[Show abstract][Hide abstract] ABSTRACT: Haemophilia A and B are hereditary X-linked disorders due to deficiency (or absence) of coagulation factor VIII or IX, respectively. Bleeding risk is related to the severity of factor deficiency. Repeated joint bleeding can lead to a severe haemophilic arthropathy resulting in disabilities. Outcome measurements in persons with haemophilia (PWH) have been limited to laboratory evaluation (factor VIII or IX levels) and clinical outcomes (such as bleeding frequency), morbidity (for example linked with arthropathy) and mortality. Due to the new standard of care of PWH, there is a need to consider other outcome measures, such as the early detection and quantification of joint disease, health-related quality of life (QoL) and economic or cost-utility analyses. To investigate this, we performed a 10-yr systematic overview of outcome measures in haemophilia. Only clinical trials including at least 20 patients with haemophilia A or B were included. To facilitate the search strategy, eight issues of outcome measures were selected: physical scores, imaging technique scores, functional scores, QoL measurement, mortality, bleeding frequency, cost and outcome and bone mineral density. The results of these will be discussed. Clearly defined outcomes in haemophilia care are important for many reasons, to evaluate new treatments, to justify treatment strategies, to allow a good follow-up, to perform studies and to allocate resources. The use of such scoring systems is clearly recommended by experts in haemophilia care. However, most centres do not perform such scores outside clinical trials due to reasons such as lack of time and resources.
European journal of haematology. Supplementum 08/2014; 76:2-15.
[Show abstract][Hide abstract] ABSTRACT: Haemophilia A is a sex-linked disorder characterised chiefly by recurrent, spontaneous joint and muscle bleedings resulting from deficiency of factor VIII (FVIII). Recurrent joint bleeds result in haemophilic arthropathy. Unless treated with factor replacement therapy, many patients with severe haemophilia become disabled. The first clinical evidence favouring prophylaxis originated from the studies in Sweden and the Netherlands in the 1960s. Later on, it was shown that prophylaxis could prevent arthropathy, if started early in life, or slow its progression in adults with established arthropathy. The optimal dosing of FVIII in long-term prophylaxis has still not been determined, and there is growing evidence that the dose and frequency of FVIII should be individualised. We conducted a systematic search of PubMed to identify all relevant articles on FVIII prophylaxis in severe haemophilia A. We focused on articles with detailed information about individualisation of prophylaxis. Long-term prophylaxis in haemophilia was introduced in Sweden in the late 1950s. However, standard prophylactic regimens may not be appropriate for all patients with severe haemophilia. Factors such as age, joint status, co-morbidities and differences in pharmacokinetics lead to interindividual variation in factor requirement. Dose tailoring of FVIII by clinical outcome was first described in 1994. Since then, several dose-finding studies questioned the necessity to maintain preinfusion levels of FVIII above 1%. Individualising prophylaxis by dose tailoring is now recommended. Each country should adopt policies for individualising prophylaxis in patients with severe haemophilia. This would lead to a better distribution of the available source of factor concentrates.
European journal of haematology. Supplementum 08/2014; 76:16-20.
[Show abstract][Hide abstract] ABSTRACT: Congenital haemophilia A and B are genetic disorders affecting factor VIII and factor IX production, respectively. Factor replacement is the only effective treatment for these deficiencies, but a patient's immune system can develop inhibitory antibodies which bind and interfere with the function of the replaced factor in a variety of ways. The main treatment goal for patients with inhibitors is to induce immune tolerance to the injected factor. If not successful, a different treatment termed bypass therapy is needed to treat bleeds. The goal of this review is to demonstrate the usefulness of haemophilia registries as information sources to supplement available evidence regarding predictors of inhibitor development and immune tolerance induction (ITI) outcomes.In this systematic review, relevant keywords were used to search online academic databases during February 2014. Inclusion criteria were original publication and data obtained from a haemophilia or ITI registry with a minimum of 30 patients. A data collection form was created to extract information from selected manuscripts. Titles, abstracts and then full texts were screened to determine the eligibility of reports for this review.Eleven manuscripts from nine registries were determined eligible and included in the study. Registries have reported on some core variables, but are inconsistent in reporting less practiced predicting variables. Variables that may affect inhibitor and ITI outcomes were each divided into two categories: patient characteristics (such as age and family history) and treatment-related variables (including exposure days, treatment duration and dose).It is recommended that, in addition to exploratory hypothesis testing, a minimum set of variables should be collected and reported by registries. International collaboration and well-designed prospective registries are of major importance to advance this field in order to determine inhibitor risks and ITI outcomes and facilitate the development of new treatments.This article is protected by copyright. All rights reserved.
