Extrarenal manifestations of the hemolytic uremic syndrome associated with Shiga toxin-producing Escherichia coli (STEC HUS)

Hemolytic uremic syndrome is commonly caused by Shiga toxin-producing Escherichia coli (STEC). Up to 15% of individuals with STEC-associated hemorrhagic diarrhea develop hemolytic uremic syndrome (STEC HUS). Hemolytic uremic syndrome (HUS) is a disorder comprising of thrombocytopenia, microangiopathic hemolytic anemia, and acute kidney injury. The kidney is the most commonly affected organ and approximately half of the affected patients require dialysis. Other organ systems can also be affected including the central nervous system and the gastrointestinal, cardiac, and musculoskeletal systems. Neurological complications include altered mental status, seizures, stroke, and coma. Gastrointestinal manifestations may present as hemorrhagic colitis, bowel ischemia/necrosis, and perforation. Pancreatitis and pancreatic beta cell dysfunction resulting in both acute and chronic insulin dependant diabetes mellitus can occur. Thrombotic microangiopathy (TMA) in cardiac microvasculature and troponin elevation has been reported, and musculoskeletal involvement manifesting as rhabdomyolysis has also been described. Extrarenal complications occur not only in the acute setting but may also be seen well after recovery from the acute phase of HUS. This review will focus on the extrarenal complications of STEC HUS. To date, management remains mainly supportive, and while there is no specific therapy for STEC HUS, supportive therapy has significantly reduced the mortality rate.