[Human immunodeficiency virus and venous thromboembolism: Role of direct oral anticoagulants]. / Modalités du traitement de la maladie veineuse thromboembolique du patient VIH par les anticoagulants oraux directs.

Nowadays, thanks to highly active antiretroviral therapy (HAART), human immunodeficiency virus (HIV) infection is transforming into a chronic disease. The life expectancy of people living with HIV (PWH) has increased, as well as their risk of developing several co-morbidities, in particular cardiovascular diseases. In addition, the incidence of venous thromboembolism (VTE) is increased in PWH with a 2 to 10 times higher incidence when compared to the general population. Over the last decade, direct oral anticoagulants (DOACs) have been widely used in the treatment and prevention of VTE and non-valvular atrial fibrillation. DOACs are characterized by a rapid onset of activity, a predictable response and a relatively wide therapeutic window. Nevertheless, drug interactions exist between HAART and DOACs, exposing PWH to a theoretically increased bleeding or thrombotic risk. DOACs are substrates of the transport protein P-glycoprotein and/or of isoforms of cytochromes P450 pathway, which can be affected by some antiretroviral drugs. Limited guidelines are available to assist physicians with the complexity of those drug-drug interactions. The aim of this paper is to provide an updated review on the evidence of the high risk of VTE in PWH and the place of DOAC therapy in this population.

Relationship between kalemia and intensive care unit admission or death in hospitalized COVID-19 patients: A cohort study.

BACKGROUND: SARS-CoV-2 uses Angiotensin-Converting Enzyme 2 as a viral gateway to the cell and could interact with the renin-angiotensin-aldosterone system. Other studies have shown kalemia abnormalities in patients with severe forms of coronavirus disease 2019. Our goal was to assess the prognosis value of kalemia within ten days of symptom offset in the COVID-19 hospitalized population. METHODS: We analyzed data from a prospective cohort that included 65 patients with COVID-19, admitted between March 15, 2020, and March 21, 2020. The study aimed at determining the relationship between baseline kalemia and the admission to an intensive care unit (ICU) or death. RESULTS: The median age of the patients was 65 [54-79] years old, and 66.2% of the patients were men. Baseline kalemia under 3.8mmol/l occurred in 31 patients (48%), including 11 patients (35.5%) who were admitted to an ICU and one patient (3.2%) who died before ICU admission. In the primary end-point analysis, the adjusted hazard ratios for admission to an ICU or death were 3.52 [95% confidence interval (CI), 1.12 to 11.04] among patients with low baseline kalemia. CONCLUSION: Our study suggests that low kalemia levels within ten days of the first symptom onset might be associated with an increased risk of intensive care unit admission or death. The future perspective should be to better understand this relationship.

Type I interferon response and vascular alteration in chilblain-like lesions during the COVID-19 outbreak.

BACKGROUND: The outbreak of chilblain-like lesions (CLL) during the COVID-19 pandemic has been reported extensively, potentially related to SARS-CoV-2 infection, yet its underlying pathophysiology is unclear. OBJECTIVES: To study skin and blood endothelial and immune system activation in CLL in comparison with healthy controls and seasonal chilblains (SC), defined as cold-induced sporadic chilblains occurring during 2015 and 2019 with exclusion of chilblain lupus. METHODS: This observational study was conducted during 9-16 April 2020 at Saint-Louis Hospital, Paris, France. All patients referred with CLL seen during this period of the COVID-19 pandemic were included in this study. We excluded patients with a history of chilblains or chilblain lupus. Fifty patients were included. RESULTS: Histological patterns were similar and transcriptomic signatures overlapped in both the CLL and SC groups, with type I interferon polarization and a cytotoxic-natural killer gene signature. CLL were characterized by higher IgA tissue deposition and more significant transcriptomic activation of complement and angiogenesis factors compared with SC. We observed in CLL a systemic immune response associated with IgA antineutrophil cytoplasmic antibodies in 73% of patients, and elevated type I interferon blood signature in comparison with healthy controls. Finally, using blood biomarkers related to endothelial dysfunction and activation, and to angiogenesis or endothelial progenitor cell mobilization, we confirmed endothelial dysfunction in CLL. CONCLUSIONS: Our findings support an activation loop in the skin in CLL associated with endothelial alteration and immune infiltration of cytotoxic and type I IFN-polarized cells leading to clinical manifestations.

