RESUMO
ABSTRACT: There is significant ongoing debate regarding type 1 von Willebrand disease (VWD) defintion. Previous guidelines recommended patients with von Willebrand factor (VWF) levels <30 IU/dL be diagnosed type 1 VWD, whereas patients with significant bleeding and VWF levels from 30 to 50 IU/dL be diagnosed with low VWF. To elucidate the relationship between type 1 VWD and low VWF in the context of age-induced increases in VWF levels, we combined data sets from 2 national cohort studies: 162 patients with low VWF from the Low VWF in Ireland Cohort (LoVIC) and 403 patients with type 1 VWD from the Willebrand in The Netherlands (WiN) studies. In 47% of type 1 VWD participants, VWF levels remained <30 IU/dL despite increasing age. Conversely, VWF levels increased to the low VWF range (30-50 IU/dL) in 30% and normalized (>50 IU/dL) in 23% of type 1 VWD cases. Crucially, absolute VWF antigen (VWF:Ag) levels and increase of VWF:Ag per year overlapped between low VWF and normalized type 1 VWD participants. Moreover, multiple regression analysis demonstrated that VWF:Ag levels in low VWF and normalized type 1 VWD patients would not have been different had they been diagnosed at the same age (ß = 0.00; 95% confidence interval, -0.03 to 0.04). Consistently, no difference was found in the prevalence of VWF sequence variants; factor VIII activity/VWF:Ag or VWF propeptide/VWF:Ag ratios; or desmopressin responses between low VWF and normalized type 1 VWD patients. In conclusion, our findings demonstrate that low VWF does not constitute a discrete clinical or pathological entity. Rather, it is part of an age-dependent type 1 VWD evolving phenotype. Collectively, these data have important implications for future VWD classification criteria.
Assuntos
Doença de von Willebrand Tipo 1 , Doenças de von Willebrand , Humanos , Fator de von Willebrand/genética , Doença de von Willebrand Tipo 1/diagnóstico , Países Baixos/epidemiologia , Doenças de von Willebrand/diagnóstico , Doenças de von Willebrand/genética , Hemorragia/patologiaRESUMO
AIM: This study aimed to examine physical activity (PA), physical fitness and cardiometabolic risk amongst people with moderate and severe haemophilia (PwMSH). METHODS: The following domains were examined: PA (accelerometry); functional aerobic capacity (6-Minute Walk Test); grip strength (dynamometry); balance (One Leg Stand Test); body composition (anthropometry and bioimpedance analysis); blood pressure; arterial stiffness; and cardiometabolic disorders. RESULTS: A total of 53 PwMSH (44 years) and 33 controls (43 years; p = .679) were recruited. Compared to controls, PwMSH were significantly less active in moderate and vigorous PA parameters (all p < .05), and less physically fit indicated by 6-Minute Walk distance (p < .0005), grip strength (p = .040) and balance (p < .0005). PwMSH had higher rates of abdominal adiposity compared to controls measured by waist circumference indices (all p < .05). Resting blood pressure and arterial stiffness were not significantly different (p = .797 and .818, respectively). With respect to overall PA, World Health Organisation recommended targets for adults were achieved by the majority of both groups (haemophilia: 72.9% vs. controls: 90.0%; p = .069). Importantly, the number of PwMSH who achieved guideline recommended PA via longer, sustained bouts of moderate-vigorous PA was significantly lower compared to controls (18.8% vs. 56.7%; p = .001). Lastly, clinically diagnosed hypertension, insulin resistance and hyperlipidaemia were more prevalent amongst PwMSH compared to controls. CONCLUSION: Low levels of PA and physical fitness, and significant rates of abdominal adiposity and hypertension may collectively influence the risk and severity of various cardiometabolic and/or musculoskeletal health issues amongst ageing PwMSH. Personalised multi-disciplinary health interventions involving PA, dietary and health psychology input for PwMSH warrant future investigation.
