[Rituximab for managing refractory thrombotic thrombocytopenic purpura: a report of three cases].

About 20% of TTP are resistant to plasma exchange. As reported in a few case reports and small case series, rituximab has been used in the treatment of TTP with some benefit. However, the optimal dosing, frequency, and timing of rituximab remain to be determined. We treated three cases of refractory TTP with rituximab. Case 1 exhibited brain sequelae probably due to the late administration of rituximab, case 2 died before the expected effect of rituximab could occur, and case 3 recovered completely because of the early administration of rituximab. These results suggest that rituximab should be given as early as possible in TTP, but large clinical studies are required to determine the optimal use of rituximab in TTP.