Anti-PF4 positivity and platelet activation after Ad26.COV2·S vaccination in Brazil.

INTRODUCTION: The Ad26.COV2·S (Janssen/Johnson & Johnson) COVID-19 vaccine, has been rarely associated with vaccine-induced immune thrombocytopenia and thrombosis (VITT). We investigated the prevalence of anti-PF4 antibody positivity, thrombocytopenia, D-dimer elevation, plasmatic thromboinflammatory markers, and platelet functional assays following Ad26.COV2·S vaccination in Rio de Janeiro, Brazil. METHODS: From July to September 2021, participants were assessed prior, 1, and 3 weeks post-vaccination. Platelet count and D-dimer were measured at each visit and anti-PF4 at week 3. A positive anti-PF4 prompted retrospective testing of the sample from week 0. Individuals with new thrombocytopenia or elevated D-dimer, positive anti-PF4, and 38 matched controls without laboratory abnormalities were evaluated for plasmatic p-selectin, tissue factor, and functional platelet activation assays. RESULTS: 630 individuals were included; 306 (48.57%) females, median age 28 years. Forty-two (6.67%) presented ≥1 laboratory abnormality in week 1 or 3. Five (0.79%) had thrombocytopenia, 31 (4.91%) elevated D-dimer, and 9 (1.57%) had positive anti-PF4 at week 3. Individuals with laboratory abnormalities and controls showed a slight increase in plasmatic p-selectin and tissue factor. Ten individuals with laboratory abnormalities yielded increased surface expression of p-selectin, and their ability to activate platelets in a FcγRIIa dependent manner was further evaluated. Two were partially inhibited by high concentrations of heparin and blockage of FcγRII with IV.3 antibody. Plasma obtained before vaccination produced similar results, suggesting a lack of association with vaccination. CONCLUSIONS: Vaccination with Ad26.COV2·S vaccine led to a very low frequency of low-titer positive anti-PF4 antibodies, elevation of D-dimer, and mild thrombocytopenia, with no associated clinically relevant increase in thromboinflammatory markers and platelet activation.

The immune thrombocytopenia paradox: Should we be concerned about thrombosis in ITP?

Despite the predisposition to bleeding, patients with immune thrombocytopenia (ITP) may also have an increased risk of arterial and venous thrombosis, which can contribute to significant morbidity. The risk of thrombosis increases with age and the presence of cardiovascular risk factors. This narrative review explores the multifactorial nature of thrombosis in ITP, focusing on new pathological mechanisms, emerging evidence on the association between established treatments and thrombotic risk, the role of novel treatment approaches, and the challenges in assessing the balance between bleeding and thrombosis in ITP. The review also explores the challenges in managing acute thrombotic events in ITP, since the platelet count does not always reliably predict either the risk of bleeding or thrombosis and antithrombotic strategies lack specific guidelines for ITP. Notably, second-line therapeutic options, such as splenectomy and thrombopoietin receptor agonists (TPO-RAs), exhibit an increased risk of thrombosis especially in older individuals or those with multiple thrombotic risk factors or previous thrombosis, emphasizing the importance of careful risk assessment before treatment selection. In this context, it is important to consider second-line therapies such as rituximab and other immunosuppressive agents, dapsone and fostamatinib, which are not associated with increased thrombotic risk. In particular, fostamatinib, an oral spleen tyrosine kinase inhibitor, has promisingly low thrombotic risk. During the current era of the emergence of several novel ITP therapies that do not pose additional risks for thrombosis, it is critical to outline evidence-based strategies for the prevention and treatment of thrombosis in ITP patients.

Direct Oral Anticoagulants versus Vitamin K Antagonists for Left Ventricular Thrombus: A Meta-Analysis with Trial Sequential Analysis. / Anticoagulantes Orais Diretos versus Antagonistas da Vitamina K para Trombo Ventricular Esquerdo: Uma Metanálise com Análise Sequencial de Ensaios.

