Glossary

Select a letter to view terms beginning with that letter.
  • A

    • Acquired: Not passed down through the genes; may develop over time.

    • Activated partial thromboplastin time: A blood test that looks at how long it takes for blood to clot. It can help tell if you have bleeding or clotting problems.

    • Anemia: A condition in which your blood has a lower than normal number of red blood cells.

    • Aggregation studies: This study checks to see how well platelets, a part of blood, clump together when stimulated by chemicals to understand how they might act when involved with blood clotting to stop a bleed.

    • Antibodies: Proteins in the blood that attack substances that the body thinks present a danger. Antibodies that attack replacement therapies for hemophilia are called inhibitors.

    • Anticoagulant: Drugs that are given to prevent your blood from clotting or prevent existing clots from getting larger. They can keep harmful clots from forming in your heart, veins or arteries because clots can block blood flow and cause a heart attack or stroke.

    • Antifibrinolytic: These type of drugs prevent the breakdown of blood clots by neutralizing chemicals in the blood and mucous membranes of the mouth, nose, and urinary tract that break down clots.

    • Antigens: Any substance that causes your immune system to produce antibodies against it. An antigen may be a foreign substance from the environment, such as chemicals, bacteria, viruses, or pollen. An antigen may also be formed inside the body, as with bacterial toxins or tissue cells.

    • Arthrodiesis: The surgical fixation of a joint by a procedure designed to accomplish fusion of the joint surfaces by promoting the proliferation of bone cells.

    • Arthropathy: Any disease or abnormal condition affecting a joint.

    • Arthroplasty: A surgery that’s done to restore the integrity and function of a joint.

    • Assay: An analysis of the chemical composition or strength of a substance like blood.

    • Autoimmune disease: Your body's immune system protects you from disease and infection. But if you have an autoimmune disease, your immune system attacks healthy cells in your body by mistake.

    • Autosomal dominant: This is one of several ways that a trait or disorder can be passed down (inherited) through families. In an autosomal dominant disease, if you inherit the abnormal gene from only one parent, you can get the disease. Often, one of the parents may also have the disease.

    • Autosomal recessive: This is one of several ways that a trait, disorder, or disease can be passed down through families. An autosomal recessive disorder means two copies of an abnormal gene must be present in order for the disease or trait to develop

  • B

    • Berichrom FXIII assay: An assay that measures the factor XIII activity levels in the blood based upon a color change associated with a chemical reaction.

    • Bethesda assay: Inhibitors are quantified by the “Bethesda” test, in which normal pooled plasma (as a source of factor VIII) is mixed with undiluted patient plasma for two hours at 37 degrees Celsius and then tested for remaining factor VIII. The resulting Bethesda Titer or Inhibitor Titer expressed in BU is a measure of the strength of the inhibitory antibody to factor.

    • Bleed: A collection of blood in an area. It is a term people with bleeding disorders use to describe their bleeding episodes.

    • Blood clot: A thick clump or mass of blood.

    • Blood clotting: The process by which the blood forms clots to stop a bleed.

    • Bleeding time: Bleeding time is a blood test that looks at how fast small blood vessels in the skin close to stop you from bleeding.

    • Bone marrow: The spongy tissue inside some of your bones, such as your hip and thigh bones. It contains immature cells, called stem cells. The stem cells can develop into the red blood cells that carry oxygen through your body, the white blood cells that fight infections, and the platelets that help with blood clotting.

    • Bypassing agents: Instead of replacing the missing factor in a patient with a factor deficiency, bypassing agents go around (or bypass) the factors that are blocked by the inhibitor to help the body form a normal clot.

  • C

    • Capillaries: Very small blood vessels.

    • Carriers: An individual who carries and is capable of passing on a genetic mutation associated with a disease and may or may not display disease symptoms.

    • Circumcision: Boys are born with a hood of skin, called the foreskin, covering the head (also called the glans) of the penis. In circumcision, the foreskin is surgically removed, exposing the end of the penis.

    • Clot solubility assay: This assay involves taking the plasma from the patient’s blood and mixing with calcium and thrombin to make a clot. In the presence of factor XIII, the clot is stable for 24 hours or more; in its absence, the clot dissolves in minutes to hours.

    • Clotting: The series of events by which the blood forms clots to stop a bleed.

    • Clotting cascade: The coagulation or clotting cascade is a compilation of steps that the blood goes through to form a blood clot.

    • Clotting factors: The proteins that circulate in the blood and are needed for normal coagulation.

    • Clotting factor disorder: A disorder in which there are missing or low levels of blood

    • Collagen: A hard, insoluble and fibrous protein that makes up one

    • Compartment syndrome: A painful condition that occurs when pressure within the muscles builds to dangerous levels. This pressure can decrease blood flow, which prevents nourishment and oxygen from reaching nerve and muscle cells.

    • Complete blood count: A blood test used to evaluate your overall health and detect a wide range of disorders, including anemia, infection and leukemia.

    • Computed tomography (CT) scan: An imaging method that uses x

    • Congenital: A condition that is present at birth, whether or not it is inherited.

