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Background SARS-CoV2 infection has been associated to a wide range of clinical scenarios, named COVID-19, ranging from acute respiratory distress syndrome to blood coagulation abnormalities and vascular manifestations related to hyper-inflammation. Recent focus has been addressed to study of microvascular alterations which may explain COVID-19 pathophysiology. Alterations in microvascular structure, identified as increased wall to lumen ratio (WLR) of retinal arterioles, have been extensively described in patients with cardiovascular diseases, such as hypertension or diabetes mellitus. Both inflammation and immune system dysregulation seem to play a role in the pathogenesis of these morphological changes. Purpose Aim of this study was to evaluate through Adaptive Optics microvascular differences of retinal arterioles between patients experienced COVID-19 and controls. Methods Patients were hospitalized between 28th February and 15th April at a Internal Medicine ward in a tertiary care hospital. All patients tested positive for a SARS-CoV-2 nasopharyngeal swab at admission and showed signs of pneumonia and respiratory insufficiency. Adaptive Optics, which allows a non-invasive evaluation of retinal arteriole structure, and blood chemistry exams were performed as part of follow up visits between 2 to 3 months after hospitalization. Baseline characteristics were collected through medical records. COVID-19 patients were compared to age- and sex-matched healthy subjects referred to our center between 2018 and 2019. Results A total of 80 patients were included in this study (of which 40 were COVID-19 patients). Apart from smoking habit, other baseline characteristics (sex, age, cardiovascular risk factors and main comorbidities) did not differ between the two groups. At follow up visit COVID-19 patients showed lower values for leukocytes (6.2 vs. 7.5x103/μL, p=0.015) and lymphocytes (1.9 vs. 2.8x103/μL, p=0.002). Creatinine values were higher in patients who suffered from COVID-19 (1.0 vs 0.8 mg/dl, p=0.004 – Figure 1, panel A). Adaptive Optics showed no differences in terms of internal lumen, wall thickness and WLR of retinal arterioles. However, the wall cross-sectional area (WCSA) was found to be higher in COVID-19 patients (p=0.039 – Figure 1, panel B). Hypertension significantly affected both WCSA and WLR between COVID-19 and healthy individuals, while diabetes only impacted on WLR (Figure 2). Conclusion Previous studies described the presence of leukopenia and lymphopenia during the acute phase of SARS-CoV2 infection. Our study demonstrates that these alterations persist several weeks after symptoms onset. Adaptive Optics showed microvascular alterations occurring in these patients: in particular, higher wall cross-sectional area of retinal arterioles were observed in patients after COVID-19 hospitalization, reflecting the complex pathogenic mechanisms which may explain the wide range of symptoms and clinical severity. Funding Acknowledgement Type of funding sources: None. Figure 1Figure 2

