Neutralization of histone H4 or PolyP reduces intravascular thrombin activity, but not platelet adhesion or NET production. Representative SD-IVM images of thrombin probe activity (green) within the liver microcirculation of endotoxemic wild-type mice treated with (A) control IgG versus (B) anti-histone H4 IgG. Bars represent 50 μm. (C-D) Quantitative analysis of (C) thrombin probe fluorescence, (D) NETs, and (E) platelet adhesion within the liver sinusoids of endotoxemic wild-type mice treated with control IgG or anti-histone H4 IgG. (F-H) Quantitative analysis of (F) thrombin probe fluorescence, (G) NETs, and (H) platelet adhesion within the liver sinusoids of endotoxemic wild-type mice treated with control IgG or antipolyphosphate IgG. Data are represented as mean ± SEM. **P < .01; N = 5 mice per group.