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It is known that a large number of both genetic and environmental factors contribute to the risk of inhibitor development, but underlying pathogenetic mechanisms are still under investigation. The clinical research on inhibitors towards factor VIII (FVIII) is challenged by the fact that this is an infrequent event occurring in a rare disease. Therefore, it is widely accepted that complementary studies involving animal models can provide important insights into the pathogenesis and treatment of this complication. In this respect, mouse models have been studied for clues to FVIII immunogenicity, natural history of immunity and for different approaches to primary and secondary tolerance induction. In the clinical setting, the type of FVIII product used and the occurrence of product switching are considered important factors which may have an influence on inhibitor development. The evaluation of data currently available in the literature does not prove unequivocally that a difference in the immunogenicity exists between particular FVIII products (e.g. recombinant vs. plasma-derived, full length vs. B-domainless). In addition, national products switches have occurred and, in this context, switching was not associated with an enhanced inhibitor risk. In contrast with severe haemophilia A, patients with moderate and mild haemophilia A receive FVIII treatment infrequently for bleeds or surgery. In this condition the inhibitor risk is low but remains present lifelong, requiring continuous vigilance, particularly after intensive FVIII exposure. [ABSTRACT FROM AUTHOR]

It is known that a large number of both genetic and environmental factors contribute to the risk of inhibitor development, but underlying pathogenetic mechanisms are still under investigation. The clinical research on inhibitors towards factor VIII ( FVIII) is challenged by the fact that this is an infrequent event occurring in a rare disease. Therefore, it is widely accepted that complementary studies involving animal models can provide important insights into the pathogenesis and treatment of this complication. In this respect, mouse models have been studied for clues to FVIII immunogenicity, natural history of immunity and for different approaches to primary and secondary tolerance induction. In the clinical setting, the type of FVIII product used and the occurrence of product switching are considered important factors which may have an influence on inhibitor development. The evaluation of data currently available in the literature does not prove unequivocally that a difference in the immunogenicity exists between particular FVIII products (e.g. recombinant vs. plasma-derived, full length vs. B-domainless). In addition, national products switches have occurred and, in this context, switching was not associated with an enhanced inhibitor risk. In contrast with severe haemophilia A, patients with moderate and mild haemophilia A receive FVIII treatment infrequently for bleeds or surgery. In this condition the inhibitor risk is low but remains present lifelong, requiring continuous vigilance, particularly after intensive FVIII exposure. [ABSTRACT FROM AUTHOR]

The prevalence of obesity, an important risk factor for both cardiovascular disease and arthropathy, is strongly increasing in the general population, but data for the haemophilia population are scarce. Obesity may have a more profound effect on arthropathy and on cardiovascular disease in patients with haemophilia. To assess the prevalence of obesity in haemophilia patients and install adequate measures, if necessary. We performed a nationwide postal survey to measure the prevalence of overweight and obesity in Dutch haemophilia patients in 1992 ( n = 980) and 2001 ( n = 1066). A random sample of the Dutch male population served as the control group. In adult haemophiliacs, the prevalence of overweight (BMI 25–30 kg m−2) increased from 27% to 35% (95% CI 31.1–38.0) and the prevalence of obesity (BMI ≥30 kg m−2) doubled from 4% to 8% (95% CI 6.0–10.1), which was comparable with the general population. The increased prevalence of obesity in boys with haemophiliacs, which tripled in 10 years, is alarming. The increased prevalence of overweight and obesity in patients with haemophilia may have a profound effect on morbidity and quality of life of haemophilia patients by aggravating pre-existing arthropathy and predisposing aged patients to cardiovascular disease. Measures to prevent overweight in haemophiliacs are therefore urgently needed. [ABSTRACT FROM AUTHOR]

This study was conducted to evaluate the effect of an unaware carriership on the delay in diagnosis of haemophilia and the resulting effect of this delay on morbidity. Information on 73 haemophilia patients (<18 years) and their mothers was gathered from data of patients’ medical records and completed by interviews with the parent(s). Although a positive family history was present in 52 gravidae, 16 of them (31%) were not aware of their carrier status at moment of delivery. Fifteen of these 16 unaware carriers, were carriers of a non-severe form of haemophilia. In mothers who were unaware of carriership for haemophilia instrumental delivery occurred more frequently than in mothers who knew they were carriers. This is disquieting since instrumental delivery poses a significant risk (relative risk: 17.8, 95% CI: 4.0–78.4) for intra- or extracranial bleedings in newborn haemophiliacs in comparison to spontaneous deliveries or caesarean sections. In 83% of the patients with a positive family history, diagnosis was established before the first bleeding episode. Patients diagnosed by bleedings presented more often with iatrogenic bleedings (38%) then patients who were diagnosed because of a positive family history (9%) (P < 0.05). In comparison to previous studies, more patients had a positive family history and in more haemophiliacs with a positive family history diagnosis was established before the first bleeding episode. Although this reflects the yield of improved diagnostic methods, further reduction of iatrogenic bleeding is possible by intensifying counselling of mild haemophilia carriers. [ABSTRACT FROM AUTHOR]

