Complement inhibitors are useful in secondary hemolytic uremic syndromes

The term hemolytic uremic syndrome (HUS) encompasses 3 different entities: typical HUS caused by a shiga toxin–producing Escherichia coli, primary atypical HUS (aHUS) resulting from the dysregulation of the complement alternative pathway, and secondary HUS caused by a variety of etiologies whose common characteristic is to induce diffuse endothelial damage leading to thrombotic microangiopathy (TMA). As shown in Supplementary Table S1, the most common causes of secondary HUS are drugs, infections, autoimmune diseases, malignancies, and hematopoietic stem cell transplantation.