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Background: The reactivity of platelets is increased in patients with peripheral artery disease (PAD). RANTES and sCD40L are chemokines which are stored in the alpha-granules of platelets. Clopidogrel inhibits and thus reduces platelet reactivity. Whether a treatment with clopidogrel is associated with an inhibition of systemic inflammation in patients with PAD has not been thoroughly explored. This study examined the effect of clopidogrel on platelet reactivation and the release of inflammatory chemokines in patients with PAD.Methods: 40 patients with PAD were randomized into two groups. In the first group A the patients were treated with 100mg acetylsalicylic acid (ASA) and additional placebo for 4weeks. The patients in group B received 75mg/d clopidogrel in addition to ASA 100mg for 4weeks. After obtaining blood at days 0, 7 and 28 the platelet activation was determined by measuring the surface protein expression of CD63, CD62p and thrombospondin (TSP) after stimulation with TRAP and ADP. The release of the chemokines RANTES and sCD40L from platelets was analyzed by ELISA.Results: Platelet activation markers (CD62p and CD63) and chemokine RANTES were significantly reduced in patients with PAD after 7 and 28days after treatment with clopidogrel. No alterations were found in TSP expression and sCD40L during the treatment.Conclusion: The treatment with clopidogrel leads to a reduction of platelet reactivity and release of RANTES from the platelets of patients with PAD. [ABSTRACT FROM AUTHOR]

Context: Experimental data suggest that placental growth factor (PlGF), a member of the vascular endothelial growth factor family, acts as a primary inflammatory instigator of atherosclerotic plaque instability and thus may be useful as a risk-predicting biomarker in patients with acute coronary syndromes (ACS). Objective: To determine whether blood levels of PlGF predict risk for death or nonfatal myocardial infarction in patients with acute chest pain. Design, Setting, and Patients: Measurement of PlGF levels as well as levels of markers of myocardial necrosis (troponin T [TnT]), platelet activation (soluble CD40 ligand [sCD40L]), and inflammation (high-sensitivity C-reactive protein [hsCRP]) in an inception cohort of 547 patients with angiographically validated ACS participating in the CAPTURE (c7E3 Fab Anti-Platelet Therapy in Unstable Refractory Angina) trial and in a heterogeneous cohort of 626 patients presenting with acute chest pain to an emergency department in Germany between December 1996 and March 1999. Main Outcome Measure: Risk for death or nonfatal myocardial infarction after 30 days. Results: In patients with ACS, elevated PlGF levels (>27.0 ng/L; 40.8% of patients) indicated a markedly increased risk of events at 30 days (14.8% vs 4.9%; unadjusted hazard ratio [HR], 3.34; 95% confidence interval [CI], 1.79-6.24; P<.001). In a multivariable model, elevated levels of TnT (HR, 1.83; 95% CI, 1.05-3.86; P = .03), sCD40L (HR, 2.65; 95% CI, 1.41-4.99; P = .002), and PlGF (HR, 3.03; 95% CI, 1.54-5.95; P<.001) were independent predictors, while elevated hsCRP level was not (HR, 0.98; 95% CI, 0.53-1.98; P = .94). In patients with acute chest pain, elevated levels of PlGF predicted risk (21.2% vs 5.3%) (unadjusted: HR, 4.80; 95% CI, 2.81-8.21; P<.001; adjusted: HR, 3.00; 95% CI, 1.68-5.38; P<.001). Patients negative for all 3 markers (TnT, sCD40L, and PlGF) were at very low cardiac risk (7 days: no event; 30 days: 2.1% event rate). Conclusions: Plasma PlGF levels may be an independent biomarker of adverse outcome in patients with suspected ACS. A single initial measurement of plasma PlGF appears to extend the predictive and prognostic information gained from traditional inflammatory markers. [ABSTRACT FROM AUTHOR]