RESUMO
von Willebrand factor (VWF) is a multimeric protein, the size of which is regulated via ADAMTS13-mediated proteolysis within the A2 domain. We aimed to isolate nanobodies distinguishing between proteolyzed and non-proteolyzed VWF, leading to the identification of a nanobody (designated KB-VWF-D3.1) targeting the A3 domain, the epitope of which overlaps the collagen-binding site. Although KB-VWF-D3.1 binds with similar efficiency to dimeric and multimeric derivatives of VWF, binding to VWF was lost upon proteolysis by ADAMTS13, suggesting that proteolysis in the A2 domain modulates exposure of its epitope in the A3 domain. We therefore used KB-VWF-D3.1 to monitor VWF degradation in plasma samples. Spiking experiments showed that a loss of 10% intact VWF could be detected using this nanobody. By comparing plasma from volunteers to that from congenital von Willebrand disease (VWD) patients, intact-VWF levels were significantly reduced for all VWD types, and most severely in VWD type 2A-group 2, in which mutations promote ADAMTS13-mediated proteolysis. Unexpectedly, we also observed increased proteolysis in some patients with VWD type 1 and VWD type 2M. A significant correlation (r = 0.51, P < .0001) between the relative amount of high-molecular weight multimers and levels of intact VWF was observed. Reduced levels of intact VWF were further found in plasmas from patients with severe aortic stenosis and patients receiving mechanical circulatory support. KB-VWF-D3.1 is thus a nanobody that detects changes in the exposure of its epitope within the collagen-binding site of the A3 domain. In view of its unique characteristics, it has the potential to be used as a diagnostic tool to investigate whether a loss of larger multimers is due to ADAMTS13-mediated proteolysis.
Assuntos
Doença de von Willebrand Tipo 2 , Doenças de von Willebrand , Humanos , Fator de von Willebrand/metabolismo , Doenças de von Willebrand/genética , Proteólise , Doença de von Willebrand Tipo 2/diagnóstico , Colágeno , Epitopos/metabolismo , Proteína ADAMTS13/metabolismoRESUMO
BACKGROUND: Thrombocytopenia has been consistently described in patients with extracorporeal membrane oxygenation (ECMO) and associated with poor outcome. However, the prevalence and underlying mechanisms remain largely unknown, and a device-related role of ECMO in thrombocytopenia has been hypothesized. This study aims to investigate the mechanisms underlying thrombocytopenia in ECMO patients. METHODS: In a prospective cohort of 107 ECMO patients, we investigated platelet count, functions, and glycoprotein shedding. In an ex vivo mock circulatory ECMO loop, we assessed platelet responses and VWF (von Willebrand factor)-GP Ibα (glycoprotein Ibα) interactions at low- and high-flow rates, in the presence or absence of red blood cells. The clearance of human platelets subjected or not to ex vivo perfusion was studied using an in vivo transfusion model in NOD/SCID (nonobese diabetic/severe combined Immunodeficient) mice. RESULTS: In ECMO patients, we observed a time-dependent decrease in platelet count starting 1 hour after device onset, with a mean drop of 7%, 35%, and 41% at 1, 24, and 48 hours post-ECMO initiation (P=0.00013, P<0.0001, and P<0.0001, respectively), regardless of the type of ECMO. This drop in platelet count was associated with a decrease in platelet GP Ibα expression (before: 47.8±9.1 versus 24 hours post-ECMO: 42.3±8.9 mean fluorescence intensity; P=0.002) and an increase in soluble GP Ibα plasma levels (before: 5.6±3.3 versus 24 hours post-ECMO: 10.8±4.1 µg/mL; P<0.0001). GP Ibα shedding was also observed ex vivo and was unaffected by (1) red blood cells, (2) the coagulation potential, (3) an antibody blocking VWF-GP Ibα interaction, (4) an antibody limiting VWF degradation, and (5) supraphysiological VWF plasma concentrations. In contrast, GP Ibα shedding was dependent on rheological conditions, with a 2.8-fold increase at high- versus low-flow rates. Platelets perfused at high-flow rates before being transfused to immunodeficient mice were eliminated faster in vivo with an accelerated clearance of GP Ibα-negative versus GP Ibα-positive platelets. CONCLUSIONS: ECMO-associated shear forces induce GP Ibα shedding and thrombocytopenia due to faster clearance of GP Ibα-negative platelets. Inhibiting GP Ibα shedding could represent an approach to reduce thrombocytopenia during ECMO.
