The Severe Chronic Neutropenia
International Registry


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Mayo Clinic Online
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ANC (Absolute Neutrophil Count): The number of neutrophils in the blood, measured by cells per cubic millimeter. ANC is determined by adding the percentage of neutrophils in the blood with the percentage of bands in the blood, multiplying that number by the white blood count and dividing the product by 100. This number represents the amount of neutrophils, which are available for defending the body at the time of the blood test. A normal ANC for a non-neutropenic person is generally within the range of 1800-7000.

Acquired: Developed after birth.

Acute Myeloid Leukemia (AML): An acute form of leukemia, a malignant disease of the white blood cells affecting monocytes or granulocytes. It is characterized by the appearance of immature, abnormal cells in the bone marrow and peripheral blood.

Alopecia: Loss of hair.

Anaemia: Too few red blood cells.

Antibodies: Proteins made by a subgroup of white blood cells, the lymphocytes that are responsible for the body's defence. Antibodies are normally directed against foreign structures like pathogens or transfused cells. However, sometimes they may also be directed against structures and cells of their own body, e.g. in the case of anti-neutrophil antibodies where the antibodies recognize and destroy the patient's own neutrophils.

Aplastic anaemia: A deficiency of all of the formed elements of the blood, representing a failure of the cell generating capacity of the bone marrow.

Arthralgia: Painful joints.

Arthritis: Inflammation of joints.

Autosomal dominant: A particular type of genetic inheritance. In a dominant inheritance pathway, like in cyclic neutropenia, the child will become a cyclic neutropenia patient if either one of her/his parents pass the affected gene on to their child. The addition 'autosomal' refers to the fact that the inheritance is independent of the child's sex.

Autosomal recessive: A particular type of genetic inheritance. In a recessive inheritance pathway, like in Kostmann syndrome, the child will become a Kostmann patient only if both parents pass the affected gene on to their child. The addition 'autosomal' refers to the fact that the inheritance is independent of the child's sex.

Bands: Juvenile neutrophils. These are usually counted as neutrophils and contribute to the absolute neutrophil count.

Basophils: A subgroup of granulocytes, which may increase after splenectomy.

Blood Count: Number of red cells, white cells and platelets in a blood sample.

Bone Marrow: The spongy material located in the center of our bones. It is the home of our stem cells, which reproduce to create our blood, including white blood cells, red blood cells, platelets, B- and T lymphocytes and macrophages.

CBC (Complete Blood Count): A summary of the numbers of various types of cells present in the blood at the time of the blood draws, same as FBC.

Chemotherapy: A drug treatment to destroy cancer cells.

Chromosomes: Carry all genetic information and are located in the cell nuclei. Changes of the chromosomes may indicate the development of a disease. They may be detected by certain examinations like cytogenetics.

Chronic: Persisting over a long period of time.

Colony-Stimulating Factor (CSF): Naturally occurring glycoproteins that regulate the proliferation, differentiation and maturation of hematopoietic growth factors, belong to a class of soluble immunity system proteins known as cytokines.

Congenital Neutropenia: Severe chronic neutropenia beginning at or before birth. It is characterized by persistent, severely diminished neutrophil counts in the bone marrow and blood due to a maturational arrest of early cells in the bone marrow. Subtypes include congenital agranulocytosis (Kostmann syndrome), Schwachman-Diamond syndrome, glycogen storage disease type 1b, and myelokathexis.

Cutaneous: Concerning the skin.

Cyclic Neutropenia: A form of severe chronic neutropenia that affects both adults and children. It is characterized by three to six day periods of severe neutropenia that occur approximately every 21 days.

Cytogenetic: Concerning the chromosomes.

Cytogenetics: A method by which chromosomes can be analysed under the microscope.

Cytopenia: Deficiency in the number of cellular elements of the blood.

Differential Blood Count: The subclassification of white blood cells.

Eosinophil: A type of white blood cell that offers important defense against allergic reactions.

Erythrocytes: Red blood cells.

FBC (Full Blood Count): Tests which show what amount of various types of cells, or substances are available in your blood; same as CBC.

Febrile Neutropenia: Dangerously low level of neutrophils in the blood (usually less than 500 cells per cubic millimeter) accompanied by fever; a condition that indicates that the patient may have a potentially life-threatening infection.

Filgrastim: The international non-proprietary name for r-metHuG-CSF.

G-CSF receptor: A structure on the surface of granulocytes to which G-CSF binds. After binding to a receptor, the cell receives information on how to proceed, e.g. grow, divide, mature etc.

Genetic engineering: A method by which, for example, the human gene for G-CSF is transferred into cells from another species like bacteria, which in turn produce the desired product in large scale.

Gingivitis: Inflammation of the tissue covering the upper and lower jaws and surrounding the necks of teeth. Occurs as a result of bacterial infection.

Granulocyte: A subtype of leukocytes, which can be further distinguished into neutrophils, eosinophils and basophils.

Granulocyte Colony-Stimulating Factor (G-CSF): A naturally occurring hormone that stimulates the growth, production, and function of neutrophils.

