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OBJECTIVES: to assess the variability in expenditure compared to 2022 assuming different rates of shifting of therapy days from current active ingredients used for the treatment of haemophilia B to nonacog beta pegolDesign: descriptive cross-sectional study. SETTING AND PARTICIPANTS: consumption in the year 2022 (data source: Medicines Utilisation Monitoring Centre, Italian Medicines Agency) of all medicinal products available in Italy containing coagulation factor IX. MAIN OUTCOMES MEASURES: for each active ingredient, the total number of therapy days and the variability in expenditure compared to 2022 were estimated on the basis of a switch of therapy days, between 5% and 20%, to nonacog beta pegol. RESULTS: on the basis of considered scenarios, the analysis shows that the total annual expenditure for clotting factors used in the treatment of haemophilia B could remain at most unchanged or reduced. Particularly, the extent of the reduction in spending could vary from 0.11% to 2.26%. This trend would be in contrast to the stable increase seen in recent years, particularly in 2022. CONCLUSIONS: this predictive spending assessment may be useful in evaluating the economic impact from new treatment options, such as etranacogene dezaparvovec gene therapy already approved by the European Medicines Agency and the Food and Drug Administration, and to improve pharmaceutical governance.
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Factor IX , Hemofilia B , Italia , Humanos , Estudios Transversales , Hemofilia B/tratamiento farmacológico , Hemofilia B/economía , Factor IX/uso terapéutico , Factor IX/economía , Costos de los Medicamentos , Proteínas Recombinantes/uso terapéutico , Proteínas Recombinantes/economía , Polietilenglicoles/uso terapéutico , Polietilenglicoles/economía , Gastos en Salud/estadística & datos numéricosRESUMEN
This study presents the clinical outcomes of using inhouse prepared fibrin glue for controlling gingival bleeding in patients with inherited bleeding disorders (IBD). The objective of the study was to assess the reduction in transfusion days and improvement in compliance for dental evaluation over a one-year period in a low-to-middle-income country. The quasiexperimental pilot study included 40 IBD patients with gingival bleeding. These were divided into two groups: Group A received fibrin glue (n=20), while Group B did not (n=20). The study compared outcome metrics, including the number of treatment days and blood components transfused, using non-parametric tests with a significance threshold of p<0.05. Results showed that Group A required fewer blood components (n=154) as compared to Group B (n=204) (p<0.001). Patients in Group A with Glanzmann thrombasthenia (GT) had a shorter treatment duration (one day) than those in group B (three days) (p<0.01). In conclusion, the application of fibrin glue effectively managed intractable gingival bleeding in IBD patients.
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Adhesivo de Tejido de Fibrina , Humanos , Adhesivo de Tejido de Fibrina/uso terapéutico , Proyectos PilotoRESUMEN
BACKGROUND: Inherited platelet disorders (IPDs) are a heterogeneous group of rare diseases that are caused by the defects in early megakaryopoiesis, proplatelet formation, and/or mature platelet function. Although genomic sequencing is increasingly used to identify genetic variants underlying IPD, this technique does not disclose resulting molecular changes that impact platelet function. Proteins are the functional units that shape platelet function; however, insights into how variants that cause IPDs impact platelet proteomes are limited. OBJECTIVES: The objective of this study was to profile the platelet proteomics signatures of IPDs. METHODS: We performed unbiased label-free quantitative mass spectrometry (MS)-based proteome profiling on platelets of 34 patients with IPDs with variants in 13 ISTH TIER1 genes that affect different stages of platelet development. RESULTS: In line with the phenotypical heterogeneity between IPDs, proteomes were diverse between IPDs. We observed extensive proteomic alterations in patients with a GFI1B variant and for genetic variants in genes encoding proteins that impact cytoskeletal processes (MYH9, TUBB1, and WAS). Using the diversity between IPDs, we clustered protein dynamics, revealing disrupted protein-protein complexes. This analysis furthermore grouped proteins with similar cellular function and location, classifying mitochondrial protein constituents and identifying both known and putative novel alpha granule associated proteins. CONCLUSIONS: With this study, we demonstrate a MS-based proteomics perspective to IPDs. By integrating the effects of IPDs that impact different aspects of platelet function, we dissected the biological contexts of protein alterations to gain further insights into the biology of platelet (dys)function.