Assuntos
Trombocitopenia , Fator de von Willebrand , Humanos , Animais , Camundongos , Fator de von Willebrand/metabolismo , Estudos Prospectivos , Camundongos Endogâmicos NOD , Camundongos SCID , Plaquetas/metabolismo , Trombocitopenia/terapia , Trombocitopenia/metabolismoRESUMO
The association between endometriosis and autoimmune diseases is well known, however no acquired platelet function defect has been described so far. We describe the case of two patients with endometriosis associated with an antiplatelet glycoprotein VI (anti-GPVI) antibody. The two women with deep pelvic endometriosis associated with secondary infertility presented a mild bleeding tendency, a deficient platelet aggregation response to collagen, convulxin or CRP and a severe GPVI deficiency. Immunoblot revealed a combined FcRγ deficiency but no indication of GPVI cleavage. In the first case, platelet count was normal and an anti-GPVI IgG was detected in plasma. A first corticosteroids administration normalized in vitro platelet functions but further administrations were unsuccessful. Three IVF attempts failed. Conservative laparoscopic surgery was carried out after antifibrinolytic treatment without bleeding. The second case presented with a history of moderate thrombocytopenia and a weak anti-GPVI in the context of infertility and autoimmune disease, the Sjögren syndrome resolved after corticosteroids and hydroxychloroquine treatment. Acquired GPVI deficiencies are rare. It would be useful to determine whether the association with endometriosis is coincidental or not by more systematic investigations. It does not seem that in these patients, GPVI deficiency is associated with an increased risk of bleeding.
What is the context? ⢠Evidence for an immune system dysfunction is reported in endometriosis and the association between endometriosis and autoimmune diseases is well known.⢠No autoimmune platelet function defect has been described so far.What is new?⢠We report two unrelated patients with endometriosis-associated infertility presenting a platelet glycoprotein VI deficiency due to an autoantibody.⢠In both cases, a deficient platelet aggregation response to collagen, convulxin or CRP and a severe GPVI deficiency were observed.⢠Immunoblot revealed no indication of GPVI cleavage.What is the impact? ⢠Our observation raises the question whether GPVI could be a preferential target for the development of anti-GPVI autoantibodies associated with endometriosis.⢠It does not seem that in these patients, GPVI deficiency is associated with an increased risk of severe bleeding disorder.
Assuntos
Endometriose , Infertilidade , Humanos , Feminino , Glicoproteínas da Membrana de Plaquetas , Endometriose/complicações , Endometriose/tratamento farmacológico , Anticorpos , Contagem de Plaquetas , PlaquetasRESUMO
OBJECTIVE: The study's aim was to analyze the capacity of human valve interstitial cells (VICs) to participate in aortic valve angiogenesis. Approach and Results: VICs were isolated from human aortic valves obtained after surgery for calcific aortic valve disease and from normal aortic valves unsuitable for grafting (control VICs). We examined VIC in vitro and in vivo potential to differentiate in endothelial and perivascular lineages. VIC paracrine effect was also examined on human endothelial colony-forming cells. A pathological VIC (VICp) mesenchymal-like phenotype was confirmed by CD90+/CD73+/CD44+ expression and multipotent-like differentiation ability. When VICp were cocultured with endothelial colony-forming cells, they formed microvessels by differentiating into perivascular cells both in vivo and in vitro. VICp and control VIC conditioned media were compared using serial ELISA regarding quantification of endothelial and angiogenic factors. Higher expression of VEGF (vascular endothelial growth factor)-A was observed at the protein level in VICp-conditioned media and confirmed at the mRNA level in VICp compared with control VIC. Conditioned media from VICp induced in vitro a significant increase in endothelial colony-forming cell proliferation, migration, and sprouting compared with conditioned media from control VIC. These effects were inhibited by blocking VEGF-A with blocking antibody or siRNA approach, confirming VICp involvement in angiogenesis by a VEGF-A dependent mechanism. CONCLUSIONS: We provide here the first proof of an angiogenic potential of human VICs isolated from patients with calcific aortic valve disease. These results point to a novel function of VICp in valve vascularization during calcific aortic valve disease, with a perivascular differentiation ability and a VEGF-A paracrine effect. Targeting perivascular differentiation and VEGF-A to slow calcific aortic valve disease progression warrants further investigation.
