Circulating microvesicles across a population with various degree of cardiovascular burden are associated with systolic blood pressure.

Circulating microvesicles (MVs) have been studied in heterogeneous, divergent, and rather small patient populations with cardiovascular risk . Therefore, we measured endothelial (EMVs), platelet (PMVs) and erythrocyte (RMVs) MVs in patients with divergent cardiovascular risk. We then compared them to coronary artery disease (CAD) and healthy subjects and identified independent MVs' predictors. We enrolled consecutive patients from our Cardiology, Hypertension, Diabetic, Rheumatic, and Nephrology Outpatient Units with MVs measurements. Central blood pressure (BP) was measured by either applanation tonometry or Mobil-O-graph device, while MVs by a standardized flow cytometry protocol. We studied 369 participants with increased cardiovascular risk: 63 with high cardiovascular risk (47 diabetes mellitus type II/DM and 16 end-stage renal disease/ESRD), 92 with chronic inflammatory disorders and 73 with untreated essential hypertension/UEH. We further included 53 subjects with CAD and 87 otherwise healthy individuals. All MVs were lower in patients with increased cardiovascular risk compared to CAD, showing predictive value with high sensitivity and specificity. Furthermore, PMVs and EMVs were increased in patients with cardiovascular risk compared to healthy individuals. DM and ESRD patients had increased EMVs versus UEH and chronic inflammatory disorders. In the whole study population, RMVs were associated only with history of essential hypertension. In multivariate analysis, systolic BP predicted PMVs. Aage, systolic BP, and DM predicted EMVs. In a large population of patients with divergent cardiovascular risk, MVs are independently associated with systolic blood pressure.

A study of endothelial and platelet microvesicles across different hypertension phenotypes.

Rather than being mere biomarkers reflecting generalized vascular injury, endothelial- (EMVs) and platelet-derived (PMVs) microvesicles have emerged as potent regulators of intercellular communication with significant biologic effects in vascular homeostasis and several pathophysiological responses including inflammation and thrombosis. So far, studies in hypertension are scarce, whereas no studies exist in masked hypertension (MH). We measured EMVs and PMVs in untreated, newly diagnosed hypertensives (HTs) and MHs compared to normotensive controls (NTs), and associated them with various cardiovascular risk factors. Sustained hypertension (SHT) and MH were defined according to standard blood pressure (BP) criteria. All HTs were free of cardiovascular disease and medications. Microvesicles' quantitation and detection were performed by flow cytometry by using cell-specific antibodies and corresponding isotypes (anti-CD105 and anti-CD144 for EMVs, anti-CD42a for PMVs, and Annexin V-fluorescein isothiocyanate for all microvesicles). In this study, we included 59 HTs (44 SHTs and 15 MHs) and 27 NTs. HTs had significantly elevated EMVs (p = 0.004), but not PMVs compared to NTs. MHs had significantly elevated EMVs compared to NTs (p = 0.012) but not compared to SHTs. Furthermore, EMVs significantly correlated with ambulatory (r = 0.214-0.284), central BP (r = 0.247-0.262), and total vascular resistance (r = 0.327-0.361). EMVs are increased not only in SHTs but also in MHs, a hypertension phenotype with a cardiovascular risk close to SHT. EMVs have emerged as active contributors to thromboinflammation and vascular damage and may explain, in part, the adverse cardiovascular profile of SHTs and MHs.

Assessment of Endothelial Injury and Pro-Coagulant Activity Using Circulating Microvesicles in Survivors of Allogeneic Hematopoietic Cell Transplantation.

(1) Background: survivors of allogeneic hematopoietic cell transplantation (alloHCT) suffer from morbidity and mortality due to cardiovascular events. We hypothesized that vascular injury and pro-coagulant activity are evident in alloHCT survivors without existing alloHCT complications or relapse. (2) Methods: we enrolled consecutive adult alloHCT survivors without established cardiovascular disease and control individuals matched for traditional cardiovascular risk factors (January-December 2019). Circulating microvesicles (MVs) of different cellular origins (platelet, erythrocyte, and endothelial) were measured by a standardized flow cytometry protocol as novel markers of vascular injury and pro-coagulant activity. (3) Results: we recruited 45 survivors after a median of 2.3 (range 1.1-13.2) years from alloHCT, and 45 controls. The majority of patients suffered from acute (44%) and/or chronic (66%) graft-versus-host disease (GVHD). Although the two groups were matched for traditional cardiovascular risk factors, alloHCT survivors showed significantly increased platelet and erythrocyte MVs compared to controls. Within alloHCT survivors, erythrocyte MVs were significantly increased in patients with a previous history of thrombotic microangiopathy. Interestingly, endothelial MVs were significantly increased only in alloHCT recipients of a myeloablative conditioning. Furthermore, MVs of different origins showed a positive association with each other. (4) Conclusions: endothelial dysfunction and increased thrombotic risk are evident in alloHCT recipients long after alloHCT, independently of traditional cardiovascular risk factors. An apparent synergism of these pathophysiological processes may be strongly involved in the subsequent establishment of cardiovascular disease.

