For ITC experiments, a micellar suspension of 10 mg l−1 was vortexed, followed by multiple serial dilutions. The South African National Blood Service (SANBS) supplied human thrombin, which was at a stock concentration of 20 U ml−1 and was made up in a PBS containing 0.2% human serum albumin. In experiments with added thrombin, 5 µl of thrombin was added to 10 µl of PPP or fibrinogen (with and without LPS exposure). Human fibrinogen was purchased from Sigma (F3879–250MG). A working solution of 0.166 mg ml−1 purified fibrinogen was prepared. This concentration was found to be the optimal concentration to form fibrin fibres in the presence of thrombin, similar to that of platelet-rich plasma fibres from healthy individuals . As noted by a referee, LPS is a common laboratory contaminant, and care is needed; however, this was not an issue here as the ‘no-added-LPS’ controls showed.