HAE Glossary

Glossary

This is a list of terms we use on HAE Hope that may require a little more explanation. If you hover your mouse over any one of these terms throughout HAE Hope, the definition will pop up.

ACE Inhibitor: Class of medicines used to treat high blood pressure and other diseases.
Activating factor: A functioning plasma protein that works in the coagulation pathway to help form a clot.
Anabolic steroid: Also referred to as attenuated androgen, a class of steroid hormones used to prevent HAE attacks. Although their mechanism of action in HAE patients is unknown, these agents are believed to partially reverse the biochemical defect by increasing levels of C1-esterase inhibitor (C1-INH), helping to prevent angioedema attacks in patients with inherited C1-INH deficiency.
Antifibrolytic agent: Medicines used to prevent HAE attacks. These agents inhibit the activation of plasmin, a chemical in the blood that can make the C1-INH less effective.
Attenuated androgen: Also referred to as anabolic steroid, a class of steroid hormones used to prevent HAE attacks. Although their mechanism of action in HAE patients is unknown, these agents are believed to partially reverse the biochemical defect by increasing levels of C1-esterase inhibitor (C1-INH), helping to prevent angioedema attacks in patients with inherited C1-INH deficiency.
Bradykinin: A protein, which when released, causes blood vessels to expand (dilate) and leak fluid, such as serum, into surrounding tissue.
C1 inhibitor: Also referred to as C1-INH, a protein found in the fluid part of your blood that controls C1, a component of your body's complement system. Abnormal swelling can result when C1-INH is insufficient or defective.
C1-INH: Also referred to as C1 inhibitor, a protein found in the fluid part of your blood that controls C1, a component of your body's complement system. Abnormal swelling can result when C1-INH is insufficient or defective.
Cleave: To cut; to split
Coagulation pathway: A process in which blood cells work together to form a clot.
Complement system: The complement system is made up of proteins like C1 that float in your bloodstream, which work with the immune system to fight organisms like bacteria, viruses and parasites.
Drug formulary: A list of prescription medications selected for coverage under a health insurance plan.
Edema: Swelling caused by an excessive amount of fluid in the body tissues.
Endothelial cells: A thin layer of cells that line the surface of blood vessels.
Enzyme: A protein that changes the rate of chemical reactions in the body.
HAE: HAE, or Hereditary Angioedema, is a rare, hereditary disease of the immune system that affects an estimated 1 in 10,000 to 1 in 50,000 adults and children globally. HAE causes attacks of spontaneous swelling that are often painful and severe, and can be life-threatening.
Hereditary Angioedema: A rare, hereditary disease of the immune system that affects an estimated 1 in 10,000 to 1 in 50,000 adults and children globally. Hereditary Angioedema (HAE) causes attacks of spontaneous swelling that are often painful and severe, and can be life-threatening.
High-molecular-weight kininogen: HMWK, a protein that acts on the inflammation and coagulation processes; inactive until it is cleaved by kallikrein and in turn, releases bradykinin.
Hypotension: Low blood pressure.
Inflammatory pathway: A process in which the body responds to an injury either inside or outside of the body.
Inhibitor: That which reduces, prevents or stops; i.e. a substance that stops enzyme activity.
Kallikrein–kinin system: A system of proteins in the blood that has a role in the inflammatory pathway; through this system, bradykinin is released.
Kinin: A protein that is a component of the kallikrein-kinin system.
Laryngeal attack: An HAE attack that affects the larynx (throat); this can block or close the airway, leading to difficulty breathing and, potentially, death.
Liberate: To release
Plasma kallikrein: An enzyme present in blood plasma, urine and tissue; responsible for cleaving high-molecular-weight kininogen (HMWK), which then releases bradykinin.
Prekallikrein: Precursor to kallikrein; inactive until it cleaved by activated factor (specifically, activated factor XII) to generate active kallikrein.
Preventive therapy: In HAE, medicine taken to prevent attacks.
Prodrome: One or more physical warnings of an HAE attack; can appear as a rash or a feeling of skin tightness.
Protease: An enzyme that breaks proteins down into a simpler form.
Proteolytic cascade: A step-by-step process in which proteins are broken down into simpler forms.
Receptor: A component in a cell that can combine with a drug or a chemical in the body (i.e. hormone) to change the function of the cell.
Serum: The clear, watery, fluid-component of blood that resembles fluid in a blister.
Subcutaneous: Beneath the skin.
Substrate: A molecule or substance acted upon by an enzyme.
Trigger: In HAE, something that causes an attack. Stress and trauma are two common HAE attack triggers.
Vascular permeability: The capacity of blood vessels to allow fluids or molecules to pass in and out of the vessel.
Vasodilator: A substance that opens, or dilates, blood vessels; e.g. bradykinin and nitric oxide.

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