Endothelial Microvesicles Circulating in Peripheral and Coronary Circulation Are Associated With Central Blood Pressure in Coronary Artery Disease.

BACKGROUND: Endothelial microvesicles (EMVs) have emerged as markers of endothelial injury. However, little is known about their levels in the coronary circulation of acute coronary syndrome (ACS) and stable coronary artery disease (CAD). We hypothesized that ACS patients exhibit a more pronounced increase of EMVs both in the peripheral and coronary circulation when compared with CAD. We also investigated possible associations of EMVs with markers preclinical target organ damage. METHODS: We enrolled consecutive eligible patients undergoing coronary angiography. Blood samples were collected from the stem of the left coronary artery and the femoral artery. ΕMVs were measured by a standardized flow cytometry protocol. Central systolic blood pressure (cSBP) was measured invasively and patients' history was recorded. RESULTS: CAD patients exhibited increased levels of EMVs compared with controls. When patients with ACS and stable CAD were compared, the former had significantly increased EMVs in both coronary and peripheral circulation. Importantly, both ACS and CAD patients exhibited increased levels of EMVs in the coronary circulation compared with periphery. In addition, EMVs were associated with cSBP. CONCLUSIONS: EMVs emerge as novel markers of ongoing underlying vascular damage, further augmenting the vicious cycle of inflammation and thrombosis mainly in ACS but also in stable CAD.

Increased erythrocyte- and platelet-derived microvesicles in newly diagnosed type 2 diabetes mellitus.

AIM: To investigate the thrombotic microenvironment in early stages of type 2 diabetes mellitus measuring platelet-derived, endothelial-derived and erythrocyte-derived microvesicles. METHODS: We recruited 50 newly diagnosed type 2 diabetes mellitus patients who did not receive glucose-lowering treatment except for metformin and 25 matched non-type 2 diabetes mellitus volunteers. Microvesicles were measured with flow cytometry, glycated haemoglobin with high-performance liquid chromatography and advanced glycation end products with enzyme-linked immunosorbent assay. RESULTS: Type 2 diabetes mellitus patients showed significantly higher levels of platelet-derived microvesicles [195/µL (115-409) vs 110/µL (73-150), p = 0.001] and erythrocyte-derived microvesicles [26/µL (9-100) vs 9/µL (4-25), p = 0.007] compared to non-type 2 diabetes mellitus individuals. Platelet-derived microvesicles were positively associated with fasting blood glucose (p = 0.026) and glycated haemoglobin (p = 0.002). Erythrocyte-derived microvesicles were also positively associated with fasting blood glucose (p = 0.018) but not with glycated haemoglobin (p = 0.193). No significant association was observed between platelet-derived microvesicles (p = 0.126) or erythrocyte-derived microvesicles (p = 0.857) and advanced glycation end products. Erythrocyte-derived microvesicles predicted the presence of type 2 diabetes mellitus, independently of platelet-derived microvesicles. CONCLUSION: In newly diagnosed type 2 diabetes mellitus, ongoing atherothrombosis is evident during the early stages as evidenced by increased microvesicles levels. Furthermore, the association with glycemic profile suggests that microvesicles represent not only a novel mechanism by which hyperglycemia amplifies thrombotic tendency in type 2 diabetes mellitus but also early markers of thrombosis highlighting the need for earlier management of hyperglycemia.

Evaluation of regulatory T cells (Tregs) alterations in patients with multiple myeloma treated with bortezomib or lenalidomide plus dexamethasone: correlations with treatment outcome.

