CMML monocytes are able to modify the PCA of HD MSCs. Lag times are expressed as fold changes of the lag time obtained with the positive control (TF 0.5 pM). The negative control used was MPR 0.5. Any thrombin generated after corresponded to contact-phase activation. HD MSCs cultured with medium are represented in green, with monocyte SN in red, TF 0.5 pM in purple, and MPR in blue. *P ≤ .05, **P ≤ .005, ****P ≤ .0001. (A) TGA curves of HD MSCs coincubated without or with CMML monocyte SN. (B) Effect of CMML monocyte SN on HD MSC coagulation lag time. (C) Effect of CMML monocyte SN on HD MSC thrombin generation. (D) Study of the effect of the different CMML monocyte SN components on HD MSCs lag time. The effect of 6 different SNs was studied: (1) medium alone, (2) monocyte culture SN, (3) monocyte culture SN without exosomes (Exofree SN), (4) mEVs isolated from CMML monocyte SN, (5) sEVs isolated from CMML monocyte SN, and (6) mEVs and sEVs isolated from CMML monocyte SN at the same time. Experiments were performed without or with a blocking anti-TF antibody (HTF-1) at a final concentration of 8 µg/mL.