RESUMEN
BACKGROUND: Hereditary thrombotic thrombocytopenia purpura (hTTP) is an ultra-rare disorder resulting from an inherited deficiency of ADAMTS13, a von Willebrand factor (VWF)-cleaving metalloprotease. The plasma-derived factor VIII/VWF Koate (FVIII/VWFKoate ) has been shown to contain ADAMTS13, allowing for its use to treat hTTP at home by the patient/caregiver. AIM: Based on prior demonstration of safe and effective use of FVIII/VWFKoate in eight patients with hTTP, we conducted a retrospective study to gather additional data regarding the use of FVIII/VWFKoate for hTTP. METHODS: This was a multicentre, retrospective, noninterventional chart review of patients who had received FVIII/VWFKoate for the management of hTTP. Data collected included demographics, medical history, relevant family history, past use and tolerability of fresh frozen plasma, and details regarding FVIII/VWFKoate therapy. RESULTS: The cohort included 11 patients (seven males, four females) with hTTP, ranging in age at study entry from 2 to 28 years. The average duration of FVIII/VWFKoate therapy was 4.8 years (range, 0.5-6.5 years). Among nine patients using FVIII/VWFKoate as prophylaxis, the normalized annual rate of breakthrough TTP episodes ranged from 0.2 to 1.1 episodes/year. All nine patients who received FVIII/VWFKoate prophylaxis had thrombocytopenia recorded at baseline, while eight (88.9%) did not have thrombocytopenia after using FVIII/VWFKoate . There was one AE (unspecified) attributed to FVIII/VWFKoate . CONCLUSION: These data suggest that FVIII/VWFKoate is a safe and well-tolerated source of the missing ADAMTS13 enzyme in patients with hTTP, producing a marked reduction in thrombocytopenia prevalence, low frequency of TTP episodes, and with the added benefit of self- or caregiver-administration.
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Hemostáticos , Púrpura Trombocitopénica Trombótica , Masculino , Femenino , Humanos , Preescolar , Niño , Adolescente , Adulto Joven , Adulto , Factor VIII/uso terapéutico , Factor de von Willebrand/uso terapéutico , Estudios Retrospectivos , Estudios de Seguimiento , Proteínas ADAM , Púrpura Trombocitopénica Trombótica/tratamiento farmacológico , Plasma , Proteína ADAMTS13RESUMEN
OBJECTIVE: We assessed sociodemographic and clinical characteristics associated with depression and anxiety in individuals with Von Willebrand disease (VWD) aged ≥12 years. METHODS: The study collected data on patients' sociodemographic, joint problems and health-related quality of life (HRQoL) using EQ-5D-3L, 8-item patient health questionnaire for depression and 7-item Generalized Anxiety Disorder Questionnaire from participants in seven geographically diverse US haemophilia treatment centres. RESULTS: Analyses included 77 participants. The rates of depression and anxiety were 63.6% and 58.3%, respectively. Persons with low VWF displayed higher rates of depression (86.7%) or anxiety (69.2%) compared to those with VWD (58.1%, p = .04 for depression, and 55.9%, p = .38 for anxiety). Logistic regression analyses demonstrated that having joint problems (odds ratio [OR] = 6.3, confidence interval [CI] = 2.0-20.1) was the most important variable associated with depression, followed by being single, divorced, widowed, or separated in adult participants or parents of participants age < 18 years (OR = 7.0, CI = 1.7-29.0. The most important variable associated with anxiety was being single or lacking a partner (OR = 10.8, CI = 2.5-47.5), followed by age 12-17 years old (OR = 6.7, CI = 1.6-26.9), or having worse health compared to 3-months ago (OR = 12.3, CI = 1.3-116.2). Mean covariates adjusted EQ visual analogue scale score was significantly lower among persons with depression (68.77 ± 3.15 vs. 77.58 ± 4.24, p = .03) than those without depression. CONCLUSIONS: Our study revealed concerning levels of depression and anxiety in this VWD sample. Lack of social support was determined an important factor associated with depression and anxiety in this sample. Mental health screening is critical in VWD clinical evaluation and care.
