ADAMTS13 activity during remission and relapse in 8 selected patients. These 8 patients were selected from the 57 patients in cohort 1 to illustrate the different patterns of ADAMTS13 activity during remission (2004-2015). At all points, ADAMTS13 activity was measured by both the FRETS-VWF73 (blue lines) and IB (red lines) methods. All ADAMTS13 activities for each patient, both during acute episodes and during relapse, are presented. The patients’ numbers refer to their number in supplemental Table 1. Each graph begins with the patients’ initial episode of TTP. Relapses are indicated by vertical broken lines. All relapses were confirmed by ADAMTS13 activity <10% with at least 1 of the 2 assays. Rituximab treatment of relapse episodes is indicated by R. None of these patients was treated with rituximab for their initial episode. The horizontal broken line indicates ADAMTS13 activity of 10%. The clinical features of each patient are described in the supplemental Legend for Text Figure 1. No treatment was given related to remission ADAMTS13 activity, and the frequency of remission ADAMTS13 measurements was not changed.