From the Guidelines
Hemolytic Uremic Syndrome (HUS) typically presents with a triad of symptoms: microangiopathic hemolytic anemia, acute kidney injury, and thrombocytopenia 1. Clinical presentation may include:
- Severe diarrhea
- Vomiting
- Abdominal pain
- Pallor
- In severe cases, patients may exhibit neurological symptoms such as seizures and altered mental status 1.
Key Features
The clinical presentation of HUS can be summarized as follows:
- Bloody diarrhea is a common symptom, although approximately 10% of patients may not exhibit this symptom 1
- Abdominal tenderness and absence of fever at first medical evaluation are independently associated with increased risk of STEC O157 infection 1
- Peripheral white blood cell count >10,000 cells/µL is observed in approximately 65% of patients infected with E. coli O157 1
- STEC carrying Shiga toxin 2 (stx2) genes are associated with increased risk of both bloody diarrhea and HUS 1
Monitoring and Management
Close monitoring of kidney function, electrolytes, and blood counts is essential in managing HUS 1. Dialysis may be required in cases of severe kidney injury. Supportive care with fluid replacement and blood transfusions as needed is crucial in the initial management of HUS. Medications such as platelet transfusions may be considered in cases of severe thrombocytopenia, but are generally avoided unless there is significant bleeding or a need for invasive procedures. Plasma exchange may be considered in certain cases, particularly those with neurological symptoms or severe kidney injury. In terms of specific medication, eculizumab, a complement inhibitor, may be considered in atypical HUS cases, with a dose of 900mg intravenously weekly for 4 weeks, then 1200mg at week 5, and then 1200mg every 2 weeks thereafter, under the guidance of a specialist.
From the Research
Clinical Presentation of Hemolytic Uremic Syndrome (HUS)
The clinical presentation of HUS can vary depending on the underlying cause, but it is typically characterized by:
- Thrombocytopenia
- Non-immune microangiopathic hemolytic anemia
- Acute renal failure 2, 3, 4 HUS can be classified into two primary types:
- HUS due to infections, often associated with diarrhea (D+HUS, Shiga toxin-producing Escherichia Coli-HUS) 2
- HUS related to complement, also known as "atypical HUS" (aHUS), which is not diarrhea-associated (D-HUS) 2, 5, 6
Symptoms and Signs
Symptoms and signs of HUS may include:
- Diarrhea, which can be bloody 2, 3
- Nausea and vomiting 3
- Abdominal pain 3
- Respiratory distress and neurological involvement in pneumococcal HUS 2
- Microangiopathic hemolytic anemia, thrombocytopenia, and acute kidney injury 2, 3, 4
Disease Course and Prognosis
The disease course and prognosis of HUS can vary depending on the underlying cause: