Biological reproducibility of circulating P-Selectin, Thrombopoietin, GPIIb/IIIa and Thrombomodulin over one year

Correlation of CLEC1B haplotypes with plasma levels of soluble CLEC-2 in healthy individuals

Binding of podoplanin to the C-type lectin-like receptor 2 (CLEC-2) promotes platelet activation and soluble CLEC-2 (sCLEC-2) is shed from activated platelets. The role of sCLEC-2 in the plasma is unknown. The expression level and plasma concentration of sCLEC-2 could be affected by variants of the corresponding gene, CLEC1B. Here, we genotyped SNVs in the promoter and coding region of CLEC1B and determined plasma levels of sCLEC-2 in healthy individuals. We genotyped 516 healthy blood donors for 7 SNVs (rs10505743, rs11053538, rs4764178, rs76016091, rs2273986, rs2273987, rs521040) by using PCR methods and calculated haplotypes from the SNV genotypes. For 313 of the donors we measured the sCLEC-2 concentration in EDTA plasma samples by using a commercial ELISA. SNV typing revealed allele frequencies comparable to database information. None of the SNVs showed significant correlation with sCLEC-2 plasma levels. Haplotype analysis indicated 6 haplotypes with frequencies >1% and haplotype h3 was the most frequent (33.8%). Donors homozygous for h3 (n = 37) showed significantly lower sCLEC-2 plasma levels (median 0.95 ng/mL) than donors being h3 negative or heterozygous (n = 276; 1.44 ng/mL; p = .0203). We found that the sCLEC-2 plasma concentration is variable in healthy individuals and the CLEC1B genotype contributes to the expression level.

Vascular injury biomarkers and stroke risk

Objective

Because little is known about associations between biomarkers of vascular injury and stroke risk, we evaluated associations between plasma concentrations of 6 novel biomarkers of vascular injury and stroke risk in a population-based study.

Methods

A case–cohort subset of EPIC-Heidelberg (European Prospective Investigation for Cancer and Nutrition–Heidelberg) including incident stroke cases (n = 335) and a random subcohort (n = 2,418) was selected. Concentrations of intercellular adhesion molecule 3 (ICAM3), soluble E-selectin and P-selectin, soluble thrombomodulin (sTM), thrombopoietin, and glycoprotein IIb/IIIa were measured in baseline plasma samples. Weighted Cox regression analyses were used to assess associations between biomarker levels and stroke risk.

Results

Median follow-up in the subcohort and among cases was 9.8 (range, 0.1–12.5) years and 6.2 (range, 0.01–12.1) years, respectively. ICAM3 levels were associated with increased risk of incident stroke after multivariable adjustment (hazard ratio, highest vs lowest quartile: 1.64 [95% confidence interval, 1.15–2.32]; plinear trend < 0.001). This association was more apparent for ischemic (1.65 [1.12–2.45]; plinear trend < 0.01) than for hemorrhagic stroke (1.29 [0.60–2.78]; plinear trend = 0.3). We further observed a borderline significant trend for a positive association between sTM and overall stroke risk (1.47 [0.99–2.19]; plinear trend = 0.05).

Conclusions

In this population-based study, circulating levels of ICAM3, an adhesion molecule shed by leukocytes, were associated with increased risk of incident stroke. Further mechanistic studies are needed to elucidate the pathophysiology underlying this association.

Classification of evidence

This study provides Class II evidence that plasma levels of ICAM3 are associated with increased stroke risk.

Biomarkers of Vascular Injury and Type 2 Diabetes: A Prospective Study, Systematic Review and Meta-Analysis

Data on biomarkers of vascular injury and type 2 diabetes (T2D) risk from prospective studies are lacking. We evaluated seven biomarkers of vascular injury in relation to T2D. Additionally, a meta-analysis was performed. From the EPIC–Heidelberg cohort, 2224 participants were followed-up from baseline for 16 (median) years. E-Selectin, P-Selectin, intercellular adhesion molecule 3 (ICAM3), thrombomodulin, thrombopoietin, glycoprotein IIb/IIIa and fibrinogen levels were measured in baseline blood samples. The systematic review and meta-analysis included prospective studies identified through MEDLINE and Web of Science that investigated the association between mentioned biomarkers and T2D. The study population included 55% women, median age was 50 years, and 163 developed T2D. ICAM3 was associated with lower T2D risk (fully adjusted HR_{highest vs. lowest} tertile 0.62 (95% CI: 0.43, 0.91)), but no other studies on ICAM3 were identified. Overall, fifteen studies were included in the systematic review and meta-analysis (6,171 cases). E-Selectin was associated with higher T2D risk HR_{per SD}: 1.34 (95% CI: 1.16, 1.54; I² = 63%, n = 9 studies), while thrombomodulin was associated with lower risk HR_{per SD}: 0.82 (95% CI: 0.71, 0.95; I² = 0%, n = 2 studies). In the EPIC–Heidelberg, ICAM3 was associated with lower T2D risk. The meta-analysis showed a consistent positive association between E-Selectin and T2D. It was also suggestive of an inverse association between thrombomodulin and T2D, although further studies are needed to corroborate this finding.

