Prasugrel and Acquired Thrombotic Thrombocytopenic Purpura Associated with ADAMTS13 Activity Deficiency

Abstract

We report a case of a 64-year-old man who, 44 days after starting treatment with prasugrel, presented with severe thrombocytopenia, anaemia, renal failure, and severe ADAMTS13 activity deficiency, along with a high titer of autoantibodies to this protease. LEARNING POINTS• Drug-induced TTP is a rare condition and difficult to diagnose.• Decreased activity of ADAMTS13, unusual in drug-induced TTP, was present in this case. KEYWORDS Thrombotic microangiopathy; thrombotic thrombocytopenic purpura; prasugrel. . INTRODUCTION Thrombotic thrombocytopenic purpura (TTP) is defined as a severe deficiency of ADAMTS13, but the diagnosis of TTP relies initially on clinical judgment, since ADAMTS13 measures are often not available for several days, and different methodologies may yield different results. ADAMTS13 can be completely deficient, genetically impaired or inhibited by autoantibody. It is now observed that all cases of acquired TTP, including those that are drug induced, are associated with inhibiting antibodies to ADAMTS13. TTP is unique among the primary thrombotic microangiopathy (TMA) syndromes, in which renal function abnormalities occur but renal failure is rare. TTP typically has more systemic manifestations of organ injury than the other primary TMA syndromes. In TTP, abnormalities of the central nervous system, heart, pancreas, thyroid glands, adrenal glands, intestinal mucosa and other tissues may occur. CASE REPORTA 64-year-old male patient with a medical history of hypertension, type 2 diabetes mellitus, and dyslipidemia was admitted to hospital due to a ST-elevated coronary syndrome in 2013. He underwent fibrinolysis with tenecteplase (metylase) without complications, followed by placement of a TAXUS drug-eluting stent, placed into the anterior descending coronary artery. He was started on prasugrel 10 mg daily and discharged from the hospital on day 12 after admission. The patient was readmitted to hospital 36 days later due to nausea, vomiting, abdominal pain, and purpuric lesions. Upon arrival to the emergency department, he was hypotensive and oliguric. An abdominal computed tomography (CT) was immediately performed and was