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1.
Transplant Cell Ther ; 2024 Jun 06.
Artículo en Inglés | MEDLINE | ID: mdl-38851322

RESUMEN

BACKGROUND: There is a large inter-individual variation in the efficacy of CD34+ cell mobilization and collection in healthy allogenic hematopoietic stem cell donors. Donor characteristics, blood cell counts, and factors related to mobilization and collection have previously been associated with blood CD34+ cell count or CD34+ cell yield after G-CSF mobilization and collection. Since the literature reporting associations is heterogeneous, we clarify the determinants of CD34+ count and yield in a scoping review. MATERIALS AND METHODS: Studies published between 2000 and 2023 were evaluated if they reported allogeneic donors undergoing G-CSF mobilization and peripheral blood stem cell collection (PBSC). Eligible studies assessed blood CD34+ cell count or CD34+ cell yield in the first PBSC collection after mobilization with 4 or 5 days of G-CSF treatment. Associations were recorded between these outcomes and donor factors (age, gender, weight, ethnicity), mobilization factors (G-CSF scheduling or dose), collection factors (venous access, processed blood volume) or laboratory factors (blood cell counts at baseline or after mobilization). RESULTS: The 52 studies each evaluated between 15 and 20,884 donors. 43 studies were retrospective, 33 assessed blood CD34+ cell counts and 39 assessed CD34+ cell yield from PBSC. Blood CD34+ cell counts consistently predicted CD34+ cell yield. Younger donors usually had higher blood CD34+ cell counts and CD34+ cell yield. Most studies that investigated the effect of donor ancestry found that non-European ancestry donors had higher blood CD34+ cell counts after mobilization and CD34+ cell yields from collection. CONCLUSIONS: There remains poor consensus about the best predictors of blood CD34+ cell counts and yield that requires further prospective study, particularly of the role of donor ancestry. The current focus on donor gender as a major predictor requires re-evaluation.

2.
Nat Med ; 2024 May 31.
Artículo en Inglés | MEDLINE | ID: mdl-38821540

RESUMEN

Most people with intellectual disability (ID) do not receive a molecular diagnosis following genetic testing. To identify new etiologies of ID, we performed a genetic association analysis comparing the burden of rare variants in 41,132 noncoding genes between 5,529 unrelated cases and 46,401 unrelated controls. RNU4-2, which encodes U4 small nuclear RNA, a critical component of the spliceosome, was the most strongly associated gene. We implicated de novo variants among 47 cases in two regions of RNU4-2 in the etiology of a syndrome characterized by ID, microcephaly, short stature, hypotonia, seizures and motor delay. We replicated this finding in three collections, bringing the number of unrelated cases to 73. Analysis of national genomic diagnostic data showed RNU4-2 to be a more common etiological gene for neurodevelopmental abnormality than any previously reported autosomal gene. Our findings add to the growing evidence of spliceosome dysfunction in the etiologies of neurological disorders.

3.
Am J Hum Genet ; 110(11): 1903-1918, 2023 11 02.
Artículo en Inglés | MEDLINE | ID: mdl-37816352

RESUMEN

Despite whole-genome sequencing (WGS), many cases of single-gene disorders remain unsolved, impeding diagnosis and preventative care for people whose disease-causing variants escape detection. Since early WGS data analytic steps prioritize protein-coding sequences, to simultaneously prioritize variants in non-coding regions rich in transcribed and critical regulatory sequences, we developed GROFFFY, an analytic tool that integrates coordinates for regions with experimental evidence of functionality. Applied to WGS data from solved and unsolved hereditary hemorrhagic telangiectasia (HHT) recruits to the 100,000 Genomes Project, GROFFFY-based filtration reduced the mean number of variants/DNA from 4,867,167 to 21,486, without deleting disease-causal variants. In three unsolved cases (two related), GROFFFY identified ultra-rare deletions within the 3' untranslated region (UTR) of the tumor suppressor SMAD4, where germline loss-of-function alleles cause combined HHT and colonic polyposis (MIM: 175050). Sited >5.4 kb distal to coding DNA, the deletions did not modify or generate microRNA binding sites, but instead disrupted the sequence context of the final cleavage and polyadenylation site necessary for protein production: By iFoldRNA, an AAUAAA-adjacent 16-nucleotide deletion brought the cleavage site into inaccessible neighboring secondary structures, while a 4-nucleotide deletion unfolded the downstream RNA polymerase II roadblock. SMAD4 RNA expression differed to control-derived RNA from resting and cycloheximide-stressed peripheral blood mononuclear cells. Patterns predicted the mutational site for an unrelated HHT/polyposis-affected individual, where a complex insertion was subsequently identified. In conclusion, we describe a functional rare variant type that impacts regulatory systems based on RNA polyadenylation. Extension of coding sequence-focused gene panels is required to capture these variants.


