 |
 |
Glossary
A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z
Don't see the term you are looking for? Let us know!
A
Acquired: A condition that is not genetic (inherited) or congenital (present at birth); usually caused by environmental factors and/or other physical conditions.
Anemia: A low red blood cell count. Anemia may be due to many causes, including low iron stores (called 'iron-deficiency anemia') or antibody-mediated destruction of red blood cells (referred to as 'autoimmune hemolytic anemia').
Antibody: A protein produced by the immune system in the body that travels in the blood and helps the body to fight infection.
Anticoagulant: A class of medications that causes the blood to take a longer time to form a blood clot. Anticoagulants are used to prevent formation of blood clots and treat them once they develop. They may be given by injections, either into a vein or under the skin (e.g., heparin, low-molecular-weight heparin), or by mouth (warfarin).
Anticoagulation: A general term for a treatment that interferes with the ability of the blood to form a normal blood clot. Anticoagulant medicines include heparin and warfarin, and are sometimes referred to as 'blood thinners'.
Antigen: A molecule, frequently a protein, which stimulates antibody formation by the immune system of the body. Usually, antigens are foreign, or 'non-self', and antibody formation is protective against developing the disease. For example, the flu vaccine generates antibodies that protect against getting influenza. When antibodies develop against host antigens, however, they are referred to as autoantibodies.
Antiphospholipid Antibody: A type of autoantibody associated with an increased risk for forming blood clots (deep venous thrombosis, pulmonary embolism, strokes and heart attacks) or recurrent miscarriages. These autoantibodies generally do not bind directly to phospholipids, but instead bind to certain proteins that bind to phospholipids.
Antiphospholipid Antibody Syndrome (APS): A rare autoimmune disorder characterized by recurrent blood clots and/or miscarriages. By definition, these patients have elevated antiphospholipid antibody levels in their blood. APS may occur in individuals with lupus or related autoimmune diseases, or as a primary syndrome in otherwise healthy individuals (referred to as "primary APS").
Aplastic Anemia: A disorder characterized by the failure of the bone marrow to produce any of the cells normally found in the blood, including red blood cells, white blood cells, and platelets.
Artery: A vessel through which the blood passes away from the heart to the various parts of the body.
Asymptomatic: Completely without any symptoms or complaints. An individual who feels completely normal would be asymptomatic
Autoantibody: An antibody that fights against the patient's own body parts. For example, autoantibodies that attack platelets may cause thrombocytopenia. Patients with autoimmune disorders, such as lupus and rheumatoid arthritis, have autoantibodies in their blood.
Autoimmune Disorder: A particular kind of medical condition in which patients make autoantibodies against specific cells, tissues, or organs. Examples of autoimmune disorders include rheumatoid arthritis and lupus. The antiphospholipid syndrome is also an autoimmune disorder.
B
Blood: Blood circulates in our arteries and veins. Blood consists of plasma, the liquid portion which contains proteins and other molecules, and cells. Blood cells include white blood cells, which fight infection, red blood cells, which carry oxygen to the tissues and carbon dioxide back to the lungs, and platelets, which are like little corks that plug up holes to stop bleeding.
Budd-Chiari Syndrome: Thrombosis of the hepatic veins (veins coming from the liver), usually presenting with abdominal pain, enlargement of the liver, and ascites (fluid in the abdomen). The Budd-Chiari syndrome can be seen in patients with paroxysmal nocturnal hemoglobinuria (PNH).
C
Catastrophic APS: A very rare form of APS, characterized by the sudden onset of multiple organ failure, usually due to blood clots developing in small blood vessels in different organs.
Clot: Another name for thrombus.
Coumadin: Brand name for warfarin.
D
Deep Vein Thrombosis (DVT): A condition in which a blood clot forms in the deep veins of the legs, pelvis, or arms. The treatment for a deep vein thrombosis includes anticoagulant therapy.
F
Factor V Leiden: Factor V is an important blood clotting protein. Factor V Leiden occurs when a specific mutation in the factor V gene results in a protein that is more resistant to being turned off, leading to an increased risk for forming blood clots. Factor V Leiden is the most common inherited hypercoagulable state.
G
Gene: Genes are located in our DNA, and are the blueprints for making individual proteins. It is estimated that the human genome codes for between 20,000 and 25,000 individual genes.
H
Hematologist: A physician who specializes in the study of blood disorders. These disorders include bleeding and clotting problems, anemia, thrombocytopenia, and white blood cell disorders.
Hemoglobin: Is the protein molecule in red blood cells which carries oxygen from the lungs to the body's tissues and returns carbon dioxide from the tissues to the lungs. The iron contained in hemoglobin is responsible for the red color of blood.
Hemoglobinuria: The presence of hemoglobin in the urine.
Hemolysis: A process resulting in the lysis, or destruction, of red blood cells, releasing their contents into the plasma. Red blood cells may undergo hemolysis because of specific antibodies that bind to their surface that cause their destruction, or other mechanisms.
