Effects of RBCs on clot contraction and dynamic viscoelastic properties. RBCs were resuspended in mixtures of PRP and autologous PFP to vary the volume fraction of RBCs from <10% to >40% while keeping the platelet count and fibrinogen concentration constant. (A) Images of the clots before (upper row) and after (bottom row) 30-minute contraction induced by thrombin and CaCl2. Plots show the effects of RBCs on (B) the kinetics of contraction, (C) the final extent of contraction, (D) the elastic properties of the contracting clot (storage modulus, G′), and (E) the ratio of viscous to elastic properties (tan δ = G″/G′). The lower plots show the (F) averaged kinetics of clot contraction and the (G) average final extent of contraction in the whole blood of SCD patients (n = 3) vs whole blood from healthy controls (n = 51). *P < .05; **P < .01; ***P < .001; ****P < .0001.