Background:T-cells play a pivotal role in the pathogenesis of rheumatoid arthritis (RA) and in its cardiovascular (CV) comorbidities, acting at microvascular level [1]. Since small artery remodeling is the earliest form of target organ damage in hypertension, the evaluation of microvascular alterations might provide clinically useful information. The evaluation of retinal arterioles is a non-invasive technique to identify a precocious microvascular damage, which is related to an increase of the wall-to-lumen ratio (WLR) [2]. CD3+CD31+CXCR4+ T-cells may be involved in damaged endothelium repair and are increased in patients with morphological microvascular alterations [3]. In addition to its effect on disease activity, abatacept (ABA), a co-stimulator blocker which is approved for the treatment of RA, may have specific CV protective action, modulating the numbers of certain subtypes of lymphocytes [4].Objectives:To non-invasively investigate morphological characteristics of retinal arterioles and to evaluate CD3+CD31+CXCR4+T-cells in a cohort of RA patients treated with ABA.Methods:Eleven RA patients [median (25th-75thpercentile) age=58 (50-65) years, baseline C-reactive protein (CRP)-DAS28=4.4 (3.8-4.6), body mass index (BMI)=23.4 (21.6-25.6) kg/m2, rheumatoid factor (RF) positive:45%, anti-citrullinated peptide autoantibodies (ACPA) positive:73%] without known CV risk factors (arterial hypertension, diabetes, hypercholesterolemia, previous CV events, smoking) were evaluated by adaptive optics, a validated technique quantifying microvascular damage [5], before and every 6 months of therapy with ABA (T0, T6 and T12). Phenotypic analysis of peripheral blood T lymphocytes was made by flow-cytometry in 5 patients of the cohort at T0 and T6.Results:A progressive significant reduction of the WLR of retinal arterioles was observed [T0=0.28 (0.25-0.30), T6=0.27 (0.24-0.31), T12=0.23 (0.23-0.26); p T0 vs T6=0.4; p T6 vs T12=0.01; p T0 vs T12=0.01] (Figure 1), without significant variations in the other parameters [internal diameter: T0=94.4 (84.1-104.0), T6=94.8 (84.6-107.7), T12=99.2 (89.1-109.1) µm; external diameter: T0=125.8 (111.1-131.0), T6=122.4 (109.1-134.5), T12=125.6 (113.9-134.4) µm; wall thickness: T0=13.2 (12.2-14.4), T6=13.4 (11.7-14.4), T12=12.5 (11.6-13.0) µm; wall cross-sectional area: T0=4581.0 (3788.7-5263.7), T6=4563.3 (3788.5-5295.2), T12=4099.7 (3899.0-5145.7) µm2)]. In 5 patients evaluated also for T-cell immunophenotyping a negative correlation was observed between CD3+CD31+CXCR4+ T-cell number and the retinal wall thickness at baseline (R=0.871;p=0.05). After ABA therapy a trend for reduction of CD3+CD31+CXCR4+T-cells [19.0 (13.8-38.3) vs 12.4 (5.2-18.0) % of CD3+], was observed as well as of significant reduction of retinal wall cross-sectional area [5123.3 (4385.0-5470.3) vs 4852.3 (4118.3-5228.0) µm2;p=0.04].Conclusion:In a cohort of RA patients without known CV risk factors, a reduction in retinal microvascular alterations arterioles was demonstrated after treatment for 12 months with ABA. CD3+CD31+CXCR4+T-cell number was inversely related to the possible presence of subclinical CV involvement. These results may suggest the possibility of microvascular abnormalities regression induced by the immune system modulation.References:[1]Dessein PH, J Rheumatol 2005.[2]Rizzoni D, Am J Hypertens. 2018.[3]Hur J, Circulation 2007.[4]Kallikourdis M, Nat Commun 2017.[5]De Ciuceis C, J Hypertens 2018.Acknowledgements:Bristol-Myers-Squibb Italy provided an unrestricted research grant for the study conduct.Figure 1.Disclosure of Interests:None declared

Objective: Acute SarsCoV2 infection is associated with endothelial dysfunction and endothelitis which might explain systemic microvascular impairment. The presence of endothelial damage can promote vasoconstriction with consequent organ ischemia, inflammation, tissue edema and a procoagulant state resulting in an increase in the incidence of cardio-and cerebrovascular events. Microvascular thrombosis has been demonstrated in post-mortem autopsy of COVID19 patients;however no data are available about skin capillary alterations in these patients. Design and method: We evaluated skin microvascular alterations in 14 patients admitted to our hospital with SarsCov2 infection. Basal capillary density was performed by capillaroscopy bedside in the nailfold and in the dorsum of the 4th finger. Results: Fourteen patients (9 males, 5 females) were evaluated: average age was 66±1 years, BMI 26±3. Nine patients were hypertensive (64%), 4 diabetic (29%), 3 were dyslipidemic (21%), 3 with cerebrovascular or cardiovascular disease history (21%). Seven patients were treated with ev steroid (50%), 3 with tocilizumab (21%) and 7 were treated with non-invasive ventilation (50%). During the hospitalisation all patients presented interstitial pneumonia SarsCov2 associated whereas vascular complication (ischaemic stroke or pulmonary embolism) were observed in 3 patients (21%) with SarsCov2 infection. Nine patients showed skin capillary alterations (5 thrombosis, 5 haemorrhage/ microbleeding, 4 neoangiogenesis). Interestingly, capillary alterations were present only in patients treated with non-invasive ventilation and/or with cardio-or cerebrovascular complications. These alterations were not detected after 2 month from the discharge. Conclusions: This is the first in vivo evidence of skin capillary thrombosis, microhaemorragia and angiogenesis in patients with acute SARS-CoV2 infection which support the presence of endothelial dysfunction and inflammation. Capillary alterations might reflect systemic vascular effects of viral infection.

