Treatment of Atypical Hemolytic-Uremic Syndrome in the Era of Eculizumab

Hemolytic-uremic syndrome (HUS) is the triad of microangiopathic hemolytic anemia (MAHA), thrombocytopenia, and acute kidney injury (AKI); the main cause of multi-organ failure is related to thrombotic microangiopathy (TMA). Atypical HUS (aHUS) is a disease of uncontrolled complement activation associated with a high mortality rate and most cases progress to end-stage renal disease. About 50% of patients with this syndrome carry mutations in genes that encode complement proteins. Also, aHUS constitutes an over-activation of the complement pathway which is either inherited, acquired, or both. This results in TMA. Plasma infusions or exchange should be performed daily until the platelet count, lactate dehydrogenase (LDH), and hemoglobin levels are substantially improved, or until an alternate treatment strategy has been decided upon. Eculizumab (a terminal complement inhibitor approved in 2011 for treating aHUS) treatment should begin immediately when the diagnosis is confirmed. There is limited evidence on the duration of the treatment despite significant clinical interest in investigating this aspect. Therefore, it is crucial to conduct further analysis on the possible dose and time adjustments.