Assuntos
Doenças Cardiovasculares , Hemofilia A , Hipertensão , Humanos , Adulto , Hemofilia A/complicações , Hemofilia A/epidemiologia , Exercício Físico/fisiologia , Aptidão Física , Doenças Cardiovasculares/epidemiologia , Doenças Cardiovasculares/etiologia , Índice de Massa CorporalRESUMO
AIM: To conduct a cross-sectional follow-up assessment of physical activity (PA) in people with moderate and severe haemophilia (PwMSH) from the Irish Personalised Approach to the Treatment of Haemophilia (iPATH) study. METHODS: Between June-December 2021, participants' PA was measured over one week using accelerometery, and was compared with their previously measured data from the original iPATH assessment. Self-awareness of PA and the impact of the Covid-19 pandemic on PA, pain, mobility and function were retrospectively examined using a survey. RESULTS: Of 30 participants who returned surveys [n = 19, severe (FVIII, <.01 IU/mL); n = 4, moderate (FVIII, .01-.05 IU/mL); n = 7, severe (FIX, <.01 IU/mL); age: 47 (36, 55) years], 28 completed accelerometery (follow-up time: 3 years). There were no significant differences in accelerometer PA (all p > .05), but achievement of World Health Organisation guidelines increased (67.9%-75.0%; p = .646). Increased self-awareness of PA was reported by 76.7%, and 66.7% reported desires to become more physically active. Compared to normal, most reported either no differences or lower levels of PA during lockdown restrictions. Self-reported PA increased for most when restrictions eased from April 2021 onwards. Beyond the pandemic, concerns included pain and access to exercise resources. CONCLUSION: Self-reported PA throughout the pandemic was variable, whilst there were no significant differences in objectively measured PA between assessment periods, despite reports of increased self-awareness and desires to be physically active at follow-up. Further qualitative research is needed to design personalised PA and health interventions, capturing perspectives of patients, their families, and multi-disciplinary haemophilia healthcare providers.
Assuntos
COVID-19 , Hemofilia A , Humanos , Adulto , Pessoa de Meia-Idade , Seguimentos , Hemofilia A/epidemiologia , Hemofilia A/terapia , Estudos Transversais , Pandemias , Estudos Retrospectivos , COVID-19/epidemiologia , Controle de Doenças Transmissíveis , Exercício FísicoRESUMO
OBJECTIVES: To establish the prevalence of pain and functional disability in Irish adults with moderate and severe haemophilia, and to examine demographic and lifestyle influences. METHODS: Males ≥18 years with moderate or severe haemophilia participated. Pain and function were examined using the PROBE questionnaire. RESULTS: Of 49 participants [median age 44 (IQR 32, 52) years], most had severe haemophilia (Factor VIII = 30; Factor IX = 13) and were on regular prophylaxis (88%). Those with moderate haemophilia (Factor VIII = 5; Factor IX = 1) treated on demand (12%). Acute (72%) and chronic pain (71%), functional difficulties (58%), and analgesic requirements (92%) were prevalent. Age was significantly associated with more advanced haemophilic arthropathy (p = .002), chronic pain (p = .029) and functional difficulties (p = .036). Adults who reported chronic pain commenced prophylaxis significantly later in life [32 (20, 51) vs. 8 (1, 23) years; p = .004]. Physical activity was significantly lower in those with functional difficulties (p < .05). A disparity between self-perceived 'target joints' and clinically defined target joints was also identified (76% vs. 23%). CONCLUSION: Haemophilic arthropathy, pain and functional disability were prevalent amongst Irish adults with moderate and severe haemophilia. Age-dependent lifestyle, analgesic and treatment influences on pain and function warrant further investigation.