Objective:Non-alcoholic fatty liver disease (NAFLD) may be detected in nearly 40% of subjects with a body mass index > 25, with a dramatic increase over time. Aim of the present observational study was to evaluate the prevalence of cardiovascular risk factors in a selected population of patients wit

Objective:Immune system (in particular T lymphocytes) is involved in the pathogenesis of arterial hypertension and microvascular remodelling. It has also been recently suggested a crucial role for spleen in the development and onset of hypertension, through a neuroimmune mechanism mediated by a sple

Background and Purpose: Protective cardiovascular effects of peroxisome proliferator activated receptor (PPAR)α and PPARγ activators have been demonstrated. If used as vasoprotective agents in high risk vascular patients rather than for their metabolic benefits, these agents could be associated with unwanted side effects. As a proof of concept to support the use of combined low doses of PPARα and PPARγ as vascular protective agents in high risk vascular patients, we tested the hypothesis that combined low doses of PPARα (fenofibrate) and PPARγ (rosiglitazone) activators would provide vascular protective benefits similar to full individual doses of these PPAR agonists. Experimental Approach: Male Sprague-Dawley rats infused with Ang II (120 ng kg−1 min−1) were treated with rosiglitazone (1 or 2 mg kg−1 day−1) alone or concomitantly with fenofibrate (30 mg kg−1 day−1) for 7 days. Thereafter, vessels was assessed on a pressurized myograph, while NAD(P)H oxidase activity was determined by lucigenin chemiluminescence. Inflammation was evaluated using ELISA for NFκB and Western blotting for adhesion molecules. Key Results: Ang II-induced blood pressure increase, impaired acetylcholine-induced vasorelaxation, altered vascular structure, and enhanced vascular NAD(P)H oxidase activity and inflammation were significantly reduced by low dose rosiglitazone+fenofibrate. Conclusions and Implications: Combined low doses of PPARα and PPARγ activators attenuated development of hypertension, corrected vascular structural abnormalities, improved endothelial function, oxidative stress, and vascular inflammation. These agents used in low-dose combination have synergistic vascular protective effects. The clinical effects of combined low-dose PPARα and PPARγ activators as vascular protective therapy, potentially with reduced side-effects and drug interactions, should be assessed. British Journal of Pharmacology (2007) 151, 45–53. doi:10.1038/sj.bjp.0707215

Hypertension and non insulin-dependent diabetes mellitus (NIDDM) are well-known risk factors for atherosclerotic disease. Intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) may exert a relevant role in the pathogenesis of atherosclerosis; their prognostic relevance has been recently demonstrated. The aim of the study was to investigate possible inter-relation between circulating adhesion molecule levels, carotid artery structure and endothelial function in 15 patients with NIDDM, as well as in 15 patients with both NIDDM and essential hypertension (NIDDM+EH) compared with 15 normal subjects (NS) and 15 euglycaemic patients with EH, matched for age, sex and body weight. All subjects were submitted to a biopsy of the gluteal subcutaneous fat. Small arteries were dissected and mounted on a micromyograph, and the media-to-lumen (M/L) ratio was then calculated. Carotid artery structure was investigated by Doppler ultrasound. Endothelial function was evaluated by investigation of the flow-mediated dilatation (FMD) of the brachial artery. ICAM-1 and VCAM-1 plasma levels were measured by ELISA. ICAM-1 and VCAM-1 plasma levels were significantly greater and FMD smaller in EH, NIDDM and NIDDM+EH than in NS, but no difference was observed among the three pathological groups. Carotid artery structural changes were more pronounced in NIDDM+EH. No significant difference was observed among NIDDM, EH and NS. The M/L ratio of subcutaneous small resistance arteries was significantly greater in NIDDM+EH than in NIDDM or EH. NS had a smaller M/L ratio than the other groups. Significant correlations were observed between ICAM-1 plasma levels and indices of carotid artery structure in diabetic patients. However, the relations were close only in NIDDM+EH. In conclusion, our data suggest that NIDDM+EH may present more pronounced vascular structural alterations than NIDDM, and that adhesion molecules plasma levels are closely inter-related with carotid artery structural alterations, at least in NIDDM+EH, but not with M/L ratio of small resistance arteries.

