1. |
- Ljung, Rolf
(author)
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Aspects of haemophilia prophylaxis in Sweden.
- 2002
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In: Haemophilia. - : Wiley. - 1351-8216 .- 1365-2516. ; 8:Suppl 2, s. 34-37
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Journal article (peer-reviewed)abstract
- Prophylactic treatment of haemophilia has been gaining acceptance as the optimal therapeutic option in an increasing number of haemophilia centres in the developed world in recent years. This paper focus on three aspects of prophylactic therapy: when to start treatment, venous access and the dose/dose interval. Evidence is in favour of prophylactic treatment to be started at an early age using either a peripheral vein with 1-2 injections per week and a successive increase in the frequency depending on the child and the veins, or, using a Port-A-Cath which allows a better prophylactic coverage by infusions preferably every second day in haemophilia A and every third day in haemophilia B.
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2. |
- Abshire, T. C., et al.
(author)
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Prophylaxis in severe forms of von Willebrand's disease: results from the von Willebrand Disease Prophylaxis Network (VWD PN)
- 2013
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In: Haemophilia. - : Wiley. - 1351-8216. ; 19:1, s. 76-81
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Journal article (peer-reviewed)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.
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5. |
- Ahnström, Josefin, et al.
(author)
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A 6-year follow-up of dosing, coagulation factor levels and bleedings in relation to joint status in the prophylactic treatment of haemophilia
- 2004
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In: Haemophilia. - : Wiley. - 1351-8216 .- 1365-2516. ; 10:6, s. 689-697
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Journal article (peer-reviewed)abstract
- The primary aim of this study was to investigate the possible relationship between coagulation factor level and bleeding frequency during prophylactic treatment of haemophilia after stratification of the patients according to joint scores. The secondary aim was to obtain a systematic overview of the doses of coagulation factors prescribed for prophylaxis at the Malmo haemophilia treatment centre during a 6-year period. A retrospective survey of medical records for the years 1997-2002 and pharmacokinetic study results from the 1990s was complemented by collection of blood samples for coagulation factor assay when needed. Information on the dosing and plasma levels of factor VIII or factor IX, joint scores and incidence of bleedings (joint bleeds and 'other bleeds') was compiled. The patients were stratified by age (0-6, 7-12, 13-18, 19-36 and >36 years) and joint score (0, 1-6 and >6). Individual pharmacokinetic parameters of plasma coagulation factor activities (FVIII:C and FIX:C) were estimated. Trough levels during the treatment were calculated, as well as the number of hours per week of treatment during which plasma FVIII:C/FIX:C fell below a 1, 2 or 3% target level. Fifty-one patients with haemophilia A (two moderate, 49 severe) and 13 with haemophilia B (all severe) were included, yielding data for 364 patient-years of treatment. There was a wide range of dosing schedules, the most common ones being three times a week or every other day for FVIII and twice a week or every third day for FIX. The overall relationship between FVIII:C/FIX:C levels and incidence of joint bleeding was very weak, even after stratification of the patients according to joint score. There was no relationship between coagulation factor level and incidence of other bleeds. In this cohort of patients on high-dose prophylactic treatment, dosing was based more on clinical outcome in terms of bleeding frequency than on the aim to maintain a 1% target level of FVIII:C/FIX:C. Some patients did not bleed in spite of a trough level of <1% and others did in spite of trough levels >3%. The practical implication of our findings is that dosing in prophylactic treatment of haemophilia should be individualized. Thus, proposed standard regimens should be implemented only after careful clinical consideration, with a high readiness for re-assessment and individual dose tailoring.
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8. |
- Andersson, Nadine, et al.