Portal vein thrombosis (PVT) is a rare disease in children and may be complicated by portal hypertension (PH), hepatopulmonary syndrome (HPS) and portopulmonary hypertension (PPHTN) but their incidence and risk factors are unknown. An observational, retrospective cohort study of all consecutive children (≤18 years) with PVT treated at the Emma Children's Hospital Amsterdam University Medical Centers between January 1996 and January 2022 was conducted to identify the incidence and risk factors of these post thrombotic complications (PTC) in pediatric patients. In total 43/ 703 thrombosis patients had PVT (boys 72.1 %; mean age 1.3 ± 0.5 years). Overall, 51 % of patients developed PH (n = 22), complicated by PPHTN in one of them. In 16 of 22 patients, PVT presented with portal hypertension. Clinically relevant bleeding due to portal hypertension occurred in 13 (59.1 %) patients with PH. The mean age at the first clinically relevant bleeding was 5.1 ± 5.9 years. Risk factors for the development of PH were lack of complete thrombus resolution (OR 24.3, 95 % CI 1.2–7.0; p = 0.008) and unprovoked VTE (OR, 35.4; 95 % CI 1.4–6.3; p = 0.012). Median time from PVT to PH was 137 days (range: 0 days to 5.04 years). We demonstrated that half of the patients develop PH after PVT, with a lack of thrombus resolution and unprovoked VTE as independent risk factors. This high incidence underlines the importance of long-term standardized follow-up of patients after PVT and standard screening in patients at risk of PTC. • Portal vein thrombosis in children has a high rate of post thrombotic complications. • Portal vein thrombosis presents with portal hypertension in 73 %. • Risk factors are a lack of thrombus resolution and unprovoked thrombosis. [ABSTRACT FROM AUTHOR]

In population pharmacokinetic (PK) models, interindividual variability is explained by implementation of covariates in the model. The widely used forward stepwise selection method is sensitive to bias, which may lead to an incorrect inclusion of covariates. Alternatives, such as the full fixed effects model, reduce this bias but are dependent on the chosen implementation of each covariate. As the correct functional forms are unknown, this may still lead to an inaccurate selection of covariates. Machine learning (ML) techniques can potentially be used to learn the optimal functional forms for implementing covariates directly from data. A recent study suggested that using ML resulted in an improved selection of influential covariates. However, how do we select the appropriate functional form for including these covariates? In this work, we use SHapley Additive exPlanations (SHAP) to infer the relationship between covariates and PK parameters from ML models. As a case‐study, we use data from 119 patients with hemophilia A receiving clotting factor VIII concentrate peri‐operatively. We fit both a random forest and a XGBoost model to predict empirical Bayes estimated clearance and central volume from a base nonlinear mixed effects model. Next, we show that SHAP reveals covariate relationships which match previous findings. In addition, we can reveal subtle effects arising from combinations of covariates difficult to obtain using other methods of covariate analysis. We conclude that the proposed method can be used to extend ML‐based covariate selection, and holds potential as a complete full model alternative to classical covariate analyses. [ABSTRACT FROM AUTHOR]

Nonlinear mixed effect (NLME) models are the gold standard for the analysis of patient response following drug exposure. However, these types of models are complex and time‐consuming to develop. There is great interest in the adoption of machine‐learning methods, but most implementations cannot be reliably extrapolated to treatment strategies outside of the training data. In order to solve this problem, we propose the deep compartment model (DCM), a combination of neural networks and ordinary differential equations. Using simulated datasets of different sizes, we show that our model remains accurate when training on small data sets. Furthermore, using a real‐world data set of patients with hemophilia A receiving factor VIII concentrate while undergoing surgery, we show that our model more accurately predicts a priori drug concentrations compared to a previous NLME model. In addition, we show that our model correctly describes the changing drug concentration over time. By adopting pharmacokinetic principles, the DCM allows for simulation of different treatment strategies and enables therapeutic drug monitoring. [ABSTRACT FROM AUTHOR]

Summary: Von Willebrand disease (VWD) is a bleeding disorder caused by quantitative (type 1 or 3) or qualitative (type 2A/2B/2M/2N) defects of circulating von Willebrand factor (VWF). Circulating VWF levels not always fully explain bleeding phenotypes, suggesting a role for alternative factors, like platelets. Here, we investigated platelet factor 4 (PF4) in a large cohort of patients with VWD. PF4 levels were lower in type 2B and current bleeding phenotype was significantly associated with higher PF4 levels, particularly in type 1 VWD. Based on our findings we speculate that platelet degranulation and cargo release may play a role across VWD subtypes. [ABSTRACT FROM AUTHOR]

