Genomic characteristics of adhesion molecules in patients with symptomatic pulmonary embolism

Reduced fibrin clot permeability on admission and elevated E-selectin at 3 months as novel risk factors of residual pulmonary vascular obstruction in patients with acute pulmonary embolism

BACKGROUND

Residual pulmonary vascular obstruction (RPVO) is common following pulmonary embolism (PE) but its association with fibrin clot properties is poorly understood. We investigated whether prothrombotic state and hypofibrinolysis markers can identify patients with RPVO.

METHODS

In 79 normotensive noncancer patients (aged 56 ± 13.3 years) with acute PE, we determined fibrin clot permeability (Ks), clot lysis time (CLT), endogenous thrombin potential (ETP), fibrinolysis proteins, oxidative stress markers, and E-selectin on admission before initiation of anticoagulant therapy, after 5-7 days, and 3 months of anticoagulation. RPVO was diagnosed using computed tomography angiography 3-6 months since PE.

RESULTS

Patients with RPVO (n = 23, 29.1%) had at baseline higher simplified Pulmonary Embolism Severity Index (sPESI) (P = 0.004), higher N-terminal brain natriuretic propeptide (P = 0.006) and higher D-dimer (P = 0.044). Patients with versus without RPVO had lower Ks (P < 0.001) and longer CLT (P < 0.05), both at baseline and 5-7 days since admission, but not at 3 months. Patients with RPVO showed 40.6% higher E-selectin (P < 0.001) solely at 3 months. By multivariable logistic regression, baseline Ks (odds ratio [OR] 0.010, 95% confidence interval [CI] 0.001-0.837, P = 0.042, per 10- 9 cm2), baseline D-dimer (OR 1.105, 95% CI 1.000-1.221, P = 0.049, per 100 ng/ml), and E-selectin levels after 3 months (OR 3.874, 95% CI 1.239-12.116, P = 0.020, per 1 ng/ml) were associated with RPVO.

CONCLUSIONS

RPVO patients despite anticoagulation characterize with the formation of denser fibrin clots on admission and higher E-selectin at 3 months. Those parameters could be the potential novel RPVO risk factors that warrant further evaluation in an independent cohort.

The High Expression of Adhering and Circulating Integrin Serves as a Diagnostic Marker in Venous Thromboembolism

Objective

To investigate the diagnostic value of circulating integrins β1, 2, and 3 in venous thrombosis (VTE).

Materials and Methods

A total of 474 VTE patients and 306 patients with nonhigh risk for VTE as the control group were studied. Levels of adhering integrins β1, 2, and 3 were detected by flow cytometry. Levels of circulating integrins β1, 2, and 3 in serum were measured by enzyme-linked immunosorbent assay.

Results

We found that integrins β1, 2, and 3 were expressed highly both in serum and on the surface of leukocytes and platelets in venous thromboembolism. The levels of circulating integrins β1, 2, and 3 are positively correlated with adhering integrins. It showed excellent clinical diagnostic performance of circulating integrins β1, 2, and 3 in venous thromboembolism.

Conclusions

Integrin subunit β can be used as a diagnostic marker with high sensitivity and specificity for venous thromboembolism.

Dysregulation of Biomarkers of Hemostatic Activation and Inflammatory Processes are Associated with Adverse Outcomes in Pulmonary Embolism

Introduction

The pathophysiology of pulmonary embolism (PE) represents complex, multifactorial processes involving blood cells, vascular endothelium, and the activation of inflammatory pathways. Platelet (P), endothelial (E), and leukocyte (L)-selectin molecules may play an important role in PE pathophysiology. We aimed to profile the biomarkers of inflammation, including selectins in PE patients, and compare them to healthy individuals.

Materials and methods

100 acute PE patients and 50 controls were included in this case control study. ELISA methods were used to quantify levels of selectins, inflammatory, and hemostatic biomarkers.

Results

In PE patients, levels of selectin molecules as compared to controls convey increased P-selectin levels (95 ng/mL vs 40 ng/mL, p < .0001) and decreased L-selectin levels (1468 ng/mL vs 1934 ng/mL, p < .0001). Significant correlations were found between selectins and Plasminogen Activating Inhibitor-1 (PAI-1), Tumor Necrosis Factor-a (TNFa), and D-dimer. Fold change between selectins and controls is compared to other biomarkers, illustrating degrees of change comparable to TNFa, alpha-2-antiplasmin, and microparticles. L-selectin levels are inversely associated with all-cause-mortality in PE patients, (p = .040).

