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Kidney Week

Abstract: PO0295

Patient with Refractory Acquired Thrombotic Thrombocytopenic Purpura Treated with a Novel Agent Caplacizumab

Session Information

Category: Acute Kidney Injury

  • 102 AKI: Clinical, Outcomes, and Trials


  • Sharma, Pranav, Rutgers The State University of New Jersey, New Brunswick, New Jersey, United States
  • Lebowitz, Jonathan, Rutgers The State University of New Jersey, New Brunswick, New Jersey, United States

Acquired or immune-mediated TTP is characterized by thrombocytopenia and anemia caused by autoantibody mediated inhibition of the von Willebrand factor (vWF) cleaving protease, ADAMTS13. This results in a microangiopathic hemolytic anemia and severe thrombocytopenia, resulting in tissue ischemia, multiorgan failure, and, potentially, death. Up until now, treatment for TTP included therapeutic plasma exchange (TPE) and immunosuppression. Recently,caplacizumab,the first targeted nanobody based therapeutic agent that prevents adhesion of platelets to vWF, has been approved for use in acquired TTP. We present a case of acquired TTP that was refractory to high dose, steroids, therapeutic plasma exchange (TPE) and rituximab but responded well to caplacizumab.

Case Description

A 53-year-old man with HIV, complicated by cryptococcal meningitis and PCP pneumonia, intermittent confusion,headache, and multiple falls, presented with anemia, thrombocytopenia, an elevated LDH, and a peripheral blood smear with numerous schistocytes with acute kidney injury with an initial serum creatinine of 1.7 mg/dl which peaked up to 5.5 mg/dl. . Further testing revealed a positive ADAMTS13 inhibitor with high titer of 3.4 and less than 5% ADAMTS13 enzyme activity, consistent with TTP. He was treated with high dose steroids, TPE, and rituximab but did not respond. He was initiated on caplacizumab on hospital day 14 and by day 18 his platelet counts began to normalize and mentation improved. He suffered only mild epistaxis as a side effect from caplacizumab. In span of few days, his neurologic symptoms resolved and he was discharged home to complete thirty days of caplacizumab treatment. At the time of follow up, he remained well and continued to have normal ADAMTS13 activity. Kidney function improved post caplacizumab to 0.8 mg/dL.


Although conventional therapy has reduced the mortality of TTP, it is not always effective and there are fair number of cases refractory to conventional treatment. Caplacizumab, the first nanobody-based therapeutic agent, has shown marked efficacy in treating TTP and its complications and is a therapeutic option for patients with refractory TTP.