(author)
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Genetic screening of children with suspected inherited bleeding disorders
- 2020
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In: Haemophilia. - : Wiley. - 1351-8216 .- 1365-2516. ; 26:2, s. 314-324
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Journal article (peer-reviewed)abstract
- INTRODUCTION: Genetic screening using high-throughput DNA sequencing has become a tool in diagnosing patients with suspected inherited bleeding disorders (IBD). However, its usefulness and diagnostic efficacy in children is unclear.AIM: To evaluate the diagnostic efficacy of genetic screening for IBD in children and downstream further testing.METHODS: After informed consent, children (<18 years) with suspected IBD underwent genetic screening with 94 selected genes.RESULTS: A total of 68 heterozygous class 3-5 variants were detected in 30 children, 2.3 variants per patient. Directed specific functional testing was performed after genetic screening in a subset of patients. Adhering to the ACMG guidelines, the results of functional testing together with family history and previous publications classified three variants as likely disease causing (class 4) and two variants as disease causing (class 5), all in children with thrombocytopenia. The overall diagnostic rate was 16.7% (5/30). Children with thrombocytopenia had a significantly higher rate of significant genetic findings, 5/9 (55.6%) vs. 0/21 (0%; P = .0009).CONCLUSION: We conclude that performing genetic screening in children is an effective tool especially for children with inherited thrombocytopenia and has the possibility to diagnose platelet disorders adequately early in life. Children with bleeding diathesis, normal coagulation work-up and without thrombocytopenia are unlikely to be diagnosed by genetic screening. Ethical issues such as incidental findings, variants associated with cancer and the interpretation of the genetic results into clinical practice remain problematic.
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17. |
- Arvanitakis, Alexandros, et al.
(author)
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A comparison of MyPKFiT and WAPPS-Hemo as dosing tools for optimizing prophylaxis in patients with severe haemophilia A treated with Octocog alfa
- 2021
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In: Haemophilia. - : Wiley. - 1351-8216 .- 1365-2516. ; 27:3, s. 417-424
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Journal article (peer-reviewed)abstract
- Introduction: MyPKFiT and the Web-Accessible Population Pharmacokinetic service—Hemophilia (WAPPS-Hemo) are web-based population-based applications developed for helping physicians individualize and optimize replacement therapy. Although MyPKFiT is intended for Octocog alfa and Rurioctocog alfa pegol use only, the WAPPS-Hemo is applicable to all factor VIII concentrates. Aim: To compare MyPKFiT and WAPPS-Hemo as dosing tools for optimizing treatment of patients with severe haemophilia A on regular prophylaxis with Octocog alfa in a real-world setting. Methods: Fourteen patients with severe haemophilia A (median age 30.8 years; range 20–71) were enrolled. The FVIII activity was measured twice after a regular dose of Octocog alfa by the chromogenic and the one-stage assays. PK analyses were performed using each tool and dosing estimations to reach trough levels of 1%, 3% or 5% after 48 h. Findings were calculated and compared. Results: The two PK algorithms yielded similar t½ independent of the type of FVIII assay used. However, there were significant differences in the time to reach 1%, 3% and 5%. The WAPPS-Hemo generated 10–12 h longer time to a trough of 1% and up to 4 h for the troughs of 3% and 5%. Accordingly, the doses estimated by WAPPS-Hemo for a daily regimen were between 28% and 100% of those proposed by MyPKFiT. Conclusions: MyPKFiT and WAPPS-Hemo provided similar half-life estimations for Octocog alfa independent of the FVIII assay used. The doses suggested by WAPPS-Hemo to reach specific troughs were overall lower, which may have implications for treatment optimization.
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18. |
- Arvanitakis, Alexandros, et al.