[Use of antiplatelet therapy and direct oral anticoagulants in candidates for renal transplantation: The French guidelines from the CTAFU]. / Recommandations françaises du Comité de transplantation de l'association française d'urologie (CTAFU) : agents antiplaquettaires et anticoagulants oraux directs en transplantation rénale.

OBJECTIVE: To define guidelines for the use of antiplatelet therapy (AT) and direct oral anticoagulants (DOAC) in candidates for kidney allotransplantation. METHOD: A review of the medical literature following a systematic approach was conducted by the CTAFU to report the use of AT and DOAC before major surgery and in the setting of advanced chronic kidney disease, defining their managment prior to kidney transplantation with the corresponding level of evidence. RESULTS: DOAC are not recommended in patients under dialysis. Aspirin therapy, but not anti-P2Y12 and DOAC, may be maintained during renal transplantation. Anti-P2Y12 and DOAC should not be use in patients awaiting a kidney transplant, except when a living donor is scheduled, therefore authorizing treatment interruption in optimal conditions. Further data regarding DOAC reversion and monitoring may improve their use in this setting. Global level of evidence is weak. CONCLUSION: These French recommendations should contribute to improve surgical management of kidney transplant candidates exposed to AT or DOA.

Respiratory mechanics and gas exchanges in the early course of COVID-19 ARDS: a hypothesis-generating study.

RATIONALE: COVID-19 ARDS could differ from typical forms of the syndrome. OBJECTIVE: Pulmonary microvascular injury and thrombosis are increasingly reported as constitutive features of COVID-19 respiratory failure. Our aim was to study pulmonary mechanics and gas exchanges in COVID-2019 ARDS patients studied early after initiating protective invasive mechanical ventilation, seeking after corresponding pathophysiological and biological characteristics. METHODS: Between March 22 and March 30, 2020 respiratory mechanics, gas exchanges, circulating endothelial cells (CEC) as markers of endothelial damage, and D-dimers were studied in 22 moderate-to-severe COVID-19 ARDS patients, 1 [1-4] day after intubation (median [IQR]). MEASUREMENTS AND MAIN RESULTS: Thirteen moderate and 9 severe COVID-19 ARDS patients were studied after initiation of high PEEP protective mechanical ventilation. We observed moderately decreased respiratory system compliance: 39.5 [33.1-44.7] mL/cmH2O and end-expiratory lung volume: 2100 [1721-2434] mL. Gas exchanges were characterized by hypercapnia 55 [44-62] mmHg, high physiological dead-space (VD/VT): 75 [69-85.5] % and ventilatory ratio (VR): 2.9 [2.2-3.4]. VD/VT and VR were significantly correlated: r2 = 0.24, p = 0.014. No pulmonary embolism was suspected at the time of measurements. CECs and D-dimers were elevated as compared to normal values: 24 [12-46] cells per mL and 1483 [999-2217] ng/mL, respectively. CONCLUSIONS: We observed early in the course of COVID-19 ARDS high VD/VT in association with biological markers of endothelial damage and thrombosis. High VD/VT can be explained by high PEEP settings and added instrumental dead space, with a possible associated role of COVID-19-triggered pulmonary microvascular endothelial damage and microthrombotic process.

Recipients with blood group A associated with longer survival rates in cardiac valvular bioprostheses.

