Glossary of terms

This glossary will help make hemophilia with inhibitors less confusing. If you find a word you do not know on this website, come to this page.

-A-

Antibody – A protein made by blood cells. It attacks substances that the body thinks present a danger. Inhibitors that attack replacement therapies for hemophilia are called antibodies.
Arthrodesis – The surgical joining or fusion of a joint.
Arthropathy – Any joint disease.
Arthroplasty – Joint replacement surgery.
Arthroscope — A very thin tube with a light at the end that is inserted into the joint through a small cut in the skin.


-B-

Bethesda inhibitor assay – A test performed in the lab that measures the strength or titer of an inhibitor.
Bethesda titer – Concentration or strength of a substance, such as an inhibitor, using Bethesda units.
Bethesda units (BUs) – Units used to measure inhibitor levels, also called titers.
Bleed – A collection of blood in an area. It is a term used by people with bleeding disorders to describe their bleeding episodes.
Blood clot – A thick clump or mass of coagulated blood.
Blood clotting – The process by which the blood forms clots to stop a bleed.
Bypassing agents – Agents or products that stimulate the blood clotting process by bypassing the deficient factor with a clotting factor that occurs later in the cascade.


-C-

Catheter – A flexible tube placed in a body cavity to allow the passage of fluids.
Chronic synovitis – Persistent, painful swelling of the tissue lining the joint.
Clotting factor – The proteins that circulate in the blood and are needed for normal coagulation.


-D-

Diaphragm – A protective membrane where a needle is inserted into a port.


-E-

Excision – During surgery, removal of something by cutting.


-F-

Factor – A protein in the blood that helps form blood clots.
Factor replacement therapy – In hemophilia, the infusion of clotting factor to serve as a temporary substitute for the body's missing or deficient factor. In hemophilia A, Factor VIII is infused as the replacement therapy.
Femur – The thigh bone.


-G-

General practitioner (GP) – Your primary doctor; often the family doctor or similar primary care physician.
Glenoid – A pit or socket.


-H-

Hemophilia – A clotting 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 or standard hemophilia.
Hemophilia B – A bleeding disorder caused by a lack of Factor IX.
Hemophilia treatment center (HTC) – A place that provides specialty care for hemophilia. Doctors, nurses, social workers, physical therapists, and dentists are part of the health care team.
Heparin – A blood thinner that stops blood clots from forming.
Hereditary link – Passed from parents to offspring.
High responder – A person whose inhibitor rises to a very high level after receiving factor replacement therapy.
High-titer inhibitor – An inhibitor that is very aggressive.
Humerus – The long bone in the upper arm. It extends from the shoulder to the elbow.


-I-

Immune system – A mechanism within the body used to protect itself from harmful substances.
Immune tolerance induction (ITI) – Therapy that tries to get rid of inhibitors. It involves regular (maybe daily) infusions of high doses of specific factor. If successful, it reduces the immune system's response to the factor. That means the body does not create antibodies to the factor. ITI is also called ITT or immune tolerance therapy.
Immune tolerance therapy (ITT) – See immune tolerance induction (ITI).
Infuse – To inject medicine directly into a vein using a needle and syringe.
Inhibitors – Antibodies in the blood that react to infused factor and hinder clotting.


-J-

Joint health – The proper working of a joint. Infusing quickly after joint injuries and getting regular physical activity help improve joint health.


-L-

Low responder – A person whose inhibitor level rises only slightly after receiving factor replacement therapy.
Low-titer inhibitor – An inhibitor that is not very aggressive.


-P-

Platelets – Tiny cells in the blood that stick to an injured vessel and to each other to form a plug.
Port – An implanted access device through which factor may be infused.
Prosthesis – An artificial substitute for a missing body part.
Psoas – The pair of muscles located in the groin area that help to flex the hip joint.


-R-

Radius – 1 of the 2 bones of the forearm; on the same side as the thumb.
Reservoir – A storage space for fluids.


-S-

Spontaneously – Something that happens without a cause.
Synovectomy – The surgical or chemical removal of the joint lining.
Synovium – The tissue lining a joint. Often the place where joint bleeds start.


-T-

Talus – The ankle bone, which works with the bones of the leg to form the ankle joint.
Target joint — A joint that bleeds over and over again.
Thrombotic events – Happen when veins or arteries become blocked by platelets that are working to "plug" an injury. This prevents blood from flowing normally through the body.
Tibia – The shin bone.
Titer – See Bethesda titer.


-U-

Ulna – 1 of the 2 bones of the forearm; on the opposite side of the thumb.