Haematopoiesis: The formation of blood.

Haematopoietic growth factor: A protein stimulating the production (growth) of blood cells.

Haematuria: The occurrence of blood in the urine.

Hepatomegaly: The enlargement of the liver.

HIV: The human immunodeficiency virus.

Idiopathic Neutropenia: An acquired form of severe chronic neutropenia of unknown cause; a broad term for unexplained neutropenia in both adults and children. The condition can be inherited or acquired.

Immunodeficiency: The state of a patient whose immune system has been compromised by disease or by administration of chemicals. This condition makes the system deficient in the number and type of blood cells needed to defend against a foreign substance.

Immunity: Resistance resulting from previous exposure to an infectious agent or antigen.

Immunotherapy: Treatment that is directed at producing immunity or resistance to a disease or condition.

Incidence: The number of new cases of a certain disease in a certain time period.

Inflammation: The body's response to injury or invasion by a foreign substance, such as a bacterial infection, during which time its immune system is activated.

Lenograstim: The international non-proprietary name for glycosilated rHuG-CSF.

glycerinated: A malignant disease of the white blood cells.

Leukocytes: White blood cells consisting of granulocytes, monocytes and lymphocytes.

Leukopenia: An abnormally low level of circulating white blood cells.

Lymphocytes: Subgroup of leukocytes, which are responsible for the body's defence against viruses (T lymphocytes) and the production of antibodies (B lymphocytes).

Metabolic: Refers to the balance between uptake, degradation and utilization of food.

Monocytes: A subgroup of leukocytes, which eliminate infectious particles and infected cells by eating and digesting them.

Morphological: Refers to the physical shape and size.

Myelodysplastic syndrome (MDS): A syndrome characterized by the appearance of atypical cells in the bone marrow. MDS can progress to characterized.

Myelokathexis: A very rare form of congenital neutropenia that is characterized by the inability of the neutrophils to leave the bone marrow and enter the blood.

Myelosuppression: Suppression of bone marrow activity, with resulting decrease in production of blood cells, especially granulocytes and platelets.

Myelosuppressive Chemotherapy: Chemical agents, used to treat malignant tumors that also can inhibit bone marrow activity, resulting in decreased production of white blood cells, red blood cells, and platelets.

Neutropenia: An abnormally low level of neutrophils in the blood.

Neutrophils: A subgroup of granulocytes defending the body against bacteria. Neutrophils are also known as segs, polys or segmented neutrophils.

Osteopenia: Mildly demineralized bone substance.

Osteoporosis: Severely demineralized bone substance.

Platelets: A subgroup of blood cells responsible for clotting, which are also called thrombocytes.

Pluripotent haematopoietic stem cell: Cells that still have the potential to develop into any blood cell.

Proliferation: Rapid and repeated production of new parts (as in a mass of cells by a rapid succession of cell divisions).

Promyelocytes: Precursors of granulocytes in the bone marrow.

Prophylaxis: Any procedure to avoid undesired events e.g. the development of infections.

Proteinuria: The occurrence of protein in the urine.

Psoriasis: A disease Protein by scaly skin.

Recombinant: A microbe, or strain, that has received chromosomal parts from different parental strains.

Recombinant Human Granulocyte Colony-Stimulating Factor: The genetically engineered version of the natural hormone, G-CSF.

Recombinant Technology: A laboratory procedure that permits the production of large quantities of a particular protein. The gene for producing that protein is isolated and introduced into a cell (such as a bacterium or yeast cell), where it becomes integrated into that cell's own DNA. As a result, the cell produces the desired protein.

Red Blood Cells (RBCs): Also called erythrocytes, RBCs supply oxygen to all cells in the body by means of hemoglobin, a protein.

Remission: Reduction of a clinically detectable disease for as long as possible, even though the disease may not have been eliminated.

Rheumatoid arthritis: Chronic inflammation of several joints also referred to as polyarthritis.

Severe Chronic Neutropenia: Encompassing a group of rare hematologic disorders in which the patient's ANC falls below 500 cells per cubic millimeter. In most cases, SCN is due to underproduction of neutrophils. The three forms of SCN are congenital neutropenia, cyclic neutropenia and idiopathic neutropenia.

Splenectomy: Surgical removal of the spleen.

Splenomegaly: The enlargement of the spleen.

Stem cells: The most immature cell in the bone marrow, which are able to reproduce themselves and develop into different types of blood cells.

Subcutaneous: Under the skin.

Syndrome: A complex of various disease symptoms.

Thrombocytes: A subgroup of blood cells responsible for clotting which are also referred to as platelets.

Thrombocytopenia: The decreased number of platelets in the blood (<150,000 per mm3).

Vasculitis: The inflammation of small blood vessels.

White Blood Count: The total number of leukocytes in the blood at the time of the blood test.

White Blood Cells: A subgroup of blood cells consisting of monocytes, granulocytes and lymphocytes, which together build the immune system and defend the body against infection.