Platelets stabilize FXIII-depleted thrombi against fibrinolytic degradation in a concentration and transglutaminase dependent manner. (A) FXIII-depleted thrombi (△ dashed line) were prepared with the addition of platelet lysates over a range of platelet concentrations (all in platelets per milliliter (plts/mL)): ▪ 5 × 108, □ 2.5 × 108, ▲ 1 × 108, ● 0.5 × 108, and ○ 0.1 × 108. The dotted line represents PNP thrombus lysis. **P < .01; ***P < .001 compared with FXIII-depleted thrombi (n = 4). (B) Thrombi were prepared from PNP or mixtures of PNP with FXIII-depleted plasma in the (▪) absence and (●) presence of platelet lysates at 2.5 × 108 plts/mL. **P < .01 compared with thrombi + 2.5 × 108 plts/mL (n = 5). (C) (△) FXIII-depleted thrombi were prepared with the addition of 5 × 108 plts/mL in the (▪) absence and (□) presence of a TG inhibitor. **P < .01; ***P < .001 compared with FXIII-depleted thrombi + 5 × 108 plts/mL (n = 6).
