From the Guidelines
Hemolytic uremic syndrome (HUS) is a serious condition that requires prompt and supportive care, with a focus on fluid and electrolyte management, blood pressure control, and often dialysis for acute kidney injury, as outlined in the 2017 Infectious Diseases Society of America clinical practice guidelines 1.
Key Components of Care
- Fluid and electrolyte management to prevent dehydration and electrolyte imbalances
- Blood pressure control to prevent further kidney damage
- Dialysis for acute kidney injury to remove waste products and excess fluids
- Platelet transfusions should generally be avoided unless there is life-threatening bleeding, as they may worsen the microthrombi formation
- Plasma exchange therapy may be beneficial in atypical HUS cases
Specific Treatment Considerations
- For complement-mediated atypical HUS, eculizumab (a complement inhibitor) is the recommended treatment, typically administered as induction therapy at 900 mg weekly for 4 weeks, followed by maintenance therapy of 1200 mg every 2 weeks
- Patients should receive meningococcal vaccination before starting eculizumab due to increased infection risk
- For typical HUS associated with Shiga toxin-producing E. coli, antibiotics are generally avoided as they may increase toxin release
Monitoring and Prevention
- Frequent monitoring of hemoglobin and platelet counts, electrolytes, and blood urea nitrogen and creatinine is recommended to detect hematologic and renal function abnormalities that are early manifestations of HUS 1
- Examining a peripheral blood smear for the presence of red blood cell fragmentation is necessary when HUS is suspected
- Early identification of STEC infections is important to reduce the risk of complications and the risk of person-to-person transmission 1
From the Research
Definition and Characteristics of HUS
- Hemolytic uremic syndrome (HUS) is a disease characterized by hemolysis, thrombocytopenia, and acute kidney injury, although other organs may be involved 2.
- HUS is classically associated with enterocolitis from Shiga toxin-producing Escherichia coli, but it can also be associated with other infections, genetic dysregulation of the alternative complement pathway or coagulation cascade, and rare hereditary disorders 3.
Types of HUS
- Most cases of HUS are due to infection with Shiga toxin-producing Escherichia coli (STEC) 2.
- Atypical HUS (aHUS) accounts for approximately 10% of HUS cases and has a diverse etiology, including inherited or acquired abnormalities that lead to a failure to control complement activation 2.
- aHUS can occur in various situations, such as related to pregnancy or kidney transplantation, and may involve excessive complement activation 2.
Treatment and Management of HUS
- Early identification and initiation of best supportive care, with microbiological input to identify the pathogen, result in a favorable outcome in most patients with STEC-HUS 2.
- Plasma therapies can reverse defective complement control, and targeting complement activation has led to improved outcomes in patients with atypical forms of HUS 2, 4.
- Therapeutic plasma exchange (TPE) and eculizumab have been used in the treatment of STEC-HUS, but the short-term benefit of eculizumab compared to TPE alone is not well established 5.
- Development of clinical prediction scores and rapid diagnostic tests for HUS based on mechanistic knowledge are needed to facilitate early diagnosis and assign timely specific treatments to patients with HUS variants 6.