Atypical Hemolytic Uremic Syndrome May Present as Severe Hypertension without Hemolysis or Thrombocytopenia

In idiopathic hypertensive emergency or malignant hypertension, it is generally assumed that high blood pressures cause or contribute to target organ injuries, and its management has focused on antihypertensive drugs. However, some patients continue to develop progressive renal failure or other organ injury even when their blood pressures are reasonably controlled with antihypertensive drugs. In such cases, both hypertension and organ injuries may be the consequences of an underlying disease. Hypertension is a common complication of atypical hemolytic uremic syndrome (AHUS), which is commonly characterized by the triad of renal failure, microangiopathic hemolytic anemia (MAHA) and thrombocytopenia. Occasionally, hypertension may be the only manifestation of AHUS for years before its characteristic triad ensues. Early recognition of the correct diagnosis may help prevent serious complications such as advanced renal failure or even death.