Twice‐daily therapeutical plasma exchange‐based salvage therapy in severe autoimmune thrombotic thrombocytopenic purpura: the French TMA Reference Center experience

Background Daily therapeutic plasma exchange ( TPE ) and rituximab improved thrombotic thrombocytopenic purpura (TTP) prognosis. In the more severe cases, salvage therapies including twice‐daily TPE and/or cyclophosphamide may be proposed and require evaluation. Methods TTP was defined as a thrombotic microangiopathy ( TMA ) with severe (<10%) acquired ADAMTS 13 deficiency. Among patients included in the French Reference Center for TMA registry, we considered those with a severe disease (i.e., unresponsive to daily TPE and rituximab) who received twice‐daily TPE . Results Nineteen of 289 (6.6%) patients with TTP were treated by twice‐daily TPE between 2008 and 2014. Twice‐daily TPE was associated with rituximab in 16 cases. The median duration of twice‐daily TPE treatment was 3 d (2–22 d). In 6 patients (31.6%), additional treatments (mainly pulses of cyclophosphamide) were performed because of a persistently refractory disease (4 cases) or an exacerbation (2 cases), despite twice‐daily TPE . Only one patient (5.3%) died. The other 18 achieved a durable complete remission 25.5 d (13–68 d) after the first TPE . The median follow‐up was 14.4 months (7 d–45 months). Conclusions Twice‐daily TPE may be an efficient strategy in the more severe TTP patients with a short‐term life‐threatening disease that could overcome their poor prognosis.