Journal of Internal Medicine 08/2014; · 6.46 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Detailed analysis of data from studies of recombinant antihemophilic factor produced using a plasma/albumin-free method (rAHF-PFM) in previously treated patients showed a substantial level of interpatient variation in pharmacokinetics (PKs), factor VIII dosing, and annualized bleed rate (ABR), suggesting that individual patient characteristics contributed to outcome. For example, plasma half-life (t1/2), recovery, and clearance appeared to differ between patients aged <6 years and 10-65 years. Prophylaxis resulted in lower ABRs than episodic treatment in both age groups; better adherence to the prophylactic regimen resulted in a lower ABR in patients aged 10-65 years. The weekly frequency of dosing and adherence to dosing were both significantly and inversely related to the rate of bleeding (young children, P<0.0001 for both all bleeds and joint bleeds; older patients, P<0.0001 for all bleeds and P<0.05 for joint bleeds), as was adherence to dosing frequency (P<0.0001 for all comparisons). A post-marketing randomized study of prophylaxis demonstrated that a PK-guided dosing regimen, based on an individual patient's rAHF-PFM PK (infusion interval, estimated t1/2, and recovery), was as effective as standard prophylaxis and that both prophylactic regimens were superior to episodic treatment with respect to ABR and quality of life measures. Thus, compared with standard prophylaxis, the PK-guided regimen achieved comparable efficacy with fewer weekly infusions. A two-compartment population PK model describes the PK data across the entire age range and forms the basis for future PK-guided therapy with rAHF-PFM. The model confirmed a shorter t1/2 and faster clearance of rAHF-PFM in children <6 years of age versus patients ≥10 years and predicted similar PK parameters with either a full or reduced blood sampling schedule, offering the potential for the use of PK-guided, individualized treatment in the routine clinical care setting.
[Show abstract][Hide abstract] ABSTRACT: Haemophilia is an X-linked inherited rare bleeding disorder affecting mainly men. The treatment consists of replacement therapy that has been associated with severe side effects, such as blood transmitted viral infections, but has markedly improved over the last decades. The aim of this study was to study family structure over time among Swedish persons with haemophilia (PWH), focusing on children, siblings and marital status. PWH A or B were identified from the haemophilia centres and the national Patient Registry. Each PWH was compared to five age- and gender-matched controls. The national Multi-Generation Registry was used to identify children and siblings. A total of 1365 children with a father suffering from haemophilia A or B and 1938 siblings of the PWH were identified. Having one or more children was significantly less common (P = 0.003) for PWH than for controls. Significantly lower rates of having a child were also found for the subgroups of persons suffering from severe haemophilia and those infected with HIV (P < 0.001). A higher proportion of PWH, with or without HIV and/or viral hepatitis had siblings compared to the controls (P < 0.001). However, the mean number of siblings was significantly lower for persons with severe haemophilia (P = 0.001). The number of marriages and divorces did not differ between PWH and controls. Our data indicate a negative impact of HIV and viral hepatitis on family structure for PWH despite the relatively good access to treatment in Sweden over the last few decades. This was particularly true for those with a severe form of haemophilia.
[Show abstract][Hide abstract] ABSTRACT: The concept of using pharmacokinetics for prophylactic dose tailoring with limited blood sampling in clinical practice has been demonstrated for factor VIII but not for factor IX. The pharmacokinetics of factor IX are more complicated than for factor VIII and also differ between plasma-derived and recombinant factor IX. Therefore, the pharmacokinetics of factor IX need to be further explored in clinical trials including comparative studies of prophylaxis with different factor IX concentrates. These are the main conclusions drawn from two of the last manuscripts written by Professor Sven Björkman and published in Haemophilia. Professor Björkman suddenly and unexpectedly died last summer. Thanks to the academic network created around his skill and through his enthusiasm for the pharmacokinetics of clotting factors and ability to convey his wisdom to others, this work will continue. Sven Björkman opened a new era in hemophilia prophylaxis.
[Show abstract][Hide abstract] ABSTRACT: Patients with haemophilia A and inhibitors are at high risk for severe bleeding, progression of joint disease and deterioration of health-related quality of life (HRQoL). To determine the impact of prophylaxis with an activated prothrombin complex concentrate (aPCC) on HRQoL, HRQoL was assessed using the Short-Form (SF)-36 Health Survey and the EQ-5D questionnaire in subjects ≥14 years participating in a prospective, randomized, crossover study comparing 6 months of aPCC prophylaxis with 6 months of on-demand therapy. Eighteen of 19 patients completed the survey or questionnaire before and after the on-demand therapy and prophylaxis periods. A general trend towards improved HRQoL after prophylaxis was observed for the 18 evaluable patients in all SF-36 dimensions except for vitality/energy and physical functioning. After prophylaxis, 'good responders,' defined as patients experiencing ≥50% reduction in bleeding, exhibited statistically and clinically significant differences in the physical component score (P = 0.021), role - physical (P = 0.042), bodily pain (P = 0.015), and social functioning (P = 0.036). Similarly, the EQ-5D health profile showed a trend towards improvement after prophylaxis in all evaluable patients. Among the good responders, improvements did not differ from those observed after on-demand treatment. EQ visual analogue scale values were slightly improved following prophylaxis for all evaluable patients and the EQ-5D utility index improved in the good responders only. During prophylaxis, patients missed significantly fewer days from school or work because of bleeding than during on-demand treatment (P = 0.01). In conclusion, by significantly reducing bleeding frequency in good responders, aPCC prophylaxis improved HRQoL compared with on-demand treatment.
