The hemolytic uremic syndrome (HUS) is defined by the simultaneous occurrence of microangiopathic hemolytic anemia, thrombocytopenia, and acute kidney injury . The most common cause of HUS is due to Shiga toxin-producing Escherichia coli (STEC), and it is one of the main causes of acute kidney injury in children under the age of three years.
The treatment and prognosis of STEC HUS is reviewed here. The clinical manifestations and diagnosis of STEC HUS are discussed separately. (See "Clinical manifestations and diagnosis of Shiga toxin-producing Escherichia coli (STEC) hemolytic uremic syndrome (HUS) in children".)
Traditionally, HUS had been divided into diarrhea-positive and diarrhea-negative HUS. The former, also referred to as typical HUS, primarily resulted from STEC infections, and less frequently from Shigella dysenteriae type 1 infection. All other causes of HUS were referred to as atypical HUS or assigned to the diarrhea-negative HUS, even though some patients with non-STEC-associated HUS also presented with diarrhea.
However, the following classification is used based on a better understanding of the various causes of HUS (see "Overview of hemolytic uremic syndrome in children"):
●Primary causes due to complement dysregulation (also referred to as atypical HUS)