Successful treatment of plasma exchange-refractory thrombotic thrombocytopenic purpura with rituximab: A case report

BACKGROUND Thrombotic thrombocytopenic purpura（TTP）, a subtype of thrombotic microangiopathy, has a very high fatality rate if there is no timely diagnosis or treatment. Here, we report a case of TTP refractory to high displacement plasma exchange, which was later successfully treated with rituximab.CASE SUMMARY Here we report a case of refractory TTP in a 63-year-old woman with a low platelet count and decreased ADAMTS13 activity. Her platelet count was 9 ×10;/L, hemoglobin level was 81 g/L, and ADAMTS13 was < 5%. She was diagnosed with thrombotic thrombocytopenic purpura. After 8 d of daily plasma exchange（PEX）, her platelet levels were still low. However, after 6 d of treatment with rituximab, her platelet count increased and ADAMTS13 activity returned to normal.CONCLUSION PEX can cure most patients, but the relapse rate can be up to 50%-60%. This case suggested that rituximab can improve the curative efficiency of PEX and prevent disease relapse in TTP.