BACKGROUND: Pigs/bovines share with humans some of the antigens present on cardiac valves. Two such antigens are: the major xenogenic Ag, "Gal" present in all pig/bovine very close to human B-antigen of ABO-blood-group system; the minor Ag, pig histo-blood-group AH-antigen identical to human AH-antigen and present by some animals. We hypothesize that these antigens may modify the immunogenicity of the bioprosthesis and also its longevity. ABO distribution may vary between patients with low (<6 years) and high (≥15 years) bioprostheses longevity. METHODS: Single-centre registry study (Paris, France) including all degenerative porcine bioprostheses (mostly Carpentier-Edwards 2nd/3rd generation heart valves) explanted between 1985 and 1998 and some bovine bioprostheses. For period 1998-2014, all porcine bioprostheses with longevity ≥13 years (follow-up ≥29 years). Important predictive factors for bioprosthesis longevity: number, site of implantation, age were collected. Blood group and other variables were entered into an ordinal logistic regression analysis model predicting valve longevity, categorized as low (<6 years), medium (6-14.9 years), and high (≥15 years). FINDINGS: Longevity and ABO-blood group were obtained for 483 explanted porcine bioprostheses. Mean longevity was 10.2 ±â€¯3.9 years [0-28] and significantly higher for A-patients than others (P = 0.009). Using multivariate analysis, group A was a strong predictive factor of longevity (OR 2.09; P < 0.001). For the 64 explanted bovine bioprosthesis with low/medium longevity, the association, with A-group was even more significant. INTERPRETATION: Patients of A-group but not B have a higher longevity of their bioprostheses. Future graft-host phenotyping and matching may give rise to a new generation of long-lasting bioprosthesis for implantation in humans, especially for the younger population. FUND: None.

[Venous thromboembolism and urological cancer: Epidemiology and therapeutically management]. / Maladie thromboembolique veineuse et cancers urologiques : épidémiologie et prise en charge thérapeutique.

INTRODUCTION: Active cancer is a risk factor in the occurrence of venous thromboembolism (VTE). This is the second cause of death for these patients. In onco-urology, some cancers are associated with an increased risk of VTE. The aim of this study was to propose a focus of epidemiology and VTE therapy management. MATERIAL AND METHODS: A systematic analysis of the PubMed® database was performed through the PRISMA methodology using the followings keywords : "neoplasm", "venous thromboembolism", "prophylaxis", "pulmonary embolism", "urology". The original papers were included with a priority on: meta-analyzes, literature reviews, randomized controlled trials and good-level proof cohort studies. Only publications in English or French have been selected. RESULTS: The incidence of VTE was more important in case of renal carcinomas (3.5%/year). When surgery was proposed cystectomy was the riskiest procedure (2.6 to 11.6% VTE). Chemotherapy alone was an important risk factor increasing by a factor of six the occurrence of VTE. Hormonotherapy also increased this risk by induced hypogonadism. The curative treatment for VTE associated with cancers has to be performed through the injection of low molecular weight heparin. The implantation of a prophylactic treatment was not systematic among patients diagnosed with urological cancer. CONCLUSION: The understanding of mechanisms associated with the occurrence of VTE among these patients has enabled to improve patient management, especially those suffering from urological cancer. Undeniably, frequency of VTE is probably underestimated by urologists during clinical practice.

[State of the art: Direct oral anticoagulants and transfusion]. / État de l'art : nouveaux anticoagulants et transfusion.

Direct oral anticoagulants (DOAC) are indicated for stroke prevention in atrial fibrillation and for the prevention and treatment of venous thromboembolism. As any anticoagulant, they are associated with a bleeding risk. Management of DOAC-induced bleeding is challenging. Idarucizumab, antidote for dabigatran, is currently available and is part of the therapeutic strategy, whereas antidotes for anti-Xa agents are under development. Activated or non-activated prothrombin concentrates are proposed, although their efficacy to reverse DOAC is uncertain. We propose an update on DOAC-associated bleeding management, integrating the availability of idarucizumab and the critical place of DOAC concentration measurements.

