LPS increases circulating MP-associated TF PCA in vivo. (A) Time-dependent increase in MP-associated TF PCA in vivo after LPS administration. EDTA-anticoagulated blood samples for assay of MP-associated TF PCA were collected at baseline and various time points after LPS infusion (2 ng/kg) in 18 male volunteers. MP-associated TF PCA was measured in platelet-free plasma as described in “Materials and methods.” Data are presented as the means ± SEM. ^*P < .05 versus baseline. (B) The MP-borne TF response following LPS exposure is highly variable between subjects. The data from panel A are replotted by individual subject to illustrate the variability of response.