Effects of 5C12 anti-FXII antibody treatment on blood cell counts, leukocyte accumulation in tissues, and neutrophil activation markers in baboons following lethal challenge with HI-SA (LDSA). (A-F) Time course dynamics of RBCs (A), hematocrit (B), white blood cells (WBCs) (C), polymorphonuclear neutrophils (PMNs) (D), lymphocytes (E), and monocytes (F) in animals infused with LDSA only or infused with LDSA and treated with 5C12 (LDSA + 5C12). (G) Immunofluorescence staining for neutrophil elastase (left), and CD68 (middle) as markers for neutrophils and monocytes/macrophages, respectively, in lungs of baboons challenged with LDSA, without (top) or with 5C12 treatment (LDSA + 5C12; bottom). Merged color images are shown in the right panels. Nuclei were stained with To-PRO-3 (blue). Scale bars, 100 µm. Confocal images were captured by using a Nikon Eclipse TE2000-U microscope equipped with a Nikon C1 scanning head; the Nikon EZ-C1 software (version 3.80) was used for image acquisition. (H) Time course changes of MPO activity in plasma. Same time points are compared between the treated and untreated baboons by using the generalized least squares (gls) function. *P < .05; **P < .01; ***P < .001. The overall P value (pvl) describing the difference between the 2 curves is shown on each graph. P < .05 is considered significant.