CH50 activity, C3d deposition, and free eculizumab dosage in PNH patients receiving eculizumab. (A) Box plot showing CH50 activity in all patients. Normal CH50 value and complete C5 blockade are represented in gray. (B) C3d deposition in all patients during the entire study period. (C) Box plot showing free eculizumab dosage in all patients. Box and whisker plots display the median and 25th and 75th percentiles of the distribution (box). Whiskers extend to the most extreme data point, no more than 1.5 times the interquartile range from the box. During the study period, patients 1 and 13 experienced thrombosis, whereas patients 1, 4, 6, 7, 15, and 19 were transfused at least once.