The exact role of regulatory T cells (Tregs) in multiple myeloma (MM) has not been yet determined. Data regarding alterations of Tregs during therapy with novel agents (NA), i.e., bortezomib and lenalidomide are conflicted and limited. We evaluated prospectively alterations of Tregs and searched for correlations with disease characteristics, response, and outcome in 29 patients with active MM treated with either bortezomib-dexamethasone (BD; 11 patients) or lenalidomide-dexamethasone (LenDex, 18 patients). Additionally, we recorded changes of lymphocytes subsets and cytokines related to Tregs function and MM biology, i.e., interleukin (IL) 6, 2, 17, and TGF-ß. Compared with controls, patients had significantly higher median levels of Tregs%, IL-6, and IL-17 (p < 0.001). Median CD4 T and B cells frequencies were significantly lower, whereas CD8 T and natural killers were increased compared to controls. In BD group, no significant alterations of Tregs% were observed. Patients treated with LenDex, displayed a significant reduction of Tregs% (p < 0.001) especially those who achieved at least very good partial response (≥vgPR) (p = 0.04). Lymphocyte subsets or cytokines did not significantly change during therapy. In summary, Tregs% are higher in patients with active MM compared with controls, and they significantly decrease after treatment with LenDex but not with BD; After therapy with LenDex, Tregs reduction between baseline and major response correlated with achievement of ≥vgPR suggesting a possible predictive role, that may contribute to therapeutic strategy.

Concurrent presentation of nodal myeloid sarcoma and bone marrow chronic lymphocytic leukemia/small lymphocytic lymphoma: a unique association.

Myeloid sarcoma (MS), previously known as granulocytic sarcoma, is a rare, localized, tumor mass composed of myeloid precursor cells, with or without maturation, and occurring at an anatomical site other than the bone marrow (BM). Chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL), in contrast, is a B-cell hematological malignancy. We describe the first reported case of concurrent presentation of nodal MS and of BM CLL/SLL in the same patient. Fatal leukemic central nervous system infiltration was the final outcome. We provide possible explanations and investigate the pathophysiology of this unique, previously unreported co-morbidity.

Platelet activation in essential hypertension during exercise: pre- and post-treatment changes with an angiotensin II receptor blocker.

BACKGROUND: Acute exercise may exert deleterious effects on the cardiovascular system through a variety of pathophysiological mechanisms, including increased platelet activation. However, the degree of exercise-induced platelet activation in untreated hypertensive (UH) individuals as compared with normotensive (NT) individuals has yet to be established. Furthermore, the effect of antihypertensive treatment on exercise-induced platelet activation in essential hypertension (EH) remains unknown. METHODS: Study 1 consisted of 30 UH and 15 NT subjects. UH subjects who received treatment were included in study 2 and were followed-up after a 3-month treatment period with an angiotensin II receptor blocker (ARB; valsartan). Circulating monocyte-platelet aggregates (MPA) and platelet P-selectin were measured as platelet activation markers at baseline, immediately after a treadmill exercise test, and 10, 30, and 90 minutes later. RESULTS: Maximal platelet activation was observed at 10 minutes after peak exercise in both groups. In UH subjects, MPA levels remained increased at 30 minutes after peak exercise, despite BP fall to baseline levels. MPA levels were significantly higher in UH subjects than NT subjects at maximal exercise and at 10 and 30 minutes of recovery. Post-treatment MPA levels increased significantly only at 10 minutes into recovery and were similar to those of NT subjects. CONCLUSIONS: Acute high-intensity exercise exaggerates platelet activation in untreated patients with EH compared with NT individuals. Angiotensin II receptor blockade with adequate BP control greatly improves exercise-induced platelet activation in EH. Further studies are needed to clarify whether this phenomenon depends purely on BP lowering or benefits also from the pleiotropic effects of ARBs.

Inhibition of indoleamine 2,3-dioxygenase in mixed lymphocyte reaction affects glucose influx and enzymes involved in aerobic glycolysis and glutaminolysis in alloreactive T-cells.

Indoleamine 2,3-dioxygenase (IDO) suppresses adaptive immunity. T-cell proliferation and differentiation to effector cells require increased glucose consumption, aerobic glycolysis and glutaminolysis. The effect of IDO on the above metabolic pathways was evaluated in alloreactive T-cells. Mixed lymphocyte reaction (MLR) in the presence or not of the IDO inhibitor, 1-methyl-dl-tryptophan (1-MT), was used. In MLRs, 1-MT decreased tryptophan consumption, increased cell proliferation, glucose influx and lactate production, whereas it decreased tricarboxylic acid cycle activity. In T-cells, from the two pathways that could sense tryptophan depletion, i.e. general control nonrepressed 2 (GCN2) kinase and mammalian target of rapamycin complex 1, 1-MT reduced only the activity of the GCN2 kinase. Additionally 1-MT treatment of MLRs altered the expression and/or the phosphorylation state of glucose transporter-1 and of key enzymes involved in glucose metabolism and glutaminolysis in alloreactive T-cells in a way that favors glucose influx, aerobic glycolysis and glutaminolysis. Thus in alloreactive T-cells, IDO through activation of the GCN2 kinase, decreases glucose influx and alters key enzymes involved in metabolism, decreasing aerobic glycolysis and glutaminolysis. Acting in such a way, IDO could be considered as a constraining factor for alloreactive T-cell proliferation and differentiation to effector T-cell subtypes.