BACKGROUND: Vitamin K antagonists (VKAs) are the recommended first-line treatment for left ventricular thrombus (LVT); however, direct oral anticoagulants (DOACs) have been considered an alternative therapy. OBJECTIVES: To evaluate the efficacy and safety of DOACs compared with VKAs therapy in patients with LVT. METHODS: PubMed, Embase, and Cochrane were systematically searched for randomized clinical trials or cohort studies that compared DOACs versus VKAs for LVT. Risk ratios (RRs) were computed for binary endpoints, with 95% confidence intervals (95% CIs). Statistical significance was defined as p value < 0.05. RESULTS: A total of 4 randomized clinical trials and 29 cohort studies were included, with 4,450 patients assigned to either DOACs or VKAs. There was no significant difference between groups for stroke or systemic embolic (SSE) events (RR 0.84; 95% CI 0.65 to 1.07; p = 0.157), stroke (RR 0.73; 95% CI 0.48 to 1.11; p = 0.140), systemic embolic (SE) events (RR 0.69; 95% CI 0.40 to 1.17; p = 0.166), thrombus resolution (RR 1.05; 95% CI 0.99 to 1.11; p = 0.077), any bleeding (RR 0.78; 95% CI 0.60 to 1.00; p = 0.054), clinically relevant bleeding (RR 0.69; 95% CI 0.46 to 1.03; p = 0.066), minor bleeding (RR 0.73; 95% CI 0.43 to 1.23; p = 0.234), major bleeding (RR 0.87; 95% CI 0.42 to 1.80; p = 0.705), and all-cause mortality (RR 1.05; 95% CI 0.79 to 1.39; p = 0.752). Compared with VKAs, rivaroxaban significantly reduced SSE events (RR 0.35; 95% CI 0.16 to 0.91; p = 0.029) and SE events (RR 0.39; 95% CI 0.16 to 0.95; p = 0.037). CONCLUSIONS: DOACs had a similar rate of thromboembolic and hemorrhagic events, as well as thrombus resolution, compared to VKAs in the treatment of LVTs. Rivaroxaban therapy had a significant reduction in thromboembolic events, compared to VKAs.

Management of Bleeding and Thrombotic Complications During Pediatric Extracorporeal Membrane Oxygenation: The Pediatric Extracorporeal Membrane Oxygenation Anticoagulation CollaborativE Consensus Conference.

OBJECTIVES: To derive systematic-review informed, modified Delphi consensus regarding the management of bleeding and thrombotic complications during pediatric extracorporeal membrane oxygenation (ECMO) for the Pediatric ECMO Anticoagulation CollaborativE Consensus Conference. DATA SOURCES: A structured literature search was performed using PubMed, EMBASE, and Cochrane Library (CENTRAL) databases from January 1988 to May 2021. STUDY SELECTION: The management of bleeding and thrombotic complications of ECMO. DATA EXTRACTION: Two authors reviewed all citations independently, with a third independent reviewer resolving conflicts. Twelve references were used for data extraction and informed recommendations. Evidence tables were constructed using a standardized data extraction form. DATA SYNTHESIS: Risk of bias was assessed using the Quality in Prognosis Studies tool. The evidence was evaluated using the Grading of Recommendations Assessment, Development, and Evaluation system. Forty-eight experts met over 2 years to develop evidence-based recommendations and, when evidence was lacking, expert-based consensus statements for the management of bleeding and thrombotic complications in pediatric ECMO patients. A web-based modified Delphi process was used to build consensus via the Research And Development/University of California Appropriateness Method. Consensus was defined as greater than 80% agreement. Two good practice statements, 5 weak recommendations, and 18 consensus statements are presented. CONCLUSIONS: Although bleeding and thrombotic complications during pediatric ECMO remain common, limited definitive data exist to support an evidence-based approach to treating these complications. Research is needed to improve hemostatic management of children supported with ECMO.

Protein C Pretreatment Protects Endothelial Cells from SARS-CoV-2-Induced Activation.