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Enfermedades de von Willebrand , Adulto , Humanos , Niño , Adolescente , Enfermedades de von Willebrand/complicaciones , Enfermedades de von Willebrand/epidemiología , Enfermedades de von Willebrand/diagnóstico , Factor de von Willebrand/análisis , Depresión/complicaciones , Depresión/epidemiología , Calidad de Vida , Ansiedad/complicaciones , Ansiedad/epidemiología , Trastornos de Ansiedad/complicaciones , Trastornos de Ansiedad/epidemiologíaRESUMEN
Graphical representation of increasing percentage of female patients seen at HTCs, percentage of females by diagnosis, number of clinics in existence, and absolute number of female patients seen over a 10-year period (top left then clockwise).
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Hemofilia A , Humanos , Femenino , Hemofilia A/epidemiología , Hemofilia A/terapiaRESUMEN
BACKGROUND: Nephrotic syndrome (NS) results in hypercoagulability and increased risk of infection. Furthermore, infection increases the risk of venous thromboembolism (VTE). Our objective was to determine the prevalence of infection, VTE, and the associated outcomes among a cohort of hospitalized children with NS. METHODS: All children with NS admitted to 17 pediatric hospitals across North America from 2010 to 2012 were included. Prevalence of infection and VTE was determined. Wilcoxon rank-sum and logistic regression were performed. RESULTS: Seven-hundred thirty hospitalizations occurred among 370 children with NS. One-hundred forty-eight children (40%) had ≥ 1 infection (211 episodes) and 11 (3%) had VTE. Those with VTE had infection more frequently (p = 0.046) and were younger at NS diagnosis (3.0 vs. 4.0 years; p = 0.008). The most common infectious pathogen identified was Streptococcus pneumoniae. The median hospital length of stay for those with infection [10 vs 5 days (p < 0.0001)] or VTE [22 vs 6 days (p < 0.0001)] was longer than those without either complication. Of those with infection, 13% had an intensive care unit (ICU) stay compared with 3.3% of those without infection. Median ICU stay was 4 days in those with VTE compared to 0 days in those without (p < 0.001). By logistic regression, only the number of ICU days was associated with VTE (OR 1.074, 95% CI 1.013-1.138). CONCLUSIONS: Hospitalized children with NS have high rates of infection. Presence of VTE was associated with infection. Both were associated with longer hospitalizations and ICU stays.
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Síndrome Nefrótico/complicaciones , Infecciones Neumocócicas/epidemiología , Streptococcus pneumoniae/aislamiento & purificación , Tromboembolia Venosa/epidemiología , Niño , Preescolar , Femenino , Humanos , Unidades de Cuidados Intensivos/estadística & datos numéricos , Tiempo de Internación/estadística & datos numéricos , Modelos Logísticos , Masculino , América del Norte/epidemiología , Infecciones Neumocócicas/etiología , Prevalencia , Estudios Retrospectivos , Factores de Riesgo , Tromboembolia Venosa/etiologíaAsunto(s)
Anticuerpos Biespecíficos , Hemofilia A , Anticuerpos Biespecíficos/farmacología , Anticuerpos Biespecíficos/uso terapéutico , Anticuerpos Monoclonales Humanizados/farmacología , Anticuerpos Monoclonales Humanizados/uso terapéutico , Factor VIII/uso terapéutico , Hemofilia A/complicaciones , Hemofilia A/tratamiento farmacológico , Humanos , Procedimientos Quirúrgicos MenoresRESUMEN
Scurvy results from a dietary deficiency of vitamin C (ascorbic acid) and is rarely thought of in modern day medicine. It now almost always occurs in pediatric patients with behavioral diagnoses, nutritionally restricted diets, and food allergies. Symptoms of scurvy include ecchymoses, bleeding gums, and arthralgias. Here, we present a 17-year-old male with autism spectrum disorder and a diet severely deficient in ascorbic acid due to textural aversion and food preferences. He presented with recurrent arthritis, hemarthrosis, bruising, and anemia. His vitamin C level was low, and his symptoms improved promptly after treatment with ascorbic acid.