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Trastornos de las Plaquetas Sanguíneas , Proteómica , Humanos , Proteoma/metabolismo , Trastornos de las Plaquetas Sanguíneas/diagnóstico , Trastornos de las Plaquetas Sanguíneas/genética , Trastornos de las Plaquetas Sanguíneas/metabolismo , Plaquetas/metabolismo , TrombopoyesisRESUMEN
PURPOSE OF REVIEW: This review describes ANKRD26-related thrombocytopenia (RT) from a molecular, clinical, and laboratory perspective, with a focus on the clinical decision-making that takes place in the diagnosis and management of families with ANKRD26-RT. RECENT FINDINGS: ANKRD26-related thrombocytopenia (ANKRD26-RT) is a non-syndromic autosomal dominant thrombocytopenia with predisposition to hematologic neoplasm. The clinical presentation is variable with moderate thrombocytopenia with normal platelet size and absent to mild bleeding being the hallmark which makes it difficult to distinguish from other inherited thrombocytopenias. The pathophysiology involves overexpression of ANKRD26 through loss of inhibitory control by transcription factors RUNX1 and FLI1. The great majority of disease-causing variants are in the 5' untranslated region. Acute myeloid leukemia, myelodysplastic syndrome, and chronic myelomonocytic leukemia have been reported to occur in the context of germline variants in ANKRD26, with the development of somatic driver mutations in hematopoietic regulators playing an important role in malignant transformation. In the absence of clear risk estimates of development of malignancy, optimal surveillance strategies and interventions to reduce risk of evolution to a myeloid disorder, multidisciplinary evaluation, with a strong genetic counseling framework is essential in the approach to these patients and their families. Gene-specific expertise and a multidisciplinary approach are important in the diagnosis and treatment of patients and families with ANKRD26-RT. These strategies help overcome the challenges faced by clinicians in the evaluation of individuals with a rare, non-syndromic, inherited disorder with predisposition to hematologic malignancy for which large data to guide decision-making is not available.
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Péptidos y Proteínas de Señalización Intercelular , Trastornos Mieloproliferativos , Neoplasias , Trombocitopenia , Regiones no Traducidas 5' , Toma de Decisiones Clínicas , Subunidad alfa 2 del Factor de Unión al Sitio Principal/genética , Predisposición Genética a la Enfermedad , Humanos , Péptidos y Proteínas de Señalización Intercelular/genética , Mutación , Trastornos Mieloproliferativos/genética , Neoplasias/genética , Trombocitopenia/etiología , Trombocitopenia/genéticaRESUMEN
BACKGROUND: Type 3 von Willebrand Disease (VWD) is a rare and severe form of VWD characterized by the absence of von Willebrand factor (VWF). OBJECTIVES: As part of the Zimmerman Program, we sought to explore the molecular pathogenesis, correlate bleeding phenotype and severity, and determine the inheritance pattern found in type 3 VWD families. PATIENTS/METHODS: 62 index cases with a pre-existing diagnosis of type 3 VWD were analyzed. Central testing included FVIII, VWF:Ag, VWF:RCo, and VWFpp. Bleeding symptoms were quantified using the ISTH bleeding score. Genetic analysis included VWF sequencing, comparative genomic hybridization and predictive computational programs. RESULTS: 75% of subjects (46) had central testing confirming type 3, while 25% were re-classified as type 1-Severe or type 1C. Candidate VWF variants were found in all subjects with 93% of expected alleles identified. The majority were null alleles including frameshift, nonsense, splice site, and large deletions, while 13% were missense variants. Additional studies on 119 family members, including 69 obligate carriers, revealed a wide range of heterogeneity in VWF levels and bleeding scores, even amongst those with the same variant. Co-dominant inheritance was present in 51% of families and recessive in 21%, however 28% were ambiguous. CONCLUSION: This report represents a large cohort of VWD families in the U.S. with extensive phenotypic and genotypic data. While co-dominant inheritance was seen in approximately 50% of families, this study highlights the complexity of VWF genetics due to the heterogeneity found in both VWF levels and bleeding tendencies amongst families with type 3 VWD.