[The role of extracorporeal removal of CO2 (ECCO2R) in the management of respiratory diseases]. / Place de l'épuration extracorporelle de CO2 (ECCO2R) dans la prise en charge des pathologies respiratoires.

INTRODUCTION: The aim of extracorporeal removal of CO2 (ECCO2R) is to ensure the removal of CO2 without any significant effect on oxygenation. ECCO2R makes use of low to moderate extracorporeal blood flow rates, whereas extracorporeal membrane oxygenation (ECMO) requires high blood flows. STATE OF THE ART: For each ECCO2R device it is important to consider not only performance in terms of CO2 removal, but also cost and safety, including the incidence of hemolysis and of hemorrhagic and thrombotic complications. In addition, it is possible that the benefits of such techniques may extend beyond simple removal of CO2. There have been preliminary reports of benefits in terms of reduced respiratory muscle workload. Mobilization of endothelial progenitor cells could also occur, in analogy to the data reported with ECMO, with a potential benefit in term of pulmonary repair. The most convincing clinical experience has been reported in the context of the acute respiratory distress syndrome (ARDS) and severe acute exacerbations of chronic obstructive pulmonary disease (COPD), especially in patients at high risk of failure of non-invasive ventilation. PERSPECTIVES: Preliminary results prompt the initiation of randomized controlled trials in these two main indications. Finally, the development of these technologies opens new perspectives in terms of long-term ventilatory support.

Increase in both angiogenic and angiostatic mediators in patients with idiopathic pulmonary fibrosis.

BACKGROUND: Idiopathic pulmonary fibrosis (IPF) is associated with a marked pulmonary vascular remodeling. The aim of this study was to investigate a potential imbalance between angiogenic and angiostatic factors in this disease. METHODS AND RESULTS: Sixty-four subjects with IPF and 10 healthy control subjects (60-70 years old) were prospectively included in this multicenter study. Plasma levels of vascular endothelial growth factor A (VEGF-A), thrombospondin-1 (TSP-1) and stem cell factor (SCF) were determined by Elisa. Comparisons between IPF and controls were made using the Mann-Whitney U test. We also analyzed these soluble mediators in relation with IPF severity (DLCO<40% or>40%) predicted or total lung capacity (TLC) and forced vital capacity (FVC) (both<55% or>55% predicted) using the same test. VEGF-A plasma levels were increased in IPF vs. controls (P=0.0008) as well as those of TSP-1 (P=0.008), irrespective of the severity of the disease as reflected by DLCO, TLC or FVC values. In contrast, SCF levels were similar in IPF and controls. CONCLUSIONS: Factors modulating angiogenic responses are dysregulated in patients with IPF with increases in VEGF-A and TSP-1. The serial assessment of VEGF-A and TSP-1 during the follow-up and the search for potential relationships with the outcome of the disease might give us hints to the clinical implication of these results.

The profibrotic cytokine transforming growth factor-ß1 increases endothelial progenitor cell angiogenic properties.

BACKGROUND: Transforming growth factor-ß1 (TGF-ß1) is a profibrotic cytokine that plays a major role in vascular biology, and is known to regulate the phenotype and activity of various vascular cell populations. Because most fibrotic diseases, such as idiopathic pulmonary fibrosis (IPF), are associated with vascular remodeling, and as endothelial progenitor cells (EPCs) may be involved in this process, we investigated the impact of TGF-ß1 modulation of EPC angiogenic properties. METHODS: TGF-ß1 plasma levels were determined in 64 patients with IPF and compared with those in controls. The effect of TGF-ß1 on angiogenesis was studied in vivo in a Matrigel plug model and in vitro on endothelial colony-forming cells (ECFCs). We studied the effects of inhibiting the expression of the three main receptors of TGF-ß1 in ECFCs by using short interfering RNA. RESULTS: Total TGF-ß1 plasma levels were significantly increased in patients with IPF as compared with controls (P < 0.0001). TGF-ß1 had proangiogenic effects in vivo by increasing hemoglobin content and blood vessel formation in Matrigel plugs implanted in C57/Bl6 mice, and in vitro by enhancing ECFC viability and migration. The effects were abolished by silencing the three main TGF-ß1 receptors. CONCLUSIONS: TGF-ß1 is proangiogenic in vivo and induces ECFC angiogenic properties in vitro, suggesting that TGF-ß1 may play a role during vascular remodeling in fibrotic disease states via EPCs.