Treatment of haemophilia has greatly improved in the last decades which led to increased life expectancy and improved health outcomes. Interestingly, we found that Dutch YAWH experience less feelings of anxiety and depression than the Dutch population, while no differences were found between subgroups within haemophilia patients. Patient-relevant health outcomes for hemophilia care: development of an international standard outcomes set. [Extracted from the article]

Purpose: Hemophilia B is a bleeding disorder, caused by a factor IX (FIX) deficiency. Recently, FIX concentrates with extended half-life (EHL) have become available. Prophylactic dosing of EHL-FIX concentrates can be optimized by assessment of individual pharmacokinetic (PK) parameters. To determine these parameters, limited sampling strategies (LSSs) may be applied. The study aims to establish adequate LSSs for estimating individual PK parameters of EHL-FIX concentrates using in silico evaluation. Methods: Monte Carlo simulations were performed to obtain FIX activity versus time profiles using published population PK models for N9-GP (Refixia), rFIXFc (Alprolix), and rIX-FP (Idelvion). Fourteen LSSs, containing three or four samples taken within 8 days after administration, were formulated. Bayesian analysis was applied to obtain estimates for clearance (CL), half-life (t1/2), time to 1% (Time1%), and calculated weekly dose (Dose1%). Bias and precision of these estimates were assessed to determine which LSS was adequate. Results: For all PK parameters of N9-GP, rFIXFc and rIX-FP bias was generally acceptable (range: −5% to 5%). For N9-GP, precision of all parameters for all LSSs was acceptable (< 25%). For rFIXFc, precision was acceptable for CL and Time1%, except for t1/2 (range: 27.1% to 44.7%) and Dose1% (range: 12% to 29.4%). For rIX-FP, all LSSs showed acceptable bias and precision, except for Dose1% using LSS with the last sample taken on day 3 (LSS 6 and 10). Conclusion: Best performing LSSs were LSS with samples taken at days 1, 5, 7, and 8 (N9-GP and rFIXFc) and at days 1, 4, 6, and 8 (rIX-FP), respectively. [ABSTRACT FROM AUTHOR]

Development of inhibitory antibodies to factor VIII (FVIII) provides a major complication of replacement therapy in patients with haemophilia A. The risk of inhibitor formation is influenced by the underlying FVIII gene defect. Moreover, genetic determinants in the promoter region of IL-10 and TNFα have been linked to an increased risk of inhibitor development. Recent cohort-studies have provided evidence that the risk of inhibitor formation is linked to intensity of treatment. Eradication of FVIII inhibitors can be achieved by frequent infusion of high dosages of FVIII, so-called immune tolerance induction (ITI). Until now, the mechanisms involved in downmodulation of the immune response to FVIII during ITI have not been unraveled. Studies performed in an animal model for haemophilia A have suggested that elimination of FVIII-specific memory B cells by high dosages of FVIII contributes to the decline in FVIII inhibitor levels during ITI. Limited knowledge is available with respect to the development and persistence of FVIII-specific memory B cells in patients with haemophilia A. Two recent studies suggest that the frequency of peripheral FVIII-specific memory B cells in haemophilia A patients with inhibitors range from <0.01 to 0.40% of that of total IgG+ B cells. No or very low frequencies of FVIII-specific memory B cells are observed in haemophilia A patients without inhibitors and in patients treated successfully by ITI. Possible implications of these findings are discussed in the context of currently available information on the role of antigen-specific memory B cells and long-living antibody producing plasma cells in humoral immunity. [ABSTRACT FROM AUTHOR]

Background: Poor growth and under-nutrition are common in children with sickle cell disease (SCD). This review summarises evidence of nutritional status in children with SCD in relation to anthropometric status, disease severity, body composition, energy metabolism, micronutrient deficiency and endocrine dysfunction. Methods: A literature search was conducted on the Medline/PUBMED, SCOPUS, SciELO and LILACS databases to July 2007 using the keywords sickle cell combined with nutrition, anthropometry, growth, height and weight, body mass index, and specific named micronutrients. Results: Forty-six studies (26 cross-sectional and 20 longitudinal) were included in the final anthropometric analysis. Fourteen of the longitudinal studies were conducted in North America, the Caribbean or Europe, representing 78.8% (2086/2645) of patients. Most studies were observational with wide variations in sample size and selection of reference growth data, which limited comparability. There was a paucity of studies from Africa and the Arabian Peninsula, highlighting a large knowledge gap for low-resource settings. There was a consistent pattern of growth failure among affected children from all geographic areas, with good evidence linking growth failure to endocrine dysfunction, metabolic derangement and specific nutrient deficiencies. Conclusions: The monitoring of growth and nutritional status in children with SCD is an essential requirement for comprehensive care, facilitating early diagnosis of growth failure and nutritional intervention. Randomised controlled trials are necessary to assess the potential benefits of nutritional interventions in relation to growth, nutritional status and the pathophysiology of the disease. [ABSTRACT FROM AUTHOR]