Asunto(s)
Proteína Smad4 , Telangiectasia Hemorrágica Hereditaria , Humanos , Secuencia de Bases , ADN , Leucocitos Mononucleares/patología , Nucleótidos , Poliadenilación/genética , ARN , Proteína Smad4/genética , Telangiectasia Hemorrágica Hereditaria/genética , Secuenciación Completa del Genoma
4.
Res Pract Thromb Haemost ; 7(4): 100175, 2023 May.
Artículo en Inglés | MEDLINE | ID: mdl-37538507

RESUMEN

Background: Blood platelets are mediators of atherothrombotic disease and are regulated by complex sets of genes. Association studies in European ancestry populations have already detected informative platelet regulatory loci. Studies in other ancestries can potentially reveal new associations because of different allele frequencies, linkage structures, and variant effects. Objectives: To reveal new regulatory genes for platelet count (PLT). Methods: Genome-wide association studies (GWAS) were performed in 20,218 Bangladeshi and 9198 Pakistani individuals from the Genes & Health study. Loci significantly associated with PLT underwent fine-mapping to identify candidate genes. Results: Of 1588 significantly associated variants (P < 5 × 10-8) at 20 loci in the Bangladeshi analysis, most replicated findings in prior transancestry GWAS and in the Pakistani analysis. However, the Bangladeshi locus defined by rs946528 (chr1:46019890) did not associate with PLT in the Pakistani analysis but was in the same linkage disequilibrium block (r2 ≥ 0.5) as PLT-associated variants in prior East Asian GWAS. The single independent association signal was refined to a 95% credible set of 343 variants spanning 8 coding genes. Functional annotation, mapping to megakaryocyte regulatory regions, and colocalization with blood expression quantitative trait loci identified the likely mediator of the PLT phenotype to be PIK3R3 encoding a regulator of phosphoinositol 3-kinase (PI3K). Conclusion: Abnormal PI3K activity in the vessel wall is already implicated in the pathogenesis of atherothrombosis. Our identification of a new association between PIK3R3 and PLT provides further mechanistic insights into the contribution of the PI3K pathway to platelet biology.

5.
BMJ Open ; 13(8): e071629, 2023 08 08.
Artículo en Inglés | MEDLINE | ID: mdl-37553192

RESUMEN

INTRODUCTION: Congenital heart disease (CHD) represents the most common birth defect, affecting from 0.4% to 1.2% of children born in developed countries. The survival of these patients has increased significantly, but CHD remains one of the major causes of neonatal and childhood death. The aetiology of CHD is complex, with some evidence of both genetic and environmental causes. However, there is still lack of knowledge regarding modifiable risk factors and molecular and genetic mechanisms underlying the development of CHD. This study aims to develop a prospective cohort of patients undergoing cardiac procedures that will bring together routinely collected clinical data and biological samples from patients and their biological mothers, in order to investigate risk factors and predictors of postoperative-outcomes, as well as better understanding the effect of the surgical intervention on the early and long-term outcomes. METHODS AND ANALYSIS: Children OMACp (OMACp, outcome monitoring after cardiac procedure in congenital heart disease) is a multicentre, prospective cohort study recruiting children with CHD undergoing a cardiac procedure. The study aims to recruit 3000 participants over 5 years (2019-2024) across multiple UK sites. Routine clinical data will be collected, as well as participant questionnaires collecting sociodemographic, NHS resource use and quality of life data. Biological samples (blood, urine and surgical waste tissue from patients, and blood and urine samples from biological mothers) will be collected where consent has been obtained. Follow-up outcome and questionnaire data will be collected for 5 years. ETHICS AND DISSEMINATION: The study was approved by the London-Brent Research Ethics Committee on 30 July 2019 (19/SW/0113). Participants (or their parent/guardian if under 16 years of age) must provide informed consent prior to being recruited into the study. Mothers who wish to take part must also provide informed consent prior to being recruited. The study is sponsored by University Hospitals Bristol and Weston Foundation Trust and is managed by the University of Bristol. Children OMACp is adopted onto the National Institute for Health Research Clinical Research Network portfolio. Findings will be disseminated through peer-reviewed publications, presentation at conference, meetings and through patient organisations and newsletters. TRIAL REGISTRATION NUMBER: ISRCTN17650644.