Assuntos
Estenose da Valva Aórtica/metabolismo , Valva Aórtica/metabolismo , Valva Aórtica/patologia , Calcinose/metabolismo , Diferenciação Celular , Linhagem da Célula , Células Progenitoras Endoteliais/metabolismo , Neovascularização Patológica , Fator A de Crescimento do Endotélio Vascular/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Estenose da Valva Aórtica/patologia , Calcinose/patologia , Estudos de Casos e Controles , Células Cultivadas , Técnicas de Cocultura , Células Progenitoras Endoteliais/patologia , Células Progenitoras Endoteliais/transplante , Feminino , Humanos , Masculino , Camundongos Nus , Pessoa de Meia-Idade , Osteogênese , Comunicação Parácrina , Fenótipo , Transdução de Sinais , Fator A de Crescimento do Endotélio Vascular/genéticaRESUMO
[Figure: see text].
Assuntos
COVID-19/complicações , COVID-19/patologia , Endotélio Vascular/patologia , Insuficiência de Múltiplos Órgãos/virologia , Trombose/virologia , Biomarcadores/sangue , COVID-19/imunologia , Ativação do Complemento , Cuidados Críticos , Citocinas/sangue , Feminino , Humanos , Falência Hepática Aguda/virologia , Masculino , Microcirculação , Pessoa de Meia-Idade , Nucleossomos/metabolismo , Insuficiência Respiratória/virologia , SARS-CoV-2RESUMO
Transcatheter aortic valve replacement (TAVR), as an alternative to open heart surgery, has revolutionized the treatment of severe aortic valve stenosis (AVS), the most common valvular disorder in the elderly. AVS is now considered a form of atherosclerosis and, like the latter, partly of inflammatory origin. Patients with high-grade AVS have a highly disturbed blood flow associated with high levels of shear stress. The immediate reopening of the valve during TAVR leads to a sudden restoration of a normal blood flow hemodynamic. Despite its good prognosis for patients, TAVR remains associated with bleeding or thrombotic postprocedural complications, involving mechanisms that are still poorly understood. Many studies report the close link between blood coagulation and inflammation, termed thromboinflammation, including monocytes as a major actor. The TAVR procedure represents a unique opportunity to study the influence of shear stress on human monocytes, key mediators of inflammation and hemostasis processes. The purpose of this study was to conduct a review of the literature to provide a comprehensive overview of the impact of TAVR on monocyte phenotype and subset repartition and the association of these parameters with the clinical outcomes of patients with severe AVS who underwent TAVR.
Assuntos
Estenose da Valva Aórtica , Próteses Valvulares Cardíacas , Trombose , Substituição da Valva Aórtica Transcateter , Idoso , Estenose da Valva Aórtica/etiologia , Humanos , Inflamação/etiologia , Monócitos , Trombose/etiologia , Substituição da Valva Aórtica Transcateter/efeitos adversos , Substituição da Valva Aórtica Transcateter/métodosRESUMO
Acquired factor V inhibitor (AFVI) is an extremely rare disorder that may cause severe bleeding. To identify factors associated with bleeding risk in AFVI patients, a national, multicentre, retrospective study was made including all AFVI patients followed in 21 centres in France between 1988 and 2015. All patients had an isolated factor V (FV) deficiency <50% associated with inhibitor activity. Patients with constitutional FV deficiency and other causes of acquired coagulation FV deficiencies were excluded. The primary outcome was incident bleeding and factors associated with the primary outcome were identified. Thirty-eight (74 [36-100] years, 42·1% females) patients with AFVI were analysed. Bleeding was reported in 18 (47·4%) patients at diagnosis and in three (7·9%) during follow-up (7 [0·2-48.7] months). At diagnosis, FV was <10% in 31 (81·6%) patients. Bleeding at diagnosis was associated with a prolonged prothrombin time that strongly correlated with the AFVI level measured in plasma {r = 0·63, 95% confidence interval (CI) [0·36-0·80], P < 0·05}. Bleeding onset during follow-up was associated with a slow AFVI clearance (P < 0·001). The corresponding receiver operating characteristics curve showed that AFVI clearance was predictive of bleeding onset with an AFVI clearance of seven months with a sensitivity of 100% (95% CI: 29-100) and a specificity of 86% (95% CI: 57-98, P = 0·02). Kaplan-Meier analysis showed that AFVI clearance >7 months increased the risk of bleeding by 8 (95% CI: [0·67-97], P = 0·075). Prothrombin time at diagnosis and time for clearance of FV inhibitor during follow-up are both associated with bleeding in patients with AFVI.
