Hemophilia Definitions

There is an entire vocabulary of new words to digest and look up if you are new to factor VIII treatment. Here is a quick reference glossary to help guide your way.

The National Hemophilia Foundation (NHF) publishes an entire vocabulary of new words to digest and look up if you are new to factor VIII treatment. The words below from The NHF's quick reference glossary may help guide your way.

Anemia

a condition in which the blood is deficient in red blood cells, either in hemoglobin (the iron-carrying component) or in total volume from loss of blood.

Bethesda unit

a laboratory measurement of an antibody, called an inhibitor. Values above 5 are considered high; the inhibitor is powerful and weakens the effect of clotting factor.

Biopsy

a procedure in which samples of tissues, cells or fluid are removed for examination. Liver biopsies reveal the extent of damage from cirrhosis, or scarring.

Bleeding disorders

several chronic health conditions in which the body does not clot properly, resulting in excessive or lengthy bleeding.

Breakthrough bleed

bleeding between infusions of factor product.

Carrier

a person who has the gene for a condition, but does not necessarily display the symptoms.

Asymptomatic carrier

a person without symptoms of a condition.

Symptomatic carrier

a person who has low factor levels and displays bleeding symptoms.

Central Venous Access Device (CVAD)

a small, flexible tube placed securely in a large vein for patients who need regular infusions.

Chromosome

structures in the cell's nucleus that contain genetic information in the form of DNA.

Clotting cascade

a series of steps that occur in the formation of a clot, involving the clotting proteins and other substances.

Clotting disorders

conditions in which there is an increased tendency toward excessive clotting.

Clotting factors

proteins in the blood that act in sequence to stop bleeding and form a clot.

Coagulation

the process of forming a blood clot.

Coagulation disorders

several chronic health conditions in which the body does not clot properly, resulting in excessive or lengthy bleeding.

DNA (deoxyribonucleic acid)

the molecular basis of heredity. The order of the four bases that compose DNA—adenine, cytosine, guanine and thymine—provides information on cell activity.

Factor assay

a lab test that determines the level of circulating factor in the body. The results are reported as a percentage of normal levels.

Factor product

treatment that is infused to replace the body's missing clotting proteins. It is made from plasma or recombinant products.

Factor deficiencies

bleeding disorders identified by the missing clotting factor. They include factors I, II, V, VII, VIII, IX, X, XI, XII and XIII.

Factor I deficiency

a rare bleeding disorder caused by deficient or defective fibrinogen.

Factor II deficiency

an extremely rare bleeding disorder caused by a deficiency of prothrombin.

Factor V deficiency

a rare bleeding disorder caused by a deficiency of factor V protein.

Factor VII deficiency

the most common rare bleeding disorder, caused by a deficiency of factor VII protein. It is usually severe.

Factor VIII deficiency

also called hemophilia A.

Factor IX deficiency

also called hemophilia B.

Factor X deficiency

a rare bleeding disorder caused by a deficiency of factor X protein, which activates enzymes that help form a clot.

Factor XI deficiency

also called hemophilia C.

Factor XII deficiency

a rare bleeding disorder. Most people who have it do not experience bleeds.

Factor XIII deficiency

the rarest bleeding disorder, caused by the deficiency of factor VIII protein, which stabilizes the clot.

Fibrosis

the accumulation of tough, fibrous scar tissue that may occur for example in some types of lung or liver disease. It is measured by stages or grades.

Gene

a sequence of DNA that occupies a specific location on a chromosome and determines a particular characteristic.

Gene therapy

replacing, manipulating or supplementing a dysfunctional gene with a functional one.

Half-life

the time it takes for the blood concentration of factor or a factor product to be reduced by one-half.

Hemarthrosis

bleeding into a joint.

Hematologist

a physician specializing in disorders of the blood.

Hemoglobin

the protein in red blood cells that contains iron and carries oxygen and carbon dioxide.

Hemophilia

a bleeding disorder in which a clotting factor protein, such as factor VIII or IX, is completely or partially lacking or does not function normally.

Hemophilia A

a deficiency or absence of factor VIII. The most common form of hemophilia, also called "classic hemophilia."

Hemophilia B

a deficiency or absence of factor IX. Also called "Christmas disease" after the first family diagnosed with the condition.

Hemophilia C

also called factor XI deficiency. Patients are deficient in or lack factor XI protein.

Mild hemophilia

a factor VIII or IX level ranging from 5% to 40% of normal blood levels.

Moderate hemophilia

a factor VIII or IX level ranging from 1% to 5% of normal blood levels.

Severe hemophilia

a factor VIII or IX level below 1% of normal blood levels.

Hemophilia Treatment Centers (HTCs)

a group of federally funded hospitals that specialize in treating patients with bleeding disorders.

Hemorrhage

rapid, uncontrollable bleeding.

Hemostasis

process by which the body stops bleeding.

Hereditary disease

a condition that is genetically passed down to offspring.

Infusion

delivering clotting factor concentrate directly into a vein.

Continuous infusion

steadily infusing clotting factor concentrate; often used during surgery.

Inheritance

the biological process of transmitting certain characteristics or conditions from parents to offspring.

Inhibitor

an antibody to infused clotting factor concentrates, making standard treatments ineffective.

Intracranial hemorrhage

a bleed into the brain.

Immunoaffinity Chromatography

antibodies bind tightly to a specific site on a protein molecule. Antibodies bound to a chromatography column can selectively bind the specific protein from a complex mixture. This is the unique chemistry used in immunoaffinity chromatography. It is a method used to help purify Kogenate FS.

Joint fusion

surgery to combine one or more bones in a joint. Most commonly used in joints where replacement surgery is not recommended, such as the ankle.

Joint replacement

using artificial components in a joint, such as the knee or elbow, to replace those that are damaged from wear and tear or chronic bleeds.

Lifetime cap

a spending limit on insurance benefits. Once it is reached, the policy no longer provides coverage.

Mutation

a change in the DNA of a cell, due to such causes as exposure to radiation or viruses, or during cell division. Hemophilia is caused by cell mutation.

Spontaneous mutation

a genetic change that occurs without a triggering agent, usually due to a malfunctioning cell enzyme.

Plasma

yellow-colored, protein-rich portion of the blood, which carries the red blood cells, white blood cells and platelets.

Platelets

tiny plate-like components of blood that help seal injured blood vessels and stop bleeding.

Port

a device that delivers intravenous drugs. It is usually implanted under the skin in the chest.

Pre-existing condition

a health condition that existed prior to obtaining health insurance.

Prophylaxis

a treatment regimen to prevent bleeds.

Primary prophylaxis

regularly scheduled factor product treatments to prevent bleeding episodes. Usually begun in childhood and performed two to three times weekly.

Secondary prophylaxis

regularly scheduled factor product treatments begun after a pattern of bleeding occurs or to treat a target joint.

Recombinant product

genetically engineered factor product made without human blood products, decreasing the risk of transmission of bloodborne infections.

Standards of Care

state legislation to protect patient access to HTCs and the full range of products and services.

Synovitis

inflammation of the synovial membrane, which surrounds joints. Can be caused by repeat bleeding into the same joint.

Thrombosis

the formation of a blood clot.

Titer

a measure of the concentration of antibodies, called inhibitors, in the blood.

Von Willebrand disease (VWD)

a bleeding disorder in which von Willebrand factor (VWF), a blood protein, is either deficient or defective.

Von Willebrand factor (VWF)

a blood protein that helps platelets plug injured blood vessel walls by causing them to stick together. It is also a carrier for factor VIII.