From the Research
Hemolytic uremic syndrome (HUS) is characterized by a triad of thrombotic microangiopathy, thrombocytopenia, and acute kidney injury, with clinical features including pallor, fatigue, petechiae or purpura, oliguria or anuria, hypertension, and edema from renal impairment, as well as potential neurological manifestations and extrarenal complications 1. The clinical presentation of HUS can vary depending on the underlying cause, with Shiga toxin-producing Escherichia coli (STEC) being the most common cause in children, and atypical HUS caused by complement dysregulation having a worse prognosis and higher risk of recurrence 2, 3. Key laboratory findings in HUS include hemoglobin below 10 g/dL, fragmented red blood cells (schistocytes) on peripheral smear, elevated lactate dehydrogenase, decreased haptoglobin, negative Coombs test, thrombocytopenia (platelets <150,000/μL), and elevated creatinine 4, 5. Some patients with HUS may develop extrarenal complications affecting the central nervous system, heart, pancreas, or gastrointestinal tract, and prompt recognition of these features is essential for early supportive care and, in atypical cases, complement inhibition therapy to improve outcomes 1, 3. The diagnosis and management of HUS require identification of the underlying pathogenetic mechanism, with specific support measures and therapies available for different forms of the disease, including complement inhibition by eculizumab administration in patients with atypical HUS 3.
- Clinical features of HUS include:
- Pallor and fatigue
- Petechiae or purpura due to thrombocytopenia
- Oliguria or anuria
- Hypertension and edema from renal impairment
- Neurological manifestations such as irritability, seizures, altered mental status, or stroke-like symptoms
- Laboratory findings in HUS include:
- Hemoglobin below 10 g/dL
- Fragmented red blood cells (schistocytes) on peripheral smear
- Elevated lactate dehydrogenase
- Decreased haptoglobin
- Negative Coombs test
- Thrombocytopenia (platelets <150,000/μL)
- Elevated creatinine
- Extrarenal complications of HUS can affect the:
- Central nervous system
- Heart
- Pancreas
- Gastrointestinal tract
- Prompt recognition and early supportive care are essential for improving outcomes in patients with HUS, particularly those with atypical HUS caused by complement dysregulation 1.