Your Comprehensive Glossary to Common aHUS Terms

We aim to provide clear and concise definitions of key terms and concepts related to atypical hemolytic uremic syndrome (aHUS), a rare and complex medical condition. Whether you’re a patient, caregiver, healthcare professional, or simply seeking to expand your knowledge, this resource will help demystify the terminology associated with aHUS, its treatment, and its impact on the body. Let’s embark on a journey to unravel the intricacies of aHUS and empower ourselves with knowledge.

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Glossary Terms

aHUS (atypical hemolytic uremic syndrome)

A rare, life-threatening disease characterized by microangiopathic hemolytic anemia, thrombocytopenia, and kidney injury. It often results from an overactivation of the complement system in the blood.

Chronic Kidney Disease (CKD)

Progressive, long-term condition where the kidneys gradually lose their ability to function properly, often characterized by a decrease in kidney function over time.

Complement System

Part of the immune system that helps the body defend against infections and remove damaged cells.


Medication used to treat aHUS by inhibiting the complement system and preventing the destruction of red blood cells.

ESRD (End-Stage Renal Disease)

Final stage of chronic kidney disease, where the kidneys have lost most of their function and patients typically require dialysis or a kidney transplant for survival.

Factor H Antibodies

Antibodies that attack and interfere with Factor H, leading to uncontrolled complement system activation and aHUS.

Factor H Deficiency

Genetic condition where the body does not produce enough Factor H, a protein that regulates the complement system and can lead to aHUS.

Factor I Deficiency

Genetic condition where the body does not produce enough Factor I, a protein that regulates the complement system and can lead to aHUS.

Genetic Mutation

Changes or alterations in the DNA sequence that can be inherited and may contribute to the development of aHUS.


Medical specialist who focuses on the diagnosis and treatment of blood disorders, including those related to aHUS such as anemia and thrombocytopenia.


Presence of blood in the urine, a common symptom in aHUS.


Medical procedure used to filter waste products and excess fluids from the blood when the kidneys are unable to do so effectively.


High blood pressure, which can be a complication of aHUS due to kidney damage.

Microangiopathic Hemolytic Anemia

Type of anemia where red blood cells are destroyed as they pass through small blood vessels, leading to a decrease in red blood cell count.


Medical specialist who focuses on the diagnosis and treatment of kidney disorders.

Neurological Symptoms

Symptoms related to the nervous system, which can be affected in severe cases of aHUS.

Peritoneal Dialysis

Type of dialysis that involves the use of the peritoneum (the lining of the abdominal cavity) as a natural filter to remove waste and excess fluids from the body.

Plasma Exchange

Procedure that removes and replaces the liquid portion of the blood (plasma); often used as a treatment for aHUS.

Platelet Transfusion

Medical procedure where platelets from a donor are transfused into a patient with thrombocytopenia to increase their platelet count.

Pulmonary Hypertension

High blood pressure in the arteries of the lungs, which can occur in aHUS patients.

Quality of Life

Measure of a person’s overall well-being and ability to lead a fulfilling life despite aHUS.


Medication used in the treatment of aHUS; a complement inhibitor that helps control the overactivation of the complement system.

Renal (Kidney) Dysfunction

Impaired kidney function, which is a common complication of aHUS.

Renal Diet

Specialized diet designed to support kidney health by managing the intake of certain nutrients, particularly protein, sodium, and potassium, to reduce the burden on the kidneys.

Renal Transplant

Surgical procedure to replace a damaged kidney with a healthy one from a donor, often considered in severe cases of aHUS.


Condition characterized by a low platelet count in the blood, which can lead to bleeding problems.


Glycoprotein present on the surface of endothelial cells that plays a crucial role in regulating blood coagulation and preventing excessive clot formation. Thrombomodulin is involved in the conversion of thrombin from a procoagulant to an anticoagulant state, contributing to the maintenance of blood vessel integrity and preventing microthrombi formation, which is relevant to conditions like aHUS.

Thrombotic Thrombocytopenic Purpura (TTP)

Rare and serious blood disorder characterized by the formation of small blood clots throughout the body’s blood vessels. TTP is often associated with low platelet counts (thrombocytopenia) and can lead to various complications, including damage to organs and tissues. It is caused by a deficiency in an enzyme called ADAMTS13, which is responsible for breaking down a protein that promotes blood clot formation.


Condition associated with kidney dysfunction where waste products that the kidneys would normally eliminate from the body build up in the blood, leading to symptoms such as fatigue, nausea, and changes in mental state.