What Is Hemolytic Uremic Syndrome (HUS)?

Hemolytic Uremic Syndrome
Hemolytic Uremic Syndrome

Hemolytic Uremic Syndrome

Hemolytic Uremic Syndrome is a medical condition that commonly affects young children. As the name indicates, hemolytic uremic syndrome is a kidney disease (the ureter) with anemia (hemolytic anemia) and abdominal pain (syndrome). The disorder can cause major damage to organs depending on the severity of the symptoms. It is a sub-type of kidney failure that occurs due to an infection. HUS is characterized by microangiopathic hemolysis, thrombocytopenia and acute renal failure.(1)

An infection that leads to HUS can be caused by E.coli or Shigella bacteria. It is a life threatening condition affecting people who suffer from an E. coli bacterial infection. E. coli is a type of gut bacteria that lives in the intestines of healthy people. However, under certain conditions the bacteria can multiply and produce toxins which attack the body’s organs, especially kidneys (this is called hemolytic uremic syndrome).

When your kidneys are inflamed, they are unable to function properly, which means they are unable to remove waste products from your body. When the waste products remain in your body and also begin to build up in your blood, fibrin heme is created. This forms clots throughout the veins of the body and can be deadly.

Progresses rapidly and usually affects children under the age of 10 and adults over the age of 65. The syndrome is characterized by the rapid onset of symptoms such as abdominal pain, nausea, vomiting and diarrhea (bloody or not bloody). In about 30% of patients there are neurological symptoms including altered consciousness, seizures and even coma. A person with Hemolytic Uremic Syndrome needs immediate medical attention to stop the clotting before it’s too late. Further on we will examine more in detail key symptoms, risk factors and methods of prevention in order to understand this syndrome both preventively and therapeutically.(2)

1Pathophysiology

Pathophysiology
Pathophysiology

Hemolytic uremic syndrome (HUS) is a serious and potentially life-threatening medical condition resulting from the destruction of red blood cells and kidney failure. HUS affects children more than adults, with a peak incidence between 4 and 10 years of age. It is the result of a bacterial blood infection, caused by certain types of E. coli bacteria. This bacteria then attacks the lining of the child’s small intestine and causes a “leakage” of various cells into the body’s circulation. If the infection to the bowel becomes severe, it can lead to the formation of red blood cells through abnormalities in the production of their membrane proteins. The composition of urine will then start to fade until it becomes very dark red or even maroon coloration.(3)

It results from immune-mediated destruction of red blood cells and platelets, as well as thrombocytopenia. The patient suffers from internal bleeding, renal failure, and neurological impairment. Eventually, the patient may develop acute renal failure leading to death.

HUS may also be precipitated by other causes such as: contaminants in food or water, the use of certain drugs such as steroids and cancer chemotherapy, exposure to monoclonal antibodies and molecularly cloned human proteins, and autoimmune disorders. HUS occurs ten to twenty times more frequently in persons under the age of five than in older children and adults. In most instances, it is self-limiting, and complete recovery takes place in two weeks to six months. The most at-risk population for developing HUS is toddlers 5 years or younger and of western European descent. If developed, there are two main complications that can lead to death: circulatory collapse and acute kidney failure. The overall mortality rate is approximately 10%.

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