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Enfermedad de von Willebrand Tipo 3 , Enfermedades de von Willebrand , Hibridación Genómica Comparativa , Hemorragia/genética , Humanos , Fenotipo , Enfermedad de von Willebrand Tipo 3/diagnóstico , Enfermedad de von Willebrand Tipo 3/genética , Enfermedades de von Willebrand/complicaciones , Enfermedades de von Willebrand/diagnóstico , Enfermedades de von Willebrand/genética , Factor de von Willebrand/análisis , Factor de von Willebrand/genéticaRESUMEN
AIM: To identify the main barriers to dental care access for patients with inherited bleeding (IBD) and hemoglobin disorders (HbD). METHODS: Patients with IBD and HbD were invited to participate in this study between August 2019 and March 2020. Data were collected through a questionnaire consisting of socioeconomic and demographic items and questions about access to dental services and history of dental treatment. Univariate and multiple Poisson regression model was used to determine associations between professional refusal of dental care and other co-variables (p < .05). RESULTS: The participants (29.1%) have already had professional refusal of dental care and participants with IBD (53.2%) did not feel confident with their local dentist due to their bleeding tendency. Most (64.6%) felt apprehensive about visiting the local dentist and high prevalence of refusal to provide dental care was associated with age (prevalence ratio [PR] = 1.021; 95% confidence interval [CI] = 1.010-1.032). Individuals with low bleeding risk were less likely to be denied dental care by a professional compared to those with high bleeding risk (PR = 0.536; 95%CI = 0.291-0.990). CONCLUSION: Professional refusal of dental care was high among patients with IBD, particularly older adults and with an increased risk of bleeding.
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Atención Odontológica , Hemoglobinas , Anciano , Humanos , Encuestas y CuestionariosRESUMEN
Bleeding and thrombocytopenia are common referrals to the pediatric and adult hematology practice. The differential diagnosis encompasses a wide spectrum of entities that vary in acuity, severity, and etiology. Most will be acquired (especially in adult patients), but many can be inherited, and some may have manifestations affecting other organ systems. The first step: defining whether the symptoms and/or laboratory findings are clinically significant and warrant additional work-up, can be equally as challenging as reaching the diagnosis itself. How much bleeding is too much to be considered normal? How low of a platelet count is too low? Once the decision has been made to pursue additional studies, considering the increasing number of laboratory tests available, the diagnostic process can be complex. In this article, we outline a general approach for the evaluation of patients in whom an inherited platelet disorder is being considered. We present two clinical vignettes as introduction to the diagnostic approach to inherited platelet disorders. We describe the rationale for the different types of tests that are clinically available, their limitations, and finally the challenges that are frequently encountered in the interpretation of results. We also intend to provide some guidance on the expected phenotype in terms of severity of bleeding and/or thrombocytopenia according to the etiology of the inherited disorder. Our goal is to provide the practicing hematologist with a practical framework that is clinically applicable in their daily practice.
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Anemia , Trastornos de las Plaquetas Sanguíneas , Trombocitopenia , Trastornos de las Plaquetas Sanguíneas/diagnóstico , Trastornos de las Plaquetas Sanguíneas/genética , Niño , Hemorragia/diagnóstico , Humanos , Recuento de Plaquetas , Trombocitopenia/diagnósticoRESUMEN
INTRODUCTION: Bleeding episodes in patients who have haemophilia A (HA), a hereditary bleeding disorder caused by a deficiency in factor VIII (FVIII), are treated or prophylactically prevented with infusions of exogenous FVIII. Neutralizing antibodies, referred to as inhibitors, against infusion products are a major complication experienced by up to 30% of patients who have severe HA. Bypassing agents (BPA), a class of therapeutics given to patients who have inhibitors, bypass the need for FVIII in the coagulation cascade, and long-term inhibitor eradication is accomplished using immune tolerance induction therapy (ITI). Data examining the antibody levels in patients receiving BPA and ITI are limited. AIM: Measure anti-FVIII antibody levels in specimens from patients receiving ITI or BPA in order to evaluate the anti-FVIII antibody response in those patients. METHODS: Specimens were tested using the CDC-modified Nijmegen-Bethesda assay (NBA) and the CDC fluorescence immunoassay (FLI) for anti-FVIII IgG1 and IgG4 . RESULTS: NBA-negative specimens from patients undergoing ITI or receiving BPAs have a higher frequency of anti-FVIII IgG4 positivity compared with the previously published level for NBA-negative HA patients. Analysis of anti-FVIII antibody levels in serial samples from patients undergoing ITI reveals that antibodies can persist even after the patient's NBA result falls into the negative range. CONCLUSIONS: Measurement of anti-FVIII antibodies may be a useful means to better contextualize NBA results in specimens from patients receiving BPA or ITI. In addition, assessment of anti-FVIII antibody levels has the potential to improve inhibitor surveillance and clinical decision-making related to the progress of ITI.