Asunto(s)
Cardiopatías Congénitas , Calidad de Vida , Recién Nacido , Embarazo , Femenino , Humanos , Lactante , Niño , Adulto Joven , Estudios Prospectivos , Parto , Cardiopatías Congénitas/cirugía , Medición de Riesgo , Estudios Multicéntricos como Asunto
6.
Blood ; 142(24): 2055-2068, 2023 12 14.
Artículo en Inglés | MEDLINE | ID: mdl-37647632

RESUMEN

Rare genetic diseases affect millions, and identifying causal DNA variants is essential for patient care. Therefore, it is imperative to estimate the effect of each independent variant and improve their pathogenicity classification. Our study of 140 214 unrelated UK Biobank (UKB) participants found that each of them carries a median of 7 variants previously reported as pathogenic or likely pathogenic. We focused on 967 diagnostic-grade gene (DGG) variants for rare bleeding, thrombotic, and platelet disorders (BTPDs) observed in 12 367 UKB participants. By association analysis, for a subset of these variants, we estimated effect sizes for platelet count and volume, and odds ratios for bleeding and thrombosis. Variants causal of some autosomal recessive platelet disorders revealed phenotypic consequences in carriers. Loss-of-function variants in MPL, which cause chronic amegakaryocytic thrombocytopenia if biallelic, were unexpectedly associated with increased platelet counts in carriers. We also demonstrated that common variants identified by genome-wide association studies (GWAS) for platelet count or thrombosis risk may influence the penetrance of rare variants in BTPD DGGs on their associated hemostasis disorders. Network-propagation analysis applied to an interactome of 18 410 nodes and 571 917 edges showed that GWAS variants with large effect sizes are enriched in DGGs and their first-order interactors. Finally, we illustrate the modifying effect of polygenic scores for platelet count and thrombosis risk on disease severity in participants carrying rare variants in TUBB1 or PROC and PROS1, respectively. Our findings demonstrate the power of association analyses using large population datasets in improving pathogenicity classifications of rare variants.


Asunto(s)
Estudio de Asociación del Genoma Completo , Trombosis , Humanos , Bancos de Muestras Biológicas , Hemostasis , Hemorragia/genética , Enfermedades Raras
9.
Blood ; 141(22): 2685-2697, 2023 06 01.
Artículo en Inglés | MEDLINE | ID: mdl-36787503

RESUMEN

Neonatal thrombocytopenia, defined as the presence of a circulating platelet count <150 × 109/L, is a common abnormality in babies admitted to neonatal intensive care units. Thrombocytopenia that is typically mild and self-limiting often accompanies neonatal stress in scenarios such as premature delivery or intrauterine growth restriction. However, the differential diagnosis of neonatal thrombocytopenia is wide and includes potentially life-threatening disorders, such as bacterial sepsis, viral infection, and necrotizing enterocolitis. Distinguishing these causes of thrombocytopenia from entities such as genetic thrombocytopenia and fetal and neonatal alloimmune thrombocytopenia is critical for the accurate quantitation of significant adverse events, such as intracranial bleeding, and for the selection of treatments, such as platelet transfusion. In this review, we focus on common differential diagnoses of neonatal thrombocytopenia and highlight how the landscape of diagnosis and management is changing with recent advances in genomic technology and the completion of pivotal clinical trials of platelet transfusion practice. Increasing evidence highlights the need for judicious and restrictive use of platelet transfusions in neonates.


