structures (dimers) in the urine in certain abnormal conditions, particularly in multiple myeloma and WM, and are called Bence-Jones proteins.
Lymph nodes: Part of the lymphatic system, these are bean-shaped organs found in the underarms, groin, neck, and abdomen that act as filters for the lymph fluid as it passes through them. The lymph nodes are major sites of antigen trapping by lymphocytes, which in turn activate an immune response.
Lymphocyte: A type of white blood cell found in the blood and in lymph tissue. The three main types of lymphocytes are B-cells (which make antibodies), T-cells (which help to kill tumor cells and help to control the immune response), and natural killer cells (which destroy infected or altered cells).
Lymphoma: A cancerous disorder of the immune system. The lymphomas are classified generally in two subsets: Hodgkin’s lymphoma and the non-Hodgkin’s lymphomas, which are then subsequently classified as low grade (includes WM), intermediate grade, and high grade.
Lymphoplasmacytic lymphoma: A type of non-Hodgkin’s lymphoma characterized by lymphoplasmacytic cells in the bone marrow. These cells share characteristics of both B-cells and plasma cells. WM is the most common type of lymphoplasmacytic lymphoma and is further characterized by the presence of monoclonal IgM antibody in the blood.
Macrophage: A type of white blood cell, found in certain tissues, which is capable of engulfing foreign substances; it also interacts with antigens and presents these antigens to T-cells, thus helping to activate the immune response.
Mast cell: A non-mobile cell distributed in many tissues; mast cells are full of granules containing inflammatory mediators and are often associated with allergic reactions.
Monoclonal: Derived from one cell.
Monoclonal antibody therapy: The use of laboratory-developed antibodies that can locate and bind to antigens in the body, including tumor cells. Each monoclonal antibody is made to bind one specific antigen. They can be used alone or to carry drugs, toxins, or radioactive materials directly to a tumor.
Monoclonal gammopathy of undetermined significance (MGUS): A benign condition in which there is a monoclonal protein in the blood but an absence of any underlying disease. Patients with MGUS are at increased risk of developing certain cancers, including WM.
Monocyte: A type of white blood cell that is present in the bloodstream.
Multiple myeloma: A cancer of plasma cells, characterized most commonly by the presence of monoclonal IgG or IgA.
Myelodysplasia: Production of abnormal blood cells in the bone marrow that can lead to leukemia.
Myelosuppression: Decreased production of blood cells in the bone marrow.
Neoplasm: An abnormal mass of tissue that results when cells divide more than they should or do not die when they should. Neoplasms may be benign (not cancer), or malignant (cancer). Also called tumor.
Neutropenia: A reduced level of neutrophils in the blood.
Neutrophil: A type of white blood cell distinguished by having a nucleus with three to five lobes (polynuclear neutrophils) connected by slender threads of DNA material. Neutrophils have the capability of engulfing foreign substances and are one of the first responders to infection.
Nucleoside analog: Also called purine analog. Part of a larger class of anti-cancer drugs termed antimetabolites, which act specifically on proliferating cells. Fludarabine (Fludara) and cladribine (2CdA or Leustatin) are two purine analogs commonly used in treating WM.
Peripheral neuropathy (PN): A clinical symptom where there is a permanent or transient problem with the functioning of the nerves outside the spinal cord. The symptoms of a neuropathy may include numbness, weakness, burning pain, and loss of reflexes. The pain may be mild or severe and disabling.
Plasma cell: A terminally differentiated white blood cell of the B-cell lineage that produce antibodies. In multiple myeloma, the plasma cell becomes malignant and produces in most cases large amounts of monoclonal IgG or IgA antibody.
Plasmapheresis (PP): The process of removing a donor’s plasma to extract a specific component (IgM in the case of WM) and returning the unneeded parts to the donor. The process uses continuous circulation of blood from a donor through an apparatus and back to the donor. This process makes it possible to remove desired elements from large volumes of plasma. Hemapheresis or apheresis is a similar procedure whereby platelets, red cells, white cells, stem cells or plasma constituents can be removed separately.
Platelet: Also called a thrombocyte. A tiny piece of a cell found in the blood that has developed from a large cell (megakaryocyte) found in the bone marrow. Platelets help wounds heal and prevent bleeding by forming blood clots.
Polyclonal: Derived from different cells
Prognosis: A prediction of the course of a disease and its outcome.
Red blood cell: See erythrocyte.
Relapse: The return of disease after it has been treated and the patient has had a favorable response to treatment.
Response: Reaction to treatment.
Serum viscosity (SV): The physical property of serum as it relates to its “thickness.” The serum viscosity is affected by the concentration of constituents in the serum; the greater the number of soluble molecules or cells in the serum, the higher the viscosity.
Spleen: The largest structure in the lymphoid system, the spleen is a gland-like organ situated in the left upper abdomen. It serves as a reservoir of blood, produces lymphocytes and plasma cells, and functions as a “filter” for the blood by removing damaged red blood cells from the circulation.
Splenectomy: Surgical removal of the spleen.
T-cell/T-lymphocyte: A type of lymphocyte that matures in the thymus gland. T-cells are responsible for cell-mediated immunity. In response to pathogens, helper T-cells produce substances that direct the immune response, while cytotoxic T-cells produce toxic granules that induce the death of cells infected with pathogens.
Thrombocyte: See platelet.
Thrombocytopenia: A reduced level of platelets in the blood.
White blood cell: See leukocyte.