Assuntos
Dor Crônica , Hemofilia A , Hemofilia B , Artropatias , Adulto , Dor Crônica/diagnóstico , Dor Crônica/epidemiologia , Dor Crônica/etiologia , Fator IX/uso terapêutico , Fator VIII/uso terapêutico , Hemartrose/tratamento farmacológico , Hemofilia A/complicações , Hemofilia A/tratamento farmacológico , Hemofilia A/epidemiologia , Humanos , MasculinoRESUMO
BACKGROUND: Patients with hemophilia (PWHs) may experience spontaneous or traumatic bleeding episodes. Recurrent bleeding can lead to end-stage hemophilic arthropathy and total knee replacement (TKR) provides an effective treatment. The aim of this study is to investigate outcomes in PWHs who undergo TKR. METHODS: A systematic review and meta-analysis was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Study outcomes included patient-reported functional outcomes, implant survivorship, and complications. Subgroup analysis was performed assessing the effect of recombinant prophylaxis medication by comparing studies that included only TKRs performed after the year 2000 (period A), to those that included TKRs before 2000 (period B). RESULTS: Twenty-eight studies were included, with a total of 1210 TKRs performed in 917 PWHs. The mean age of patients was 38.5 years (standard deviation 5.1) with a mean length of follow-up of 7.1 years (standard deviation 2.9). The total complication rate was 28.7%, with 19.3% requiring a further procedure. Hospital for Special Surgery Knee Score improved by 44.6 points (confidence interval 38.9-50.4) and Knee Society Score function improved by 35.9 points (confidence interval 30.1-41.8). Total range of motion improved by 22.3°. The most common complication was post-operative hemarthrosis (7.6%, 92 TKRs). Deep infection (6.2% vs 3.9%) and aseptic loosening (3.8% vs 2.1%) rates fell between period B and period A. CONCLUSION: TKR in PWHs is a successful procedure improving function, reducing pain, and improving range of motion. PWHs undergo TKR at a younger age and have a higher risk of complications, though contemporary treatment has reduced these risks. PWHs can expect similar survivorship to the general population.
Assuntos
Artroplastia do Joelho , Hemofilia A , Prótese do Joelho , Adulto , Artroplastia do Joelho/efeitos adversos , Hemartrose/etiologia , Hemartrose/cirurgia , Hemofilia A/complicações , Humanos , Articulação do Joelho/cirurgia , Sobrevivência , Resultado do TratamentoRESUMO
Vaccine-induced immune thrombotic thrombocytopenia (VITT) is a novel entity that emerged in March 2021 following reports of unusual thrombosis after ChAdOx1 nCoV-19, (AstraZeneca) vaccination. Following the recognition of this syndrome, multiple consensus guidelines have been released to risk stratify patients presenting with possible symptoms after ChAdOx1 nCoV-19 vaccination. All guidelines rapidly identify VITT in patients with the complete triad of thrombocytopenia, thrombosis and elevated D-dimers after ChAdOx1 nCoV-19 vaccination. However, with earlier recognition of the associated symptoms, the clinical manifestations are likely to be more heterogeneous and represent an evolving spectrum of disease. In this setting, current guidelines may lack the sensitivity to detect early cases of VITT and risk missed or delayed diagnoses. The broad clinical phenotype and challenges associated with diagnosis of VITT are highlighted in our present case series of four patients with confirmed VITT. Dependent on the guidance used, each patient could have been classified as a low probability of VITT at presentation. The present study highlights the issues associated with the recognition of VITT, the limitations of current guidance and the need for heightened clinical vigilance as our understanding of the pathophysiology of this novel condition evolves.
Assuntos
Púrpura Trombocitopênica Idiopática/induzido quimicamente , Vacinas/efeitos adversos , Adulto , COVID-19 , Feminino , Humanos , Pessoa de Meia-Idade , SARS-CoV-2RESUMO
Glycan determinants on von Willebrand factor (VWF) play critical roles in regulating its susceptibility to proteolysis and clearance. Abnormal glycosylation has been shown to cause von Willebrand disease (VWD) in a number of different mouse models. However, because of the significant technical challenges associated with accurate assessment of VWF glycan composition, the importance of carbohydrates in human VWD pathogenesis remains largely unexplored. To address this, we developed a novel lectin-binding panel to enable human VWF glycan characterization. This methodology was then used to study glycan expression in a cohort of 110 patients with low VWF compared with O blood group-matched healthy controls. Interestingly, significant interindividual heterogeneity in VWF glycan expression was seen in the healthy control population. This variation included terminal sialylation and ABO(H) blood group expression on VWF. Importantly, we also observed evidence of aberrant glycosylation in a subgroup of patients with low VWF. In particular, terminal α(2-6)-linked sialylation was reduced in patients with low VWF, with a secondary increase in galactose (Gal) exposure. Furthermore, an inverse correlation between Gal exposure and estimated VWF half-life was observed in those patients with enhanced VWF clearance. Together, these findings support the hypothesis that loss of terminal sialylation contributes to the pathophysiology underpinning low VWF in at least a subgroup of patients by promoting enhanced clearance. In addition, alterations in VWF carbohydrate expression are likely to contribute to quantitative and qualitative variations in VWF levels in the normal population. This trial was registered at www.clinicaltrials.gov as #NCT03167320.