Asunto(s)
Trombocitopenia Neonatal Aloinmune , Humanos , Recién Nacido , Hemorragias Intracraneales/complicaciones , Recuento de Plaquetas , Transfusión de Plaquetas , Atención Prenatal , Trombocitopenia Neonatal Aloinmune/diagnóstico , Trombocitopenia Neonatal Aloinmune/terapia
10.
medRxiv ; 2023 Dec 21.
Artículo en Inglés | MEDLINE | ID: mdl-38196618

RESUMEN

To discover rare disease-gene associations, we developed a gene burden analytical framework and applied it to rare, protein-coding variants from whole genome sequencing of 35,008 cases with rare diseases and their family members recruited to the 100,000 Genomes Project (100KGP). Following in silico triaging of the results, 88 novel associations were identified including 38 with existing experimental evidence. We have published the confirmation of one of these associations, hereditary ataxia with UCHL1 , and independent confirmatory evidence has recently been published for four more. We highlight a further seven compelling associations: hypertrophic cardiomyopathy with DYSF and SLC4A3 where both genes show high/specific heart expression and existing associations to skeletal dystrophies or short QT syndrome respectively; monogenic diabetes with UNC13A with a known role in the regulation of ß cells and a mouse model with impaired glucose tolerance; epilepsy with KCNQ1 where a mouse model shows seizures and the existing long QT syndrome association may be linked; early onset Parkinson's disease with RYR1 with existing links to tremor pathophysiology and a mouse model with neurological phenotypes; anterior segment ocular abnormalities associated with POMK showing expression in corneal cells and with a zebrafish model with developmental ocular abnormalities; and cystic kidney disease with COL4A3 showing high renal expression and prior evidence for a digenic or modifying role in renal disease. Confirmation of all 88 associations would lead to potential diagnoses in 456 molecularly undiagnosed cases within the 100KGP, as well as other rare disease patients worldwide, highlighting the clinical impact of a large-scale statistical approach to rare disease gene discovery.

11.
J Thromb Haemost ; 20(9): 2127-2135, 2022 09.
Artículo en Inglés | MEDLINE | ID: mdl-35770723

RESUMEN

Assessment of platelet secretion is crucial for diagnosing suspected inherited platelet function disorders (IPFD). A previous survey of the SSC on Platelet Physiology of the ISTH and a comprehensive review highlighted that most of the platelet secretion assays (PSAs) lack standardization and validation. The aim of this study was to provide expert consensus guidance on the use of PSAs for IPFD diagnosis. We surveyed 26 experts from 10 different countries using the RAND/UCLA methodology, to attain a consensus on sensitivity, specificity, feasibility, time to readout, and cost of most PSAs. Answers were then graded in three categories: appropriate, uncertain, and inappropriate. Equivocal or misinterpretable statements required a second and third round survey involving 14 of the original 26 experts. We report here the consolidated results of the entire procedure. There was uniform agreement on several general statements, including that PSAs should be performed in hemostasis laboratories as first line diagnostic tests even in patients with normal platelet aggregation, and should include a δ-granule secretion marker. Among the specific assays examined, lumiaggregometry, other luciferin/luciferase-based assays, high-performance liquid chromatography methods, radiolabeled-serotonin based assays, and whole-mount transmission electron microscopy were rated as appropriate for the measurement of δ-granule release, and platelet P-selectin expression by flow cytometry and released proteins by ELISA for α-granule release. For most of the other PSAs, the expert opinions were widely dispersed. Lack of expert consensus on many PSAs clearly indicates an unmet need for rigorous standardization, multicenter comparison of results, and validation of PSAs for clinical laboratory practice.


Asunto(s)
Trastornos de las Plaquetas Sanguíneas , Trombastenia , Trastornos de las Plaquetas Sanguíneas/diagnóstico , Trastornos de las Plaquetas Sanguíneas/metabolismo , Plaquetas/metabolismo , Comunicación , Testimonio de Experto , Hemostasis , Humanos , Estudios Multicéntricos como Asunto , Pruebas de Función Plaquetaria/métodos
12.
J Thromb Haemost ; 20(7): 1735-1743, 2022 07.
Artículo en Inglés | MEDLINE | ID: mdl-35570324

RESUMEN

Severe congenital protein C deficiency (SCPCD) is rare and there is currently substantial variation in the management of this condition. A joint project by three Scientific and Standardization Committees of the ISTH: Plasma Coagulation Inhibitors, Pediatric/Neonatal Thrombosis and Hemostasis, and Women's Health Issues in Thrombosis and Hemostasis, was developed to review the current evidence and help guide on diagnosis and management of SCPCD. We provide a summary of the clinical presentations, differential diagnoses, appropriate investigations to confirm the diagnosis, approaches for management of the acute situation, and options for long-term management including subsequent pregnancies. We finally provide a set of recommendations to help in this regard.