SARS-CoV-2 can induce vascular dysfunction and thrombotic events in patients with severe COVID-19; however, the cellular and molecular mechanisms behind these effects remain largely unknown. In this study, we used a combination of experimental and in silico approaches to investigate the role of PC in vascular and thrombotic events in COVID-19. Single-cell RNA-sequencing data from patients with COVID-19 and healthy subjects were obtained from the publicly available Gene Expression Omnibus (GEO) repository. In addition, HUVECs were treated with inactive protein C before exposure to SARS-CoV-2 infection or a severe COVID-19 serum. An RT-qPCR array containing 84 related genes was used, and the candidate genes obtained were evaluated. Activated protein C levels were measured using an ELISA kit. We identified at the single-cell level the expression of several pro-inflammatory and pro-coagulation genes in endothelial cells from the patients with COVID-19. Furthermore, we demonstrated that exposure to SARS-CoV-2 promoted transcriptional changes in HUVECs that were partly reversed by the activated protein C pretreatment. We also observed that the serum of severe COVID-19 had a significant amount of activated protein C that could protect endothelial cells from serum-induced activation. In conclusion, activated protein C protects endothelial cells from pro-inflammatory and pro-coagulant effects during exposure to the SARS-CoV-2 virus.

Altered dynamics of calcium fluxes and mitochondrial metabolism in platelet activation-related disease and aging.

Understanding the mechanisms controlling platelet function is crucial for exploring potential therapeutic targets related to atherothrombotic pathologies and primary hemostasis disorders. Our research, which focuses on the role of platelet mitochondria and Ca2+ fluxes in platelet activation, the formation of the procoagulant phenotype, and thrombosis, has significant implications for the development of new therapeutic strategies. Traditionally, Ca2+-dependent cellular signaling has been recognized as a determinant process throughout the platelet activation, controlled primarily by store-operated Ca2+ entry and the PLC-PKC signaling pathway. However, despite the accumulated knowledge of these regulatory mechanisms, the effectiveness of therapy based on various commonly used antiplatelet drugs (such as acetylsalicylic acid and clopidogrel, among others) has faced challenges due to bleeding risks and reduced efficacy associated with the phenomenon of high platelet reactivity. Recent evidence suggests that platelet mitochondria could play a fundamental role in these aspects through Ca2+-dependent mechanisms linked to apoptosis and forming a procoagulant phenotype. In this context, the present review describes the latest advances regarding the role of platelet mitochondria and Ca2+ fluxes in platelet activation, the formation of the procoagulant phenotype, and thrombosis.

Retransplantation for Late Hepatic Artery Thrombosis: Results from a Single Center.

BACKGROUND: Hepatic artery thrombosis is the most common vascular complication of liver transplantation. When occurring late in the postoperative course, it may have no clinical repercussions, and conservative treatment may be implemented. Some patients, however, will develop severe biliary complications due to ischemic cholangiopathy and require retransplantation. The aim of this study is to report the outcomes of retransplantation in this population. METHODS: This is a single-center retrospective study involving all adult patients who underwent liver retransplantation due to late hepatic artery thrombosis from January/2010 to December/2022. RESULTS: During the study period, 1378 liver transplants were performed in our center; 147 were retransplantations, with 13 cases of late hepatic artery thrombosis (0.94%). All had symptomatic ischemic cholangiopathy. Twelve of them had already presented previous cholangitis, bilomas, or liver abscesses and had undergone biliary stenting or percutaneous drainage. The median time between the first liver transplant and late hepatic artery thrombosis diagnosis and between this diagnosis and retransplantation were 73 and 50 days, respectively. Arterial reconstruction using splenic artery, celiac trunk, or arterial conduit from the aorta was performed in 7 cases, whereas biliary reconstruction was mostly done with choledochojejunostomy (n = 8). There were 4 perioperative deaths, 2 due to primary non-function and 2 due to refractory shock after exceedingly complex retransplants. CONCLUSION: Liver retransplantation due to late hepatic artery thrombosis is a rare condition that should be offered to patients who develop severe biliary complications and recurrent infections. It is nonetheless a challenging procedure associated with significant perioperative mortality.

El papel del estetrol en la anticoncepción: una revisión integral / The role of estetrol in contraception: a comprehensive review