Assuntos
Fator V/antagonistas & inibidores , Hemorragia/etiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Antibacterianos/efeitos adversos , Autoanticorpos/imunologia , Comorbidade , Reações Cruzadas , Fator V/imunologia , Feminino , Seguimentos , França/epidemiologia , Hemorragia/epidemiologia , Humanos , Imunoglobulina G/imunologia , Imunoglobulinas Intravenosas/efeitos adversos , Imunoglobulinas Intravenosas/uso terapêutico , Imunossupressores/uso terapêutico , Isoanticorpos/imunologia , Masculino , Pessoa de Meia-Idade , Tempo de Protrombina , Estudos Retrospectivos , RiscoRESUMO
Patients with type 2B von Willebrand disease (vWD) (caused by gain-of-function mutations in the gene coding for von Willebrand factor) display bleeding to a variable extent and, in some cases, thrombocytopenia. There are several underlying causes of thrombocytopenia in type 2B vWD. It was recently suggested that desialylation-mediated platelet clearance leads to thrombocytopenia in this disease. However, this hypothesis has not been tested in vivo The relationship between platelet desialylation and the platelet count was probed in 36 patients with type 2B von Willebrand disease (p.R1306Q, p.R1341Q, and p.V1316M mutations) and in a mouse model carrying the severe p.V1316M mutation (the 2B mouse). We observed abnormally high elevated levels of platelet desialylation in both patients with the p.V1316M mutation and the 2B mice. In vitro, we demonstrated that 2B p.V1316M/von Willebrand factor induced more desialylation of normal platelets than wild-type von Willebrand factor did. Furthermore, we found that N-glycans were desialylated and we identified αIIb and ß3 as desialylation targets. Treatment of 2B mice with sialidase inhibitors (which correct platelet desialylation) was not associated with the recovery of a normal platelet count. Lastly, we demonstrated that a critical platelet desialylation threshold (not achieved in either 2B patients or 2B mice) was required to induce thrombocytopenia in vivo In conclusion, in type 2B vWD, platelet desialylation has a minor role and is not sufficient to mediate thrombocytopenia.
Assuntos
Plaquetas/patologia , Mutação , Ácido N-Acetilneuramínico/química , Trombocitopenia/patologia , Doença de von Willebrand Tipo 2/complicações , Fator de von Willebrand/genética , Animais , Plaquetas/metabolismo , Estudos de Casos e Controles , Feminino , Seguimentos , Humanos , Integrina alfa2beta1/metabolismo , Integrina beta3/metabolismo , Masculino , Camundongos , Ácido N-Acetilneuramínico/metabolismo , Contagem de Plaquetas , Polissacarídeos/metabolismo , Prognóstico , Processamento de Proteína Pós-Traducional , Trombocitopenia/etiologia , Trombocitopenia/metabolismo , Doença de von Willebrand Tipo 2/genética , Doença de von Willebrand Tipo 2/patologiaRESUMO
RATIONALE: Percutaneous aortic valve procedures are a major breakthrough in the management of patients with aortic stenosis. Residual gradient and residual aortic regurgitation are major predictors of midterm and long-term outcome after percutaneous aortic valve procedures. We hypothesized that (1) induction/recovery of high molecular weight (HMW) multimers of von Willebrand factor defect could be instantaneous after acute changes in blood flow, (2) a bedside point-of-care assay (platelet function analyzer-closure time adenine DI-phosphate [PFA-CADP]), reflecting HMW multimers changes, could be used to monitor in real-time percutaneous aortic valve procedures. OBJECTIVE: To investigate the time course of HMW multimers changes in models and patients with instantaneous induction/reversal of pathological high shear and its related bedside assessment. METHODS AND RESULTS: We investigated the time course of the induction/recovery of HMW multimers defects under instantaneous changes in shear stress in an aortic stenosis rabbit model and in patients undergoing implantation of a continuous flow left ventricular assist device. We further investigated the recovery of HMW multimers and monitored these changes with PFA-CADP in aortic stenosis patients undergoing transcatheter aortic valve implantation or balloon valvuloplasty. Experiments in the aortic stenosis rabbit model and in left ventricular assist device patients demonstrated that induction/recovery of HMW multimers occurs within 5 minutes. Transcatheter aortic valve implantation patients experienced an acute decrease in shear stress and a recovery of HMW multimers within minutes of implantation which was sustained overtime. In patients with residual high shear or with residual aortic regurgitation, no recovery of HMW multimers was observed. PFA-CADP profiles mimicked HMW multimers recovery both in transcatheter aortic valve implantation patients without aortic regurgitation (correction) and transcatheter aortic valve implantation patients with aortic regurgitation or balloon valvuloplasty patients (no correction). CONCLUSIONS: These results demonstrate that variations in von Willebrand factor multimeric pattern are highly dynamic, occurring within minutes after changes in blood flow. It also demonstrates that PFA-CADP can evaluate in real time the results of transcatheter aortic valve procedures.