Objective: It has been previously demonstrated that T lymphocytes may be involved in the development of hypertension and microvascular remodeling, and that circulating T effector lymphocytes may be increased in hypertension. In particular, Th1 and Th17 lymphocytes may contribute to the progression of hypertension and microvascular damage while TREG lymphocytes seem to be protective. However, no data is available about patients with severe obesity, in which pronounced microvascular alterations were observed. Methods: We have investigated 32 severely obese patients undergoing bariatric surgery, 24 normotensive lean subjects and 11 hypertensive lean subjects undergoing an election surgical intervention. No sign of local or systemic inflammation was present in any subject or patient. A peripheral blood sample was obtained before surgery for assessment of CD4+ T lymphocyte subpopulations. Lymphocyte phenotype was evaluated by flow cytometry after 5 hour in vitro activation in order to assess T-effector and T-regulatory (TREG) lymphocytes. Subsets of TREGS were defined as follows: −TREGS recent thymic emigrants (RTE), directly derived from thymus: CD31+; −TREGS naïve: CCR7+CD45RA+; −TREGS central memory (CM): CCR7+CD45RA−; −TREGS effector memory (EM): CCR7−CD45RA−; −TREGS terminal differentiated effector memory (TDEM): CCR7−CD45RA+. Results: The results are summarized in the Table (*p < 0.05, **p < 0.01, ***p < 0.001 vs. lean normotensives; #p < 0.05, ##p < 0.01, ###p < 0.001 vs. lean hypertensives). A marked reduction of several TREG subpopulations was observed in obese patients compared with controls, together with an increased in some T-effector cells. Lean normotensives Lean hypertensives Obese patients TREGs (%) 4.11 ± 1.60 4.64 ± 1.66 2.69 ± 1.81**## TREGs (abs number) 45.4 ± 24.3 45.4 ± 23.8 27.3 ± 21.1**# TREGs naíve (%) 22.1 ± 10.1 18.1 ± 13.1 13.34 ± 12.9** TREGs naíve (abs number) 10.6 ± 7.75 9.71 ± 8.87 3.87 ± 5.28***## TREG CM (%) 32.3 ± 13.8 32.8 ± 17.8 22.7 ± 15.2*# TREGs CM (abs number) 14.7 ± 10.2 14.2 ± 9.08 6.10 ± 8.08***## CD4+ EM (%) 24.4 ± 9.96 26.8 ± 12.5 34.1 ± 13.3** CD161+CD28+ (%) 86.2 ± 28.5 94.9 ± 5.63 97.2 ± 5.39* Conclusion: TREG lymphocytes are clearly reduced in severely obese patients, possibly contributing to the development of marked microvascular alterations previously observed in such a population.

Objective: A relevant biological role of circulating endothelial progenitor cells (EPC) was recently demonstrated. EPC are generated in the bone marrow, and interact with damaged endothelium, restoring the integrity of the monolayer. Therefore, aim of the present study was to evaluate EPC in the blood of patients with untreated Graves’ hyperthyroidism (GD), in whom an increased oxidative stress was observed. Design and methods: Twenty-three patients with untreated active GD and 18 matched normal controls (NC) were included in the study. Circulating EPC were isolated from peripheral blood. Mononuclear cells were cultured with endothelial basal medium supplemented with EGM SingleQuots, and were identified by positive double staining after 7 days in culture. Circulating levels of C reactive protein, total antioxidant power, interleukin (IL)-6, IL-18, monocyte chemoattractant protein-1, tumor necrosis facotr-α, soluble vascular cell adhesion molecule (VCAM) and intracellular adhesion molecule were evaluated by enzyme-linked immunosorbent assay kit. EPC number was also evaluated in a subgroup of GD patients after restoration of euthyroidism. Results: Systolic blood pressure resulted increased in GD patients compared with control subjects whereas diastolic blood pressure was not significantly different. Patients with GD showed an increase in circulating levels of IL-18 and VCAM-1 and a reduction of total antioxidant power (p