Asunto(s)
Coagulación Intravascular Diseminada , Deficiencia de Proteína C , Trombosis , Niño , Femenino , Hemostasis , Humanos , Recién Nacido , Embarazo , Deficiencia de Proteína C/diagnóstico , Trombosis/diagnóstico , Trombosis/terapia
13.
Circ Res ; 130(3): 384-400, 2022 02 04.
Artículo en Inglés | MEDLINE | ID: mdl-35012325

RESUMEN

BACKGROUND: DNA hypomethylation at the F2RL3 (F2R like thrombin or trypsin receptor 3) locus has been associated with both smoking and atherosclerotic cardiovascular disease; whether these smoking-related associations form a pathway to disease is unknown. F2RL3 encodes protease-activated receptor 4, a potent thrombin receptor expressed on platelets. Given the role of thrombin in platelet activation and the role of thrombus formation in myocardial infarction, alterations to this biological pathway could be important for ischemic cardiovascular disease. METHODS: We conducted multiple independent experiments to assess whether DNA hypomethylation at F2RL3 in response to smoking is associated with risk of myocardial infarction via changes to platelet reactivity. Using cohort data (N=3205), we explored the relationship between smoking, DNA hypomethylation at F2RL3, and myocardial infarction. We compared platelet reactivity in individuals with low versus high DNA methylation at F2RL3 (N=41). We used an in vitro model to explore the biological response of F2RL3 to cigarette smoke extract. Finally, a series of reporter constructs were used to investigate how differential methylation could impact F2RL3 gene expression. RESULTS: Observationally, DNA methylation at F2RL3 mediated an estimated 34% of the smoking effect on increased risk of myocardial infarction. An association between methylation group (low/high) and platelet reactivity was observed in response to PAR4 (protease-activated receptor 4) stimulation. In cells, cigarette smoke extract exposure was associated with a 4.9% to 9.3% reduction in DNA methylation at F2RL3 and a corresponding 1.7-(95% CI, 1.2-2.4, P=0.04) fold increase in F2RL3 mRNA. Results from reporter assays suggest the exon 2 region of F2RL3 may help control gene expression. CONCLUSIONS: Smoking-induced epigenetic DNA hypomethylation at F2RL3 appears to increase PAR4 expression with potential downstream consequences for platelet reactivity. Combined evidence here not only identifies F2RL3 DNA methylation as a possible contributory pathway from smoking to cardiovascular disease risk but from any feature potentially influencing F2RL3 regulation in a similar manner.


Asunto(s)
Plaquetas/metabolismo , Epigénesis Genética , Infarto del Miocardio/genética , Receptores de Trombina/genética , Anciano , Metilación de ADN , Femenino , Humanos , Masculino , Persona de Mediana Edad , Infarto del Miocardio/sangre , Infarto del Miocardio/epidemiología , Receptores de Trombina/metabolismo , Fumar/epidemiología
14.
Semin Thorac Cardiovasc Surg ; 34(1): 277-288, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-33444767

RESUMEN

Bleeding caused by coagulopathy is common in children undergoing cardiac surgery and causes adverse outcomes. Coagulation testing assists selection of treatments to stop bleeding but has an uncertain role for predicting bleeding. We aimed to evaluate how well prospective coagulation testing predicted excessive bleeding during and after cardiac surgery compared to prediction using clinical characteristics alone. The study was a single-center, prospective cohort study in children having a range of cardiac surgery procedures with coagulation testing at anesthetic induction and immediately after cardiopulmonary bypass. The primary outcome was clinical concern about bleeding (CCB), a composite of either administration of prohemostatic treatments in response to bleeding or a high chest drain volume after surgery. In 225 children, CCB occurred in 26 (12%) during surgery and in 68 (30%) after surgery. Multivariable fractional polynomial models using the clinical characteristics of the children alone predicted CCB during surgery (c-statistic 0.64; 95% confidence interval 0.53, 0.76) and after surgery (0.74; 0.67, 0.82). Incorporating coagulation test results into these models improved prediction (c-statistics 0.79; 0.70, 0.87, and 0.80; 0.74, 0.87, respectively). However, this increased the overall proportion of children classified correctly as CCB or not CCB during surgery by only 0.9% and after surgery by only 0.4%. Incorporating coagulation test results into predictive models had no effect on prediction of blood transfusion or postoperative complications. Prospective coagulation testing marginally improves prediction of CCB during and after cardiac surgery but the clinical impact of this is small when compared to prediction using clinical characteristics.