Crocetin administration ameliorates endotoxin-induced disseminated intravascular coagulation in rabbits.

Disseminated intravascular coagulation (DIC), a life-threatening secondary complication in several diseases, is characterized by large amounts of thrombin that lead to fibrin deposition and microthrombus formation throughout the microcirculation. Recent in-vitro studies suggest that crocin, crocetin or safranal, carotenoid constituents of the spice Crocus sativus L. (saffron), have antithrombotic properties, especially anti-Xa activity. The present study was designed to evaluate the effect of crocetin on thrombosis procedure using a rabbit model of bacterial endotoxin-induced DIC. Crocetin administration (3 mg/kg), 30 min before the beginning of endotoxin infusion, improved DIC-related haemostatic indices such as platelet blood counts (P≤ 0.05), blood plasma fibrinogen and protein C concentration (P≤ 0.05). In addition, it ameliorated DIC-associated disease and fibrin deposition in the glomeruli (P≤ 0.05). These results indicate that crocetin reveals a preventive antithrombotic role in vivo and prescribe further investigation on the possibility of developing crocetin-based DIC treatment modalities.

Decreased CD3+CD16+ natural killer-like T-cell percentage and zeta-chain expression accompany chronic inflammation in haemodialysis patients.

AIM: Clinical and experimental data indicate a deficient immune response in haemodialysis (HD) patients. Natural killer-like (NKL) T cells express on their surface both the T-cell antigen receptor (TCR) and a diverse set of NK-cell receptors (NKR) and share properties of both T cells and NK cells. zeta-Chain phosphorylation is an early event that follows TCR activation or some NKR activation. The zeta-chain of both T cell and NK cells is downregulated in many chronic inflammatory states, HD included. In the present study, NKL T-cell percentage and zeta-chain expression in HD patients were evaluated. METHODS: Thirty-three stable HD patients and 30 healthy volunteers were enrolled into the study. NKL T-cell percentage and NKL T-cell zeta-chain mean fluorescence intensity (MFI) were evaluated with flow cytometry. The inflammatory markers C-reactive protein, interleukin-6 and tumour necrosis factor-alpha were measured in the serum by means of enzyme-linked immunosorbent assay. RESULTS: All the evaluated markers of inflammation were increased in HD patients. In these patients, NKL T-cell percentage (1.71 +/- 1.69% vs 3.94 +/- 3.86%) and zeta-chain MFI (3.66 +/- 2.79 vs 7.03 +/- 7.91) were decreased. CONCLUSIONS: NKL T-cell percentage and zeta-chain expression is decreased in HD patients. Taking into consideration the continuously increasing age of the HD patients and that normally NKL T-cell numbers increase with age counteracting the impaired T-cell and NK-cell function accompanying advancing age, the above NKL T-cell disturbances could contribute to the impaired immune response in this population. Measures towards alleviating chronic inflammation could partially restore NKL T-cell impairment.

Chronic inflammation and CD16+ natural killer cell zeta-chain downregulation in hemodialysis patients.

BACKGROUND: Natural killer (NK) cell activity is decreased in hemodialysis (HD) patients. Zeta-chain phosphorylation is an early event that follows the triggering of some NK cell-activating receptors. NK cell zeta-chain is downregulated in patients with cancer due to chronic inflammation. HD is also a chronic inflammatory state. NK cell zeta-chain expression in HD was evaluated. PATIENTS AND METHODS: Thirty-three HD patients and 30 healthy volunteers were enrolled into the study. The CD3-CD16+ subpopulation was examined, since it corresponds to 90% of all NK cells and has the highest cytotoxicity.NK cell count and zeta-chain mean fluorescence intensity were evaluated with flow cytometry. The inflammatory markers C-reactive protein, IL-6 and tumor necrosis factor-alpha were measured with ELISA. RESULTS: The inflammatory markers were increased in HD patients. NK cell count did not differ between HD patients and healthy volunteers. NK cell zeta-chain mean fluorescence intensity was decreased in the patient group. CONCLUSIONS: Chronic inflammation could be responsible for the NK cell zeta- chain downregulation in HD patients, contributing to the decreased NK cell activity.

