Efficacy of eculizumab in severe ADAMTS13-deficient thrombotic thrombocytopenic purpura (TTP) refractory to standard therapies.

Thrombotic thrombocytopenic purpura (TTP) is a rare microangiopathic hemolytic anemia (MAHA) defined by mechanical hemolytic anemia, severe thrombocytopenia, and systemic visceral ischemia due to systemic platelet-rich microthrombi. Forty percent of patients with autoimmune TTP experience one or multiple relapses. Patients with refractory TTP are currently managed by corticosteroids, twice-daily PEX, and the anti-CD20 monoclonal antibody rituximab. Herein, we report two cases of severe TTP, refractory to those standard agents. On the basis of the fact that in cases of severe TTP the classical complement pathway is activated, and that the alternative pathway is also involved, both patients underwent eculizumab (anti-C5 monoclonal antibody) therapy. We observed prompt hematological and organ system responses to the eculizumab and the recovery of plasma ADAMTS-13 activity in both cases. Moreover, the fact that both patients discontinued eculizumab, maintaining the response, emphasizes the possibility of its usefulness for limited treatment periods. In conclusion, the diagnostic and therapeutic algorithm in TTP appears complicated by increasing evidence of complement involvement and the eculizumab seems to be a potential agent for refractory patients.

Safe and Effective Administration of Caplacizumab in COVID-19-Associated Thrombotic Thrombocytopenic Purpura.

Thrombotic thrombocytopenic purpura (TTP) is a potentially life-threatening, rare acute thrombotic microangiopathy (TMA), caused by a severe ADAMTS13 deficiency. As the COVID-19 pandemic rapidly spread around the globe, much data about the pathogenicity of this virus were published. Soon after the detection of the first cases of COVID-19, it was clear that there was a wide range of COVID coagulopathy manifestations, such as deep venous thrombosis, pulmonary thromboembolism, and thrombotic microangiopathies. In the literature, little data have been reported about the association between TTP and COVID-19, and the treatment of COVID-19-associated TTP is still under debate. Here we present the case of a 46-year-old woman who developed a COVID-associated TTP, successfully treated with plasma exchange (PEX), steroids, and caplacizumab.