[Show abstract][Hide abstract] ABSTRACT: Venous thromboembolism is common in the general population with increasing age as one of the most important risk factors. The care of hemophilia and von Willebrand disease has improved in recent decades, resulting in the expectation of a growing population of aging people with these disorders. Thrombosis seems rare in hemorrhagic disorders but studies documenting the true epidemiology are virtually lacking. Events have been reported, however, primarily catheter-related thrombophlebitis in hemophilia, but also deep vein thrombosis and pulmonary embolism have been described in von Willebrand disease, usually in conjunction with major surgery and prolonged replacement therapy with high factor levels. Thromboprophylaxis is likely not warrented in most cases. Instead, well-designed therapy and careful monitoring are important measures to prevent risk. In von Willebrand disease particularly, the variation of the phenotype and products used for replacement are challenges, as infusion of von Willebrand factor will increase the endogenous level of factor VIII. Long-term replacement therapy into old age is becoming more common in hemophilia but will not increase occurrence of thromboembolic disease, as factor levels still will be low and have a preventive effect.
[Show abstract][Hide abstract] ABSTRACT: The first meeting of international specialists in the field of von Willebrand disease (VWD) was held in the Åland islands in 1998 where Erik von Willebrand had first observed a bleeding disorder in some members of a family from Föglö and a summary of the meeting was published in 1999. The second meeting was held in 2010 and a report of the meeting was published in 2012. Topics covered included progress in understanding of VWD over the last 50 years; multimers; classification of VWD; pharmacokinetics and laboratory assays; genetics; treating the paediatric patient; prophylaxis; geriatrics; gene therapy and treatment guidelines. This third meeting held over 3 days covered the structure and function of von Willebrand factor (VWF); type 1 VWD, the most common form of the disease; a lifespan of pharmacokinetics in VWD; detecting inhibitors in VWD patients; and special challenges in understanding and treating the female VWD patient.
[Show abstract][Hide abstract] ABSTRACT: Sweden has been a pioneer in the treatment of haemophilia, with the first concentrate available in the 1950s. Treatment has improved over the years to its current state-of-the art. The aim of the current study was to evaluate the long-term outcome of haemophilia in terms of incidence, morbidity and mortality. Patients diagnosed with haemophilia A or B registered at the national haemophilia centres and/or the Patient Registry and born before 2009 and alive in 1968 were enrolled and linked to the Cause of Death-, Migration- and Medical Birth registries. Five age- and sex-matched controls were selected for each patient. A total of 1431 patients with haemophilia A or B were compared with 7150 controls. The 3-year moving average incidence rate per 100 000 population varied between 21 and 36. The hazard ratio for all-cause mortality compared with controls was 2.2, 95% CI: [1.8; 2.7], P < 0.001 for the entire group of patients and 1.7, 95% CI: [1.3; 2.2], P < 0.001 when patients with HIV and/or viral hepatitis were excluded. The corresponding figures for the severe haemophilia subgroup were 6.6, 95% CI: [4.5; 10.0], P < 0.001 and 8.2, 95% CI [3.2; 20.8], P < 0.001 respectively. The most common causes of death were related to malignancies and the haemostatic defect. People with haemophilia were 57% less likely to die from ischaemic heart disease than controls. People with haemophilia in Sweden demonstrate higher mortality over time, independent of HIV and viral hepatitis, despite relatively advantageous access to clotting factor concentrates.
