Increased ITGA2B and αIIb expression in sepsis is associated with both clinical and experimentally induced sepsis-related mortality. (A) In septic patients (n = 94), sepsis-related mortality is more than threefold higher in patients with thrombocytopenia at ICU admission (day 1). (B) Platelet counts in septic patients are inversely associated with MPV. (C) ITGA2B expression is significantly higher in newly released platelets (ie, platelets with a larger MPV) from septic patients. Quartiles for MPV were determined a priori and assigned as follows: quartile 1 (Q1), MPV <7.5 fL; Q2, MPV between 7.6 and 8.1 fL; Q3, MPV between 8.2 and 8.7 fL; Q4, MPV >8.7 fL. (D) ITGA2B expression is higher in septic patients who did not survive. Quartiles of ITGA2B mRNA expression were determined a priori and assigned as follows: Q1, <2.56 fold-change; Q2 between 2.56 and 4.09 fold-change; Q3, between 4.09 and 6.95 fold-change; Q4, >6.95 fold-change. Analyses in panels C-D were performed by analysis of variance. (E) Kaplan-Meier curve of mortality in mice following CLP (n = 20 mice). (F) Whole blood (2 μL) sampled from the tail vein 24 hours following CLP. Platelet αIIb surface protein was assessed 24 hours following CLP by flow cytometry, stratified for mice that subsequently did not survive (dead) or survived (alive) CLP. MFI, mean fluorescence intensity.