Platelet CLEC-2 deficiency protects mice from thrombotic injury in a mouse model of TTP. Mice were injected with antibodies to ADAMTS13 and human plasma VWF to induce TTP. At 24 hours after TTP induction, blood was collected to analyze VWF levels and platelet count, and lungs were collected to analyze thrombus formation. (A) Representative immunofluorescence images of thrombi in lungs of mice with TTP. (B) Quantification of thrombus formation in lung shown in (A). Quantification of the pixels of CD41-positive areas in each field of images. (C) Platelet counts in mice with TTP. Platelet counts in mice at 7 days before experiments (basal level) and at 24 hours after induction of TTP (by injecting antibodies to ADAMTS13 and VWF) were quantified. Each dot represented a datum from 1 mouse. Comparisons marked by asterisks are significantly different (P < .05). (D) Blood LDH activity of mice at basal level and at 24 hours after TTP induction. (E) Analysis of VWF in blood of mice with TTP by electrophoresis on agarose gel and by densitometric scanning. The data are representative of 5 independent experiments, and data represent mean ± SD. *P < .05.