Compaction of fibrin clots reveals the antifibrinolytic effect of factor XIII

Essentials•Factor XIIIa inhibits fibrinolysis by forming fibrin‐fibrin and fibrin‐inhibitor cross‐links.•Conflicting studies about magnitude and mechanisms of inhibition have been reported.•Factor XIIIa most strongly inhibits lysis of mechanically compacted or retracted plasma clots.•Cross‐links of α2‐antiplasmin to fibrin prevent the inhibitor from being expelled from the clot.AcknowledgementsThis research was supported by a grant from the...