Keywords: intracranial haemorrhage; neonatal haematology; children; haemophilia; \sequelae EN intracranial haemorrhage neonatal haematology children haemophilia \sequelae e101 e104 4 07/20/20 20200715 NES 200715 Intracranial haemorrhage (ICH) in neonates with severe haemophilia is a potentially life-threatening complication and has been reported to occur in about 2-4% of boys with severe haemophilia; around 44-60 times higher than that expected in a non-haemophilia population.1,2 ICH requires intensive replacement therapy with factor concentrates, which has been identified as a risk factor for inhibitor development in patients with haemophilia A (HA).3 Death and neurological sequelae (motor function problems, seizures and developmental delay) are the most feared complications and have been reported to affect 50-60% of children with ICH.4 The aim of this paper was to study the incidence and symptoms of ICH in neonates with severe haemophilia and the impact of early diagnosis and treatment of ICH on long-term outcomes. The case report form registered patients' type of haemophilia, mode of delivery, ICH, and in cases of ICH, neurological signs and symptoms at presentation, treatment and sequelae. To be able to compare neonatal ICH incidences to ICH incidences later in life, the 450 neonatal months were added up to 34-52 patient years, resulting in an incidence of 0-26 ICH/patient year. The neonate might not be diagnosed as having haemophilia if there is no family history of haemophilia, symptoms like lethargy and vomiting are non-specific and not all cases of ICH are detected. [Extracted from the article]

Introduction: Haemophilia B is caused by a deficiency of coagulation factor IX (FIX) and characterized by bleeding in muscles and joints. In the perioperative setting, patients are treated with FIX replacement therapy to secure haemostasis. Targeting of specified FIX levels is challenging and requires frequent monitoring and adjustment of therapy. Aim: To evaluate perioperative management in haemophilia B, including monitoring of FIX infusions and observed FIX levels, whereby predictors of low and high FIX levels were assessed. Methods: In this international multicentre study, haemophilia B patients with FIX < 0.05 IU mL−1 undergoing elective, minor or major surgical procedures between 2000 and 2015 were included. Data were collected on patient, surgical and treatment characteristics. Observed FIX levels were compared to target levels as recommended by guidelines. Results: A total of 255 surgical procedures were performed in 118 patients (median age 40 years, median body weight 79 kg). Sixty percent of FIX levels within 24 hours of surgery were below target with a median difference of 0.22 IU mL−1 [IQR 0.12‐0.36]; while >6 days after surgery, 59% of FIX levels were above target with a median difference of 0.19 IU mL−1 [IQR 0.10‐0.39]. Clinically relevant bleeding complications (necessity of a second surgical intervention or red blood cell transfusion) occurred in 7 procedures (2.7%). Conclusion: This study demonstrates that targeting of FIX levels in the perioperative setting is complex and suboptimal, but although this bleeding is minimal. Alternative dosing strategies taking patient and surgical characteristics as well as pharmacokinetic principles into account may help to optimize and individualize treatment. [ABSTRACT FROM AUTHOR]

Introduction: Patients with Von Willebrand disease (VWD) are regularly treated with VWF‐containing concentrates in case of acute bleeding, trauma and dental or surgical procedures. Aim: In this multicentre retrospective study, current perioperative management with a von Willebrand factor (VWF)/Factor VIII (FVIII) concentrate (Haemate® P) in patients with VWD was evaluated. Patients/Methods: Patients with VWD undergoing minor or major surgery between 2000 and 2015, requiring treatment with a VWF/FVIII concentrate (Haemate® P), were included. Achieved VWF activity (VWF:Act) and FVIII during FVIII‐based treatment regimens were compared to predefined target levels in national guidelines. Results: In total, 103 patients with VWD (148 surgeries) were included: 54 type 1 (73 surgeries), 43 type 2 (67 surgeries) and 6 type 3 (8 surgeries). Overall, treatment resulted in high VWF:Act and FVIII levels, defined as ≥0.20 IU/mL above predefined levels. In patients with type 1 VWD, respectively, 65% and 91% of trough VWF:Act and FVIII levels were higher than target levels. In patients with type 2 and type 3 VWD, respectively, 53% and 57% of trough VWF:Act and 72% and 73% of trough FVIII levels were higher than target level. Furthermore, FVIII accumulation over time was observed, while VWF:Act showed a declining trend, leading to significantly higher levels of FVIII than VWF:Act. Conclusion: High VWF:Act and accumulation of FVIII were observed after perioperative FVIII‐based replacement therapy in patients with VWD, both underlining the necessity of personalization of dosing regimens to optimize perioperative treatment. [ABSTRACT FROM AUTHOR]

