Expression Of Plasma Microparticles In Patients With Pulmonary Thromboembolism And Its Diagnostic Significance

Objective:To investigate the expression of platelet microparticles,endothelial microparticles and tissue factor positive microparticles in peripheral blood of patients with pulmonary thromboembolism and its clinical significance.To find a biomarker with high sensitivity and specificity as the diagnostic index of the disease.Method:Blood samples from 40 patients with pulmonary thromboembolism who were newly diagnosed without anticoagulant therapy,and 40 healthy controls were collected.We used flowcytometry to measure Annexin V+/CD41+platelet microparticles ? Annexin V+/CD144+endothelial microparticles ? Annexin V+/CD142+tissue factor positive particles.At the same time,D-dimer was detected by enzyme-linked immunofluorescence assay.Microparticles and D-dimer were analyzed by ROC curve to evaluate the diagnostic value of pulmonary thromboembolic disease and to find out the clinical diagnostic threshold.Results:Platelet microparticles in patients with pulmonary embolism were significantly higher than those of healthy control group [(734.4±293.5)vs(569.2±180.6)counts/ul;P=0.004];Endothelial microparticles in patients with pulmonary embolism increased significantly[(1030.7±857.4)vs(671.1±370.5)counts/ul;P=0.019];In the40 patients,EMPsin patients with pulmonary hypertension(18 cases)were higher than those in normal group(22 cases),but the difference was not statistically significant(P>0.05).Tissue factor positive microparticles were higher than those of healthy control group [(883.1±417.4)vs(676.1±237.5)counts/ul;P=0.011].The AUC of platelet microparticles,endothelial microparticles and tissue factor positive microparticles were 0.66,0.715,0.61,respectively;the sensitivity of above microparticles under ROC curve were 50%?60%?51.4%,respectively;the specificity of above microparticles under ROC curve were 82.1%?84.6%?83.8%;the cut-off point of above microparticles under ROC curve were 716.9 counts/ul ? 805.5counts/ul?823.0 counts/ul?500 ng / ml as the clinical exclusion criteria,The AUC of D-dimer was 0.973,the sensitivity was 97.3%,and the specificity was 67.5%-70%.Conclusion:1.The levelof Plateletmicroparticles,endothelial microparticles and tissue factor positive microparticles were significantly elevated in patients with pulmonary thromboembolism,suggesting that platelet microparticles,endothelial micro-particles and tissue factor positive microparticles have low sensitivity to pulmonary thromboembolis,but the specificity is high,combined with clinical symptoms can be used as diagnostic index of reference.