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Ácido Ascórbico/administración & dosificación , Trastorno del Espectro Autista , Hemorragia , Escorbuto , Adolescente , Hemorragia/diagnóstico , Hemorragia/tratamiento farmacológico , Hemorragia/patología , Humanos , Masculino , Escorbuto/diagnóstico , Escorbuto/tratamiento farmacológico , Escorbuto/patologíaRESUMEN
BACKGROUND: The National Hemophilia Foundation (NHF) conducted extensive, inclusive community consultations to guide prioritization of research in coming decades in alignment with its mission to find cures and address and prevent complications enabling people and families with blood disorders to thrive. RESEARCH DESIGN AND METHODS: With the American Thrombosis and Hemostasis Network, NHF recruited multidisciplinary expert working groups (WG) to distill the community-identified priorities into concrete research questions and score their feasibility, impact, and risk. WG6 was charged with identifying the infrastructure, workforce development, and funding and resources to facilitate the prioritized research. Community input on conclusions was gathered at the NHF State of the Science Research Summit. RESULTS: WG6 detailed a minimal research capacity infrastructure threshold, and opportunities to enable its attainment, for bleeding disorders centers to participate in prospective, multicenter national registries. They identified challenges and opportunities to recruit, retain, and train the diverse multidisciplinary care and research workforce required into the future. Innovative collaborative approaches to trial design, resource networking, and funding to surmount obstacles facing research in rare disorders were elucidated. CONCLUSIONS: The innovations in infrastructure, workforce development, and resources and funding proposed herein may contribute to facilitating a National Research Blueprint for Inherited Bleeding Disorders.
Research is critical to advancing the diagnosis and care of people with inherited bleeding disorders (PWIBD). This research requires significant infrastructure, including people and resources. Hemophilia treatment centers (HTC) need many different skilled care professionals including doctors, nurses, and other providers; also statisticians, data managers, and other experts to process patients' clinical information into research. Attracting diverse qualified professionals to the clinical and research work requires long-term planning, recruiting individuals in training programs and retaining them as they become experts. Research infrastructure includes physical servers running database software, networks that link them, and the environment in which these components function. US Centers for Disease Control and Prevention (CDC) and American Thrombosis and Hemostasis Network (ATHN) coordinate and fund data collection at HTCs on the health and well-being of thousands of PWIBD into a registry used in research studies.National Hemophilia Foundation (NHF) and ATHN asked our group of health care professionals, technology experts, and lived experience experts (LEE) to identify the infrastructure, workforce, and resources needed to do the research most important to PWIBD. We identified the types of CDC/ATHN studies all HTCs should be able to perform, and the physical and human infrastructure this requires. We prioritized finding the best clinical trial designs to study inherited bleeding disorders, identifying ways to share personnel and tools between HTCs, and innovating how research is governed and funded. Involving LEEs in designing, managing, and carrying out research will be key in conducting research to improve the lives of PWIBD.
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Hemofilia A , Trombosis , Humanos , Estados Unidos , Estudios Prospectivos , Hemostasis , Recursos HumanosRESUMEN
Child abuse might be suspected when children present with cutaneous bruising, intracranial hemorrhage, or other manifestations of bleeding. In these cases, it is necessary to consider medical conditions that predispose to easy bleeding or bruising. When evaluating for the possibility of bleeding disorders and other conditions that predispose to hemorrhage, it is important for pediatricians to consider the child's presenting history, medical history, and physical examination findings before initiating a laboratory investigation. Many medical conditions can predispose to easy bleeding. Before ordering laboratory tests for a disease, it is useful to understand the biochemical basis and clinical presentation of the disorder, condition prevalence, and test characteristics. This technical report reviews the major medical conditions that predispose to bruising or bleeding and should be considered when evaluating for abusive injury.
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Trastornos de la Coagulación Sanguínea , Maltrato a los Niños , Contusiones , Trastornos de la Coagulación Sanguínea/diagnóstico , Niño , Maltrato a los Niños/diagnóstico , Contusiones/diagnóstico , Contusiones/etiología , Diagnóstico Diferencial , Hemorragia/diagnóstico , HumanosRESUMEN
Caring for children and adolescents with disorders of hemostasis and thrombosis (HAT) has become more specialized and requires a unique skill set that many providers are not able to obtain in standard pediatric hematology/oncology/bone marrow transplant fellowship training programs. The influx of numerous therapeutic advances and increasing medical complexity has expanded the need for experienced HAT providers and subspecialty collaboration in the inpatient setting due to the nuances in the management of patients with HAT complications and concerns. While there are data highlighting the benefits of an inpatient hemostasis, thrombosis, and anticoagulation management service in adult hospitals, there are limited pediatric data supporting such programs. In this article, we summarize the current practices of various pediatric institutions in the inpatient management of HAT patients and provide a consensus opinion for the development of a pediatric inpatient HAT service at tertiary care referral centers.
