Case Report: Caplacizumab in a case of very late diagnosis of congenital thrombotic thrombocytopenic purpura

Abstract Congenital thrombotic thrombocytopenic purpura (cTTP) is an ultra-rare thrombotic microangiopathy caused by inherited deficiency of ADAMTS13. This enzymatic defect results in the accumulation of ultra-large VWF multimers, predisposing to microvascular thrombosis. Clinical presentation usually occurs in neonatal period or childhood, more rarely in adults, especially during pregnancy. Treatment involves support with fresh frozen plasma transfusions to normalize ADAMTS13 levels. Caplacizumab, an anti-VWF antibody, is approved for the treatment of acquired TTP and the use in congenital forms should be considered off-label in selected cases with severe clinical manifestations. In this case, we describe our experience with Caplaczumab, highlighting its therapeutic potential in congenital forms for rapid clinical and hematological improvement, reducing both the number of plasmapheresis sessions and the length of stay in intensive care. Although off-label, Caplacizumab may represent a valuable option in selected cTTP patients with severe manifestations or refractory to the standard procedures. Further studies to define its role in congenital TTP management are warranted.