Individual variation in platelet thrombus formation induced by S pyogenes.
(A) Anti-M5 antibody titer in 2 individuals with a high (donor 1) or low (donor 9) platelet reactivity toward immobilized M5 protein. (B) M5 streptococci (coating suspension: 108 bacteria/mL) were immobilized on glass coverslips coated with human serum albumin (100 μg/mL) and then exposed to blood from the 2 donors with different anti-M5 antibody titer perfused at the wall shear rate of 340 s−1. The total volume of platelet thrombi on an area of 45 000 μm2 was measured after 9 minutes. (C) Surface coverage by platelets and platelet thrombi measured at the indicated time points using the same conditions as described in the legend to panel B. Images of the surface at different time points are also shown.
