rsTREM-1 does not induce platelet aggregation or CD62P up-regulation. (A) Platelets in plasma were analyzed for aggregation state by photometry after incubation with the indicated stimuli. Adding rsTREM-1 or human IgG (10 μg/mL) does not result in aggregation of platelets. Stimulation with collagen was used as a positive control. Shown is percentage of aggregated cells. Data are representative of 3 experiments. (B) Citrated blood samples were stimulated for 10 minutes and analyzed for CD62p expression by FACS analysis. Platelets were gated on CD41a high and CD45 low as shown in the dot plot. Compared with thrombin, rsTREM-1 or human IgG has negligible effect on CD62P up-regulation. The depicted data are representative of 3 independent experiments, as mean of triplicates. Error bars represent standard deviation (SD).