Malignant hypertension as a rare cause of thrombotic microangiopathy

Malignant hypertension can occasionally be associated with microangiopathic haemolytic anaemia. A 38-year-old male presented with nausea, vomiting, loss of appetite and oliguria for 2 weeks. He was diagnosed with hypertensive emergency with cardiac and renal dysfunction. Interestingly, further workup was diagnostic for the presence of thrombotic microangiopathy (TMA): haemoglobin =12.7 g/dL, indirect bilirubin =2.0 mg/dL, haptoglobin ≤6 mg/dL, platelet count =121 000/μL and schistocytes on peripheral smear. At the outset, the cause of TMA was unclear. Patient denied having diarrhoea, making haemolytic uremic syndrome less likely. A normal ADAMTS13 activity test ruled out thrombotic thrombocytopaenic purpura. Malignant hypertension induced TMA was highest on the differential and plasma exchange was deferred. Renal biopsy revealed features of TMA and malignant nephrosclerosis. Patient eventually became dialysis dependent. Aggressive blood pressure control was obtained with multiple medications.