Asunto(s)
Procedimientos Quirúrgicos Cardíacos , Hemorragia Posoperatoria , Pruebas de Coagulación Sanguínea/efectos adversos , Pruebas de Coagulación Sanguínea/métodos , Procedimientos Quirúrgicos Cardíacos/efectos adversos , Puente Cardiopulmonar/efectos adversos , Niño , Humanos , Hemorragia Posoperatoria/diagnóstico , Hemorragia Posoperatoria/etiología , Estudios Prospectivos , Resultado del Tratamiento
15.
Res Pract Thromb Haemost ; 5(6): e12568, 2021 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-34458664

RESUMEN

Hypodysfibrinogenemia (HD) is a heterogeneous disorder in which plasma fibrinogen antigen and function are both reduced but discordant. This report addresses the key clinical question of whether genetic analysis enables clinically useful subclassification of patients with HD. We report a new case and identify a further eight previously documented cases that have the laboratory features of HD but biallelic inheritance of quantitative and qualitative fibrinogen gene variants. The cases displayed both bleeding and thrombosis and sometimes had undetectable fibrinogen activity. In all cases, the predicted effect of the coinherited variants is reduced levels of circulating fibrinogen that is all dysfunctional. We propose the term pseudohomozygous dysfibrinogenemia for this subtype of recessively inherited HD that is distinct from the more commonly recognized monoallelic HD caused by a single fibrinogen gene variant.

16.
Br J Haematol ; 195(1): 25-45, 2021 10.
Artículo en Inglés | MEDLINE | ID: mdl-33783834

RESUMEN

Low platelet count, or thrombocytopenia, is a common haematological abnormality, with a wide differential diagnosis, which may represent a clinically significant underlying pathology. Macrothrombocytopenia, the presence of large platelets in combination with thrombocytopenia, can be acquired or hereditary and indicative of a complex disorder. In this review, we discuss the interpretation of platelet count and volume measured by automated haematology analysers and highlight some important technical considerations relevant to the analysis of blood samples with macrothrombocytopenia. We review how large cohorts, such as the UK Biobank and INTERVAL studies, have enabled an accurate description of the distribution and co-variation of platelet parameters in adult populations. We discuss how genome-wide association studies have identified hundreds of genetic associations with platelet count and mean platelet volume, which in aggregate can explain large fractions of phenotypic variance, consistent with a complex genetic architecture and polygenic inheritance. Finally, we describe the large genetic diagnostic and discovery programmes, which, simultaneously to genome-wide association studies, have expanded the repertoire of genes and variants associated with extreme platelet phenotypes. These have advanced our understanding of the pathogenesis of hereditary macrothrombocytopenia and support a future clinical diagnostic strategy that utilises genotype alongside clinical and laboratory phenotype data.


Asunto(s)
Plaquetas/patología , Trombocitopenia/genética , Adolescente , Adulto , Anciano , Tamaño de la Célula , Estudios de Cohortes , Femenino , Heterogeneidad Genética , Estudio de Asociación del Genoma Completo , Humanos , Masculino , Volúmen Plaquetario Medio , Persona de Mediana Edad , Herencia Multifactorial , Fenotipo , Recuento de Plaquetas , Trombocitopenia/sangre , Factores de Transcripción/genética , Adulto Joven
17.
Thromb Res ; 201: 100-112, 2021 05.
Artículo en Inglés | MEDLINE | ID: mdl-33662796

RESUMEN

Thrombosis affecting the pulmonary and systemic vasculature is common during severe COVID-19 and causes adverse outcomes. Although thrombosis likely results from inflammatory activation of vascular cells, the mediators of thrombosis remain unconfirmed. In a cross-sectional cohort of 36 severe COVID-19 patients, we show that markedly increased plasma von Willebrand factor (VWF) levels were accompanied by a partial reduction in the VWF regulatory protease ADAMTS13. In all patients we find this VWF/ADAMTS13 imbalance to be associated with persistence of ultra-high-molecular-weight (UHMW) VWF multimers that are highly thrombogenic in some disease settings. Incubation of plasma samples from patients with severe COVID-19 with recombinant ADAMTS13 (rADAMTS13) substantially reduced the abnormally high VWF activity, reduced overall multimer size and depleted UHMW VWF multimers in a time and concentration dependent manner. Our data implicate disruption of normal VWF/ADAMTS13 homeostasis in the pathogenesis of severe COVID-19 and indicate that this can be reversed ex vivo by correction of low plasma ADAMTS13 levels. These findings suggest a potential therapeutic role for rADAMTS13 in helping restore haemostatic balance in COVID-19 patients.