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Hemofilia A , Hemostáticos , Anticuerpos Neutralizantes , Factor VIII , Hemofilia A/tratamiento farmacológico , Humanos , Tolerancia InmunológicaRESUMEN
Inherited bleeding and platelet disorders (BPD) are highly heterogeneous and their diagnosis involves a combination of clinical investigations, laboratory tests, and genetic screening. This review will outline some of the challenges that geneticists and experts in clinical hemostasis face when implementing high-throughput sequencing (HTS) for patient care. We will provide an overview of the strengths and limitations of the different HTS techniques that can be used to diagnose BPD. An HTS test is cost-efficient and expected to increase the diagnostic rate with a possibility to detect unexpected diagnoses and decrease the turnaround time to diagnose patients. On the other hand, technical shortcomings, variant interpretation difficulties, and ethical issues related to HTS for BPD will also be documented. Delivering a genetic diagnosis to patients is highly desirable to improve clinical management and allow family counseling, but making incorrect assumptions about variants and providing insufficient information to patients before initiating the test could be harmful. Data-sharing and improved HTS guidelines are essential to limit these major drawbacks of HTS.
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Trastornos de la Coagulación Sanguínea Heredados , Trastornos de las Plaquetas Sanguíneas , Trastornos de la Coagulación Sanguínea Heredados/diagnóstico , Trastornos de la Coagulación Sanguínea Heredados/genética , Trastornos de las Plaquetas Sanguíneas/diagnóstico , Trastornos de las Plaquetas Sanguíneas/genética , Plaquetas , Pruebas Genéticas , Secuenciación de Nucleótidos de Alto Rendimiento , HumanosRESUMEN
BACKGROUND: Hemophilia carriers (HCs) face specific psychosocial challenges related to pregnancy, caused by their inherited bleeding disorder. Optimal support from healthcare providers can only be realized by exploring medical and psychological healthcare requirements. OBJECTIVE: To review all published evidence on the experiences and attitudes of HCs regarding reproductive decision-making, prenatal diagnosis, pregnancy, childbirth, and puerperium to provide an accessible overview of this information for health care providers. STUDY SELECTION: Cochrane library, PubMed/MEDLINE, EMBASE, CINAHL, and PsycINFO were searched for original qualitative data. Two authors performed study selection, risk-of-bias assessment, data extraction, and data analysis through meta-summary. The extracted themes were discussed within the research team. FINDINGS: Fifteen studies with an overall moderate quality were included. The following findings were identified: (a) Quality of life of family members with hemophilia influences reproductive decision-making; (b) Genetic counselling is generally considered useful; (c) The development of a specialized carrier clinic is considered valuable; (d) HCs describe prenatal diagnosis as beneficial yet psychosocially challenging; and (e) noninvasive prenatal diagnosis and preimplantation genetic diagnosis are predominantly considered beneficial. These findings are limited by the overall moderate quality of included studies and the possibly partly outdated results in the current era of hemophilia treatment. CONCLUSIONS: Available qualitative literature on HCs around pregnancy focuses on genetic counselling and prenatal diagnosis. Future studies are needed on the experiences and needs of HCs through pregnancy and puerperium as well as in light of emerging hemophilia diagnosis and treatment options.
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Hemofilia A , Actitud , Femenino , Asesoramiento Genético , Hemofilia A/diagnóstico , Hemofilia A/genética , Hemofilia A/terapia , Humanos , Embarazo , Investigación Cualitativa , Calidad de VidaRESUMEN
Due to the global prevalence of oral disease, tooth extraction is the most common surgical procedure required in general population thus likely to be similarly common in patients with haemophilia, especially those in older age and those living in countries with restricted resources. There are little or no consensus about optimal level and duration of factor replacement (FRP) therapy required to prevent bleeding complication following surgery and low levels of evidence to inform protocols and guidelines. The goal of this article was to review the literature regarding haematological treatment protocols and to assess their effectiveness in prevention of bleeding complications during and after tooth extractions in people with haemophilia. A total number of 29 articles were identified. Only two of the studies were randomized controlled trials, and meta-analysis was not possible. Significant heterogeneity regarding haematological regimes, dental surgical procedures, disease severity and sample size of published studies which are unable to reliably inform the provision of safe dental surgery was noted. Based on the haematological regimens, all studies were classified into one of three groups: pre- and postoperative FRP or DDAVP, single preoperative FRP or DDAVP, and no FRP treatment. The overall reported bleeding rate in case of both pre- and postoperative FRP and single dose FRP preoperative is similar, 11.9% and 11.4%, respectively, indicating that minimizing the use of clotting factor concentrate is possible if proper local haemostatic measures are provided. Strictly designed prospective studies with higher number of patients are necessary to get firm conclusions about optimal FRP treatment required to prevent bleeding complications during and after oral surgery in patients with haemophilia.