(author)
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Clinical outcome and adherence rate in Scandinavian patients with intermediate-intensity prophylaxis before and after the switch of standard half-life FVIII products to BAY 81–8973
- 2022
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In: Haemophilia. - : Wiley. - 1351-8216 .- 1365-2516. ; 28:2, s. 223-229
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Journal article (peer-reviewed)abstract
- Introduction: Treatment optimization in haemophilia A can be achieved by choice of FVIII product and knowledge of pharmacokinetics (PK), phenotype and adherence. A favourable PK profile of BAY 81–8973 (octocog alfa) (Kovaltry, Bayer AB) compared to other standard half-life (SHL) FVIII products has been suggested. Aim: To evaluate whether the switch to BAY 81–8973, using the same dosing schedule, impact factor consumption and bleed rates, taking arthropathy and adherence into account. Methods: Forty patients on prophylaxis with SHL (median age 40.5 years) attending the haemophilia treatment centres in Malmö and Oslo were enrolled. The annualised bleeding rate (ABR) and joint bleeding rate (AJBR) before and after the switch to BAY 81–8973 was calculated. PK analyses were performed with WAPPS-Hemo. Joint health status and treatment adherence were assessed. Results: The median ABR and AJBR was 0 before and after the switch, at both centres. The median yearly factor consumption was 3,345 IU/Kg/year in the entire study group corresponding to intermediate-intensity prophylaxis in most patients and with significantly more used in Malmö (3,862 IU/Kg/year), compared to Oslo (2,337 IU/Kg/year) (P.006). There was no correlation between arthropathy and bleeding. The median BAY 81–8973 t½ was 20 h (range 7.5–29 h), with significant correlation to VWF levels, and 13.4 h after exclusion of VWF outliers. Adherence to treatment was 97%. Conclusions: Concentrate switch, using mainly intermediate-intensity regimens with high adherence rates, preserves excellent prophylaxis outcome using standard half-life FVIII products, indicating the value of individualized prophylaxis and close follow-up.
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19. |
- Arvanitakis, Alexandros, et al.
(author)
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Impact of timing of prophylaxis commencement, F8 genotype and age on factor consumption and health-related quality of life in patients with severe haemophilia A
- 2023
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In: Haemophilia. - 1351-8216. ; 29:4, s. 1032-1038
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Journal article (peer-reviewed)abstract
- Introduction: The timing of prophylaxis and F8 genotype can impact treatment outcomes in adults with severe haemophilia A (HA). Aim: To investigate how F8 genotype, timing, and type of prophylaxis influence arthropathy, bleeding rates, factor consumption and health-related quality of life (HRQoL). Methods: Thirty-eight patients with severe HA were enrolled. Bleeding events were recorded retrospectively during median 12.5 months. F8 gene variants were classified as null or non-null. Joint health and HRQoL were assessed with HJHS and EQ-5D-5L, respectively. Results: The median age at prophylaxis start was 1.25 years in the primary prophylaxis group (N = 15, median age 26 years) and 31.5 years in the secondary group (N = 22, 45 years), respectively. There were significant differences in the medians of HJHS (4 vs. 20, p <.001), EQ-5D-5L index (0.9647 vs. 0.904, p =.022), EQ VAS (87 vs. 75, p =.01) and FVIII consumption (3883 vs. 2737 IU/kg/year, p =.02), between the primary and secondary groups, respectively. Median annualized bleeding rate (ABR) was 0 for both groups. Twenty-five null and thirteen non-null F8 gene variants were identified. In the secondary prophylaxis group, lower median FVIII consumption (1926 vs. 3370 IU/kg/year) was shown for non-null compared to null variants, respectively, with similar ABR and HJHS. Conclusion: Delayed prophylaxis start with intermediate dose intensity prevents bleeds but at a cost of more arthropathy and reduced HRQoL, compared to higher intensity primary prophylaxis. Non-null F8 genotype may allow lower factor consumption with similar HJHS and bleeding rates, compared to null genotype.
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20. |
- Arvanitakis, Alexandros, et al.
(author)
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Primary prophylaxis implementation and long-term joint outcomes in Swedish haemophilia A patients
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In: Haemophilia. - 1351-8216.
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Journal article (peer-reviewed)abstract
- Introduction: Primary prophylaxis is the gold standard in severe haemophilia A (SHA) but time to escalate the prophylaxis regimen varies. Aim: Assess prophylaxis implementation and long-term joint health outcomes in SHA with primary prophylaxis. Methods: Adult male patients born after 1980, with SHA on primary prophylaxis, started before the age of 3 years and second joint bleed, and no history of FVIII inhibitors, were enrolled. Repeated joint-health examinations were performed with HJHS or HEAD-US; VERITAS-PRO assessed adherence. Results: Thirty patients were enrolled with, at inclusion, median age 33.5 years, annualized bleed rate and joint bleed rate 0, and FVIII consumption 4232 IU/kg/year, respectively. The median age was 1.2 years, at prophylaxis start once weekly with a median FVIII dose of 47.7 IU/kg, and 1.7 years, by the time escalation to a final regimen had occurred, with a median infusion frequency of thrice weekly and FVIII dose 41.7 IU/kg, respectively. Older age correlated with later transition to escalated prophylaxis (p <.001). Longer time to escalated prophylaxis correlated to more bleeds (p <.001). Median HJHS increased slowly, reaching 4 at 35–40 years. HJHS at 15–20 years correlated with higher HJHS afterwards. Median total HEAD-US score was 1 and correlated with HJHS (p <.001). Median VERITAS-PRO score was 36, indicating good treatment adherence. Conclusion: Primary prophylaxis is effective but does not completely prevent the gradual development of arthropathy in SHA. Joint assessments with HJHS should start at an early age, as they correlate with arthropathy in later life. Prophylaxis escalation should proceed expeditiously to prevent bleeds.
