At a glance
This page defines medicines, scientific terms, and medical terms commonly used in bleeding disorder treatment and diagnosis.
Terms
Aminocaproic acid: Medicine (for example, Amicar®) that can be injected into a vein or taken as a pill or liquid. It prevents blood clots from breaking down, resulting in a firmer clot, and is often used for bleeding in the mouth or after a tooth has been removed because it blocks a substance found in the saliva (spit) that breaks down clots.
Antifibrinolytics: A category of treatment products (or medicines) that includes aminocaproic acid and tranexamic acid. An antifibrinolytic is either injected or taken orally (by mouth as a pill or liquid) to help slow or prevent the breakdown of blood clots.
Baseline clotting factor activity level: The level of clotting factor VIII (8) or factor IX (9) occurring naturally in the blood, without recent use of treatment products, that can help to stop bleeding. The baseline factor level and other laboratory values may help healthcare providers determine the severity of a patient's bleeding disorder.
Blood products: A substance taken from donated blood that may be used in the treatment of hemophilia and other blood problems. Whole blood, packed red blood cells, fresh-frozen plasma, platelets, and cryoprecipitate are all types of blood products.
Bypassing agents: Medications that help the blood form normal clots in people with inhibitors. Bypassing agents do not replace the missing clotting factor; instead, they correct the clotting process by going around (or bypassing) the factor that does not work because of the inhibitor. Bypassing agents can also be given on a routine schedule to prevent bleeding episodes.
Coagulation: The process by which clotting factor proteins work with platelets to form a clot and stop a bleeding episode.
Clotting factor: Proteins in the blood that stop bleeding.
Clotting factor concentrate: A concentrated mixture of the missing or defective blood clotting factor (proteins that stop bleeding) that is injected into the affected person's vein. Clotting factor concentrate can be used as needed when a person is bleeding (also called episodic, or on demand), or it can be used on a regular basis to prevent bleeds from occurring (also called prophylaxis).
Cryoprecipitate: A substance that comes from thawing fresh frozen plasma. It has a lot of factor VIII and was commonly used to control serious bleeding in the past. However, because there is no method to kill viruses such as HIV and hepatitis in cryoprecipitate, it is no longer used as the current standard of treatment in the United States.
Desmopressin: A medicine that can be given in two ways: injected into a vein (DDAVP®) or as a nasal spray (Stimate®). These medicines are similar to a hormone that occurs naturally in the body. They cause the body to release factor VIII and von Willebrand factor (VWF) from where it is stored in the body tissues. For people with mild von Willebrand disease (VWD), mild hemophilia, and sometimes moderate hemophilia, these medicines can work to increase the person's own factor VIII and VWF levels so that they do not have to use clotting factors to stop bleeding episodes.
Fresh frozen plasma: The liquid part of blood. It is pale yellow or straw colored and contains proteins such as clotting factors.
Genetic condition: A condition that is caused by a difference in the genes from what is typical. Because genes are inherited from one's parents, some genetic conditions may be passed down from one generation to the next.
Hemlibra®: The brand name for a medicine to treat hemophilia A. (It's also sometimes called ACE 910 or emicizumab.) Instead of replacing the missing factor VIII, it works by replacing the function of factor VIII, without being affected by inhibitors. It can be used to either prevent or reduce the frequency of bleeding episodes. It is not FDA approved to treat active bleeding episodes.
HAV (hepatitis A virus): The virus that causes the liver infection hepatitis A. The hepatitis A virus is spread through personal contact with an infected person or through eating contaminated food or drink.
HBV (hepatitis B virus): The virus that causes the liver infection hepatitis B. The hepatitis B virus is spread through personal contact with blood, semen, or other body fluids from an infected person.
HCV (hepatitis C virus): The virus that causes the liver infection hepatitis C. The hepatitis C virus is spread through contact with blood.