Asunto(s)
COVID-19 , Proteínas Recombinantes , Trombosis , Proteína ADAMTS13 , Estudios Transversales , Humanos , Proteínas Recombinantes/uso terapéutico , SARS-CoV-2 , Factor de von Willebrand
18.
J Am Heart Assoc ; 9(24): e016495, 2020 12 15.
Artículo en Inglés | MEDLINE | ID: mdl-33305660

RESUMEN

Background To assess differences in platelet inhibition during ticagrelor monotherapy (TIC) or dual therapy with ticagrelor and aspirin (TIC+ASP) in patients after percutaneous coronary intervention using a comprehensive panel of functional tests. Methods and Results In a single-center parallel group, open label, randomized controlled trial, 110 participants were randomized to receive either TIC (n=55) or TIC+ASP (n=55) for 4 weeks. The primary outcome was the platelet aggregation response with 10 µmol/L thrombin receptor activation peptide-6 (TRAP-6). The secondary outcomes were platelet aggregation responses and binding of surface activation markers with a panel of other activators. The mean percentage aggregation for 10 µmol/L TRAP-6 was similar for the TIC and TIC+ASP groups (mean difference+4.29; 95% CI, -0.87 to +9.46). Aggregation was higher in the TIC group compared with the TIC+ASP group with 1 µg/mL (+6.47; +2.04 to +10.90) and 0.5 µg/mL (+14.00; +7.63 to +20.39) collagen related peptide. Aggregation responses with 5 µmol/L TRAP-6, 5 µmol/L or 2.5 µmol/L thromboxane A2 receptor agonist and surface activation marker binding with 5 µmol/L TRAP-6 or 0.5 µg/mL collagen related peptide were the same between the treatment groups. Conclusions Patients with PCI show similar levels of inhibition of most platelet activation pathways with TIC compared with dual therapy with TIC + ASP. However, the greater aggregation response with collagen related peptide during TIC indicates incomplete inhibition of glycoprotein VI (collagen) receptor-mediated platelet activation. This difference in pharmacodynamic response to anti-platelet medication may contribute to the lower bleeding rates observed with TIC compared with dual antiplatelet therapy in recent clinical trials. Registration Information URL: https://www.isrctn.com; Unique Identifier ISRCTN84335288.


Asunto(s)
Síndrome Coronario Agudo/tratamiento farmacológico , Quimioterapia Combinada/efectos adversos , Intervención Coronaria Percutánea/efectos adversos , Antagonistas del Receptor Purinérgico P2Y/farmacología , Ticagrelor/farmacología , Síndrome Coronario Agudo/sangre , Anciano , Ácido Araquidónico/sangre , Aspirina/uso terapéutico , Quimioterapia Combinada/métodos , Terapia Antiplaquetaria Doble/efectos adversos , Terapia Antiplaquetaria Doble/métodos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Fragmentos de Péptidos/efectos de los fármacos , Agregación Plaquetaria/efectos de los fármacos , Inhibidores de Agregación Plaquetaria/uso terapéutico , Pruebas de Función Plaquetaria/métodos , Antagonistas del Receptor Purinérgico P2Y/administración & dosificación , Antagonistas del Receptor Purinérgico P2Y/uso terapéutico , Receptores de Tromboxano A2 y Prostaglandina H2/agonistas , Ticagrelor/administración & dosificación , Ticagrelor/uso terapéutico
19.
J Thromb Haemost ; 18(9): 2209-2214, 2020 09.
Artículo en Inglés | MEDLINE | ID: mdl-32634856

