Atypical Hemolytic Uremic Syndrome: Beyond Hemolysis and Uremia

Atypical hemolytic uremic syndrome commonly presents with the triad of microangiopathic hemolytic anemia, thrombocytopenia, and renal function impairment without an antecedent hemorrhagic diarrhea. Less known are extrarenal complications due to abnormal vascular permeability, although these are a major cause of morbidity and mortality for the patients. Furthermore, it is increasingly recognized that the disease may present with hypertension or renal function impairment with no or mild thrombocytopenia and microangiopathic hemolytic anemia. Awareness of the full spectrum of atypical hemolytic uremic syndrome may facilitate its diagnosis and treatment before serious complications or death occurs.