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22. |
- Astermark, Jan
(author)
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Basic aspects of inhibitors to factors VIII and IX and the influence of non-genetic risk factors.
- 2006
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In: Haemophilia. - 1351-8216. ; 12 Suppl 6, s. 41499-41499
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Journal article (peer-reviewed)abstract
- The appearance of polyclonal antibodies inhibiting the function of exogenous factors VIII (FVIII) and IX (FIX) continues to be a major challenge in the treatment of patients with congenital haemophilia. Why these inhibitors develop in 10-20% of patients with haemophilia A, and in 1-5% of patients with haemophilia B, remains largely unexplained. The antibodies, however, are characterized by several features that may have implications for the immune process by which they occur. The FVIII antibodies are mainly directed towards the A2, A3 and C2 domains, thereby interfering with the function of the factor Xase complex, the binding of FVIII to von Willebrand factor, and the binding of FVIII to phospholipid membranes. The FIX epitopes are localized to the NH2-terminal gamma-carboxyglutamic acid region and the serine protease domain. Genetic risk factors are known to be of importance in the development of inhibitors, whereas the impact of non-genetic factors is less clear. However, based on studies of related subjects, it is obvious that non-genetic factors are of importance as well. Putative factors currently debated include age at the start of treatment, treatment in association with immune challenges, the type of product, and the mode of administration. Most of the findings reported to date, however, derive from small cohorts that have not been sufficiently well characterized with respect to genetic risk profile. Therefore, additional studies are required to quantify the impact of non-genetic factors on the pathophysiologic process of inhibitor development.
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23. |
- Astermark, Jan, et al.
(author)
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Clinical issues in inhibitors
- 2010
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In: Haemophilia. - : Wiley. - 1351-8216 .- 1365-2516. ; 16, s. 54-60
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Research review (peer-reviewed)abstract
- Anamestic inhibitors represent the major complication of haemophilia therapy now that clotting factor concentrates are virtually free of pathogen-transmission risk. Conventional clotting factor replacement is usually insufficient to prevent or treat bleeding in a haemophilia patient with a high responding inhibitor so that alternative treatment with bypassing agents is required. Despite their relative efficacy, their use does not achieve the same invariable haemostasis that patients without inhibitors do following treatment with factor concentrate replacement. This has led to the attempt to eradicate such inhibitors with immune tolerance induction. Success is not invariable, however, and many patients with long-term persistent high-titre inhibitors continue to experience great morbidity. Recently, this has given rise on a limited basis to attempts to use bypassing agents in prophylaxis regimens in an effort to alleviate this extreme morbidity. Each of these strategies is discussed in the context of their relative benefits and risks.
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24. |
- Astermark, Jan, et al.