[Show abstract][Hide abstract] ABSTRACT: Ancestral background, specifically African descent, confers higher risk for development of inhibitory antibodies to factor VIII (FVIII) in haemophilia A. It has been suggested that differences in the distribution of FVIII gene (F8) haplotypes, and mismatch between endogenous F8 haplotypes and those comprising products used for treatment could contribute to risk. Data from the Hemophilia Inhibitor Genetics Study (HIGS) Combined Cohort were used to determine the association between F8 haplotype 3 (H3) vs. haplotypes 1 and 2 (H1 + H2) and inhibitor risk among individuals of genetically determined African descent. Other variables known to affect inhibitor risk including type of F8 mutation and human leucocyte antigen (HLA) were included in the analysis. A second research question regarding risk related to mismatch in endogenous F8 haplotype and recombinant FVIII products used for treatment was addressed. Haplotype 3 was associated with higher inhibitor risk among those genetically identified (N = 49) as of African ancestry, but the association did not remain significant after adjustment for F8 mutation type and the HLA variables. Among subjects of all racial ancestries enrolled in HIGS who reported early use of recombinant products (N = 223), mismatch in endogenous haplotype and the FVIII proteins constituting the products used did not confer greater risk for inhibitor development. Haplotype 3 was not an independent predictor of inhibitor risk. Furthermore, our findings did not support a higher risk of inhibitors in the presence of a haplotype mismatch between the FVIII molecule infused and that of the individual.
[Show abstract][Hide abstract] ABSTRACT: von Willebrand's disease (VWD) is probably the most common bleeding disorder, with some studies indicating that up to 1% of the population may have the condition. Over recent years interest in VWD has fallen compared to that of haemophilia, partly the result of focus on blood-borne diseases such as HIV and hepatitis. Now the time has come to revisit VWD, and in view of this some 60 international physicians with clinical and scientific interest in VWD met over 4 days in 2010 in the Åland islands to discuss state-of-the-art issues in the disease. The Åland islands are where Erik von Willebrand had first observed a bleeding disorder in a number of members of a family from Föglö, and 2010 was also the 140th anniversary of his birth. This report summarizes the main papers presented at the symposium; topics ranged from genetics and biochemistry through to classification of VWD, pharmacokinetics and laboratory assays used in the diagnosis of the disease, inhibitors, treatment guidelines in different age groups including the elderly who often have comorbid conditions that present challenges, and prophylaxis. Other topics included managing surgeries in patients with VWD and the role of FVIII in VWF replacement, a controversial subject.
[Show abstract][Hide abstract] ABSTRACT: The bleeding patterns of severe von Willebrand's disease (VWD) adversely affect quality of life, and may be life threatening. There is a presumed role for prophylaxis with VWF-containing concentrates, but data are scarce. The von Willebrand Disease Prophylaxis Network (VWD PN) was formed to investigate the role of prophylaxis in clinically severe VWD that is not responsive to other treatment(s).Using a retrospective design, the effect of prophylaxis was studied. Availability of records to document, or reliably assess, the type and frequency of bleeding episodes prior to, and after, the initiation of prophylaxis was required. Annualized bleeding rates were calculated for the period prior to prophylaxis, during prophylaxis and by primary bleeding indication defined as the site accounting for more than half of all bleeding symptoms. The Wilcoxon signed-rank test of differences in the medians was used. Sixty-one subjects from 20 centres in 10 countries were enrolled. Data for 59 were used in the analysis. The median age at onset of prophylaxis was 22.4 years. Type 3 VWD accounted for the largest number (N = 34, 57.6%). Differences in bleeding rates within individuals during compared with before prophylaxis were significant for the total group (P < 0.0001), and for those with primary bleeding indications of epistaxis (P = 0.0005), joint bleeding (P = 0.002) and GI bleeding (P = 0.001). The effect of prophylaxis was similar among those age < 18 years and those ≥18. One person developed an inhibitor during treatment. We conclude that prophylactic treatment of VWD is efficacious.
[Show abstract][Hide abstract] ABSTRACT: Antibodies directed towards non-neutralizing epitopes on the factor VIII protein (FVIII) may be detected in patients with haemophilia A. We evaluated the prevalence of non-neutralizing antibodies, in 201 inhibitor-negative brother pairs with severe haemophilia A, enrolled in the Malmö International Brother Study and the Haemophilia Inhibitor Genetics Study. To evaluate binding specificity of the antibodies, ELISA plates were coated with two recombinant full-length (FL) FVIII-products and one recombinant B-domain-deleted (BDD) product. Seventy-nine patients (39.3%) had a history of positive inhibitor titre measured by Bethesda assay, and FVIII antibodies were detected in 20 of them (25.3%). Additional 23 samples from subjects without a history of FVIII inhibitors were ELISA-positive corresponding to a frequency of non-neutralizing antibodies of 18.9%. The antibody response towards the different FVIII products was heterogenous, and was raised not only towards the non-functional B-domain but also towards both FL-rFVIII and BDD-rFVIII. In patients considered successfully treated with immune tolerance induction, 25.4% had remaining FVIII antibodies. The number of families with an antibody response in all siblings was increased when the total antibody response was taken into account, further supporting the concept of a genetic predisposition of the immune response. Further studies and careful monitoring over time are required to appreciate the immune response on the risk of inhibitor development or recurrence in the future.