INTRODUCTION
Thrombotic thrombocytopenic purpura (TTP) is a thrombotic microangiopathy caused by reduced activity of the von Willebrand factor (VWF) - cleaving protease ADAMTS13. TTP can be acquired, due to an autoantibody inhibitor, or hereditary, due to inherited variant in the ADAMTS13 gene [1]. Over 95% of cases are attributable to acquired autoimmune TTP [2]. Acquired TTP is very rare in children, the incidence is approximately 30-fold less common than in adults [3]. TTP can be life-threatening and 34% of patients present a relapsing disease [4]. Several therapies are available for treatment of TTP, including plasma exchange (PEX) and immunosuppressive agents [5,6,7]. Recently, Caplacizumab has been approved for the treatment of the TTP in the adult population [8, 9,10]. Despite increasing knowledge on the pathogenesis of TTP in the last years, the therapeutic approach varies significantly, due to the lack of high-quality evidence to support strong recommendations [11]. Moreover, no guidelines or clinical trials for the pediatric population are available at present day.