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Medicina Basada en la Evidencia/métodos , Hemofilia A/complicaciones , Extracción Dental/métodos , Consenso , HumanosRESUMEN
INTRODUCTION: Postpartum haemorrhage (PPH) is the major cause of maternal death worldwide. Haemostatic abnormalities are independently associated with a significantly increased risk for severe PPH. In this study, the value of haemostatic evaluation in women with severe PPH was explored. AIM: To investigate the occurrence of previously unknown inherited bleeding disorders in women with severe PPH. METHODS: Women with severe PPH (blood loss of ≥2000 mL) between 2011 and 2017, referred to the haematology outpatient clinic for haemostatic evaluation, were retrospectively included. A bleeding disorder was diagnosed based on (inter)national guidelines, or when having a clear bleeding phenotype, not fulfilling any diagnostic criteria or laboratory abnormalities, this being classified as Bleeding of Unknown Cause (BUC). Logistic regression was used to model the association between diagnosis and obstetrical causes and risk factors for PPH. RESULTS: In total, 85 women with PPH were included. In 23% (n = 16), a mild bleeding disorder was diagnosed, including low von Willebrand factor (Low VWF 8/16), platelet function disorders (PFD 5/16), BUC (2/16) and von Willebrand disease type 1 (1/16). No significant associations were found between obstetrical causes or risk factors for PPH and the presence of a bleeding disorder. CONCLUSION: In 23% of women with severe PPH, a mild bleeding disorder was diagnosed, independent of obstetrical causes or risk factors for PPH. This implies that severe PPH can be the first clinical symptom of an inherited bleeding disorder. Therefore, to optimize clinical management, haemostatic evaluation after severe PPH is recommended.
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Trastornos de la Coagulación Sanguínea/complicaciones , Trastornos de la Coagulación Sanguínea/genética , Hemorragia Posparto/epidemiología , Adulto , Femenino , Humanos , Estudios Retrospectivos , Factores de RiesgoRESUMEN
BACKGROUND: Haemophilia and von Willebrand disease (VWD) are common inherited bleeding disorders. Although patients with haemophilia or VWD have a high risk of hepatitis virus infection and hepatocellular carcinoma (HCC), little is known about the safety of liver resection in these patients. METHODS: From 2006 to 2016, there were seven hepatectomies with haemophilia A and three hepatectomies with VWD for malignant liver tumours at tertiary care hospitals in Japan and Switzerland. To evaluate the safety of hepatectomy in the blood coagulation disorder group (BD group), short-term outcomes in these patients were compared with 20 hepatectomies (non-BD group) for HCC, matched to a 2:1, operative procedure, period and background liver. RESULTS: Ten liver resections were performed in patients with haemophilia or VWD with administration of recombinant FVIII or VWF concentrate. Comparison of the BD vs non-BD group revealed no significant differences in the operative time (327 vs 407 minutes, P = 0.359), estimated blood loss (730 vs 820 mL, P = 0.748), red blood cell transfusion rate (10.0% vs 5.0%, P = 0.605), major complication rate (Clavien-Dindo grade III or IV) (10.0% vs 5.0%, P = 0.605) or mortality rate (0% vs 0%, P > 0.999). Additionally, the length of the postoperative hospital stay was similar between the two groups (13 vs 14 days, P = 0.296). CONCLUSION: Liver resection for treatment of HCC in patients with haemophilia or VWD can be safely performed through an appropriate perioperative administration protocol of coagulation factors.