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Pacientes Internos , Trombosis , Adolescente , Adulto , Niño , Comunicación , Consenso , Hemostasis , Hospitales Pediátricos , Humanos , Recién Nacido , Derivación y Consulta , Trombosis/diagnóstico , Trombosis/terapiaRESUMEN
Bruising or bleeding in a child can raise the concern for child abuse. Assessing whether the findings are the result of trauma and/or whether the child has a bleeding disorder is critical. Many bleeding disorders are rare, and not every child with bruising/bleeding that may raise a concern for abuse requires an evaluation for bleeding disorders. However, in some instances, bleeding disorders can present in a manner similar to child abuse. Bleeding disorders cannot be ruled out solely on the basis of patient and family history, no matter how extensive. The history and clinical evaluation can be used to determine the necessity of an evaluation for a possible bleeding disorder, and prevalence and known clinical presentations of individual bleeding disorders can be used to guide the extent of laboratory testing. This clinical report provides guidance to pediatricians and other clinicians regarding the evaluation for bleeding disorders when child abuse is suspected.
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Trastornos de la Coagulación Sanguínea , Maltrato a los Niños , Contusiones , Niño , Maltrato a los Niños/diagnóstico , Contusiones/diagnóstico , Contusiones/etiología , Hemorragia/diagnóstico , Hemorragia/etiología , Humanos , PrevalenciaRESUMEN
BACKGROUND: The characteristic findings of abusive head trauma (AHT) include retinal hemorrhages (RH). RH have many etiologies in childhood, which should be considered in the differential diagnosis of possible child abuse. The relationship between RH and thrombophilia in children is not well established. OBJECTIVE: In this literature review, we sought to assess whether retinal findings in pediatric patients with thrombophilia could mimic those of AHT. METHODS: A literature search was performed to identify all cases of thrombophilia in children less than 18 years old with ocular manifestations. Disorders of thrombophilia including protein C and S deficiency, factor V Leiden (FVL), prothrombin variant, MTHFR mutation, hyperhomocysteinemia, elevated factor VIII, and elevated lipoprotein (a) were considered. All cases of pediatric thrombophilia with retinal examination or intraocular bleeding were included. If provided, descriptions of the RH were reviewed. RESULTS: Our initial search yielded 514 results. Forty-three articles met our inclusion criteria. We identified 3 children with RH within the AHT usual age range (<5 years old), ages 5 weeks and 7 weeks old, in the setting of thrombophilia. One child had ocular findings that could potentially mimic abuse. No other indicators of abuse were present in this case. CONCLUSIONS: Based on previous reports, thrombophilia alone has not been shown to clearly mimic abusive head trauma. In reported cases of thrombophilia with RH, the clinical picture and ophthalmic findings are usually distinct from abuse.
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Maltrato a los Niños , Traumatismos Craneocerebrales , Adolescente , Niño , Maltrato a los Niños/diagnóstico , Preescolar , Traumatismos Craneocerebrales/diagnóstico , Diagnóstico Diferencial , Humanos , Lactante , Retina , Hemorragia Retiniana/diagnóstico , Hemorragia Retiniana/etiologíaRESUMEN
BACKGROUND: Retinal hemorrhages (RH) are a common manifestation of abusive head trauma (AHT) resulting from acceleration-deceleration injury with or without blunt impact. Evaluation of a child with RH requires careful consideration of these differential diagnoses. The extent to which coagulopathy alone can cause RH would be useful to understand as coagulopathy may accompany AHT. OBJECTIVE: In this systematic review, we sought to identify whether coagulopathies have been reported with RH similar to those of AHT. METHODS: We performed a literature search for ocular manifestations of bleeding disorders in children less than 18 years old. We included clotting factor deficiencies, vitamin K deficiency, platelet function abnormalities, thrombocytopenia, disseminated intravascular coagulation (DIC), and trauma induced coagulopathy (TIC). We included only pediatric reports of intraocular bleeding or documented eye examinations that indicated no hemorrhages. We then re-examined cases for ocular and systemic findings that could potentially mimic abuse. RESULTS: Our initial search yielded 816 results. Sixty-one articles met our inclusion criteria. Of these, there were 32 children within the AHT age range (less than 5 years old) who had RH and concomitant coagulopathy. Only 5 cases might potentially be confused for abuse. Of these, no classic characteristics of RH from abuse such as retinoschisis or retinal folds were found. Systemic features were inconsistent with AHT. CONCLUSIONS: The presence of coagulopathy alone does not rule out the possibility that the child has been abused. Coagulopathy alone has not been reported as an etiology of RH that are consistent with AHT, especially when other findings are present.