Esta revisión narrativa explora el papel potencial del estetrol (E4), un esteroide estrogénico natural, en la anticoncepción, analizando sus propiedades farmacológicas, su efectividad y su seguridad. Se revisaron estudios preclínicos, ensayos clínicos y evaluaciones de seguridad del E4 como anticonceptivo oral combinado (AOC). Se investigó el impacto en parámetros endocrinos, metabólicos y hemostáticos, así como su tolerabilidad. En los resultados, el E4 tiene menor afinidad por el receptor de estrógeno-α de membrana, pero mantiene la actividad agonista en los receptores nucleares. E4/DRSP (drospirenona) demostró ser un AOC eficaz, con ciclos de sangrado regulares y predecibles en la mayoría de las mujeres. La tolerabilidad fue favorable, con eventos adversos leves o moderados y bajas tasas de interrupción. El sangrado fue el evento adverso más común, y se reportaron casos raros de migrañas con aura, trombosis venosa profunda, hiperpotasemia y depresión. E4/DRSP tuvo mínimo impacto en los parámetros lipídicos, hepáticos, de globulina fijadora de hormonas sexuales y de metabolismo de hidratos de carbono, y efecto neutral o mínimo en los parámetros hemostáticos. Se concluye que E4/DRSP parece ser una opción anticonceptiva eficaz y segura, con reducido riesgo trombótico y mínimo impacto en los parámetros endocrinos y metabólicos. Se requiere más investigación para confirmar su seguridad y eficacia a largo plazo.

This narrative review explores the potential role of estetrol (E4), a natural estrogenic steroid, in contraception, analyzing its pharmacological properties, effectiveness, and safety. Preclinical studies, clinical trials, and safety assessments of E4/DRSP (drospirenone) as a combined oral contraceptive (COC) were reviewed. The impact on endocrine, metabolic, and hemostatic parameters, as well as tolerability, was investigated. In results, E4 exhibits lower affinity for estrogen transmembrane receptor-α but maintains agonistic activity on nuclear receptors. E4/DRSP proved to be an effective COC with regular and predictable bleeding cycles in most women. Tolerability was favorable with mild or moderate adverse events and low discontinuation rates. Bleeding was the most common adverse event, and rare cases of aura migraines, deep vein thrombosis, hyperkalemia, and depression were reported. E4/DRSP had minimal impact on lipid, hepatic, sex hormone-binding globulin, and carbohydrate metabolism parameters, with a neutral or minimal effect on hemostatic parameters. The conclusion is that E4/DRSP seems to be an effective and safe contraceptive option, with reduced thrombotic risk and minimal impact on endocrine and metabolic parameters. Further research is needed to confirm long-term safety and efficacy.

Packaging of supplemented urokinase into alpha granules of in vitro-grown megakaryocytes for targeted nascent clot lysis.

ABSTRACT: Fibrinolytics delivered into the general circulation lack selectivity for nascent thrombi, reducing efficacy and increasing the risk of bleeding. Urokinase-type plasminogen activator (uPA) transgenically expressed within murine platelets provided targeted thromboprophylaxis without causing bleeding but is not clinically feasible. Recent advances in generating megakaryocytes prompted us to develop a potentially clinically relevant means to produce "antithrombotic" platelets from CD34+ hematopoietic stem cell-derived in vitro-grown megakaryocytes. CD34+ megakaryocytes internalize and store in alpha granules (α-granules) single-chain uPA (scuPA) and a plasmin-resistant thrombin-activatable variant (uPAT). Both uPAs colocalized with internalized factor V (FV), fibrinogen and plasminogen, low-density lipoprotein receptor-related protein 1 (LRP1), and interferon-induced transmembrane protein 3, but not with endogenous von Willebrand factor (VWF). Endocytosis of uPA by CD34+ megakaryocytes was mediated, in part, via LRP1 and αIIbß3. scuPA-containing megakaryocytes degraded endocytosed intragranular FV but not endogenous VWF in the presence of internalized plasminogen, whereas uPAT-megakaryocytes did not significantly degrade either protein. We used a carotid artery injury model in nonobese diabetic-severe combined immunodeficiency IL2rγnull (NSG) mice homozygous for VWFR1326H (a mutation switching binding VWF specificity from mouse to human glycoprotein Ibα) to test whether platelets derived from scuPA- or uPAT-megakaryocytes would prevent thrombus formation. NSG/VWFR1326H mice exhibited a lower thrombotic burden after carotid artery injury compared with NSG mice unless infused with human platelets or megakaryocytes, whereas intravenous injection of uPA-megakaryocytes generated sufficient uPA-containing human platelets to lyse nascent thrombi. These studies describe the use of in vitro-generated megakaryocytes as a potential platform for delivering uPA or other ectopic proteins within platelet α-granules to sites of vascular injury.

Predictors of bleeding and thrombotic events among patients admitted to the hospital with COVID-19 and elevated D-dimer: insights from the ACTION randomized clinical trial.