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Factores de Coagulación Sanguínea/metabolismo , Hemofilia A/metabolismo , Hemofilia A/cirugía , Hepatectomía/efectos adversos , Seguridad , Enfermedades de von Willebrand/metabolismo , Enfermedades de von Willebrand/cirugía , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Resultado del TratamientoRESUMEN
Historically, the bleeding episodes in subjects with coagulation disorders were treated with substitution therapy, initially with whole blood and fresh frozen plasma, and more recently with specific factor concentrate. Currently, patients with hemophilia have the possibility of choosing different effective and safe treatments, including novel extended half-life and alternative hemostatic drugs. The availability of novel extended half-life products could probably overcome current prophylaxis limitations, particularly in hemophilia B patients, by reducing the frequency of injections, achieving a higher trough level, and improving the quality of life of the patients. In addition, subcutaneous administration of alternative therapeutics would simplify prophylaxis in patients with hemophilia A and B with and without inhibitors. Regarding von Willebrand disease, a recombinant von Willebrand factor was recently developed to control bleeding episodes in patients with this disease, in addition to available von Willebrand factor/factor VIII concentrates. The management of patients affected by rare bleeding disorders (RBDs) is still a challenge, owing to the limited number of specific products, which are mainly available only in countries with high resources. Some improvements have recently been achieved by the production of new recombinant factor (F) XIII A subunit-derived and FX plasma-derived products for the treatment of patients affected by FXIII and FX deficiency. In addition, the development of novel alternative therapeutics, such as anti-tissue factor pathway inhibitor, ALN-AT3, and ACE910, for patients with hemophilia might also have a role in the treatment of patients affected by RBDs.
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Enfermedades Hematológicas/terapia , Hematología/métodos , Animales , Coagulación Sanguínea , Combinación de Medicamentos , Factor VIII/uso terapéutico , Factor X/análisis , Deficiencia del Factor X/terapia , Deficiencia del Factor XIII/terapia , Hemofilia A/terapia , Humanos , Masculino , Ratones , Proteínas Recombinantes/uso terapéutico , Resultado del Tratamiento , Factor de von Willebrand/análisis , Factor de von Willebrand/uso terapéuticoRESUMEN
Essentials Studies characterizing neutralizing antibodies (inhibitors) in hemophilia B (HB) are lacking. The current study describes anti-factor (F) IX antibody profiles in 37 patients who have HB. Anti-FIX IgG4 levels exhibited a strong positive correlation with Nijmegen-Bethesda results. These data will help to more clearly define, predict, and treat alloantibody formation in HB. SUMMARY: Background Hemophilia B (HB) is an inherited bleeding disorder caused by the absence or dysfunction of coagulation factor IX (FIX). A subset of patients who have HB develop neutralizing alloantibodies (inhibitors) against FIX after infusion therapy. HB prevalence and the proportion of patients who develop inhibitors are much lower than those for hemophilia A (HA), which makes studies of inhibitors in patients with HB challenging due to the limited availability of samples. As a result, there is a knowledge gap regarding HB inhibitors. Objective Evaluate the largest group of patients with inhibitor-positive HB studied to date to assess the relationship between anti-FIX antibody profiles and inhibitor formation. Methods A fluorescence immunoassay was used to detect anti-FIX antibodies in plasma samples from 37 patients with HB. Results Assessments of antibody profiles showed that anti-FIX IgG1-4 , IgA, and IgE were detected significantly more often in patients with a positive Nijmegen-Bethesda assay (NBA). All NBA-positive samples were positive for IgG4 . Anti-FIX IgG4 demonstrated a strong correlation with the NBA, while correlations were significant, yet more moderate, for anti-FIX IgG1-2 and IgA. Conclusions The anti-FIX antibody profile in HB patients who develop inhibitors is diverse and correlates well with the NBA across immunoglobulin (sub)class, and anti-FIX IgG4 is particularly relevant to functional inhibition. The anti-FIX fluorescence immunoassay may serve as a useful tool to confirm the presence of antibodies in patients who have low positive NBA results and to more clearly define, predict, and treat alloantibody formation against FIX.