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Maltrato a los Niños , Traumatismos Craneocerebrales , Retinosquisis , Adolescente , Niño , Preescolar , Traumatismos Craneocerebrales/diagnóstico , Diagnóstico Diferencial , Humanos , Lactante , Hemorragia Retiniana/etiología , Retinosquisis/diagnósticoRESUMEN
INTRODUCTION: High collision-risk physical activity can increase bleeding risk in people with hemophilia A, as can increasing the time between factor VIII (FVIII) administration and physical activity. FVIII prophylaxis may be tailored to planned activities to prevent activity-related bleeding. AIM: To explore the relationship between physical activity levels, FVIII infusion timing, and occurrence of bleeding in patients with severe/moderately severe hemophilia A without FVIII inhibitors receiving antihemophilic factor (recombinant) (rAHF; ADVATE®; Baxalta US Inc., a Takeda company, Lexington, MA, USA). METHODS: SPACE was a 6-month, prospective, multicenter, observational outcomes study (NCT02190149). Enrolled patients received an eDiary application and a wearable activity tracker, which recorded physical activity, rAHF infusion, and occurrence of bleeding. Physical activity risks were ranked using National Hemophilia Foundation criteria. RESULTS: Fifty-four patients aged 11-58 years (n = 47 prophylaxis, n = 7 on-demand) were included in the analysis. Patients had a mean (SD) 8.14 (10.94) annualized bleeding rate, and recorded 4980 intervals between an rAHF infusion and physical activity; 1759 (35.3%) of these intervals were ≤24 hours. Analysis of recorded eDiary data showed that the risk of activity-related bleeding did not significantly increase with time between last infusion and activity, but did increase with higher-risk physical activities. Analysis of activity tracker recorded data showed that the risk of bleeding reported by patients as spontaneous increased with prolonging time (≤24 to >24 hours) from last infusion to physical activity start (odds ratio 2.65, p < 0.05). Joint health data collected at baseline were not included in the regression analysis because of small sample size; therefore the study could not assess whether patients with more joint disease at baseline were at higher risk of injury-related and reported spontaneous occurrence of bleeding. CONCLUSION: These results show that activities with a high risk of collision lead to an increased risk of bleeding. Further investigation is warranted to explore potential benefits of FVIII infusion timing to reduce the risks of activity-related occurrence of bleeding.
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BACKGROUND: With the consequences of inadequate dosing ranging from increased bleeding risk to excessive drug costs and undesirable administration regimens, the antihemophilic factors are uniquely suited to dose individualization. However, existing options for individualization are limited and exist outside the flow of care. We developed clinical decision support (CDS) software that is integrated with our electronic health record (EHR) and designed to streamline the process for our hematology providers. OBJECTIVES: The aim of this study is to develop and examine the usability of a CDS tool for antihemophilic factor dose individualization. METHODS: Our development strategy was based on the features associated with successful CDS tools and driven by a formal requirements analysis. The back-end code was based on algorithms developed for manual individualization and unit tested with 23,000 simulated patient profiles created from the range of patient-derived pharmacokinetic parameter estimates defined in children and adults. A 296-item heuristic checklist was used to guide design of the front-end user interface. Content experts and end-users were recruited to participate in traditional usability testing under an institutional review board approved protocol. RESULTS: CDS software was developed to systematically walk the point-of-care clinician through dose individualization after seamlessly importing the requisite patient data from the EHR. Classical and population pharmacokinetic approaches were incorporated with clearly displayed estimates of reliability and uncertainty. Users can perform simulations for prophylaxis and acute bleeds by providing two of four therapeutic targets. Testers were highly satisfied with our CDS and quickly became proficient with the tool. CONCLUSION: With early and broad stakeholder engagement, we developed a CDS tool for hematology provider that affords seamless transition from patient assessment, to pharmacokinetic modeling and simulation, and subsequent dose selection.
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Sistemas de Apoyo a Decisiones Clínicas , Registros Electrónicos de Salud , Hemofilia A/tratamiento farmacológico , Sistemas de Atención de Punto , Adulto , HumanosRESUMEN
In Texas, apprentice midwives do not have prescriptive authority to administer parenteral vitamin K. This case report underscores the importance of parenteral vitamin K administration in preventing vitamin K deficiency bleeding and the potential danger in prohibiting apprentice midwives from providing this standard of care to the newborn.