Assuntos
Galactose/metabolismo , Galactose/farmacocinética , Fator de von Willebrand/metabolismo , Sistema ABO de Grupos Sanguíneos/química , Estudos de Casos e Controles , Glicosilação , Humanos , Taxa de Depuração Metabólica , Ácido N-Acetilneuramínico/metabolismo , Polissacarídeos/química , Polissacarídeos/metabolismo , Fator de von Willebrand/químicaRESUMO
INTRODUCTION: In 2017, all people with severe haemophilia B (PWSHB) in Ireland switched from standard half-life (SHL) recombinant FIX (rFIX) to rFIX Fc fusion protein (rFIXFc) prophylaxis. AIMS: To evaluate prophylaxis regimens, bleeding rates and factor usage for two years of rFIXFc prophylaxis in a real-world setting. METHODS: Data collected retrospectively from electronic diaries and medical records of PWSHB for a two-year period on rFIXFc prophylaxis were compared with paired baseline data on SHL rFIX treatment. RESULTS: 28 PWSHB (≥18 years) were enrolled, and at switchover 79% were receiving prophylaxis and 21% episodic treatment with SHL rFIX. At 24 months following switchover, all remained on rFIXFc prophylaxis with reduced infusion frequency; median dose per infusion once weekly (55 IU/kg, 20/28), every 10 days (63 IU/kg, 2/28) or every 14 days (98 IU/kg, 6/28). Median annualised bleed rate improved significantly on rFIXFc prophylaxis (2.0 versus 3.3 on SHL FIX) (p = 0.01). Median FIX trough level with once-weekly infusions was 0.09 IU/ml (0.06-0.14 IU/ml). Management of bleeding episodes was similar with rFIXFc and SHL rFIX; one infusion was sufficient to treat 74% and 77% of bleeds, respectively, with similar total median treatment per bleeding episode. Factor consumption reduced by 28% with rFIXFc prophylaxis (57 IU/kg/week, range 40-86 IU/kg/week) compared with SHL rFIX (79 IU/kg/week, range 44-210 IU/kg/week) (p = 0.002). CONCLUSION: This study provides important insights into real-world experience of switching to rFIXFc prophylaxis in an adult population, demonstrating high rates of prophylaxis, with reduced infusion frequency, bleeding and FIX consumption.
Assuntos
Fator IX , Hemofilia B , Adulto , Fator IX/uso terapêutico , Seguimentos , Hemofilia B/tratamento farmacológico , Humanos , Fragmentos Fc das Imunoglobulinas/uso terapêutico , Proteínas Recombinantes de Fusão , Estudos RetrospectivosRESUMO
INTRODUCTION: Although the measurement of physical activity (PA) amongst people with haemophilia (PWH) has become increasingly widespread in recent years, the relationship between PA and bleeding phenotype remains poorly understood. In addition, the influence of various treatment regimens on this relationship has not been defined. AIM: This review aimed to systematically assess the data that are available regarding PA levels amongst PWH, as well as the relationship between PA and bleeding. METHODS: A systematic search of the online databases EMBASE, Cochrane, MEDLINE Ovid, CINAHL and Web of Science was conducted by two independent reviewers. Quality assessment was undertaken using the AXIS Critical Appraisal Tool for Cross-sectional Studies and the STROBE checklist. RESULTS: Of 1902 sources identified overall, 36 articles were included. Low-to-moderate transparency of reporting and various sources of bias were identified. PA levels varied amongst heterogeneous samples of PWH. The relationship between PA and bleeds was inconclusive, although there was evidence that improvements in treatment over recent decades have appeared to enable PWH to become more physically active. CONCLUSION: Based upon the limited available evidence, the relationship between PA and bleeding phenotype in PWH remains unclear. However, with the development of improved prophylaxis treatment regimens in recent years, there is evidence that PA levels have increased, especially amongst people with severe haemophilia. The use of validated outcome measures of PA and more robust reporting of bleeds and treatment regimen are warranted in future research, especially in a rapidly evolving era of new treatments for PWH.
