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.

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.

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.

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.

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.

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.

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.

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.