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Anticuerpos Neutralizantes/inmunología , Factor IX/inmunología , Técnica del Anticuerpo Fluorescente , Hemofilia B/inmunología , Inmunoglobulinas/inmunología , Adolescente , Adulto , Anciano , Coagulación Sanguínea , Estudios de Casos y Controles , Niño , Preescolar , Estudios Transversales , Humanos , Inmunoglobulina G/inmunología , Lactante , Isoanticuerpos/inmunología , Persona de Mediana Edad , Prevalencia , Índice de Severidad de la Enfermedad , Adulto JovenRESUMEN
BACKGROUND: The FYB gene encodes adhesion and degranulation-promoting adaptor protein (ADAP), a hematopoietic-specific protein involved in platelet activation, cell motility and proliferation, and integrin-mediated cell adhesion. No ADAP-related diseases have been described in humans, but ADAP-deficient mice have mild thrombocytopenia and increased rebleeding from tail wounds. PATIENTS AND METHODS: We studied a previously reported family of five children from two consanguineous sibships of Arab Christian descent affected with a novel autosomal recessive bleeding disorder with small-platelet thrombocytopenia. Homozygosity mapping and exome sequencing were used to identify the genetic lesion causing the disease phenotype on chromosome 5. Bone-marrow morphology and platelet function were analyzed. Platelets were characterized by scanning electron microscopy. RESULTS: We identified a homozygous deleterious nonsense mutation, c.393G>A, in FYB. A reduced percentage of mature megakaryocytes was found in the bone marrow. Patients' platelets showed increased basal expression of P-selectin and PAC-1, and reduced increments of activation markers after stimulation with ADP, as detected by flow cytometry; they also showed reduced pseudopodium formation and the presence of trapped platelets between the fibrin fibers after thrombin addition, as observed on scanning electron microscopy. CONCLUSIONS: This is the first report of a disease caused by an FYB defect in humans, manifested by remarkable small-platelet thrombocytopenia and a significant bleeding tendency. The described phenotype shows ADAP to be important for normal platelet production, morphologic changes, and function. It is suggested that mutation analysis of this gene be included in the diagnosis of inherited thrombocytopenia.
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Proteínas Adaptadoras Transductoras de Señales/genética , Plaquetas/ultraestructura , Codón sin Sentido , Hemorragia/genética , Hemostasis/genética , Trombocitopenia/genética , Árabes/genética , Plaquetas/metabolismo , Tamaño de la Célula , Análisis Mutacional de ADN , Fosfatasa 2 de Especificidad Dual/sangre , Exoma , Marcadores Genéticos , Predisposición Genética a la Enfermedad , Hemorragia/sangre , Hemorragia/diagnóstico , Hemorragia/etnología , Heterocigoto , Homocigoto , Humanos , Israel/epidemiología , Microscopía Electrónica de Rastreo , Selectina-P/sangre , Linaje , Fenotipo , Pruebas de Función Plaquetaria , Valor Predictivo de las Pruebas , Factores de Riesgo , Trombocitopenia/sangre , Trombocitopenia/diagnóstico , Trombocitopenia/etnologíaRESUMEN
BACKGROUND: Hemophilia A (HA) is an X-linked bleeding disorder caused by a deficiency in factor VIII (FVIII). von Willebrand disease (VWD) is characterized by a quantitative or qualitative defect in von Willebrand factor (VWF). Patients with VWD with severely low VWF or VWD Type 2N (VWD2N), a VWD subtype distinguished by defective VWF binding to FVIII, may have reduced FVIII levels secondary to their VWD. These patients superficially resemble patients with HA and pose a potential for misdiagnosis. OBJECTIVES: To investigate the unexplained cause of bleeding in HA patients without known FVIII mutations by assessing plasma VWF antigen (VWF:Ag), FVIII binding capacities and VWF genotypes. PATIENTS/METHODS: Thirty-seven of 1027 patients with HA studied as part of the Hemophilia Inhibitor Research Study lacked identifiable F8 mutations. These patients (cases) and 73 patients with identified F8 mutations (controls) were evaluated for VWF:Ag, a patient's VWF capacity to bind FVIII (VWF:FVIIIB) and VWF sequence. RESULTS: Four cases had VWF:Ag < 3 IU dL(-1) and VWF mutations consistent with Type 3 VWD. Six cases and one control were heterozygous for mutations previously reported to cause Type 1 VWD (VWD1) (n = five cases and one control) or predicted to be deleterious by Polyphen2 and SIFT prediction tools (n = 1 case). One control had VWF:Ag < 30 IU dL(-1) and seven patients (four cases and three controls), including two cases who were heterozygous for a known VWD2N mutation, had reduced VWF:FVIIIB. CONCLUSIONS: These data emphasize that some patients diagnosed with HA require VWF assessments in order to achieve a comprehensive diagnosis and an optimal treatment strategy.