Background: This study assesses health‐related quality of life (HRQOL), and variables associated with HRQOL, in children and adolescents with haemophilia and congenital bleeding disorders (CBD) in the Netherlands. Methods: Patients <18 years with CBD under treatment at the Hemophilia Comprehensive Care Center of the Academic Medical Center were included. Participants completed generic HRQOL questionnaires (TAPQOL 0‐5 years; PedsQL 6‐18 years). Differences and effect sizes in HRQOL compared to healthy peers, and between hemophilia severity groups, were tested using Mann Whitney U‐tests. Multivariate regression analyses were performed to assess variables associated with HRQOL. Results: Data of 145 patients (81%) were analyzed (N = 32 with severe haemophilia). Children (0‐12 years) show no significant impairments in HRQOL compared to healthy peers. Adolescent boys (13‐18 years) with CBD report a slightly higher HRQOL on the total and emotional functioning scales than healthy peers (small‐moderate effect sizes). In contrast, adolescent girls experience lower HRQOL on total, social functioning and psychosocial health scales compared to healthy peers (moderate effect sizes). No differences between severity groups were found in HRQOL, but more problem behaviour was found in young boys (0‐5 years) with severe haemophilia. Male gender, participation in sports and school attendance are positively associated with HRQOL. Parental country of birth, type of treatment and number of bleeds are not associated with HRQOL. Conclusion: Continuing monitoring HRQOL in daily clinical practice for children with CBD is important, since possible influencing psychosocial factors can change over time, with special focus on adolescent girls, sports participation and school absence. [ABSTRACT FROM AUTHOR]

Introduction Children growing up with haemophilia are at greater risk for psychosocial problems than their healthy peers. Providing psychosocial care to children with haemophilia and their families is indispensable, since psychosocial factors can have a significant impact on health and health-related quality of life (HRQOL). Aims Our aim was to give a description of psychosocial care provided by the multidisciplinary team of the Hemophilia Comprehensive Care Centre (HCCC) at the Emma Children's Hospital in Amsterdam, the Netherlands. With this overview, other caregivers and hospitals can benefit in organizing their psychosocial care for children with haemophilia. Methods The focus of the psychosocial care provided by the multidisciplinary team is on preventing psychosocial problems and medical-related stress, and supporting and equipping the child with haemophilia and its parents with as many skills as possible to lead an independent life with a high HRQOL. Results Core elements of the psychosocial care are therefore monitoring and screening of HRQOL (e.g. in daily clinical practice via ), psychoeducation (haemophilia camp, haemophilia school, disease-specific activities, meetings for girls, parent meetings), practical help (Emma at Work, an employment agency for adolescents and young adults; Educational Facility and school visits), psychosocial interventions (the On Track group intervention and the Haemophilia Coping and Perception Test) and individual care (psychological counselling and referrals). Conclusion By providing this overview of psychosocial support offered and by sharing this knowledge, psychosocial care can become more structured and consistent between HCCCs around the world. Potentially, processes and outcomes of care can be improved. [ABSTRACT FROM AUTHOR]

Introduction This study was conducted to evaluate the current implementation of outcome measures in routine clinical haemophilia practice and to explore and appreciate the perception of the relevance of such measures by treaters. Methods A survey was completed by 19 of the 26 physicians involved in the European Haemophilia Therapy Strategy Board ( EHTSB). Employing an extensive inventory of outcome measures used in patients with haemophilia, information was collected about the frequency of data collection and the subjective appreciation of their importance during clinic review. Results The survey revealed that most treaters currently collect data that are mainly related to the haemostatic treatment (consumption of concentrates) and the bleeding symptoms (number and location of bleeds) in a non-uniform and non-standardized way. By contrast, functional, physical and quality of life scorings are rarely used and show considerable heterogeneity between treaters. Also, many disparities emerged between practice and perception, in particular quality of life data that are perceived as being important but for most of the time are not collected. Conclusions This survey represents, in our view, the first attempt to evaluate the actual utilization of outcome measures in haemophilia care. While the value of outcome measures is appreciated, they are not assessed regularly. Therefore, there is a need to include appropriate performance indicators (outcome measures) of haemophilia care in routine clinical practice. Consensus recommendations to provide a framework for achieving this aim are provided. [ABSTRACT FROM AUTHOR]