(author)
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Comparison of single subject and population-based pharmacokinetics for optimizing prophylaxis with simoctocog alfa in patients with haemophilia A
- 2021
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In: Haemophilia. - : Wiley. - 1351-8216 .- 1365-2516. ; 27:4, s. 626-633
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Journal article (peer-reviewed)abstract
- Introduction: The use of pharmacokinetic assessment for optimal prophylactic dosing of factor concentrates in haemophilia has gained increasing enthusiasm over the last decade. However, blood sampling on several occasions is burdensome and limited sampling using population-based PK is appealing. Aim: To compare the pharmacokinetics and dosing recommendations for prophylaxis using six-point single subject versus population-based method (WAPPS-Hemo) for simoctocog alfa (Nuwiq®). Methods: Twelve adult patients with severe haemophilia A received a factor VIII (FVIII) dose of ≈50 IU/kg, and the activity was measured pre-infusion and at 30 min, 6, 9, 24 and 48 h post-infusion. Half-life (t1/2), weight-normalized AUC and time to troughs of 5%, 3% and 1% were calculated. The correlation between the PK algorithms was assessed using intraclass correlations (ICC) and dosing estimations were provided. Results: WAPPS-Hemo yielded a slightly longer mean t1/2, but the overall correlation between the methods was good (ICC ≥0.79) The time to troughs of 5%, 3% and 1% showed ICCs ≥0.86. For all variables, the most converging limited time point was 6+48 h. Additional time points did not improve the correlation. Despite similar pharmacokinetics, the mean estimated dose for a specific trough level varied from 60% less to 20% more using the population-based approach. The time to 1% and the corresponding dose was sensitive to the baseline assumption. Conclusion: Our data support the use of population-based PK for patients on simoctocog alfa prophylaxis but also indicates differences, stressing the importance of the sampling scheme and monitoring actual FVIII levels achieved.
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26. |
- Astermark, Jan, et al.
(author)
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Current European practice in immune tolerance induction therapy in patients with haemophilia and inhibitors.
- 2006
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In: Haemophilia. - : Wiley. - 1351-8216 .- 1365-2516. ; 12:4, s. 363-371
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Journal article (peer-reviewed)abstract
- The management of patients with inhibitors is an important challenge in haemophilia care. The lack of randomized controlled trials means that clinical decisions are generally based on subjective opinions, and purchasers' attention is likely to focus on the costs of treatment. In order to assess the current management of inhibitor patients and use of immune tolerance induction therapy (ITI) in Europe, we performed a survey within a European network of 21 comprehensive care centres from 14 countries (the European Haemophilia Therapy Standardisation Board). The survey identified a total of 381 patients with inhibitors attending the centres, 211 (55.4%) of whom had never been exposed to ITI. Between 1998 and 2003, the centres performed 233 procedures and 114 (48.9%) were successful. The survey demonstrated that dosing, which is the time to start and stop the ITI, the type of concentrate to use and the definition of success varied among the centres. Well-designed trials are warranted to guide decision-making, but in the absence of these studies we have developed consensus guidance for the management of inhibitor patients based on current clinical practice, as identified by the survey, and review of the literature.
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27. |
- Astermark, Jan, et al.
(author)
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Current use of by-passing agents in Europe in the management of acute bleeds in patients with haemophilia and inhibitors.
- 2007
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In: Haemophilia. - : Wiley. - 1351-8216 .- 1365-2516. ; 13:1, s. 38-45
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Journal article (peer-reviewed)abstract
- The ultimate goal of treatment for patients with inhibitory antibodies should be to permanently eradicate the inhibitor by immune tolerance induction therapy (ITI). However, ITI procedures fail in a substantial number of patients and in many countries ITI is not even offered owing to its high cost. How patients with inhibitors are managed in different European countries is evaluated with a special focus on the use of by-passing agents, i.e. recombinant FVIIa (rFVIIa) and activated prothrombin complex concentrates (aPCC), as well as the type of monitoring performed. Investigators from 22 large haemophilia centres participating within the network of the European Haemophilia Therapy Standardisation Board (EHTSB) were asked to complete a questionnaire. rFVIIa was routinely used in all centres for both children and adults at dosages ranging from 90 to 250 mu g kg(-1) at an interval of 2-4 h. aPCC was used in 85% of the centres in adults and in 25% of the centres in children with haemophilia A at dosages of 50-100 IU kg(-1) every 6-12 h. The corresponding figures for children and adults with haemophilia B were 40% and 15% of the centres, respectively. Higher dosages of both agents were considered in the case of life-threatening bleeds. General recommendations were developed, based on the information provided by the survey. The results clearly indicate the need for well-designed comparative studies to optimize the use of by-passing agents.