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Coagulación Sanguínea/genética , Factor VIII/genética , Hemofilia A/genética , Mutación , Factor de von Willebrand/genética , Adolescente , Adulto , Biomarcadores/sangre , Pruebas de Coagulación Sanguínea , Estudios de Casos y Controles , Niño , Análisis Mutacional de ADN , Factor VIII/metabolismo , Predisposición Genética a la Enfermedad , Hemofilia A/sangre , Hemofilia A/diagnóstico , Hemorragia/sangre , Hemorragia/diagnóstico , Hemorragia/genética , Heterocigoto , Homocigoto , Humanos , Masculino , Fenotipo , Valor Predictivo de las Pruebas , Unión Proteica , Estados Unidos , Adulto Joven , Factor de von Willebrand/metabolismoRESUMEN
BACKGROUND: The development of neutralizing antibodies, referred to as inhibitors, against factor VIII is a major complication associated with FVIII infusion therapy for the treatment of hemophilia A (HA). Previous studies have shown that a subset of HA patients and a low percentage of healthy individuals harbor non-neutralizing anti-FVIII antibodies that do not elicit the clinical manifestations associated with inhibitor development. OBJECTIVE: To assess HA patients' anti-FVIII antibody profiles as potential predictors of clinical outcomes. METHODS: A fluorescence immunoassay (FLI) was used to detect anti-FVIII antibodies in 491 samples from 371 HA patients. RESULTS: Assessments of antibody profiles showed that the presence of anti-FVIII IgG1 , IgG2 or IgG4 correlated qualitatively and quantitatively with the presence of an FVIII inhibitor as determined with the Nijmegen-Bethesda assay (NBA). Forty-eight patients with a negative inhibitor history contributed serial samples to the study, including seven patients who had negative NBA titers initially and later converted to being NBA-positive. The FLI detected anti-FVIII IgG1 in five of those seven patients prior to their conversion to NBA-positive. Five of 15 serial-sample patients who had a negative inhibitor history and had anti-FVIII IgG1 later developed an inhibitor, as compared with two of 33 patients with a negative inhibitor history without anti-FVIII IgG1 . CONCLUSIONS: These data provide a rationale for future studies designed both to monitor the dynamics of anti-FVIII antibody profiles in HA patients as a potential predictor of future inhibitor development and to assess the value of the anti-FVIII FLI as a supplement to traditional inhibitor testing.
Asunto(s)
Autoanticuerpos/sangre , Factor VIII/inmunología , Inmunoensayo de Polarización Fluorescente/métodos , Hemofilia A/inmunología , Inmunoglobulina G/sangre , Espectrometría de Fluorescencia , Adolescente , Biomarcadores/sangre , Hemofilia A/sangre , Hemofilia A/diagnóstico , Humanos , Masculino , Valor Predictivo de las Pruebas , Pronóstico , Factores de Tiempo , Adulto JovenRESUMEN
OBJECTIVE: The aim of this study was to assess the effectiveness of localized treatments to persistently stop epistaxis in patients with inherited bleeding disorders. METHODS: In a self-controlled comparative clinical trial, to offer the best solution to stop epistaxis at home (within 10 minutes), patients with inherited bleeding disorders were treated using three different topical hemostatic agents, including Tranexamic acid impregnated tampon, EpiCell tampon prepared from oxidized regenerated cellulose pad, and ChitoHem tampon (reinforced with chitosan). The results of using these different products on three groups of randomly selected patients were ultimately compared using the χ(2) and Fisher's exact test statistics. RESULTS: A total of 31 patients, 5 females and 26 males with a mean age of 5.6 years, were included in the study. Twenty-three patients had Glanzmann disease, four had von-Willebrand disease, two had Bernard soulier syndrome, two had activated factor VII deficiency, and one patient had impaired secretion of adenosine deaminase. The study exhibited that statistically there was no significant difference between EpiCell tampon and Tranexamic acid impregnated tampon treatments with respect to the hemostasis duration. However, ChitoHem tampon was more efficient than Tranexamic acid impregnated tampon (P value <0.001) and EpiCell tampon (P value < 0.05). CONCLUSION: ChitoHem tampon, the chitosan-reinforced product, was the best therapy solution to stop epistaxis. We recommend further research on the use of other hemostatic agents for localized bleeding in patients with inherited bleeding disorders.