Acquired thrombotic thrombocytopenic purpura (TTP) in children is a rare but severe disease, which is caused by Immunoglobulin G antibodies, which inactivate a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13 (ADAMTS13). Daily high-volume plasma exchange (PEX) and immunosuppression with glucocorticoids and rituximab is the current standard of treatment for TTP. We report two females aged 5 and 12 years, with TTP, induced by anti-ADAMTS13 inhibitory antibodies who relapsed very shortly after PEX, rituximab and glucocorticoids, in whom long-term remission with disappearance of ADAMTS13 inhibitors was achieved after one course of bortezomib.