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Objective: The risk of stroke in patients with recently symptomatic carotid stenosis is considerably higher than in patients with asymptomatic stenosis. In the present study it was hypothesised that excessive platelet activation might partly contribute to this difference. Methods: A full blood count was done and whole blood flow cytometry used to measure platelet surface expression of CD62P, CD63, and PAC1 binding and the percentage of leucocyte–platelet complexes in patients with acute (0–21 days, n = 19) and convalescent (79–365 days) symptomatic (n = 16) and asymptomatic (n = 16) severe (⩾70%) carotid stenosis. Most patients were treated with aspirin (37.5–300 mg daily) although alternative antithrombotic regimens were more commonly used in the symptomatic group. Results: The mean platelet count was higher in patients with acute and convalescent symptomatic compared with asymptomatic carotid stenosis. There were no significant differences in the median percentage expression of CD62P and CD63, or PAC1 binding between the acute or convalescent symptomatic and asymptomatic patients. The median percentages of neutrophil–platelet (p = 0.004), monocyte–platelet (p = 0.046), and lymphocyte–platelet complexes (p = 0.02) were higher in acute symptomatic than in asymptomatic patients. In patients on aspirin monotherapy, the percentages of neutrophil–platelet and monocyte–platelet complexes (p = 0.03) were higher in acute symptomatic (n = 11) than asymptomatic patients (n = 14). In the convalescent phase, the median percentages of all leucocyte–platelet complexes in the symptomatic group dropped to levels similar to those found in the asymptomatic group. Conclusion: Increased platelet count and leucocyte–platelet complex formation may contribute to the early excess risk of stroke in patients with recently symptomatic carotid stenosis.

This study has investigated quantification of chimerism in sex-mismatched transplantations by quantitative real time PCR (RQ-PCR) using FTA paper for blood sampling. First, we demonstrate that the quantification of DNA from EDTA-blood which has been deposit on FTA card is accurate and reproducible. Secondly, we show that fraction of recipient cells detected by RQ-PCR was concordant between the FTA and salting-out method, reference DNA extraction method. Furthermore, the sensitivity of detection of recipient cells is relatively similar with the two methods. Our results show that this innovative method can be used for MC assessment by RQ-PCR.