Hemophilia: An inherited bleeding disorder characterized by the absence or decreased levels of certain blood clotting proteins.
Hemostasis: The normal physiologic process whereby liquid blood forms a clot to stop bleeding.
Heparin: Heparin is a blood thinning medicine that is routinely prescribed for the treatment of clotting disorders, including treatment of clots in the coronary arteries (causing heart attacks), clots in the blood vessels of the brain (leading to stroke), clots that occur in leg veins (deep vein thrombosis) or clots that obstruct blood flow to the lungs (pulmonary emboli). An estimated 5-6 million patients with cardiovascular disease receive heparin each year. In addition, an equivalent or greater number of patients take heparin for other indications, including during heart surgery or dialysis, or for the prevention of blood clots.
Hypercoagulable: Refers to an increased tendency to form blood clots, either due to an inherited state (for example, factor V Leiden) or an acquired disorder (for example, cancer).
Hypercoagulable State: An inherited or acquired risk for developing thrombosis (blood clots). Common inherited causes of blood clots include factor V Leiden and the prothrombin gene mutation G20210A. Common acquired causes of blood clots include pregnancy, certain medications (for example, birth control pills), and cancer.
I
International Normalized Ratio (INR): A measurement of the blood's ability to clot, based on the prothrombin time. In a normal individual, the INR should be 1. In a patient taking warfarin therapy, the blood takes longer to form a clot in a test tube, and the INR will be higher. The target INR for many patients taking warfarin is 2 to 3 , but some patients with antiphospholipid syndrome are maintained at a higher INR.
L
Lupus: An autoimmune disorder characterized by multiple types of autoantibodies. Common clinical manifestations include symptomatic arthritis, facial rashes, and fatigue. Many patients with lupus will have antiphospholipid antibodies, referred to as secondary antiphospholipid syndrome.
Lupus Anticoagulant: A type of antiphospholipid antibody that is detected through blood clotting tests, especially the activated partial thromboplastin time (aPTT). This autoantibody is associated with an increased risk for blood clots.
M
Manifestation: A particular symptom or observation that may be of help in making a specific diagnosis. (For example, a common manifestation of patients with APS is recurrent blood clots.)
Mutation: A change in a gene from its natural state. Mutations may cause disease or result in a normal variant that causes no problems for the patient. For example, mutations in the blood clotting protein factor VIII cause hemophilia A.
P
Phospholipid: A type of fat molecule found in many locations throughout the body, including in the membranes that surround all of our cells.
Plasma: The liquid part of the blood, which contains all the proteins necessary to form a blood clot, antibodies, and a variety of other components.
Platelet: The smallest cell in the blood, important for normal hemostasis, or blood clotting
Proteins: Proteins are essential molecules in the body that are made up of strings of amino acids. The genes in our DNA contain the necessary information to make all the proteins in our bodies. Examples of proteins include antibodies and blood clotting factors.
Prothrombin Time (PT): Is a measure of how long it takes blood to clot in a test tube. This blood test is very sensitive to the effects of warfarin, vitamin K deficiency, or liver disease.
Pulmonary Embolism: A blood clot from a deep vein, usually in the legs, pelvis, or arms, that breaks loose and travels through the veins and then through the heart to lodge in the blood vessels in the lung. Large pulmonary emboli can be life-threatening and may need to be treated with fibrinolytic therapy, such as tPA (referred to as "clot-busters").
Purpura: A general term describing red blood cells in the skin. Very small areas are referred to as petechiae, and larger areas are referred to as ecchymoses, or bruises.
R
Rheumatologist: A physician who specializes in the study of disorders of the immune system. These disorders include lupus, rheumatoid arthritis, scleroderma, and a variety of related disorders.
S
Schistocyte: A red blood cell that has been damaged or torn, frequently with sharp edges. This type of red blood cell is frequently seen in patients with thrombotic thrombocytopenic purpura.
Serum: The liquid part of the blood that remains after the blood has been allowed to form a blood clot.
T
Thalassemia: An inherited form of anemia characterized by the defective production of hemoglobin. This inherited disorder is most commonly found in individuals of Mediterranean, black, or southeast Asian ancestry. In addition to the anemia, these patients also have an increased risk for thrombotic complications.
Thrombocytopenia: A low platelet count.
Thrombosis: The pathologic (abnormal) process whereby liquid blood forms a clot within a blood vessel or the heart.
Thrombotic Storm: A general term describing the rapid development of multiple blood clots. Treatment consists of the aggressive use of anticoagulant medicines. Catastrophic APS is a type of thrombotic storm seen in patients with APS.
V
Vein: A vessel through which blood passes from various organs back to the heart.
von Willebrand factor: A protein in the blood that is involved in normal blood clotting by binding to platelets. Abnormalities in the normal processing of von Willebrand factor are seen in patients with thrombotic thrombocytopenic purpura and hemolytic uremic syndrome.
W
Warfarin: A medicine given by mouth that interferes with blood clotting, generally used for the prevention or treatment of blood clots. Often referred to as a "blood thinner".
|
Return to RDCRN Main Page