Assuntos
Hemofilia A , Estudos Transversais , Exercício Físico , Hemorragia/etiologia , Humanos , FenótipoRESUMO
INTRODUCTION: Recombinant factor IX fusion protein concentrate (rFIXFc) is increasingly used for prophylaxis in people with haemophilia B (PWHB), but experience in the perioperative setting is limited. AIMS: To evaluate real-world perioperative factor usage, bleeding and complications in PWHB (≥18 years) who received rFIXFc for surgical haemostasis and to describe the treatment regimens used. METHODS: Single centre, retrospective review of all PWHB who underwent a major or minor surgical procedure between June 2017 and July 2020 and received rFIXFc perioperatively for maintenance of surgical haemostasis. RESULTS: A total of 56 PWHB (45 male and 11 female), including people with mild (n = 32), moderate (n = 4) and severe (n = 20) haemophilia B, underwent 11 major and 131 minor procedures with rFIXFc for surgical haemostasis. Haemostasis was rated as excellent (9/11) or good (2/11) in all major procedures. Median total rFIXFc consumption for orthopaedic surgeries was 972 IU/kg (range 812-1031 IU/kg) and for other major (non-orthopaedic) surgeries was 323 IU/kg (range 167-760 IU/kg). The median number of perioperative rFIXFc infusions was 19 (range 17-26) for orthopaedic surgery and 7 (range 5-17) for other major surgeries. The number of infusions in the postoperative period was determined by procedure and patient factors. Complications included bowel ileus and wound infection. Most minor procedures were managed with single infusion of rFIXFc, with no bleeding complications in 95% of minor procedures. There were no thromboembolic events or inhibitor formation. CONCLUSION: This unique data provides real-world evidence that rFIXFc is safe and effective in achieving haemostasis in PWHB undergoing surgery.
Assuntos
Hemofilia A , Hemofilia B , Adulto , Fator IX/uso terapêutico , Feminino , Hemofilia B/tratamento farmacológico , Humanos , Masculino , Procedimentos Cirúrgicos Menores , Proteínas Recombinantes de Fusão , Estudos RetrospectivosRESUMO
INTRODUCTION: The COVID-19 pandemic caused an unprecedented impact to haemophilia healthcare delivery. In particular, rapid implementation of telehealth solutions was required to ensure continued access to comprehensive care. AIMS: To explore patient and healthcare provider (HCP) experience of telehealth in a European Haemophilia Comprehensive Care Centre. METHOD: A systematic evaluation was performed to survey patient and HCP experience and compare clinical activity levels with telehealth to in-person attendances. RESULTS: Public health measures implemented in March 2020 to reduce COVID-19 spread resulted in a 63% decrease in medical/nursing clinic consultation activity compared to the same period in 2019. Implementation of digital care pathways resulted in marked increase in activity (52% greater than 2019). Importantly, enhanced patient engagement was noted, with a 60% reduction in non-attendance rates. Survey of patients who had participated in medical/nursing teleconsultations demonstrated that teleconsultations improved access (79%), reduced inconvenience (82%), was easy to use (94%) and facilitated good communication with the HCP (97%). A survey exploring the telemedicine experience of HCPs, illustrated that HCPs were satisfied with teleconsultation and the majority (79%) would like to continue to offer teleconsultation as part of routine patient care. In addition to medical/nursing reviews, continued access to physiotherapy with virtual exercise classes for people with haemophilia and teleconsultation for acute dental issues was equally successful. CONCLUSION: During an unprecedented public health emergency, telehealth has enabled continued access to specialized haemophilia comprehensive care. Our novel findings show that this alternative is acceptable to both patients and HCPs and offers future novel opportunities.
