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 ADAMTS13 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.