Assuntos
Valva Aórtica/cirurgia , Coração Auxiliar , Hemorreologia , Multimerização Proteica , Substituição da Valva Aórtica Transcateter , Fator de von Willebrand/química , Idoso , Idoso de 80 Anos ou mais , Angioplastia com Balão , Animais , Insuficiência da Valva Aórtica/sangue , Insuficiência da Valva Aórtica/fisiopatologia , Insuficiência da Valva Aórtica/cirurgia , Estenose da Valva Aórtica/sangue , Estenose da Valva Aórtica/fisiopatologia , Estenose da Valva Aórtica/cirurgia , Biomarcadores , Velocidade do Fluxo Sanguíneo , Sistemas Computacionais , Modelos Animais de Doenças , Feminino , Humanos , Masculino , Testes de Função Plaquetária/métodos , Estudos Prospectivos , CoelhosAssuntos
Infecções por Coronavirus/patologia , Plasma/química , Pneumonia Viral/patologia , Betacoronavirus/isolamento & purificação , COVID-19 , Sobrevivência Celular , Ácidos Nucleicos Livres/metabolismo , Células Cultivadas , Infecções por Coronavirus/complicações , Infecções por Coronavirus/virologia , Estado Terminal , Células Endoteliais/citologia , Células Endoteliais/metabolismo , Humanos , Interleucina-6/metabolismo , Microvasos/citologia , Insuficiência de Múltiplos Órgãos/etiologia , Pandemias , Plasma/metabolismo , Pneumonia Viral/complicações , Pneumonia Viral/virologia , SARS-CoV-2 , Índice de Gravidade de Doença , Sindecana-1/metabolismoRESUMO
BACKGROUND: Granulocyte colony-stimulating factor (G-CSF) is a pharmacologic agent inducing neutrophil mobilization and a new candidate for neuroprotection and neuroregeneration in stroke. Its effects when used in combination with tissue plasminogen activator (tPA) were explored during the acute phase of ischemic stroke. METHODS: We used a middle cerebral artery occlusion (MCAO) model of cerebral ischemia, associated with treatment with tPA, in male spontaneously hypertensive rats (SHR). Granulocyte colony-stimulating factor (G-CSF; 60 µg/kg) was injected just before tPA. Neutrophil response in peripheral blood and in the infarct area was quantified in parallel to the infarct volume. Protease matrix metallopeptidase 9 (MMP-9) release from circulating neutrophils was analyzed by immunochemistry and zymography. Vascular reactivity and hemorrhagic volume in the infarct area was also assessed. RESULTS: Twenty four hours after ischemia and tPA, G-CSF administration induced a significant increase of neutrophils in peripheral blood (P <0.05). At 72 hours post-ischemia, G-CSF was significantly associated with an increased risk of hemorrhage in the infarct area (2.5 times more likely; P <0.05) and significant cerebral endothelium-dependent dysfunction. Ex vivo, an increased MMP-9 release from neutrophils after tPA administration correlated to the increased hemorrhagic risk (P <0.05). In parallel, G-CSF administration was associated with a decreased neutrophil infiltration in the infarct area (-50%; P <0.05), with a concomitant significant neuroprotective effect (infarct volume: -40%; P <0.05). CONCLUSIONS: We demonstrate that G-CSF potentiates the risk of hemorrhage in experimental stroke when used in combination with tPA by inducing neutrophilia. This effect is concomitant to an increased MMP-9 release from peripheral neutrophils induced by the tPA treatment. These results highlight the potential hemorrhagic risk of associating G-CSF to thrombolysis during the acute phase of stroke.