Therapeutic anticoagulation showed inconsistent results in hospitalized patients with COVID-19 and selection of the best patients to use this strategy still a challenge balancing the risk of thrombotic and hemorrhagic outcomes. The present post-hoc analysis of the ACTION trial evaluated the variables independently associated with both bleeding events (major bleeding or clinically relevant non-major bleeding) and the composite outcomes thrombotic events (venous thromboembolism, myocardial infarction, stroke, systemic embolism, or major adverse limb events). Variables were assessed one by one with independent logistic regressions and final models were chosen based on Akaike information criteria. The model for bleeding events showed an area under the curve of 0.63 (95% confidence interval [CI] 0.53 to 0.73), while the model for thrombotic events had an area under the curve of 0.72 (95% CI 0.65 to 0.79). Non-invasive respiratory support was associated with thrombotic but not bleeding events, while invasive ventilation was associated with both outcomes (Odds Ratio of 7.03 [95 CI% 1.95 to 25.18] for thrombotic and 3.14 [95% CI 1.11 to 8.84] for bleeding events). Beyond respiratory support, creatinine level (Odds Ratio [OR] 1.01 95% CI 1.00 to 1.02 for every 1.0 mg/dL) and history of coronary disease (OR 3.67; 95% CI 1.32 to 10.29) were also independently associated to the risk of thrombotic events. Non-invasive respiratory support, history of coronary disease, and creatinine level may help to identify hospitalized COVID-19 patients at higher risk of thrombotic complications.ClinicalTrials.gov: NCT04394377.

RhoA/rho kinase pathway activation in age-associated endothelial cell dysfunction and thrombosis.

The small GTPase RhoA and the downstream Rho kinase (ROCK) regulate several cell functions and pathological processes in the vascular system that contribute to the age-dependent risk of cardiovascular disease, including endothelial dysfunction, excessive permeability, inflammation, impaired angiogenesis, abnormal vasoconstriction, decreased nitric oxide production and apoptosis. Frailty is a loss of physiological reserve and adaptive capacity with advanced age and is accompanied by a pro-inflammatory and pro-oxidative state that promotes vascular dysfunction and thrombosis. This review summarises the role of the RhoA/Rho kinase signalling pathway in endothelial dysfunction, the acquisition of the pro-thrombotic state and vascular ageing. We also discuss the possible role of RhoA/Rho kinase signalling as a promising therapeutic target for the prevention and treatment of age-related cardiovascular disease.

Prevalence of Pulmonary Embolism in COVID-19 at Quaternary Hospital Running Head: Pulmonary Embolism in COVID-19.

Background: Patients with COVID-19 are at greater risk of pulmonary embolism. Objective: The aim of the present study was to evaluate the monthly prevalence of pulmonary embolism diagnosed by angiotomography and mortality between March 2020 and May 2021 in more than 6000 patients hospitalized with COVID-19 at a single institution. Methods: A clinical trial was conducted with evaluated medical records the patients hospitalized at the institution who developed pulmonary embolism determined by angiotomography. Monthly and overall mortality rates between March 2020 and May 2021 in this population were evaluated. Results: A total of 6040 patients were hospitalized in this period, 203 of whom (3.36%) had an angiotomographic diagnosis of pulmonary embolism and 119 of these patients (58.62%) died. The largest number of patients with pulmonary embolism occurred in the periods from July to September 2020 and March to May 2021. No significant difference was found between mortality and the two peaks of the pandemic (p = 0.9, Fisher's exact test). Conclusion: Pulmonary embolism is associated a higher mortality rate among patients with COVID-19. Therefore, one of the strategies is an emphasis on the prevention of thrombotic and embolic events.