Introduction Inhibitor development in people with haemophilia is a serious complication that may require intensive and costly interventions. The goal of inhibitor management should be permanent inhibitor eradication through immune tolerance induction (ITI), but well-designed studies are lacking and the management of patients is therefore defined by the experience and views of the clinician. Objectives To explore the current clinical practice and outcome of ITI therapy in Europe and how this may have changed over the last decade, as well as to provide consensus recommendations to guide clinicians in their clinical practice. Methods A survey was conducted among 16 European haemophilia comprehensive care centres to evaluate current ITI treatment regimens and success rates in severe and mild/moderate haemophilia A and haemophilia B. In addition, an updated literature review was performed as guidance for providing recommendations. Results We demonstrated successful inhibitor treatment in 86% of severe haemophilia A patients with low responding (LR) and 59% of patients with high responding (HR) inhibitors. Some new trends in the management of patients with inhibitors were identified, including a tendency to use low-dose regimens (< 50 IU/kg/d) in both children and adults with HR inhibitors possibly based on similar success rates demonstrated in the I-ITI study compared to a high-dose protocol. Data on ITI therapy in mild and moderate haemophilia as well as haemophilia B were limited. Conclusions The outcome of ITI therapy seems to be stable over time, and treatment regimens remain heterogeneous. The use of low dose regimens however is considered more frequently. [ABSTRACT FROM AUTHOR]

Thrombocytopenia is a common finding in small for gestational age (SGA) neonates and is thought to result from a unique pathophysiologic mechanism related to chronic intrauterine hypoxia. Our objective was to estimate the incidence and severity of early-onset thrombocytopenia in SGA neonates, and to identify risk factors for thrombocytopenia. We performed a retrospective cohort study of all consecutive SGA neonates admitted to our ward and a control group of appropriate for gestational age (AGA) neonates matched for gestational age at birth. Main outcome measures were incidence and severity of thrombocytopenia, hematological and clinical risk factors for thrombocytopenia, and bleeding. A total of 330 SGA and 330 AGA neonates were included, with a mean gestational age at birth of 32.9 ± 4 weeks. Thrombocytopenia (<150x109/L) was found in 53% (176/329) of SGA neonates and 20% (66/330) of AGA neonates (relative risk (RR) 2.7, 95% confidence interval (CI) [2.1, 3.4]). Severe thrombocytopenia (21-50x109/L) occurred in 25 neonates (8%) in the SGA and 2 neonates (1%) in the AGA group (RR 12.5, 95% CI [3.0, 52.5]). Platelet counts <20x109/L were not recorded. Within the SGA group, lower gestational age at birth (p = <0.01) and erythroblastosis (p<0.01) were independently associated with a decrease in platelet count. Platelet count was positively correlated with birth weight centiles. In conclusion, early-onset thrombocytopenia is present in over 50% of SGA neonates and occurs 2.7 times as often as in AGA neonates. Thrombocytopenia is seldom severe and is independently associated with lower gestational age at birth and erythroblastosis. [ABSTRACT FROM AUTHOR]

Background Joint bleeds are reported by 23% of von Willebrand disease (VWD) patients and associated with orthopaedic surgery. Limited data are available on joint surgery in VWD. Aim To assess the prevalence, indications, management and complications of joint surgery in VWD patients. Methods 804 VWD patients with historically lowest von Willebrand factor (VWF) activity ≤30 U dL−1 completed a questionnaire on joint bleeds, joint damage and orthopaedic surgery. We retrieved additional medical file data of patients who underwent surgery on large joints (shoulder, elbow, hip, knee or ankle). Results 116 out of 804 patients (14%) reported large joint surgery. Compared to VWD patients without previous orthopaedic surgery, these 116 patients reported more frequently a history of joint bleeds and joint damage (41% vs. 20%, P < 0.001 and 61% vs. 20%, P < 0.001). Medical file data on 126 large joint surgeries in 79 VWD patients revealed that this surgery was associated with joint damage due to prior joint bleeds in 24% of the procedures. Preoperative clotting factor correction (CFC) to prevent bleeding was administered in most cases (81%). Documentation on postoperative bleeding was found in 23 surgeries (18%). Conclusions Large joint surgery is reported by 14% of VWD patients, related to joint bleeds in 24% and seems associated with bleeding complications frequently despite perioperative CFC. [ABSTRACT FROM AUTHOR]

Introduction Although immune tolerance induction ( ITI) is considered the first choice treatment to eradicate inhibitors in haemophilia A patients, little is known about outcomes determinants and cost magnitude. Aim and Methods A retrospective, multicentre study was conducted to assess the relationship between ITI outcome, clinical and treatment characteristics and cost of ITI treatment in haemophilia A patients. Data from 12 months before inhibitor diagnosis to 12 months after ITI completion were collected. Treatment cost was calculated in the third-party perspective and expressed as mean € per patient-month. Cox regression models were used to identify predictors of better outcome and the time taken to achieve tolerance. Results Seventy-one patients, aged 0.4-41 years (median: 3.8 years) at ITI start, were enrolled. Undetectable inhibitor was achieved in 84.5% of patients and inhibitor eradication with normal factor VIII ( FVIII) pharmacokinetics in 74.2%. Median time to successful tolerance was 10.7 months (range 2.0-90.0 months). Peak inhibitor level on ITI was a significant predictor of ITI success. Breakthrough bleeding event incidence during ITI was associated with time to success. The mean cost of treatment for the time period between inhibitor diagnosis and ITI start was €3188 per patient-month (92.1% for bypassing agents), and €60 078 during ITI (76.8% for FVIII use in ITI). Conclusion Immune tolerance induction in this patient cohort was successful in 84.5% of patients with a mean cost of €60 000 per patient-month. This high cost is dwarfed by comparison with the prospect of lifelong care of an inhibitor patient, in addition to gains in life expectancy and health-related quality of life. [ABSTRACT FROM AUTHOR]

