Fig. 3. Scatter plots and bar graph with arithmetic means ± SEM showing annexin-PE binding to O RBCs and effect of C5 complement component. Compared to negative control (A), phosphatidylserin (PS) exposure was significantly (p<0.001) increased after incubation with fresh serum from patients with cold AIHA (B, G). Pre-treatment of patient serum with anti-C5 (Eculizumab, Soliris^(r)) significantly (p<0.001) reduced PS exposure (C, G). Heat-inactivated patient serum and C5-depleted serum were incapable of inducing PS exposure (D) as compared to negative control (E, G) but supplementation with the missing C5 complement component resulted in a significant (p<0.05) increase of PS exposure (F, G). (***) p<0.001, (*) p<0.05 between the bracketed bars.