    • Creutzfeldt Jacob Disease (CJD): A rare, progressive, invariably fatal brain disorder. CJD usually appears in later life and runs a rapid course. In the early stages of disease, people may have failing memory, behavioral changes, lack of coordination and visual disturbances. As the illness progresses, mental decline becomes pronounced and involuntary movements, blindness, weakness of extremities, and coma may occur.

    • Chromosomes: In the nucleus of each cell, the DNA molecule is packaged into thread

  • D

    • Deep vein thrombosis: A blood clot that forms in a vein deep inside a part of the body. It mainly affects the large veins in the lower leg and thigh.

    • Desmopressin: A class of medications called hormones. It works by replacing vasopressin, a hormone that is normally produced in the body to help balance the amount of water and salt.

  • E

    • Enzyme: Complex proteins that cause a specific chemical change in all parts of the body. For example, they can help break down the foods we eat so the body can use them. Blood clotting is another example of enzymes at work.

  • F

    • Factor: A protein in the blood that helps form blood clots.

    • Fibrin: A protein that helps form a stable clot.

    • Fibrin glue: A unique surgical hemostatic/adhesive material that is being utilized with increasing frequency in a variety of surgical situations.

    • Fibrinogen (factor I): A protein needed to make fibrin, which helps form a stable clot.

    • Flow cytometry: A technology that is used to analyze the physical and chemical characteristics of particles in a fluid as it passes through at least one laser.

    • Fresh frozen plasma: The fluid portion of human blood that has been collected and frozen solid.

  • G

    • Gene: The basic physical and functional unit of heredity. Genes, which are made up of DNA, act as instructions to make molecules called proteins.

    • Gene therapy: An experimental technique that uses genes to treat or prevent disease. In the future, this technique may allow doctors to treat a disorder by inserting a gene into a patient’s cells instead of using drugs or surgery.

    • Genotyping: Testing that reveals the specific alleles inherited by an individual.

    • Glycoprotein: These are found on the platelet surface and work together like a bridge to connect platelets with each other and to the wall of the injured blood vessel.

  • H

    • Hematologist: Physicians trained to treat disorders of the blood.

    • Hemophilia: A bleeding disorder that occurs mostly in males. The disorder makes bleeding hard to control.

    • Hemophilia A: A bleeding disorder caused by a lack of factor VIII. It is sometimes called “classic hemophilia.”

    • Hemophilia B: A bleeding disorder caused by a lack of factor IX. It is sometimes called “Christmas disease.”

    • Hemophilia Treatment Center (HTC): A place that provides specialty care for hemophilia. Doctors, nurses, social workers, physical therapists, and dentists are part of the healthcare team.

    • Hereditary: Passed from parents to children. Diseases and disorders can be hereditary.

    • Heterozygous: This refers to having inherited different forms of a particular gene from each parent. A heterozygous genotype stands in contrast to a homozygous genotype, where an individual inherits identical forms of a particular gene from each parent.

    • HLA matched: Many factors play a role in how the immune system knows the difference between self and non–self, but the most important for transplants is the human leukocyte antigen (HLA) system. Human leukocyte antigens are proteins found on the surface of most cells. They make up a person’s tissue type, which is different from a person’s blood type. Each person has a number of pairs of HLA antigens. We inherit one of each of these pairs from each of our parents (and pass one of each pair on to each of our children). Doctors try to match these antigens when finding a donor for a person getting a stem cell transplant.

  • I

    • Idiopathic: Of unknown cause. Any disease that is of uncertain or unknown origin may be termed idiopathic.

    • Immune system: A bodily system that protects the body from foreign or harmful substances.

    • Immune tolerance therapy: With this therapy, factor concentrate is given regularly over a period of time until the body is trained to recognize the treatment product without reacting to it. When immune tolerance induction is successful, the inhibitors disappear and the patient’s response to factor concentrates returns to normal.

    • Inhibitors: With rare bleeding disorders, inhibitors are antibodies in the blood that react to infused factor and slow the clotting process.

    • Integrin: Member of a large family of transmembrane proteins involved in the connection of cells to the extracellular matrix and to each other.

    • International normalized ratio (INR): A comparative rating of a patient's prothrombin time (PT) ratio, used as a standard for monitoring the effects of warfarin. The INR indicates what the patient's PT ratio would have been if measured by using the primary World Health Organization International Reference reagent.

  • L

    • Lyonization: In females, the phenomenon by which one X chromosome (either maternally or paternally derived) is randomly inactivated in early embryonic cells, with fixed inactivation in all descendant cells is called lyonization. So, only one of the two X

  • M

    • MRI: A technique that uses a magnetic field and radio waves to create detailed images of the organs and tissues within your body.

    • Malignancy: Refers to cancerous cells that have the ability to spread to other sites in the body or to invade and destroy tissues. Malignant cells tend to have fast, uncontrolled growth.

