β₂GPI in experimental endotoxemia. (A) Twenty-three healthy volunteers were challenged with a bolus injection of LPS. Immediately after LPS injection (black dotted arrow at time point 0), a reduction of 25% in β₂GPI levels (●) occurred in all volunteers. As a control, AT levels were measured (▴). Data are represented as mean ± SEM. β₂GPI levels before LPS infusion were negatively associated with the AUC for TNF-α (B), IL-6 (C), and IL-8 (D; all P < .01). AUC for temperature rise on LPS challenge was highly significantly inversely related to baseline β₂GPI levels (P = .0003; E).