C3 coating in PNH patients. (A) Absolute percentage of C3⁺ RBCs in untreated (n = 28) and eculizumab-treated (n = 41) PNH patients. Each dot represents a single case; bar represents median value. (B) Linear correlation between percentage of C3⁺ RBCs (y-axis) and PNH RBC clone size (in percentage; x-axis). Each dot represents a single case, with correlation line. Spearman rank order correlation, r = 0.70, P < .001. (C) Percentage of C3⁺ RBCs within the PNH RBC population in untreated (n = 28) and eculizumab-treated (n = 41) PNH patients. Each dot represents a single case; bar represents median value. (D) Percentage of C3⁺ RBCs within the PNH RBC population in eculizumab-treated PNH patients achieving optimal (n = 15), major (n = 18), or partial (n = 5) hematologic response. Each dot represents a single case; bars represent median values. Kruskal-Wallis U test; P = .01. (E) Linear correlation between percentage of C3⁺ PNH RBCs (y-axis) and absolute reticulocyte count (cells × 10⁹/L) during eculizumab treatment. Each dot represents a single case, with correlation line. Spearman rank order correlation, r = 0.39, P = .001. (F) Linear correlation between percentage of C3⁺ PNH RBCs (y-axis) and pretreatment LDH level (IU/L; normal range, < 223). Each dot represents a single case, with correlation line. Spearman rank order correlation, r = 0.54, P < .001.