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31. |
- Astermark, Jan, et al.
(author)
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Inhibitor development.
- 2008
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In: Haemophilia. - : Wiley. - 1351-8216 .- 1365-2516. ; 14 Suppl 3, s. 36-42
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Journal article (peer-reviewed)abstract
- The immune response to factor VIII and the development of inhibitory antibodies is a complex multi-factorial process involving a variety of immune regulatory genes and cells, several of which have the potential to determine risk. A better understanding of the mechanisms involved will increase the likelihood of development of new therapeutic options for patients with hemophilia. This review summarizes genetic and non-genetic risk factors currently under evaluation, and the potential modulative effect of the von Willebrand factor on factor VIII immuno- and antigenicity. In addition, the role of T-regulatory cells in the pathogenicity of inhibitors will be discussed.
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32. |
- Astermark, Jan
(author)
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Inhibitor development: patient-determined risk factors.
- 2010
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In: Haemophilia. - : Wiley. - 1351-8216 .- 1365-2516. ; 16, s. 66-70
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Journal article (peer-reviewed)abstract
- Summary. The reasons that inhibitory factor VIII antibodies develop in only a fraction of patients with haemophilia A remain unclear, but studies of genetically related subjects have indicated that the immunological outcome of replacement therapy is to a large extent determined by patient-related risk factors. Non-genetic factors will also influence the inhibitor risk, since events challenging the immune system will elicit and stimulate immune regulatory processes with the potential of modifying the immune response. Further insight into the immunological pathways and risk factors involved will be important in order to better predict and prevent this complication. This review will briefly summarize the data obtained to date in unrelated and related subjects in the Malmö International Brother Study (MIBS) regarding genetic factors and discuss how these factors might interact with non-genetically determined factors and events.
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33. |
- Astermark, Jan, et al.
(author)
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Malignant disease in the haemophilic population: moving towards a management consensus?
- 2012
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In: Haemophilia. - : Wiley. - 1351-8216. ; 18:5, s. 664-671
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Journal article (peer-reviewed)abstract
- The Malignancy in Haemophilia Workshop Group convened a consensus working group of haematologists and oncologists to review topics related to malignancy in haemophilia. The treatment of malignant disease in this population is increasingly relevant as both outcome and lifespan continue to improve. Although adequate guidance exists for control of spontaneous bleeding episodes and of haemostasis in general surgery, information for management of haemostasis in patients with various malignancies is sparse. To date, no clinical guidelines exist for management of complex bleeding problems, diagnosis, therapy and follow-up of malignancies in haemophilia. Furthermore, it remains unclear whether or not morbidity and mortality outcomes associated with malignancies are affected by haemophilia or by its treatment. Through presentation of five malignancies - prostate cancer, colorectal cancer, acute leukaemia, bladder cancer and hepatocellular carcinoma - important issues are highlighted, such as risk from bleeding as a symptom of malignancy; risks from invasive screenings and how these should be handled in haemophilic individuals; the implications of chemotherapy and treatment schedules, bone marrow suppression, radiotherapy, or surgery; and the likelihood of an interaction between treatment for haemophilia and malignancy outcomes. Ultimately, the aim is to establish consensus guidelines to direct and harmonize future treatment policy for malignant disease in the haemophilic population.
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34. |
- Astermark, Jan, et al.
(author)
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Managing Haemophilia for Life: 4th Haemophilia Global Summit
- 2014
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In: Haemophilia. - : Wiley. - 1351-8216. ; 20, s. 1-20
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Research review (peer-reviewed)abstract
- The 4th Haemophilia Global Summit was held in Potsdam, Germany, in September 2013 and brought together an international faculty of haemophilia experts and delegates from multidisciplinary backgrounds. The programme was designed by an independent Scientific Steering Committee of haemophilia experts and explored global perspectives in haemophilia care, discussing practical approaches to the optimal management of haemophilia now and in the future. The topics outlined in this supplement were selected by the Scientific Steering Committee for their relevance and potential to influence haemophilia care globally. In this supplement from the meeting, Jan Astermark reviews current understanding of risk factors for the development of inhibitory antibodies and discusses whether this risk can be modulated and minimized. Factors key to the improvement of joint health in people with haemophilia are explored, with Carlo Martinoli and Victor Jimenez-Yuste discussing the utility of ultrasound for the early detection of haemophilic arthropathy. Other aspects of care necessary for the prevention and management of joint disease in people with haemophilia are outlined by Thomas Hilberg and Sebastian Lobet, who highlight the therapeutic benefits of physiotherapy and sports therapy. Riitta Lassila and Carlo-Federico Perno describe current knowledge surrounding the risk of transmission of infectious agents via clotting factor concentrates. Finally, different types of extended half-life technology are evaluated by Mike Laffan, with a focus on the practicalities and challenges associated with these products.