RESUMEN

BACKGROUND: Thrombomodulin-associated coagulopathy (TM-AC) is a rare bleeding disorder in which a single reported p.Cys537* variant in the thrombomodulin gene THBD causes high plasma thrombomodulin (TM) levels. High TM levels attenuate thrombin generation and delay fibrinolysis. OBJECTIVES: To report the characteristics of pedigree with a novel THBD variant causing TM-AC, and co-inherited deficiency of thrombin-activatable fibrinolysis inhibitor (TAFI). PATIENTS/METHODS: Identification of pathogenic variants in hemostasis genes by next-generation sequencing and case recall for deep phenotyping. RESULTS: Pedigree members with a previously reported THBD variant predicting p.Pro496Argfs*10 and chain truncation in TM transmembrane domain had abnormal bleeding and greatly increased plasma TM levels. Affected cases had attenuated thrombin generation and delayed fibrinolysis similar to previous reported TM_AC cases with THBD p.Cys537*. Coincidentally, some pedigree members also harbored a stop-gain variant in CPB2 encoding TAFI. This reduced plasma TAFI levels but was asymptomatic. Pedigree members with TM-AC caused by the p.Pro496Argfs*10 THBD variant and also TAFI deficiency had a partially attenuated delay in fibrinolysis, but no change in the defective thrombin generation. CONCLUSIONS: These data extend the reported genetic repertoire of TM-AC and establish a common molecular pathogenesis arising from high plasma levels of TM extra-cellular domain. The data further confirm that the delay in fibrinolysis associated with TM-AC is directly linked to increased TAFI activation. The combination of the rare variants in the pedigree members provides a unique genetic model to develop understanding of the thrombin-TM system and its regulation of TAFI.


Asunto(s)
Trastornos de la Coagulación Sanguínea , Carboxipeptidasa B2 , Carboxipeptidasa B2/genética , Fibrinólisis/genética , Humanos , Linaje , Trombina , Trombomodulina/genética
20.
Transfusion ; 60 Suppl 3: S119-S123, 2020 06.
Artículo en Inglés | MEDLINE | ID: mdl-32478898

RESUMEN

BACKGROUND: Viscoelastic tests (VETs) are used widely to monitor hemostasis in settings such as cardiac surgery. There has also been renewed interest in cold stored platelets (CSPs) to manage bleeding in this setting. CSPs are reported to have altered hemostatic properties compared to room temperature platelets (RTPs), including activation of GPIIb/IIIa. We investigated whether the functional differences between CSP and RTP affected the performance of the PlateletMapping VET on the TEG 5000 and 6s analyzer. METHOD: Platelet concentrates were divided equally into CSP (stored at 4°C ± 2°C) and RTP (stored at 22°C ± 2°C) fractions. Whole blood was treated to induce platelet dysfunction (WBIPD) by incubating with anti-platelet drugs (1.0 µM ticagrelor and 10 µM aspirin) or by simulating cardiopulmonary bypass. WBIPD samples were then mixed with 20% by volume of CSPs or RTPs to model platelet transfusion before analysis using the PlateletMapping VET. RESULTS: Addition of CSPs to WBIPD increased the PlateletMapping MAFIBRIN and MAADP parameters with the TEG 5000 analyzer (both p < 0.0001 compared to addition of buffer alone). This effect was not observed with RTPs. The differential effect of CSPs on the MAFIBRIN corrected after pre-incubation with the GPIIb/IIIa antagonist tirofiban and was quantitatively less with the PlateletMapping test for the TEG 6s analyzer which contains the GPIIb/IIa antagonist abciximab. DISCUSSION: The PlateletMapping MAFIBRIN and MAADP test results may be misleadingly high with CSPs, particularly with the TEG 5000 analyzer, most likely due to constitutive activation of GPIIb/IIIa on CSPs during storage. TEG PlateletMapping results should be interpreted with caution following CSP transfusion.


Asunto(s)
Plaquetas/metabolismo , Tromboelastografía/métodos , Eliminación de Componentes Sanguíneos , Plaquetas/citología , Plaquetas/efectos de los fármacos , Conservación de la Sangre , Frío , Humanos , Agregación Plaquetaria/efectos de los fármacos , Inhibidores de Agregación Plaquetaria/farmacología , Complejo GPIIb-IIIa de Glicoproteína Plaquetaria/antagonistas & inhibidores , Complejo GPIIb-IIIa de Glicoproteína Plaquetaria/metabolismo , Tromboelastografía/instrumentación , Ticagrelor/farmacología , Tirofibán/farmacología
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