Thrombotic Thrombocytopenic Purpura with Preserved ADAMTS13: A Case Report

Abstract

Abstract Background: Thrombotic thrombocytopenic purpura (TTP) is a rare, potentially fatal disease with multisystem involvement. ADAMTS13 assays are often used for supporting the diagnosis, we present a rare case of TTP with normal ADAMTS13 levels. Case presentation: A 39-year-old female with syncopes, blurred vision in both eyes on patch test, headaches, and tenderness over the abdomen on a background of hypertensive emergency. She had a history of chronic hypertension managed on medications, iron deficiency secondary to fibroid and an episode of provoked deep vein thrombosis and pulmonary embolism with negative work-up of thrombophilia. Labs revealed low hemoglobin of 9.8 mg/dl, platelet in the range of 52,000/ml, 3 mEq/L potassium, with high levels of creatinine (Cr) 6.7 mg/dl and blood urea nitrogen (BUN) levels of 59 mg/dl. Due to the clinical triad of thrombocytopenia, hemolysis pattern, and neurological manifestation, an ADAMTS13 essay was ordered. Thrombophilia work-up showed haptoglobin was less than 20 mg/dl, LDH of 752 U/L, and a normal ADAMTS13 level. The PLASMIC score was 5, suggestive of moderate risk. With high levels of abnormal creatinine levels and BUN, renal biopsy was done to look for the cause of acute kidney injury in the setting of suspected TTP which revealed diffuse thrombotic microangiopathy, along with moderate to chronic changes with greater than 50% tubular atrophy and interstitial fibrosis. CT scan of the brain was negative for detecting any cause of syncope; MRI showed lacunar infarcts secondary to thromboembolism. A provisional diagnosis of TTP with normal ADAMTS13 level was made and she was started on plasma exchange. Drastic symptom improvement was noted with FFP and 8 units of plasma exchange.