Chronic inflammation and T cell zeta-chain downregulation in hemodialysis patients.

BACKGROUND: Clinical and experimental data indicate a deficient immune response in hemodialysis (HD) patients. zeta-Chain phosphorylation is an early and central event in the process that follows antigen recognition by the T cell antigen receptor (TCR). T cell zeta-chain is downregulated in many chronic inflammatory states, such as cancer, autoimmune disease and chronic infection. HD is also characterized as a chronic inflammatory state. The aim of the present study was to evaluate T cell zeta-chain expression in HD patients. PATIENTS AND METHODS: Thirty-three stable HD patients and 30 healthy volunteers were enrolled into the study. T cell count, the percentage of zeta-chain-positive T cells, as well as T cell zeta-chain mean fluorescence intensity (MFI) were evaluated with flow cytometry. The inflammatory markers C-reactive protein, interleukin-6 and tumor necrosis factor-alpha were measured in the serum by means of ELISA. RESULTS: All the evaluated markers of inflammation were increased in HD patients. In these patients, T cell zeta-chain MFI was decreased. CD3-epsilon MFI did not differ between the two groups indicating that among the TCR complex constituents, zeta-chain is selectively downregulated. CONCLUSIONS: HD is a state of chronic inflammation. Like in other pathological chronic inflammatory conditions, T cell zeta-chain is downregulated in HD patients. Since zeta-chain plays a key role in the transduction of the signal that follows antigen recognition by the TCR, its downregulation could be responsible for the deficient cellular immune response observed in HD patients.

Patterns of cell death and cell cycle profiles of cultured WEHI 13 var fibroblasts exposed to eluates of composite resins used for direct and indirect restorations.

Previous studies have shown that in vitro exposure to single compounds released from composite resins may induce cell death. In the present study the effects of eluates from commercially available composite resins used for direct or indirect restorations were evaluated on the cell cycle progression and type of cell death of cultured WEHI 13 var fibroblasts. Cells exposed to eluates of the materials were assessed for cytotoxicity by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay for cell death, for cell cycle profiles by flow cytometry, for caspase-3 biochemically and by immunocytochemistry, and for morphological changes by fluorescence microscopy with acridine orange. The direct composite resin eluates induced extensive apoptosis, followed by secondary necrosis. This was accompanied by cell enlargement, micromultinucleation, chromatin disintegration, cell cycle arrest at different phases, and caspase-3 activation. The composites for indirect restorations were much less cytotoxic at all biological end-points investigated. The findings suggest that composite resins used for direct and indirect dental restorations differ in their cytotoxic potential and their ability to affect basic cellular functions. This underlines the impact of improved polymerization with respect to their biologic behavior.

Does hepcidin affect erythropoiesis in hemodialysis patients?

INTRODUCTION: Prohepcidin is the precursor of hepcidin, a liver-derived peptide involved in iron metabolism by blocking its intestinal absorption and its release by the reticuloendothelial system. Iron overload and inflammation increase hepcidin expression, whereas anemia and hypoxia suppress it. In the present study prohepcidin levels were determined in the serum of hemodialysis (HD) patients and its correlations with iron metabolism markers, C-reactive protein (CRP) and hematocrit (Hct) were assessed. PATIENTS AND METHODS: Forty-sixHD patients and 22 healthy volunteers were enrolled in the study. Hct, serum prohepcidin, CRP, iron, ferritin, transferrin saturation and transferrin receptors were measured. The weekly erythropoietin dose, last-month intravenous iron dose and the patients' demographics were recorded. RESULTS: In comparison to the healthy volunteers, the HD patients had higher serum ferritin, transferrin receptors and CRP, lower serum iron and similar transferrin saturation and prohepcidin levels. In the patient group prohepcidin levels were negatively correlated with Hct but not with any other of the examined parameters. Multiple linear regression analysis considering age, inflammation, iron adequacy, erythropoietin dose and prohepcidin levels revealed that prohepcidin was the predominant determinant of Hct. CONCLUSIONS: Taking into account the low Hct levels in the HD patients of our study, it seems plausible that the prohepcidin levels assessed in this group are inappropriately high. These functionally high prohepcidin levels may be associated with the factors that inhibit erythropoiesis in HD patients. On the other hand, the absence of other expected correlations indicates that further studies are needed in order to definitely clarify this aspect.