GPVI-induced thrombin generation is dependent on fibrin(ogen). (A) Peak of thrombin generation in reconstituted PRP containing increasing concentrations of fibrinogen (0-6 g/L) in the presence of a control Fab and the anti-GPVI Fab 9O12. (B) Curves of thrombin generation in PRP from a control (plain lines) and the AF patient 1 (dotted lines) in the presence of a control Fab (black) and the Fab 9O12 (gray). (C-E) Peak of thrombin generation in: (C) human PRP, (D) PRP from a control and the AF patient 2, and (E) PRP from controls and 2 GPVI-deficient patients. (C-D) Peak of thrombin generation in the presence or absence of the Fab 9O12 and (D) after addition of FGN to plasma (C-E) with or without GPRP. (F) Increasing concentrations of GPVI–Alexa 488 were added to microwells coated with fibrin, fibrinogen, collagen I, or BSA in the presence of a control Fab or the Fab 9O12. Protein binding was assessed by measuring the fluorescence intensity at 485 nm. (A,C,F) Data are the mean ± SEM of 3 separate experiments. Mean ± SEM, *P < .05, **P < .01, ***P < .001, Mann-Whitney U test. BSA, bovine serum albumin; FGN, fibrinogen.