Assuntos
COVID-19/epidemiologia , Atenção à Saúde/estatística & dados numéricos , Hemofilia A/epidemiologia , SARS-CoV-2/fisiologia , Telemedicina/estatística & dados numéricos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Assistência Integral à Saúde , Feminino , Humanos , Irlanda/epidemiologia , Masculino , Pessoa de Meia-Idade , Pandemias , Adulto JovemRESUMO
Critical clinical questions remain unanswered regarding diagnosis and management of patients with low von Willebrand factor (VWF) levels (30-50 IU/dL). To address these questions, the Low VWF Ireland Cohort (LoVIC) study investigated 126 patients registered with low VWF levels. Despite marginally reduced plasma VWF levels, International Society of Thrombosis and Haemostasis Bleeding Assessment Tool (ISTH BAT) confirmed significant bleeding phenotypes in the majority of LoVIC patients. Importantly, bleeding tendency did not correlate with plasma VWF levels within the 30 to 50 IU/dL range. Furthermore, bleeding phenotypes could not be explained by concurrent hemostatic defects. Plasma factor VIII to VWF antigen (VWF:Ag) ratios were significantly increased in LoVIC patients compared with controls (P < .0001). In contrast, VWF propeptide to VWF:Ag ratios >3 were observed in only 6% of the LoVIC cohort. Furthermore, platelet-VWF collagen binding activity levels were both significantly reduced compared with controls (P < .05). In response to 1-desamino-8-D-arginine vasopressin (DDAVP), peak VWF:Ag levels exceeded 100 IU/dL in 88% of patients and was sustained >100 IU/dL after 4 hours in 72% of subjects. In conclusion, our novel data suggest that low VWF levels can be associated with significant bleeding and are predominantly due to reductions in VWF synthesis and/or constitutive secretion. Although enhanced VWF clearance may contribute to the pathophysiology in some individuals, the absolute reduction in VWF plasma half-life is usually mild and not sufficient to significantly impact upon the duration of DDAVP-induced VWF response. This trial was registered at www.clinicaltrials.gov as #NCT03167320.
Assuntos
Hemorragia/patologia , Hemorragia/fisiopatologia , Fator de von Willebrand/metabolismo , Adolescente , Adulto , Fatores Etários , Idoso , Estudos de Coortes , Feminino , Hemorragia/sangue , Humanos , Irlanda , Masculino , Pessoa de Meia-Idade , Fenótipo , Adulto JovemRESUMO
Glanzmann thrombasthenia (GT) is an autosomal recessive bleeding disorder caused by a defect in platelet integrin αIIbß3. Given the rarity of the condition (1/1,000,000), assessment and diagnosis should be undertaken in a specialist centre. We report the case of a 34 year old woman with severe menorrhagia and a childhood diagnosis from another centre of Von Willebrand Disease. She had an extensive bleeding history, with epistaxis, menorrhagia and postoperative bleeding requiring multiple previous transfusions. Repeat haemostatic workup in our centre revealed normal Von Willebrand levels but abnormal platelet aggregation consistent with Glanzmann thrombasthenia. Antibody screening detected both anti-HLA and anti-αIIbß3 antibodies, complicating subsequent haemostatic management. This case highlights the importance of diagnostic accuracy, the potential negative sequelae of misdiagnosis and subsequent therapeutic interventions.