Pseudoaneurisma de ventriculo esquerdo, aneurisma ventricular associado e trombose mural após iam: complicações triplas na era da intervenção coronária percutânea / Left ventricular pseudoaneurysm, associated ventricular aneurysm and mural thrombosis after MI: triple complications in the era of percutaneous coronary intervention

INTRODUÇÃO: O Pseudoaneurisma do ventrículo esquerdo (PSAVE), aneurisma de ventrículo esquerdo (VE) e trombo mural são ocorrências incomuns no infarto agudo do miocárdio (IAM), sendo o PSAVE uma complicação ainda mais rara, correspondendo a menos de 0,1% dos pacientes com diagnóstico de IAM e com alta letalidade. Decorrem de ruptura miocárdica por necrose e o tratamento definitivo cirúrgico modifica o curso natural da doença. RELATO DE CASO: Paciente masculino, 70 anos, com hipertensão e diabetes apresentou IAM com supradesnivelamento de ST (IAMCSST) de parede anterior, sem reperfusão e foi submetido à estratificação invasiva em outro serviço após 72 horas. Foi tratado com implante de Stent farmacológico na artéria descendente anterior. Procurou assistência médica após 2 meses devido a quadro de insuficiência cardíaca (IC). Realizado ecocardiograma transtorácico que evidenciou PSAVE, recebendo alta com orientação de procurar esta instituição. Nova ecocardiografia evidenciou fração de ejeção do VE de 22% e grande aneurisma da região apical do VE, trombo mural e PSAVE na região ínfero-apical. Recebeu manejo com inotrópico intravenoso e após melhora clínica foi encaminhado para aneurismectomia com reconstrução do VE roto e trombectomia. Recebeu alta da UTI com18 dias de pós-operatório. DISCUSSÃO: Complicações mecânicas decorrentes da rotura por necrose miocárdica estão associadas à elevada mortalidade e as apresentações tardias após o evento agudo são relatos de seleção natural e achados incidentais. São associadas à necessidade de tratamento cirúrgico, especialmente em casos agudos, quando a ruptura pode ser fatal em até 45% dos casos. Na fase crônica, os sintomas por vezes são inespecíficos, podendo se apresentar com IC, insuficiência mitral, embolia sistêmica e arritmias cardíacas. CONCLUSÃO: Até o presente momento, este representa o primeiro relato de caso de tripla ocorrência de complicações associadas à grande massa miocárdica necrótica na era contemporânea da intervenção coronária percutânea no Brasil. Reiteramos a relevância dos casos com IAMCSST serem tratados com reperfusão precoce, fator independente para redução de mortalidade e salvamento miocárdico, portanto com menor risco desenvolvimento dessas complicações em pacientes tratados com implante de stent coronario após IAM, porém associada à elevada morbimortalidade na fase aguda. Sua suspeição, diagnóstico precoce e tratamento cirúrgico são essenciais para um desfecho clínico favorável.

Concerns about the application of resistance exercise with blood-flow restriction and thrombosis risk in hemodialysis patients.

BACKGROUND: Hemodialysis (HD) per se is a risk factor for thrombosis. Considering the growing body of evidence on blood-flow restriction (BFR) exercise in HD patients, identification of possible risk factors related to the prothrombotic agent D-dimer is required for the safety and feasibility of this training model. The aim of the present study was to identify risk factors associated with higher D-dimer levels and to determine the acute effect of resistance exercise (RE) with BFR on this molecule. METHODS: Two hundred and six HD patients volunteered for this study (all with a glomerular filtration rate of <15 mL/min/1.73 m2). The RE + BFR session consisted of 50% arterial occlusion pressure during 50 min sessions of HD (intradialytic exercise). RE repetitions included concentric and eccentric lifting phases (each lasting 2 s) and were supervised by a strength and conditioning specialist. RESULTS: Several variables were associated with elevated levels of D-dimer, including higher blood glucose, citrate use, recent cardiovascular events, recent intercurrents, higher inflammatory status, catheter as vascular access, older patients (>70 years old), and HD vintage. Furthermore, RE + BFR significantly increases D-dimer after 4 h. Patients with borderline baseline D-dimer levels (400-490 ng/mL) displayed increased risk of elevating D-dimer over the normal range (≥500 ng/mL). CONCLUSION: These results identified factors associated with a heightened prothrombotic state and may assist in the screening process for HD patients who wish to undergo RE + BFR. D-dimer and/or other fibrinolysis factors should be assessed at baseline and throughout the protocol as a precautionary measure to maximize safety during RE + BFR.

Loss of opportunities in the diagnosis and treatment of primary obstetric antiphospholipid syndrome (POAPS): from theory to reality.

