While TPE and steroids are the mainstay of TTP treatment, some experts recommend the inclusion of rituximab and/or caplacizumab under certain situations. Presence of ADAMTS13 inhibitor consistent with acquired autoimmune TTP, while their absence is suggestive of congenital TTP. Plasma infusion is usually sufficient to treat acute episodes in patients with hereditary TTP. According to ISTH guideline: continuing or stopping treatments (eg, TPE, corticosteroids, rituximab, caplacizumab) when plasma ADAMTS13 activity is between 10 and 20 IU/dL (or 10%−20% of normal) (an equivocal result). Abbreviations: TTP, thrombocytic thrombocytopenic purpura.