Changes in platelets, CD19 lymphocytes, ADAMTS13 activity following initial treatment with weekly rituximab 100 mg and plasma exchange. Box plots of platelet count (A) and absolute CD19⁺ lymphocyte % (B), and ADAMTS13% activity (C) are shown at time intervals. An Illustrative case of relapse (D) following 4 weekly doses of rituxan 100 mg (labeled rit100) and 4 weekly doses of rituxan 375 mg/m² (labeled rit375) administered at time of relapse. Serial measurements of platelet count (green) and absolute CD19 lymphocyte count (blue) shown over time with relapse occurring around years 1 and 2. ADAMTS13 activity shown in red. A similar pattern of CD19 lymphocyte count rise and platelet decline observed following both dosing regimens of rituximab.