Introduction Patients', parents' and providers' preferences with regard to medical innovations may have a major impact on their implementation. Aim To evaluate barriers and facilitators for individualized pharmacokinetic (PK)-guided dosing of prophylaxis in haemophilia patients, parents of young patients, and treating professionals by discrete choice experiment (DCE) questionnaire. Patients/Methods The study population consisted of patients with haemophilia currently or previously on prophylactic treatment with factor concentrate ( n = 114), parents of patients aged 12-18 years ( n = 19) and haemophilia professionals ( n = 91). DCE data analysis was performed, taking preference heterogeneity into account. Results Overall, patients and parents, and especially professionals were inclined to opt for PK-guided dosing of prophylaxis. In addition, if bleeding was consequently reduced, more frequent infusions were acceptable. However, daily dosing remained an important barrier for all involved. 'Reduction of costs for society' was a facilitator for implementation in all groups. Conclusions To achieve implementation of individualized PK-guided dosing of prophylaxis in haemophilia, reduction of bleeding risk and reduction of costs for society should be actively discussed as they are motivating for implementation; daily dosing is still reported to be a barrier for all groups. The knowledge of these preferences will enlarge support for this innovation, and aid in the drafting of implementable guidelines and information brochures for patients, parents and professionals. [ABSTRACT FROM AUTHOR]

Background: Joint bleeds ( JB) are reported in a minority of patients with von Willebrand disease ( VWD) but may lead to structural joint damage. Prevalence, severity and impact of JB in VWD are largely unknown. Objectives: The aim of this study was to assess JB prevalence, onset, treatment and impact on health-related quality of life ( HR-QoL) and joint integrity in moderate and severe VWD. Methods: In the Willebrand in the Netherlands study 804 moderate and severe VWD patients [von Willebrand factor ( VWF) activity ≤30U dL−1] completed a questionnaire on occurrence, sites and consequences of JB. To analyse JB number, onset, treatment and impact on joint integrity we additionally performed a patient-control study on medical file data comparing patients with JB to age, gender, factor VIII (FVIII)- and VWF activity matched VWD patients without JB. Results: Of all VWD patients 23% (184/804) self-reported JB. These 184 patients reported joint damage more often (54% vs. 18%, P < 0.001) and had lower HR-QoL (SF36, P < 0.05) compared to VWD patients not reporting JB. Of 55 patients with available JB data, 65% had the first JB before age 16. These 55 patients used more clotting factor concentrate ( CFC; median dose 43 vs. 0 IE FVIII kg−1 year−1, P < 0.001), more often had X-ray joint damage (44% vs. 11%, P = 0.001] and chronic joint pain (44% vs. 18%, P = 0.008) compared to 55 control VWD patients without JB. Conclusion: In conclusion, joint bleeds are reported by 23% of moderate and severe VWD patients, mostly start in childhood, are associated with more CFC use, joint pain, lower HR-QoL and significantly more radiological and self-reported joint damage. [ABSTRACT FROM AUTHOR]

. Continuous infusion (CI) of factor VIII (FVIII) is an effective method for replacement therapy in haemophilia. Recently, concerns have been raised regarding association of CI with the development of inhibitors. The aim of this study was to gain information on the current practices in Europe regarding CI and the true inhibitor incidence after this mode of therapy. In a cross sectional study performed in 22 Comprehensive Care Centres (CCCs), we evaluated CI techniques, treatment protocols, efficacy, safety and complications of CI including inhibitors. Thirteen (59%) CCCs reported a total of 1079 CI treatments, given peri-operatively or for major bleeds, in 742 patients. Most centres used 'adjusted dose' CI aimed at median target FVIII level of 0.8 IU mL-1. CI was haemostatically very effective with a low incidence of complications: median incidence of postoperative bleeding was 1.8%, six centres observed phlebitis in 2-11% of CI treatments. Only nine (1.2%) patients developed inhibitors (0.45% of 659 severe and 7.2% of 83 mild haemophilia patients). Additional analysis of inhibitor patients revealed several confounding factors (low number of prior FVIII exposure days, high steady-state factor levels during CI, high-risk genotype). In this unprecedentedly large cohort, CI treatment appears to be an effective and safe treatment that does not increase the risk of inhibitor development in patients with severe haemophilia. Thus, previous small case series reports suggesting that CI may increase inhibitorsb cannot be confirmed. Inhibitor risk in mild haemophilia could not be evaluated as the influence of other, potentially confounding, risk factors could not be excluded. [ABSTRACT FROM AUTHOR]

