aHUS Glossary

ADAMTS13: a type of protein that occurs naturally in the body. It helps break up a different protein that can help produce clots. An ADAMTS13 test can identify patients with TTP because they have low levels of ADAMTS13. aHUS patients have normal or only slightly reduced levels1

atypical Hemolytic Uremic Syndrome (aHUS): a disease of the blood that causes low red blood cell and platelet counts, kidney failure, and damage to other vital organs, such as the heart and brain2

Colon: the lower part of the large intestine3

Complement system: a network of proteins and enzymes that interact with each other to protect the body against foreign substances, like bacteria and other invading organisms. aHUS is a disease in which the complement system has trouble figuring out who is “one of us” and who is “one of them”1,4

Creatinine: a chemical excreted by the kidneys which, when measured, shows whether the kidneys are functioning properly5

Dialysis: a management option for kidney failure. Normally, the kidneys work to filter the blood and remove waste, excess salt, and water. Kidney failure, also called “end-stage renal disease,” occurs when the kidneys stop working completely. During hemodialysis, a machine takes over the job of the kidney by filtering the blood outside of the body, and then returning the filtered blood back to the body6

E. coli: bacteria that normally exist in the lower intestines of humans and other animals, which can cause illness7

Edema: swelling of certain parts of the body due to the presence of abnormally large amounts of fluid8

Enzyme: a protein that starts a chemical reaction within the body9

Immune system: a complex group of cells, proteins, and other molecules that work together to identify foreign organisms and substances, such as bacteria; the main role of the system is to protect the body against these foreign organisms10

Infusion: a process during which fluid is introduced into the body through a vein11

Microangiopathy: a disease of very small blood vessels12

Monoclonal antibodies: special proteins designed to target other very specific cells or proteins in the body13

Mutation: a permanent change in genetic material, usually in a single gene14

Plasma: the pale yellow liquid part of whole blood, in which the red and white blood cells and various other elements are suspended15

Plasma exchange: a process of removing, treating, and returning plasma to the body16

Purpura: any condition characterized by bleeding in the skin and mucous membranes, which can appear as bruises on the surface of the skin17

Shiga toxin: a poison produced by E. coli bacteria that causes severe diarrhea1

Shiga toxin–producing E. coli hemolytic uremic syndrome (STEC-HUS): a syndrome triggered by Shiga toxin–producing E. coli. The disease is characterized by diarrhea that is often bloody and followed by acute renal failure1

Stroke: damage to the brain. Strokes can happen when an artery in the brain becomes clogged or starts bleeding and cuts off the blood supply to that portion of the brain18

Syndrome: a set of symptoms that occur together in a pattern19

Systemic: spread throughout the body20

Thrombocytopenia: decreased numbers of platelets1

Thrombotic: producing blood clots21

Thrombotic Microangiopathy (TMA): clotting and inflammation that damages small blood vessels throughout the body; this is a symptom or a result of diseases such as aHUS and TTP22

Thrombotic Thrombocytopenic Purpura (TTP): a rare condition that causes blood clots to form in small blood vessels throughout the body, leading to widespread thrombotic microangiopathy. ADAMTS13 enzyme activity is low (≤5%) in individuals with TTP1

Uremia: signs and symptoms of kidney failure; signs and symptoms of uremia can include nausea, vomiting, metallic taste in the mouth, muscle pain, and swelling23

1. Laurence J, et al. Clin Adv Hematol Oncol. 2016;14(suppl 11):2-15. 2. Atypical hemolytic uremic syndrome. National Organization for Rare Disorders website. https://rarediseases.org/ rare-diseases/atypical-hemolytic-uremic-syndrome/. Accessed September 7, 2017. 3. Colon. Taber’s Medical Dictionary Online website. https://www.tabers.com/tabersonline/view/Tabers-Dictionary/745071/all/colon. Accessed April 23, 2018. 4. Complement. Free Medical Dictionary website. http://medical-dictionary.thefreedictionary.com/complement. Accessed September 7, 2017. 5. Creatinine. Taber’s Medical Dictionary Online website. https://www.tabers.com/ tabersonline/view/Tabers-Dictionary/746245/0/creatinine. Accessed April 23, 2018. 6. Hemodialysis. Free Medical Dictionary website. http://medical-dictionary.thefreedictionary.com /hemodialysis. Accessed September 7, 2017. 7. Escherichia. Taber’s Medical Dictionary Online website. https://www.tabers.com/tabersonline/view/Tabers-Dictionary/740406/all/Escherichia#1. Accessed April 23, 2018. 8. Edema. Taber’s Medical Dictionary Online website. https://www.tabers.com/tabersonline/view/Tabers-Dictionary/766687/all/edema. Accessed April 23, 2018. 9. Enzyme. Merriam-Webster website. https://www.merriam-webster.com/dictionary/ enzyme. Accessed September 7, 2017. 10. Immune System. Merriam-Webster website. https://www.merriam-webster.com/dictionary/immune%20system. Accessed September 8, 2017. 11. Infusion. Merriam-Webster website. https://www.merriam-webster.com/dictionary /infusion. Accessed September 8, 2017. 12. Microangiopathy. Taber’s Medical Dictionary Online website. https://www.tabers.com/tabersonline/view/Tabers-Dictionary/753025/all/ microangiopathy. Accessed April 23, 2018. 13. Antibody. Taber’s Medical Dictionary Online website. https://www.tabers.com/tabersonline/view/Tabers-Dictionary/750957/all/antibody#0. Accessed April 23, 2018. 14. Mutation. Taber’s Medical Dictionary Online website. https://www.tabers.com/tabersonline/view/Tabers-Dictionary/765409/all/mutation. Accessed April 23, 2018. 15. Plasma. Free Medical Dictionary website. http://medical-dictionary. thefreedictionary.com/plasma. Accessed September 8, 2017. 16. Plasma exchange. Free Medical Dictionary website. http://medical-dictionary.thefreedictionary.com/plasma+exchange. Accessed September 8, 2017. 17. Purpura. Taber’s Medical Dictionary Online website. https://www.tabers.com/tabersonline/view/Tabers-Dictionary/763997/all/purpura. Accessed April 23, 2018. 18. Stroke. Taber’s Medical Dictionary Online website. https://www.tabers.com/ tabersonline/view/Tabers-Dictionary/764837/all/stroke. Accessed April 24, 2018. 19. Syndrome. Taber’s Medical Dictionary Online website. https://www.tabers.com/tabersonline/view/Tabers-Dictionary/736973/0/syndrome. Accessed April 24, 2018. 20. Systemic. Taber’s Medical Dictionary Online website. https://www.tabers.com/tabersonline/view/Tabers-Dictionary/734145/0/systemic. Accessed April 24, 2018. 21. Thrombotic. Taber’s Medical Dictionary Online website. https://www.tabers.com/tabersonline/view/Tabers-Dictionary/739257/0/thrombotic. Accessed April 24, 2018. 22. Thrombotic Microangiopathy. Free Medical Dictionary website. http://encyclopedia.thefreedictionary.com/ Thrombotic+microangiopathies. Accessed September 8, 2017. 23. Uremia Clinical Presentation. Medscape website. https://emedicine.medscape.com/article/245296-clinical. Updated November 14, 2017. Accessed April 24, 2018.