    • Menstruation: A woman's monthly bleeding. When you menstruate, your body sheds the lining of the uterus (womb). Menstrual blood flows from the uterus through the small opening in the cervix and passes out of the body through the vagina.

    • Missense mutation: This happens when the change of a single base pair of the DNA sequence causes the substitution of a different amino acid in the resulting protein. This amino acid substitution may have no effect, or it may render the protein nonfunctional.

    • Mixing studies: A study in which patient plasma is mixed with normal plasma [ratio 1:1] to help distinguish between a clotting factor deficiency and an inhibitor.

    • Monoclonal gammopathy of undetermined significance (MGUS): A condition in which an abnormal protein (monoclonal protein or M protein) is in the blood. M protein is produced by plasma cells, a type of white blood cell. MGUS usually causes no problems. Sometimes, MGUS is either associated with another disease or can progress over years to other disorders, including some forms of blood cancer.

    • Mucocutaneous: Pertaining to mucous membrane and skin.

    • Mutation: A change in a DNA sequence. Mutations can result from DNA copying mistakes made during cell division, exposure to ionizing radiation, exposure to chemicals called mutagens, or infection by viruses.

  • N

    • Nasal cauterization: During nose bleeds, if the source of the bleeding is a blood vessel that is easily seen, a doctor may cauterize it (seal the blood vessel) with a chemical called silver nitrate. Cauterization is most effective when the bleeding is coming from the very front part of the nose.

    • Nasal packing: This involves putting pressure from inside the nostril to halt the bleeding. Many different types of packings are available, ranging from petroleum (Vaseline) gauze to balloon packs to synthetic sponge packs that expand when moistened.

    • Necrosis: Early death of cells or living tissue by damage or disease.

    • Nephrotic syndrome: A kidney disorder that causes your body to excrete too much protein in your urine.

  • P

    • Plasma: The liquid portion of blood – a protein

    • Platelet deficiency or platelet disorder: A defect in the number and/or function of platelets.

    • Platelet aggregation test: This test checks to see how well platelets, a part of blood, clump together when stimulated by chemicals to evaluate how they might contribute to blood clotting.

    • Platelet plug: After bleeding initiates, cells called platelets stick to the walls of the injured blood vessel and they stick to each other to form an initial plug before forming a blood clot. This plug is called platelet plug.

    • Platelets: Tiny cells in the blood that stick to an injured blood vessel, and to each other, to form a plug.

    • Polymyalgia rheumatica: A disorder associated with moderate

    • Prophylaxis: The regular infusion of clotting factor concentrates in order to prevent bleeding.

    • Proteins: Compounds that do vital tasks in the body.

    • Prothrombin (factor II): A protein needed to form a stable blood clot.

    • Prothrombin time: A blood test that measures the time it takes for the liquid portion (plasma) of your blood to clot.

    • Psuedotumors: An enlargement that resembles a tumor, resulting from inflammation, fluid accumulation, or other causes.

  • R

    • Rare bleeding disorders: Conditions in which defects and/or low levels of platelets or clotting factors lead to lifelong bleeding problems.

    • Recombinant: DNA artificially constructed by combining genes from different organisms or by cloning chemically altered DNA, usually for the purpose of genetic manipulation.

    • Recessive: A gene which will be expressed only if there are 2 identical copies or, for a male, if one copy is present on the X chromosome.

    • Refractoriness: When platelet transfusions may not work as well as expected or at all in treating a bleeding episode or preventing bleeding during a procedure.

    • Ristocetin: This molecule causes vWF to bind to platelets, resulting in platelet clumps and their removal from the circulation.

  • S

    • Stuart: Prower deficiency

    • Synovectomy: This surgery is done to remove inflamed joint tissue (synovium) that is causing unacceptable pain or is limiting a person’s ability to function.

    • Synovitis: Inflammation of the synovium, a membrane found inside joints.

    • Synovium: A joint is lined by a synovial membrane (i.e., the synovium). The synovium produces synovial fluid, a clear substance that lubricates and nourishes the cartilage and bones inside the joint capsule.

  • T

    • Thrombin: A protein needed to form a stable clot.

    • Thrombin time: Duration needed for a fibrin clot to form after the addition of thrombin to citrated plasma.

    • Thrombocytopenia: A condition in which you have a low blood platelet count.

    • Tissue factor: A plasma protein present in tissues, platelets, and white blood cells necessary for the blood clotting. Also, in the presence of calcium, TF is necessary for the conversion of prothrombin to thrombin.

    • Tonsillectomy: The surgical removal of the tonsils, two oval

    • Transfusions: This is a safe, common procedure in which blood is given to you through an intravenous (IV) line in one of your blood vessels.

    • Turner’s syndrome: A chromosomal condition that affects development in females. The most common feature of Turner syndrome is short stature, which becomes evident by about age 5.

  • U

    • Umbilical cord: A cord that connects a baby in the womb to its mother. It runs from an opening in the baby’s stomach to the placenta in the womb.

  • V

    • von Willebrand Factor: This protein contains regions that attach (bind) to specific cells and proteins during the formation of a blood clot.