Assuntos
Fibrinolíticos/efeitos adversos , Fator Estimulador de Colônias de Granulócitos/administração & dosagem , Hemorragia/induzido quimicamente , Infarto da Artéria Cerebral Média/tratamento farmacológico , Neutrófilos/efeitos dos fármacos , Ativador de Plasminogênio Tecidual/efeitos adversos , Animais , Infarto Encefálico/etiologia , Modelos Animais de Doenças , Esquema de Medicação , Endotélio/efeitos dos fármacos , Masculino , Metaloproteinase 9 da Matriz/metabolismo , Infiltração de Neutrófilos/efeitos dos fármacos , Neutrófilos/metabolismo , Peroxidase/metabolismo , Ratos , Ratos Endogâmicos SHR , Traumatismo por Reperfusão/tratamento farmacológico , Traumatismo por Reperfusão/etiologia , Estatísticas não Paramétricas , Fatores de TempoRESUMO
In France, both students from medicine and pharmacy background can have access to the residency in laboratory medicine (LM). The current curriculum of LM residency includes an early choice of option after the first two years of residency, which subsequently guides the rest of the training. This study aimed to analyze these choice and motivational factors, since its implementation in 2017. A national survey was conducted among LM residents and former residents who underwent the early option choice process. A questionnaire was developed and sent to residents via Google Forms. Several groups of items corresponding to potential motivational factors were included and rated on a 5-point Likert scale. A psychometric analysis allowed to identify the main motivational factors. A total of 178 responses from 24 residency regions were recorded. The median age was 28 years, with a slight female predominance (52%), and three-quarters of the participants had a pharmacy training background. The "hematology and immunology" option was the most chosen (35%). The psychometric analysis enabled to identify 7 motivational factors, and the most important is the training during the residency, which weights approximately 21 % in the choice. Several associations have been observed between the motivational factors and the background training, origin, the chosen option and the planned career. Several factors influence the choice of early option among LM residents, and some of these factors are associated with the background training, origin, chosen option and planned career.
Assuntos
Internato e Residência , Medicina , Humanos , Feminino , Adulto , Masculino , Escolha da Profissão , Inquéritos e Questionários , França/epidemiologiaRESUMO
BACKGROUND: Type 2 Normandy von Willebrand disease (VWD2N) is usually perceived as a mild bleeding disorder that can be treated with desmopressin (DDAVP). However, VWD2N patients can be compound heterozygous or homozygous for different variants, with p.Arg854Gln (R854Q) being the most frequent causative one. There are limited data about the impact of 2N variants on VWD2N phenotype and DDAVP response. OBJECTIVES: This study aims to describe the phenotype of VWD2N, including DDAVP response, according to genotype. METHODS: VWD2N patients with a complete genotype/phenotype characterization by the French reference center for VWD, including MCMDM-1VWD bleeding score, were eligible to be included in the study. Results of the DDAVP trial were also collected. RESULTS: A total of 123 VWD2N patients from the French registry were included in this study. Results were stratified according to the presence (R854QPos, n = 114) or absence (R854QNeg, n = 9) of at least 1 R854Q allele. Three R854QPos subgroups were further individualized: patients homozygous (R854QHmz, n = 55), compound heterozygous for R854Q and a null allele (R854Q/3, n = 48), or compound heterozygous for R854Q and another 2N variant (R854Q/2N, n = 11). FVIII: C levels were significantly lower in R854QNeg and R854Q/3 patients compared with R854QHmz ones (P < .001 and P < .0001, respectively). R854QNeg patients were diagnosed earlier due to bleeding symptoms and had a higher bleeding score than R854QPos patients (P < .001). In DDAVP trial, FVIII:C survival was lower in VWD type 2N than in type 1 patients. R854QPos patients had a heterogeneous DDAVP response, which was best predicted by baseline FVIII:C level. CONCLUSION: The heterogeneous genetic background of VWD2N drives different bleeding phenotypes and response patterns to DDAVP, underlining the clinical relevance of DDAVP trial to identify patients potentially eligible to alternative therapeutic options.