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35. |
- Astermark, Jan, et al.
(author)
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Matching-adjusted indirect comparison of bleeding outcomes in severe haemophilia A : Comparing valoctocogene roxaparvovec gene therapy, emicizumab prophylaxis, and FVIII replacement prophylaxis
- 2023
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In: Haemophilia. - 1351-8216. ; 29:4, s. 1087-1094
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Journal article (peer-reviewed)abstract
- Introduction: Head-to-head evaluation of valoctocogene roxaparvovec, the first gene therapy approved for haemophilia A, with emicizumab is not available. Therefore, phase 3 trial data were indirectly compared. Aim: To compare bleeding rates in trials evaluating 6 × 1013 vg/kg valoctocogene roxaparvovec (GENEr8-1; NCT03370913), 1.5 mg/kg emicizumab dosed every week (HAVEN 3; NCT02847637), and FVIII prophylaxis (270–902) in participants with severe haemophilia A (FVIII ≤1 IU/dL). Methods: Valoctocogene roxaparvovec versus emicizumab and FVIII prophylaxis as used in 270–902 versus emicizumab cross-trial comparisons were performed using matching-adjusted indirect comparison (MAIC). Individual participant data from GENEr8-1 and 270–902 were weighted to equalise aggregate participant baseline characteristics from HAVEN 3. After MAIC weighting, annualised bleeding rates (ABR) and proportions of participants without bleeds were compared for treated bleeds, all bleeds, treated joint bleeds, and treated spontaneous bleeds. Results: After MAIC weighting, ABR for all bleeds was statistically significantly lower with valoctocogene roxaparvovec than emicizumab (rate ratio [95% CI],.55 [.33–.93]). Additionally, significantly higher proportions of participants had no treated joint bleeds (odds ratio [95% CI], 2.75 [1.20–6.31]) and no treated bleeds (3.25 [1.53–6.90]) with valoctocogene roxaparvovec versus emicizumab. When compared with the mainly standard half-life FVIII prophylaxis regimens in 270–902, mean ABRs (except for all bleeds) were significantly lower, and significantly higher proportions reported 0 bleeds for all outcomes with emicizumab. Conclusion: Valoctocogene roxaparvovec provided generally lower bleeding rates and higher probability of no bleeds, including treated joint bleeds, than emicizumab. Emicizumab was more effective than FVIII prophylaxis regimens used in 270–902.
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37. |
- Astermark, Jan, et al.
(author)
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Non-genetic risk factors and the development of inhibitors in haemophilia: a comprehensive review and consensus report.
- 2010
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In: Haemophilia. - : Wiley. - 1351-8216. ; May 4, s. 747-766
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Journal article (peer-reviewed)abstract
- Summary. 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.
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38. |
- Astermark, Jan
(author)
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Prevention and prediction of inhibitor risk.
