Transfusion medicine illustrated: An imPRESsive mimic.

A 20-year-old G1P1 woman presented to a local hospital with a 2-week history of headache, blurry vision, photophobia, edema, and easy bruising. She was found to be hypertensive (blood pressure, 180/90) with acute renal failure (Cr = 8.5), thrombocytopenia (platelet [PLT] count, 81 ¥ 10/L), elevated lactate deydrogenase (LDH; (698 IU/L), and severe microcytic anemia (hemoglobin, 5.9 mg/dL; mean corpuscular volume, 74) with occasional schistocytes. An ADAMTS13 drawn on Day 2 was 59%. Her medical history was significant for migraines, chronic fatigue after a cesarean section 6 months previously, and a progesterone intrauterine device for birth control. She was diagnosed with thrombotic thrombocytopenic purpura (TTP)/hemolytic uremic syndrome (HUS) and treated with dialysis, plasma exchange, steroids, and rituximab with minimal clinical improvement. She was transferred to a university hospital after a documented episode of flash pulmonary edema (FPE) and possible seizure. After transfer, the patient was diagnosed with possible HUS. Her laboratory results were significant for a PLT count of 108 ¥ 10/L, an LDH level of 260 (range, 252-297), a haptoglobin level of 10 to 15 mg/dL, and ADAMTS13 activity of 78%. Shortly after admission, the patient developed a severe acute headache and underwent plasma exchange, which was complicated by FPE (see figure, B). A cardiac evaluation revealed left ventricular hypertrophy with mild ventricular systolic dysfunction and mitral regurgitation. On Day 5, the patient developed a visual field defect. An MRI showed increased T2 and FLAIR signal, without restricted diffusion or contrast enhancement, in the subcortical white matter of both occipital and parietal lobes, consistent with posterior reversible encephalopathy syndrome (PRES) (see figure, A; arrow). The patient’s PLT counts, hallucinations, confusion, and vision subsequently recovered with aggressive blood pressure control and steroid taper. A renal biopsy showed a chronic ischemic vasculopathy due to hypertension with no