Biomarkers of vascular injury in relation to myocardial infarction risk: A population-based study

Little is known about circulating biomarkers of vascular injury in relation to cardiovascular disease risk. Thus, we evaluated associations between six novel markers (E-Selectin, P-Selectin, thrombomodulin, thrombopoietin, intercellular adhesion molecule 3 and GPIIb/IIIa) and established cardiovascular risk factors as well as the risk of myocardial infarction (MI) in a population-based study. Biomarkers were measured in pre-diagnostic plasma samples of a case-cohort subset of EPIC-Heidelberg (incident MI cases: n = 369, random sub-cohort: n = 2,418). Generalized Linear models were used to analyse cross-sectional associations between biomarkers and cardiovascular risk factors. Multivariable Cox Regression analyses were carried out to obtain Hazard Ratios (HRs) of MI across quartiles of biomarkers levels. Cross-sectional analyses showed that sex, smoking, alcohol consumption, diabetes and exogenous hormone use were associated with biomarker levels. However, while fibrinogen was associated with MI risk (HR per standard deviation: 2.97 [95% confidence interval: 1.61, 5.46]), none of the six novel biomarkers was associated with MI risk after multivariable adjustment. In a population-based cohort, biomarkers of vascular injury were associated with established cardiovascular risk factors, but not MI risk. The tested biomarkers may reflect pathophysiological alterations in cardiovascular disease development rather than constituting independent MI risk factors.

Diagnostic value of platelet-derived microparticles in pulmonary thromboembolism: A population-based study

An early and accurate diagnosis of pulmonary thromboembolism (PTE) remains challenging. The present study aimed to evaluate the diagnostic value of platelet-derived microparticles in PTE based on a population study. A total of 102 patients with PTE, 102 healthy controls and 40 patients suspected with PTE were enrolled in this study. The platelet count, mean platelet volume and platelet distribution width were assessed using an automated hematology analyzer, P-selectin was assessed using an ELISA kit and PMPs were explored using flow cytometry using Megamix beads. Receiver operating characteristic curves were established to evaluate the diagnostic values of PMPs, D-dimer, PMPs combined with D-dimer, and multiple parameters (including PMPs, platelet distribution width, P-selectin and D-dimer in PTE). The PMP levels were significantly higher in the patients with PTE (609.10/µl) compared with those in the healthy controls (230.60/µl) and patients with suspicious PTE (166.70/µl; P<0.01). The accuracy (72.06%) of PMPs in the diagnosis of PTE was similar to those of D-dimer (P>0.05). The combination of D-dimer and PMPs significantly increased the sensitivity (86.27%) of D-dimer and the specificity of PMP for the diagnosis of PTE (P<0.01). The combination of PMPs, platelet distribution width, P-selectin and D-dimer exhibited high sensitivity (88.24%), specificity (91.18%) and accuracy (89.71%) in the diagnosis of PTE. These findings suggest that elevated PMP levels are an effective predictor of PTE. The combination of PMPs, platelet distribution width, P-selectin and D-dimer may be used in the diagnosis of PTE with high sensitivity and specificity.

IQCA-TAVV: To explore the effect of P-selectin, GPIIb/IIIa, IL-2, IL-6 and IL-8 on deep venous thrombosis

Deep vein thrombosis (DVT) associates with considerable morbidity, functional disability and mortality. Due to the lack of suitable inhibitor the correlation of various factors in DVT onset remains unknown. In this context we analyzed the structure of anti-platelet aggregation agent, P-selectin down-regulator, GPIIb/IIIa down-regulator and anti-inflammatory agent, thereby designed N-(3S-1,2,3,4-tetrahydroisoquinoline-3-carbonyl)- Thr-Ala-Arg-Gly-Asp(Val)-Val (IQCA-TAVV) as an inhibitor of DVT to receive evaluations. The docking predicted that IQCA-TAVV can target P-selectin and GPIIb/IIIa. The UV showed that IQCA-TAVV can act on P-selectin and GPIIb/IIIa. ELISA indicated that IQCA-TAVV concentration dependently inhibited activated platelets to express P-selectin and GPIIb/IIIa, and the minimal effective concentration was 1 nM. IC50 of IQCA-TAVV against platelet aggregation induced by arachidonic acid, adenosine diphosphate and platelet activating factor fell within a range of 0.13 nM to 0.30 nM. In vivo IQCA-TAVV dose-dependently inhibited venous thrombosis and the minimal effective dose was 1 nmol/kg. On ear edema model the anti-inflammation activity of 10 nmol/kg IQCA-TAVV equaled that of 1.1mmol/kg aspirin. The concentration of IL-2, IL-6 and IL-8 in the serum of the ear edema mice were also significantly decreased by 10 nmol/kg IQCA-TAVV. Even at 1 μmol/kg of dose IQCA-TAVV still did not injure the kidney, the liver, and the nerves of healthy mice. Thereby IQCA-TAVV depicts a relationship of three levels (inhibiting platelet activation, targeting externalized membrane receptor, decreasing serum inflammatory factor) for the down-regulation of P-selectin, GPIIb/IIIa, IL-2, IL-6 and IL-8 in DVT.