Assuntos
Trombastenia/diagnóstico , Doenças de von Willebrand/diagnóstico , Adulto , Feminino , Humanos , Trombastenia/patologia , Doenças de von Willebrand/patologiaAssuntos
Deficiência do Fator V/terapia , Hemofilia A/terapia , Complicações Hematológicas na Gravidez/terapia , Adulto , Cesárea , Deficiência do Fator V/sangue , Feminino , Hemofilia A/sangue , Humanos , Gravidez , Complicações Hematológicas na Gravidez/sangue , Gravidez de Alto Risco , Tempo de Protrombina , Fatores de RiscoRESUMO
Increased von Willebrand factor (VWF) clearance plays a key role in the pathogenesis of type 1 and type 2 von Willebrand disease (VWD). However, the pathological mechanisms involved in patients with mild to moderate reductions in plasma VWF:Ag (range, 30-50 IU/dL; low VWF) remain poorly understood. In this study, we investigated the hypothesis that enhanced VWF clearance may contribute to the pathobiology of low VWF. Patients with low VWF were recruited to the LoVIC study after ethics approval and receipt of informed consent. Desmopressin was administered IV in 75 patients, and blood samples were drawn at baseline and at the 1-hour and 4-hour time points. As defined by recent ASH/ISTH/NHF/WFH guidelines, 20% of our low-VWF cohort demonstrated significantly enhanced VWF clearance. Importantly, from a clinical perspective, this enhanced VWF clearance was seen after desmopressin infusion, but did not affect the steady-state VWF propeptide (VWFpp)-to-VWF antigen (VWF:Ag) ratio (VWFpp/VWF:Ag) in most cases. The discrepancy between the VWFpp/VWF:Ag ratio and desmopressin fall-off rates in patients with mild quantitative VWD may have reflected alteration in VWFpp clearance kinetics. Finally, bleeding scores were significantly lower in patients with low VWF with enhanced VWF clearance, compared with those in whom reduced VWF biosynthesis represented the principle pathogenic mechanism. This trial was registered at http://www.clinicaltrials.gov as #NCT03167320.
Assuntos
Doenças de von Willebrand , Fator de von Willebrand , Humanos , Desamino Arginina Vasopressina/uso terapêutico , Relevância Clínica , Precursores de ProteínasRESUMO
BACKGROUND: Previous studies have reported marked interindividual variation in factor VIII (FVIII) clearance in patients with hemophilia (PWH) and proposed a number of factors that influence this heterogeneity. OBJECTIVES: To investigate the importance of the clearance rates of endogenous von Willebrand factor (VWF) compared with those of other FVIII half-life modifiers in adult PWH. METHODS: The half-life of recombinant FVIII was determined in a cohort of 61 adult PWH. A range of reported modifiers of FVIII clearance was assessed (including plasma VWF:antigen and VWF propeptide levels; VWF-FVIII binding capacity; ABO blood group; and nonneutralizing anti-FVIII antibodies). The FVIII-binding region of the VWF gene was sequenced. Finally, the effects of variation in FVIII half-life on clinical phenotype were investigated. RESULTS: We demonstrated that heterogeneity in the clearance of endogenous plasma VWF is a key determinant of variable FVIII half-life in PWH. Both ABO blood group and age significantly impact FVIII clearance. The effect of ABO blood group on FVIII half-life in PWH is modulated entirely through its effect on the clearance rates of endogenous VWF. In contrast, the age-related effect on FVIII clearance is, at least in part, VWF independent. In contrast to previous studies, no major effects of variation in VWF-FVIII binding affinity on FVIII clearance were observed. Although high-titer immunoglobulin G antibodies (≥1:80) were observed in 26% of PWH, these did not impact FVIII half-life. Importantly, the annual FVIII usage (IU/kg/y) was significantly (p = .0035) increased in patients with an FVIII half-life of <12 hours. CONCLUSION: Our data demonstrate that heterogeneity in the half-life of FVIII concentrates in patients with hemophilia A is primarily attributable to variability in the clearance of endogenous VWF.