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Antifibrinolíticos/uso terapéutico , Partería/legislación & jurisprudencia , Deficiencia de Vitamina K/prevención & control , Vitamina K/uso terapéutico , Muerte Encefálica , Humanos , Lactante , Inyecciones Intramusculares , Hemorragias Intracraneales/etiología , Hemorragias Intracraneales/terapia , Masculino , Texas , Deficiencia de Vitamina K/complicacionesRESUMEN
BACKGROUND/OBJECTIVES: Hospital acquired venous thromboembolism in children is associated with significant morbidity/mortality. Prevention strategies include sequential compression devices and prophylactic anticoagulation but these interventions carry risk and are poorly studied in children. Objectives were to evaluate primary thromboprophylaxis use in hospitalized children over time and the associated bleeding risk. MATERIALS AND METHODS: Retrospective study of hospitalized patients aged 10-18â¯years within the Pediatric Health Information System administrative database from January 2008-September 2015. Factors associated with thromboprophylaxis receipt and bleeding were identified using generalized linear mixed effects models. RESULTS: Of 1,075,383 hospitalizations, 10,544 (1%) received prophylactic enoxaparin and 58,768 (5%) received mechanical compression. Mechanical thromboprophylaxis increased slightly over time (4.3% in 2008, 6.2% in 2015), enoxaparin use did not (0.8% in 2008, 1.2% in 2015). Patients aged 16-18 were more likely than younger children (10-12) to receive pharmacologic (adjusted odds ratio [aOR] 3.1, 95% confidence interval [CI] 2.9-3.3) or mechanical thromboprophylaxis (aOR 2.9, 95% CI 2.9-3). Patients on rehabilitation medical service were more likely to receive prophylactic enoxaparin (aOR 53, 95% CI 44.1-64.5). 5.6% (589/10,544) of patients receiving enoxaparin prophylaxis had bleeding. Thromboprophylaxis use by hospital varied with a range of 0.25-3.3% for enoxaparin and 2-26.2% for mechanical compression. CONCLUSION: Thromboprophylaxis is infrequently utilized in hospitalized children. Pharmacologic prophylaxis with enoxaparin remains low and has not substantially increased over time. Significant variability exists across hospitals and services in the administration of both mechanical and pharmacologic thromboprophylaxis highlighting the need for further evidence to standardize practice.
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Anticoagulantes/uso terapéutico , Enoxaparina/uso terapéutico , Trombolisis Mecánica , Tromboembolia/prevención & control , Adolescente , Anticoagulantes/efectos adversos , Niño , Enoxaparina/efectos adversos , Femenino , Hemorragia/etiología , Humanos , Masculino , Trombolisis Mecánica/efectos adversos , Trombolisis Mecánica/métodos , Estudios Retrospectivos , Tromboembolia/terapia , Resultado del TratamientoRESUMEN
Genetic modifiers contribute to phenotypic variability in patients with sickle cell anemia (SCA). The influence of the bilirubin UDP-glucuronosyltransferase (UGT) 1A1 (TA)(n)TAA promoter polymorphism on bilirubin levels and gallbladder disease in SCA was examined using prospectively collected data from the Cooperative Study of Sickle Cell Disease. A total of 324 children with HbSS (median age 6.9 years) had UGT1A1 genotyping; 243 (75%) had common (TA)(6) or (TA)(7) alleles, whereas 81 (25.0%) had variant (TA)(5) or (TA)(8) alleles. The UGT1A1 genotype significantly influenced average bilirubin levels for the common alleles: 6/6 genotype = 2.36 +/- 1.13 mg/dL, 6/7 genotype = 2.90 +/- 1.54 mg/dL, and 7/7 genotype = 4.24 +/- 2.11 mg/dL (P < 0.0001). Thirty-nine percent of children with the 7/7 genotype had documented gallbladder disease, compared with 18.2% with the 6/7 genotype and only 9.9% with the wildtype 6/6 UGT1A1 genotype (P = 0.001). To analyze the (TA)(5) and (TA)(8) variant alleles, three groups were generated, showing increasing bilirubin levels with increasing TA repeats and age. Group 3 (genotypes 6/8, 7/7, and 7/8) had a significantly greater rate of bilirubin change than Groups 1 (genotypes 5/6, 5/7, and 6/6) or 2 (genotype 6/7). These results validate previous smaller studies and confirm that the UGT1A1 promoter polymorphism exerts a powerful influence on bilirubin levels and the development of gallbladder disease in children with SCA. UGT1A1 genotyping should be considered as a screening tool for predicting children most likely to develop gallbladder disease at a young age.