RESUMO
The recreational use of nitrous oxide (N2O) is an emerging public health issue. Chronic N2O abuse may result in various clinical symptoms, encompassing neurological, psychiatric and cardiovascular outcomes. Despite the difficulties for the laboratory investigation of N2O intoxication, there is currently no guidelines in France to help both clinicians and biologists use appropriate biomarkers for the diagnosis and monitoring of patients with clinical symptoms potentially related to N2O intoxication. A multi-disciplinary Working Group, carried out under the auspices of the French Society of Clinical Biology (SFBC) and in collaboration with the French Societies of Emergency Medicine (SFMU), Analytical Toxicology (SFTA), Hemostasis and Thrombosis (SFTH), Vitamins and Biofactors (SFVB), and the French Federation of Neurology (FFN), was recently implemented to elaborate practical guidelines. The methodology of the Working Group is based on the critical analysis of the literature, and raising concerns and objectives are grouped into five working packages. The present manuscript primarily aims to expound upon the methodology and objectives of the ongoing SFBC Working Group on N2O.
Assuntos
Óxido Nitroso , Transtornos Relacionados ao Uso de Substâncias , Humanos , Óxido Nitroso/toxicidade , Biomarcadores , França , Vitamina B 12RESUMO
BACKGROUND: Aortic valve stenosis involves inflammation, excess deposition of a collagen-rich extracellular matrix, and calcification. Recent studies have shown that M1 or inflammatory macrophages derived from infiltrating monocytes promote calcification of valvular interstitial cells, the most prevalent cell type of the aortic valve. We hypothesized that valvular interstitial cells could modulate inflammatory macrophages phenotype. METHODS: We first assessed macrophage phenotype in human aortic valve stenosis and control aortic valves from donors. Then, we examined profibrotic and inflammatory-related gene expression in valves and valvular interstitial cells. Finally, we investigated whether valvular interstitial cells can modify the phenotype of inflammatory macrophages. RESULTS: Circulating monocytes and plasma transforming growth factor beta-1 levels of patients with aortic valve stenosis were significantly higher compared with patients without aortic valve stenosis. Histologic analysis of thickened spongiosa of the aortic valve from patients with aortic valve stenosis showed a high macrophage infiltration but a low matrix metalloproteinase-9 expression compared with control aortic valves. On the other hand, valvular interstitial cell culture of aortic valve stenosis exhibited a profibrotic phenotype with a high expression of transforming growth factor beta-1 and transforming growth factor beta-1/transforming growth factor beta-3 ratio but a decreased expression of the peroxisome proliferator-activated receptor gamma nuclear receptor. Valvular interstitial cell-conditioned media of aortic valve stenosis led to a decrease in enzymatic activity of matrix metalloproteinase-9 and an increase in production of collagen in inflammatory macrophages compared with valvular interstitial cell-conditioned media from control aortic valve donors. CONCLUSIONS: These findings indicate that profibrotic valvular interstitial cells promote the imbalance of extracellular matrix remodeling by reducing matrix metalloproteinase-9 production on inflammatory macrophages that lead to excessive collagen deposition observed in aortic valve stenosis. Further investigation is needed to clarify the role of transforming growth factor beta-1/proliferator-activated receptor gamma nuclear receptor/matrix metalloproteinase-9 in aortic valve stenosis.