Assuntos
Hemofilia A , Hemostáticos , Doenças de von Willebrand , Humanos , Fator VIII/uso terapêutico , Fator VIII/metabolismo , Fator de von Willebrand/metabolismo , Hemofilia A/diagnóstico , Hemofilia A/tratamento farmacológico , Meia-Vida , Sistema ABO de Grupos SanguíneosRESUMO
INTRODUCTION: In 2017, all people with severe hemophilia B in Ireland switched to recombinant factor IX Fc fusion protein concentrate (rFIXFc) prophylaxis. Patient-reported outcomes (PROs) and health-related quality of life (HRQoL) are important to evaluate with new treatments. AIMS: To assess HRQoL in people with severe hemophilia B and their experience after switching to rFIXFc prophylaxis. METHODS: Participants completed a Patient Reported Outcomes Burden and Experience (PROBE) questionnaire on initiation and following two years of rFIXFc prophylaxis. The PROBE questionnaire has four domains: demographics, general health, haemophilia-specific, and European Quality of Life 5-Dimensions (EQ-5D-5L) questionnaire. RESULTS: Twenty-three participants completed the questionnaire at both time points. The number of activities where chronic pain occurred and interfered with the activity was reduced by 25% and 33%, respectively (P < .001), following two years of rFIXFc prophylaxis. There was a 9% decrease in chronic pain during the second year of rFIXFc prophylaxis compared to baseline, but the rate remained high, at 74%. A 25% reduction in the number of affected activities of daily living (ADLs) was reported following 2 years of rFIXFc prophylaxis (P = .007). The most common health problems were arthritis, hypertension, anxiety/depression, and gingivitis. The median EQ-5D-5L score was similar following two years of rFIXFc prophylaxis, 0.76 (range, -0.01 to 0.95), compared to 0.77 (range, 0.36-1) at baseline. CONCLUSION: This study of real-world patient experience using PROs demonstrates a reduction in chronic pain and improvement in ADLs in participants after switching to rFIXFc prophylaxis. It provides important insights into patient-identified health care needs and living with severe hemophilia B.
RESUMO
BACKGROUND: Most individuals with mild to moderate reductions in plasma von Willebrand factor (VWF) levels do not demonstrate increased bleeding. However, some patients with plasma VWF levels of 30-50 IU/dl do have a significant bleeding phenotype. Management of these "low VWF" patients, who may have significant bleeding scores >10, around times of elective procedures continues to pose a common clinical challenge because of a lack of evidence. OBJECTIVE: To investigate the safety and efficacy of different periprocedural management options for adult patients with low VWF. METHODS: Treatment and outcomes were retrospectively reviewed for 160 invasive procedures performed in 60 patients with well characterized low VWF enrolled in the previously described Low Von Willebrand factor Ireland Cohort study. RESULTS: We demonstrate that 1-desamino-8-D-arginine vasopressin is efficacious in preventing bleeding for both minor or major elective procedures in adult low VWF patients, even in those with significant bleeding histories. In addition, tranexamic acid alone is effective for low VWF patients undergoing nondental minor procedures. Importantly, age-related increases in plasma VWF:antigen levels above 50 IU/dl were not necessarily associated with complete correction of bleeding phenotype. Procedure-related bleeding complications were increased in low VWF patients who did not receive any hemostatic cover before their procedure. CONCLUSION: Elective procedures in adult patients with low VWF should be managed in liaison with a comprehensive care tertiary referral center so that personalized treatment plans may be implemented before all minor or major elective procedures.
Assuntos
Doenças de von Willebrand , Fator de von Willebrand , Adulto , Estudos de Coortes , Fator VIII , Humanos , Irlanda , Estudos RetrospectivosRESUMO
RATIONALE AND OBJECTIVES: Radiologic image details are best discriminated at luminance levels to which the eye is adapted. Recommendations that ambient light conditions are matched to overall monitor luminance to encourage appropriate adaptation are based on an assumption that clinically significant regions within the image match average monitor luminance. The current work examines this assumption. MATERIALS AND METHODS: Three image types were considered: posteroanterior (PA) chest; PA wrist; and computed tomography (CT) head. Luminance at clinically significant regions was measured at hilar region and peripheral lung (chest), distal radius (wrist), and supraventricular white matter (head). Average monitor luminances were calculated from measurements at 16 regions of the display face plate. Three ambient light levels-30, 100 and 400 lux-were employed. Thirty samples of each image type were used. RESULTS: Statistically significant differences were noted between average monitor luminances and clinically important regions of interest of up to a factor of 3.8, 2, and 6.3 for chest, wrist, and CT head images respectively (P < .0001). Values for the hilum of the chest and distal radius were higher than average monitor levels, whereas the reverse was observed for the peripheral lung and CT brain. Increasing ambient light had no impact on results. CONCLUSIONS: Clinically important radiologic information for common radiologic examinations is not being presented to observers in a way that facilitates optimized adaptation. This may have a significant impact on the ability of the observer to identify details with low contrast discriminability. The importance of image-processing algorithms focussing on clinically significant abnormalities rather than anatomic regions is highlighted.