HIV (human immunodeficiency virus): A virus that infects specific cells of the immune system, called CD4 cells or T cells. Over time, HIV can destroy so many of these cells that the body can't fight off infections and disease. When this happens, HIV infection leads to acquired immunodeficiency syndrome, or AIDS. Unlike some other viruses, the human body cannot get rid of HIV. HIV is spread from one person to another through body fluids, such as blood or semen.
Hormonal birth control/therapy: Can be used to treat heavy menstrual bleeding. Hormonal birth control includes hormonal drugs used for birth control (pills or shots [for example, Depo-Provera®]), implants (Nexplanon®), and hormone-containing intrauterine devices (Mirena®, Kyleena®). Other hormone therapies may also be used.
Immune tolerance induction (ITI): A treatment regimen that is used to get rid of an inhibitor. 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 ITI is successful, the inhibitors disappear and the patient's response to factor concentrate returns to normal.
Inhibitor titer: A blood test used to diagnose inhibitors. The blood test measures inhibitor levels (called inhibitor titers) in the blood. The amount of inhibitor is measured in Bethesda units (BU). The higher the number of BU, the more inhibitor is present.
Novel products: A category of treatment products (or medicines) that includes those that control or prevent bleeding using "new" methods of action. This includes products that do not replace the missing clotting factor or increase its release from body tissues and are not antifibrinolytics. Examples include Hemlibra®, gene therapy, fitusiran, and concizumab.
Other treatment product types: A category of treatment products (or medicines) that includes a variety of medicines that were infrequently reported and could not be placed in another category. Examples include unspecified clotting factor concentrate, unspecified clinical trial products, porcine products, and thrombin (an enzyme in blood plasma that promotes blood clotting).
Plasma-derived (factor concentrate): Factor concentrate treatment products that are made from plasma proteins. Plasma is the liquid part of blood. It is pale yellow or straw-colored and contains proteins such as clotting factors. Plasma-derived factor concentrates are made by separating the clotting proteins from other parts of donated blood.
Platelets: Blood cells that help the blood form clots, which in turn stop a bleeding episode. They are smaller than red or white blood cells.
Port: A device that is surgically placed under the skin of the chest and attached to a tube that is inserted directly into a large vein in the upper chest. It is used for giving clotting factor concentrates or other medications.
Prophylaxis: Receiving treatment on a regular schedule to prevent an illness, condition, or negative health outcome. For people with a bleeding disorder, prophylaxis refers to regular injections with clotting factor concentrate to prevent a bleeding episode.
QR powder: a powder that is applied to and sticks to the skin to form a flexible scab and stop bleeding.
Recombinant, standard half-life: "Recombinant" refers to clotting factor concentrates that are genetically engineered using DNA technology and do not come from human blood. For factor VIII products, "standard half-life" means the product has not been modified to extend the half-life (the amount of time it takes one's body to reduce the clotting factor to half in the bloodstream) (for example, Advate®, Helixate®). For factor IX products, "standard half-life" means that the half-life is less than or equal to 24 hours (for example, Benefix®).
Recombinant extended half-life: "Recombinant" refers to clotting factor concentrates that are genetically engineered using DNA technology and do not come from human blood. For factor VIII products, "extended half-life" means the product has been modified to extend the half-life (the amount of time it takes one's body to reduce the clotting factor to half in the bloodstream) (for example, Eloctate®, Adynovate®). For factor IX products, "extended half-life" means the product half-life is greater than 24 hours (for example, Alprolix®).
Tranexamic acid: A medicine that can be given in two ways: injected into a vein (Cycklokapron®) or taken orally as a pill (Lysteda®). These medicines slow or prevent blood clots from breaking down, resulting in a firmer clot, and is often used for bleeding in the mouth or nose. They can be used for mild bleeding symptoms, heavy menstrual bleeding, and minor outpatient procedures. They can also be used in combination with other therapies.
Whole blood/blood products: "Whole blood" is blood drawn directly from the body and none of the blood components, such as plasma or platelets, have been removed. "Blood products" are the components separated from whole blood (cryoprecipitate, fresh-frozen plasma, packed red blood cells, platelets) but not clotting factor concentrates.