. Patients with von Willebrand disease (VWD), the most common inherited bleeding disorder, display large variation in bleeding tendency, which is not completely related to VWF levels. The cause of variability in clinical expression is largely unknown. The effect of plasma fibrinolytic capacity on bleeding tendency in VWD patients has not been investigated. We hypothesized that enhanced fibrinolysis may result in a more severe bleeding phenotype. Therefore, we measured the fibrinolytic potential in patients with moderate or severe VWD to investigate the contribution of fibrinolysis to the bleeding tendency. Fibrinolytic potential was measured as plasma clot lysis time (CLT) with and without addition of potato carboxypeptidase inhibitor (PCI) in 638 patients with moderate or severe VWD who participated in a nationwide multicentre cross-sectional study. Bleeding severity was measured using the Bleeding Score (BS).The CLTs were significantly longer, indicative of hypofibrinolysis, in men compared to women with VWD [106.2 (IQR 95.7-118.1) vs. 101.9 (IQR 92.8-114.0) min]. The CLTs prolonged with increasing age. No association was found between VWF or FVIII levels and CLT, or between VWF or FVIII levels and CLT+PCI. No association was observed for BS in a model with 10log-transformed CLT, adjusted for age, gender, VWF:Act and FVIII [ b = 6.5 (95%CI −0.3 to 13.4)]. Our study showed that the plasma fibrinolytic potential does not influence bleeding tendency in VWD patients and therefore does not explain the variability in bleeding phenotype in VWD. [ABSTRACT FROM AUTHOR]

Summary Birth is the first haemostatic challenge for a child with haemophilia. Our aim was to examine the association between perinatal risk factors and major neonatal bleeding in infants with haemophilia. This observational cohort study in 12 European haemophilia treatment centres (HTC) incorporated 508 children with haemophilia A or B, born between 1990 and 2008. Risk factors for bleeding were analysed by univariate analysis. Head bleeds occurred in 18 (3·5%) children within the first 28 d of life, including three intraparenchymal bleeds, one subdural haematoma and 14 cephalohaematomas. Intra-cranial bleeds were associated with long-term neurological sequelae in two (0·4%) cases; no deaths occurred. Assisted delivery (forceps/vacuum) was the only risk factor for neonatal head bleeding [Odds Ratio (OR) 8·84: 95% confidence interval (CI) 3·05-25·61]. Mild haemophilia and maternal awareness of her haemophilia carrier status seemed to be protective (OR 0·24; 95%CI 0·05-1·05 and OR 0·34; 95%CI 0·10-1·21, respectively), but due to the low number of events this was not statistically significant. We found no association between neonatal head bleeding and country, maternal age, parity, gestational age or presence of HTC. Maternal awareness of carrier status protected against assisted delivery (unadjusted OR 0·37; 95%CI 0·15-0·90; adjusted OR 0·47 (95%CI 0·18-1·21). [ABSTRACT FROM AUTHOR]

The development of inhibitors to the infused factor in patients with haemophilia is a serious clinical problem. Recent evidence suggests that alongside the strong genetic contribution to inhibitor formation, there are a number of non-genetic factors – perceived by the immune system as danger signals – which promote formation of inhibitors. This study provides a comprehensive review of clinical studies relating to these factors and also presents a survey of opinion concerning their importance and clinical influence, conducted among the members of the European Haemophilia Treatment Standardisation Board (EHTSB). Taken together, this information highlights the lack of robust data concerning the influence of several non-genetic risk factors on inhibitor development, and an urgent need for prospective, well-conducted studies that adhere to recommendations made by the European Medicines Agency (EMEA) for studying inhibitors. Based on current literature, the EHTSB formulated consensus recommendations. It is desirable to minimize intensive treatment wherever possible, given the clinical situation. Prophylaxis should be offered to all children, although we still need to determine optimal dosing with respect to inhibitor development, and age for starting treatment. Vaccinations should be given subcutaneously and concomitant factor concentrate infusions avoided. According to the board, there is no evidence in the literature supporting suggestions that the type of concentrate influences inhibitor risk; but all patients should be monitored during their first exposures. Furthermore, there is no evidence to support an association between pregnancy-related issues, breast feeding and treatment-related factors (e.g. route of administration, or use of blood components) and inhibitor development. [ABSTRACT FROM AUTHOR]

The article discusses whether combined oral dexamethasone and epinephrine inhalation assist infants with bronchiolitis in recovering quickly. The combination of oral dexamethasone and nebulised epinephrine in children with bronchiolitis probably lessens hospital admission within the first 7 days and is favorable in lessening the duration of symptoms and length of hospital stay.