Effect of compstatin treatment on blood cells. Time course of WBC (A) and platelet (B) counts in the blood of baboons treated with compstatin during the first (T0) and second (T + 5) stage of experimental sepsis. Data are presented as mean ± SEM; 2-tailed Student t test; *P < .05. (C) Immunostaining and quantitation of CD68 positive macrophages in the lung of healthy controls, septic baboons (E coli), and septic baboons treated with compstatin (CS) during the first (E coli + CS T0) or the second (E coli + CS T + 5) stage. Scatter-plot data are shown as mean ± SEM; 1-way ANOVA with Dunnett multicomparison test. ***P < .001 compared with E coli group. (D-E) Immunostaining for C5b9 neo-antigen showing TCC deposition on platelets (D) or vascular endothelium (E) in the lung of septic baboons without (E coli) vs with compstatin (CS) treatment during second stage (E coli + CS T + 5). Note the absence of TCC on gpIIIa-positive platelets in compstatin-treated animals. Magnification bars for all images, 50μm.