A Case of Recurrent Thrombotic Microangiopathy Caused by Hypertensive Urgency

A 26-year-old man presented to the emergency room with abdominal pain, nausea, and vomiting for four days. His medical history was significant for hypertension and end-stage renal disease managed with hemodialysis. He had been noncompliant with the antihypertensive regimen which included nifedipine, hydralazine, and spironolactone. At presentation, his blood pressure was 231/123 mmHg. Laboratory workup showed white blood count 17.3 × 109/L (normal range: 4.5 to 11.0 × 109/L), hemoglobin 7.8 gm/dL (normal range: 13.5 to 17.5 g/dL), platelet count 46 × 109/L (normal range: 150 to 400 × 109/L), reticulocyte count 7.8%, total bilirubin 1 mg/dL (normal range: 0.1 to 1.2 mg/dL), lactate dehydrogenase 1,235 U/L (normal range: 140 to 280 U/L), haptoglobin < 10 mg/dL, and a direct Coomb's test was negative. Numerous schistocytes were identified on the peripheral blood smear. The patient was diagnosed with thrombotic microangiopathy secondary to severe hypertension and was started on intravenous nicardipine. With appropriate blood pressure control, hematological parameters improved with normalization of the platelet count within 10 days. Notably, the patient had one similar episode of hypertension-induced thrombotic microangiopathy within a period of the last three months and ADAMTS-13 (a disintegrin and metalloprotease with thrombospondin type 1 motif 13) activity was normal on his previous admission.