Osteoprotegerin, a new actor in vasculogenesis, stimulates endothelial colony-forming cells properties.

BACKGROUND: Osteoprotegerin (OPG), a soluble receptor of the tumour necrosis factor family, and its ligand, the receptor activator of nuclear factor-κB ligand (RANKL), are emerging as important regulators of vascular pathophysiology. OBJECTIVES: We evaluated their effects on vasculogenesis induced by endothelial colony-forming cells (ECFC) and on neovessel formation in vivo. METHODS: Effects of OPG and RANKL on in vitro angiogenesis were evaluated after ECFC incubation with OPG or RANKL (0-50 ng mL(-1)). Effects on microvessel formation were evaluated with an in vivo murin Matrigel plug assay. Vascularization was evaluated by measuring plug hemoglobin and vascular endothelial growth factor (VEGF)-R2 content 14 days after implantation. RESULTS: We found that ECFC expressed OPG and RANK but not RANKL mRNA. Treatment of ECFC with VEGF or stromal cell-derived factor-1 (SDF-1) upregulated OPG mRNA expression. OPG stimulated ECFC migration (P < 0.05), chemotaxis (P < 0.05) and vascular cord formation on Matrigel(®) (P < 0.01). These effects were correlated with SDF-1 mRNA overexpression, which was 30-fold higher after 4 h of OPG stimulation (P < 0.01). OPG-mediated angiogenesis involved the MAPK signaling pathway as well as Akt or mTOR cascades. RANKL also showed pro-vasculogenic effects in vitro. OPG combined with FGF-2 promoted neovessel formation in vivo, whereas RANKL had no effect. CONCLUSIONS: OPG induces ECFC activation and is a positive regulator of microvessel formation in vivo. Our results suggest that the OPG/RANK/RANKL axis may be involved in vasculogenesis and strongly support a modulatory role in tissue revascularization.

Distinct patterns of circulating endothelial cells in pulmonary hypertension.

The respective abundance of circulating endothelial cells and endothelial progenitor cells may reflect the balance between vascular injury and repair. As pulmonary arterial hypertension (PAH) and chronic thromboembolic pulmonary hypertension (CTEPH) can share features of pulmonary remodelling, we postulated that the two disorders might be associated with different types of pulmonary endothelial dysfunction. We studied 25 consecutive patients undergoing cardiac catheterisation for suspected pulmonary hypertension. Nine patients had PAH, nine had CTEPH, and seven had normal pulmonary arterial pressure and served as controls. Circulating endothelial cells were isolated with CD146-coated beads. CD34(+)CD133(+) cell and endothelial progenitor cell numbers were respectively determined by flow cytometry and cell culture, in peripheral vein and pulmonary artery blood. Plasma levels of soluble vascular endothelial growth factor (VEGF), soluble E-selectin and soluble vascular cell adhesion molecule (sVCAM) were measured by ELISA. No difference in progenitor counts or VEGF levels was found across the three groups. Compared to controls, circulating endothelial cell numbers were significantly increased in PAH but not in CTEPH, in keeping with the elevated soluble E-selectin and sVCAM levels found in PAH alone. In conclusion, PAH, in contrast to CTEPH, is associated with markers of vascular injury (circulating endothelial cells, soluble E-selectin and sVCAM) but not with markers of remodelling (endothelial progenitor cells, CD34(+)CD133(+) cells and VEGF).