Direct PIFT results and platelet counts prior to initiation with rituximab and at the time of the highest platelet counts reached within 10 weeks after start of rituximab treatment of 80 serially tested ITP patients. X-axis for panel B also applies for panel A. (A) CR, n = 16; PR, n = 16; MR, n = 8; NR, n = 40. Direct PIFT scores before (pre) and at the time of the highest platelet count within 10 weeks after (post) treatment with rituximab: 0, negative; 1, positive; 2, strong positive; and 3, very strong positive. Changes in antibody detection results are indicated by means of connecting lines. (B) Platelet counts before and the highest platelet count within 10 weeks after treatment with rituximab.