RESUMO
Severe COVID-19 infections are at high risk of causing thromboembolic events (TEEs). However, the usual exams may be unavailable or unreliable in predicting the risk of TEEs at admission or during hospitalization. We performed a retrospective analysis of two centers (n = 124 patients) including severe COVID-19 patients to determine the specific risk factors of TEEs in SARS-CoV-2 infection at admission and during stays at the intensive care unit (ICU). We used stepwise regression to create two composite scores in order to predict TEEs in the first 48 h (H0-H48) and during the first 15 days (D1-D15) in ICU. We then evaluated the performance of our scores in our cohort. During the period H0-H48, patients with a TEE diagnosis had higher D-Dimers and ferritin values at day 1 (D1) and day 3 (D3) and a greater drop in fibrinogen between D1 and D3 compared with patients without TEEs. Over the period D1-D15, patients with a diagnosis of a TEE showed a more marked drop in fibrinogen and had higher D-Dimers and lactate dehydrogenase (LDH) values at D1 and D3. Based on ROC analysis, the COVID-related acute lung and deep vein thrombosis (CALT) 1 score, calculated at D1, had a diagnostic performance for TEEs at H0-H48, estimated using an area under the curve (AUC) of 0.85 (CI95%: 0.76-0.93, p < 10-3). The CALT 2 score, calculated at D3, predicted the occurrence of TEEs over the period D1-D15 with an estimated AUC of 0.85 (CI95%: 0.77-0.93, p < 10-3). These two scores were used as the basis for the development of the CALT protocol, a tool to assist in the decision to use anticoagulation during severe SARS-CoV-2 infections. The CALT scores showed good performances in predicting the risk of TEEs in severe COVID-19 patients at admission and during ICU stays. They could, therefore, be used as a decision support protocol on whether or not to initiate therapeutic anticoagulation.
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Clonal hematopoiesis of indeterminate potential (CHIP) is considered as being a novel age-related risk factor for cardiovascular diseases. By capture-sequencing of a 67-gene panel, we established a large spectrum of CHIP in 258 patients with aortic valve stenosis undergoing transcatheter aortic valve replacement (TAVR) and assessed their association with long-term survival after TAVR. One or several CHIP variants in 35 genes were identified in 68% of the cohort, DNMT3A and TET2 being the 2 most frequently mutated genes. Patients carrying a TET2-CHIP-driver variant with low variant allele frequency (2%-10%) had a significant decrease in overall survival 5 years after TAVR.
RESUMO
Ibrutinib, a first-class Bruton tyrosine kinase inhibitor, is known to be associated with adverse bleeding events and has been recently approved for the treatment of relapse Waldenström macroglobulinemia (WM). Here, we report the exhaustive clinical and biological follow-up of 2 patients treated by ibrutinib alone in the context of relapsed WM with an acquired von Willebrand syndrome (AVWS) complication. In two cases, ibrutinib has been shown to be quickly efficient and safe for treating both AVWS and its underlying condition the WM, without bleeding complications. Interestingly, ibrutinib treatment brings a rapid and extended over time normalization of von Willebrand factor clearance. These observations show that ibrutinib is a valuable therapeutic option in relapsed WM patients associated with AVWS and highlighting the need for further cohort studies with long-term follow-up of patients to confirm the efficacy and safety of a treatment by ibrutinib for WM patients with AVWS complication.
Assuntos
Macroglobulinemia de Waldenstrom , Doenças de von Willebrand , Humanos , Recidiva Local de Neoplasia , Doenças de von Willebrand/diagnóstico , Doenças de von Willebrand/tratamento farmacológico , Doenças de von Willebrand/etiologia , Piperidinas/uso terapêutico , Macroglobulinemia de Waldenstrom/complicações , Macroglobulinemia de Waldenstrom/diagnóstico , Macroglobulinemia de Waldenstrom/tratamento farmacológicoRESUMO
Predictive scores assessing the risk of respiratory failure in COVID-19 mostly focused on the prediction of early intubation. A combined assessment of clinical parameters and biomarkers of endotheliopathy could allow to predict late worsening of acute respiratory failure (ARF), subsequently warranting intubation in COVID-19. Retrospective single-center derivation (n = 92 subjects) and validation cohorts (n = 59 subjects), including severe COVID-19 patients with non-invasive respiratory support, were assessed for at least 48 h following intensive care unit (ICU) admission. We used stepwise regression to construct the COVID endothelial and respiratory failure (CERES) score in a derivation cohort, and secondly assessed its accuracy for the prediction of late ARF worsening, requiring intubation within 15 days following ICU admission in an independent validation cohort. Platelet count, fraction of inspired oxygen, and endocan measured on ICU admission were identified as the top three predictive variables for late ARF worsening and subsequently included in the CERES score. The area under the ROC curve of the CERES score to predict late ARF worsening was calculated in the derivation and validation cohorts at 0.834 and 0.780, respectively. The CERES score is a simple tool with good performances to predict respiratory failure worsening, leading to secondary intubation, in COVID-19 patients.