Conclusion

These studies suggest that various thrombo-inflammatory biomarkers are elevated in PE patients. Furthermore, L-selectin levels are inversely associated with mortality outcomes.

Venous Thrombus

Venous thromboembolism (VTE) includes pulmonary thromboembolism (PE) and deep venous thrombosis (DVT). Both belonging to thrombus, acute arterial thrombus is white thrombus, while acute venous thrombus is red thrombus. What does the pathological difference mean? Venous thrombosis can autolyze, while arterial thrombosis cannot. For VTE patients, oral anticoagulants are usually recommended for 3, 6, or 12 months and occasionally lifelong, but the course cannot be determined. Furthermore, even with standard anticoagulation therapy and INR, some patients still develop chronic thromboembolic pulmonary hypertension (CTEPH). Thus, the physicians are extremely puzzled about anticoagulant usage. Proposed risk factors for VTE include advanced age, infection, malignancy, autoimmune disease, surgery, trauma, pregnancy, long trip syndrome, family history, AMI, heart failure, and so on. Relevant risk factors are increasing over time. Risk factors are derived from the summary of evidence-based medicine. Although these factors are found to be associated with venous thrombosis, the intrinsic factors have not been well elucidated.

Increased Expressions of Integrin Subunit β1, β2 and β3 in Patients with Acute Infection

OBJECTIVE

Our previous studies have shown that integrin subunits β1, β2 and β3 were the core proteins of venous thrombi and potential useful biomarker of venous thromboembolism (VTE). Patients with acute infection have a high risk of VTE. In this study we explored that is there any relevance between core proteins and acute infection.

METHODS

A total of 230 patients (112 females) with clinically proven acute infection in the emergency unit were recruited into this study, meanwhile 230 patients without acute infection matched in sex and age were recruited as control group. Flow cytometry was done to measure the expressions of blood integrin β1, β2, β3 and cellular immunity (CD3, CD4, CD8, CD4/CD8, CD16CD56 and CD19). The association degree between increased core proteins and acute infection was analyzed by calculating the relative risk (RR).

RESULTS

The expression of integrin β1, β2 and β3 was markedly increased in patients with acute infection (P=0.000, 0.000 and 0.015, respectively). The relative risk ratio (RR) of increased integrin β1, β2 and β3 in acute infection patients was 1.424 (95%CI: 1.156-1.755, P=0.001), 1.535 (95%CI: 1.263-1.865, P=0.000) and 1.20 (95%CI: 0.947-1.521, P=0.148), respectively. Combined integrin β1, β2 and β3 analysis showed that the relative risk ratio (RR) of increased in patients with acute infection was 2.962 (95%CI: 1.621-5.410, P=0.001), and this relative risk (RR) rise to 3.176 (95%CI: 1.730-5.829, P=0.000) in patients with respiratory tract infection (RTI).

CONCLUSION

As the core proteins of venous thrombi, integrinβ1, β2 and β3 were markedly increased expression in patients with acute infection, which maybe explain the increased risk of VTE in acute infection patients. A weakened immune system could be the basic condition of VTE occurrence.

Differential expression of leukocyte β2 integrin signal transduction‑associated genes in patients with symptomatic pulmonary embolism

Whole human genome oligo microarrays were employed to systematically investigate the differential expression characteristics of associated mRNAs, which were found in the signal transduction pathway of β2 integrins in peripheral blood mononuclear cells (PBMCs) between patients with symptomatic pulmonary embolism (PE) and controls. A total of 20 cases of PE patients and twenty gender‑ and age‑matched controls were recruited for the study. Human cDNA microarray analysis was used to detect the differences in mRNA expression between the two groups and a random variance model corrected t‑test was used to analyze the statistical data. A total of 80 associated mRNAs were detected. The mRNA expression of chemokines, ligands, inside‑out and outside‑in signaling pathway‑associated proteins were upregulated significantly in the PE group, compared with the controls. In five subunit‑associated mRNAs, the mRNA expression of ITGAL, ITGAM, ITGAX and ITGB2, which encode for the subunits of αL, αM, αX and β2, were upregulated in the PE group and the differences, with the exception of ITGB2, were statistically significant (P<0.05). The mRNA expression of ITGAD was downregulated; however, there was no significant difference (P>0.05). The expression of Fgr mRNA was significantly downregulated (P<0.01). Thus, in PE patients, bilateral signal transduction pathways of β2 integrins in neutrophils and monocytes were activated, enhancing innate immunity.