OBJECTIVES: (I) To identify and measure the clinical consequences of a delayed diagnosis in patients with primary obstetric antiphospholipid syndrome (POAPS), in terms of time and events associated to antiphospholipid syndrome (APS), and (II) to evaluate the impact of their treatment status on perinatal outcomes, before and after diagnosis. METHODS: This retrospective multicentre study included 99 POAPS women who were separated in two groups of timelines based on their diagnostic status: group 1: women who met the clinical criteria for POAPS; group 2: included the same patients from group 1 since they meet the laboratory criteria for APS. In group 1, we assessed the following variables: obstetric events, thrombotic events and time (years) to diagnosis of APS. We also compared perinatal outcomes between patients in group 1 vs. group 2. Women in group 2 were treated with standard of care for POAPS. Simple and multivariable logistic regression analyses were performed. RESULTS: Regarding the impact of the delay on diagnosis, a total of 87 APS-related events were recorded: 46 miscarriages, 32 foetal losses and 9 premature deliveries before the 34th week due to preeclampsia, and one thrombosis. The estimated rate of preventable events was 20.58 per year/100 patients. The mean diagnostic delay time was 4.27 years. When we compared both groups during pregnancy, we found that patients in group 1 (no treatment) had a higher association with pregnancy losses [OR = 6.71 (95% CI: 3.59-12.55), p < 0.0001]. CONCLUSION: Our findings emphasize the negative impact of POAPS underdiagnosis on patient health and the critical importance of a timely intervention to improve pregnancy outcomes. Key Points •Our study shows the relevance of underdiagnosis on primary obstetric antiphospholipid syndrome (POAPS). •These patients presented a high risk of APS-related events with each passing year. •Shorter diagnostic delay time was observed in the reference centres.

Anti-hemostatic, antithrombotic, and chemical profiles of a curly-leaf variety of Petroselinum crispum (Apiaceae), a food and medicinal aromatic herb.

Thrombosis is currently among the major causes of morbidity and mortality in the World. New prevention and therapy alternatives have been increasingly sought in medicinal plants. In this context, we have been investigating parsley, Petroselinum crispum (Mill.) Nym, an aromatic herb with two leaf varieties. We report here the in vitro, in vivo, and ex vivo anti-hemostatic and antithrombotic activities of a parsley curly-leaf variety. Aqueous extracts of aerial parts (PCC-AP), stems (PCC-S), and leaves (PCC-L) showed significant in vitro antiplatelet activity. PCC-AP extract exhibited the highest activity (IC50 2.92 mg/mL) when using ADP and collagen as agonists. All extracts also presented in vitro anticoagulant activity (APTT and PT) and anti-thrombogenic activity. PCC-S was the most active, with more significant interference in the factors of the intrinsic coagulation pathway. The oral administration of PCC-AP extract in rats caused a greater inhibitory activity in the deep vein thrombi (50%; 65 mg/kg) than in arterial thrombi formation (50%; 200 mg/kg), without cumulative effect after consecutive five-day administration. PCC-AP extract was safe in the induced bleeding time test. Its anti-aggregating profile was similar in ex vivo and in vitro conditions but was more effective in the extrinsic pathway when compared to in vitro results. Apiin and coumaric acid derivatives are the main compounds in PCC-AP according to the HPLC-DAD-ESI-MS/MS profile. We demonstrated for the first time that extracts from different parts of curly parsley have significant antiplatelet, anticoagulant, and antithrombotic activity without inducing hemorrhage, proving its potential as a source of antithrombotic compounds.

Potential Biotechnological Applications of Venoms from the Viperidae Family in Central America for Thrombosis.

Central America is home to one of the most abundant herpetofauna in the Americas, occupying only 7% of the continent's total area. Vipers and lizards are among the most relevant venomous animals in medical practice due to the consequences of envenomation from the bite of these animals. A great diversity of biomolecules with immense therapeutic and biotechnological value is contained in their venom. This paper describes the prominent leading representatives of the family Viperidae, emphasizing their morphology, distribution, habitat, feeding, and venom composition, as well as the biotechnological application of some isolated components from the venom of the animals from these families, focusing on molecules with potential anti-thrombotic action. We present the leading protein families that interfere with blood clotting, platelet activity, or the endothelium pro-thrombotic profile. In conclusion, Central America is an endemic region of venomous animals that can provide many molecules for biotechnological applications.