- 2012
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In: Haemophilia. - : Wiley. - 1351-8216. ; 18 Suppl 4, s. 38-42
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Journal article (peer-reviewed)abstract
- Summary: Studies of determinants of the development of inhibitory antibodies in patients with haemophilia indicate that this is a complex process involving several factors. The foundation is characterized by the T- and B-cell repertoire and the antigen presenting cells and to elicit an immune response to the deficient factor, a pre-disposing foundation is needed. Hence, in the absence of a certain set of circumstances, there will be no risk for development of inhibitors. Conversely, in patients fundamentally at risk, genetic and non-genetic factors might add to the risk. These factors may be additive or interactive, and ultimately promote or counteract the immune reaction by modifying immune regulators and the cytokine profile in an individual. In some subjects, only minor inflammatory signals might be needed, whereas in others a more pronounced pro-inflammatory state will be required. Regarding genetic markers other than the type of mutation and the HLA class II molecules, polymorphisms in various immune regulatory genes have been associated with inhibitor risk. These associations have not, however, been consistent across all patient groups. The reason for this is not clear, but could be related to study design or statistical power, family relationships among those studied, the complexity of interacting molecules and ethnic genomic variation. The Hemophilia Inhibitor Genetics Study (HIGS) has identified additional candidates within the intracellular pathways, all of which require additional evaluation to be fully appreciated. In the case of non-genetic factors, the overall view is that immune system challenges might add to the risk. HIGS data suggest that it will be possible to calculate a genetic score to identify patients at high risk for inhibitor development before the start of treatment. By doing so, it may hopefully be possible in the future to prevent the formation of inhibitors in these patients by offering therapeutic options other than the native factor VIII or IX molecule in an inflammatory setting.
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39. |
- Astermark, Jan, et al.
(author)
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rFIXFc prophylaxis improves pain and levels of physical activity in haemophilia B : Post hoc analysis of B-LONG using haemophilia-specific quality of life questionnaires
- 2022
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In: Haemophilia. - : Wiley. - 1351-8216 .- 1365-2516. ; 28:1, s. 18-26
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Journal article (peer-reviewed)abstract
- Introduction: Recurrent bleeding in severe haemophilia B causes painful hemarthroses and reduces capacity for physical activity. Recombinant factor IX Fc fusion protein (rFIXFc) prophylaxis results in low annualised bleeding rates, with the potential to improve patients’ health-related quality of life (HRQoL). Aim: To present a post hoc analysis of data from B-LONG describing change over time in patient-reported outcomes associated with pain and physical activity. Methods: Patients (≥12 years) who received weekly dose-adjusted or interval-adjusted rFIXFc prophylaxis and completed the Haemophilia-Specific QoL questionnaire for adolescents (Haemo-QoL) or adults (Haem-A-QoL) at baseline (BL) and end of study (EoS). Individual level changes in items of the ‘Physical Health’ and ‘Sports and Leisure’ domains, categorised as ‘never/rarely/seldom’ or ‘sometimes/often/all the time’, were analysed using McNemar's test to compare distribution of responses at EoS versus BL. Results: At EoS versus BL, a significantly greater proportion of patients did not experience painful swellings (64% vs. 44%; P =.004), painful joints (44% vs. 28%; P =.003) or pain when moving (54% vs. 41%; P =.026). Additionally, at EoS versus BL, patients were less likely to avoid participating in sports like football (30% vs. 8%; P =.002), avoid sports due to their haemophilia (47% vs. 27%; P =.007), or experience difficulty walking as far as they wanted (63% vs. 43%; P =.001). The proportion of patients who played sports as much as the general population was numerically increased (52% vs. 37%; P =.033) at EoS versus BL. Conclusion: Results of the analysis suggest that over time, rFIXFc prophylaxis is associated with significant improvements in pain and physical functioning. This contributes to previous evidence of overall HRQoL improvements in patients with haemophilia B treated with rFIXFc.
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40. |
- Astermark, J., et al.
(author)
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Symposium in memory of Professor Inga Marie Nilsson
- 2001
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In: Haemophilia. - : Wiley. - 1351-8216. ; 7:4, s. 401-410
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Conference paper (peer-reviewed)abstract
- Professor Inga Marie Nilsson (1923-99) was a pioneer in the field of bleeding and thrombo-embolic disorders and made several major scientific contributions during her career. To honour her memory, colleagues from all over the world were invited to cover several aspects of haemostasis by giving state-of-the-art lectures at an international symposium in Malmö on September 22-23, 2000, chaired by Professors Lou Aledort and Erik Berntorp. Colleagues of Professor Nilsson in Malmö gave a short introduction to each topic. A short review of the meeting will be presented.
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41. |
- Astermark, Jan
(author)
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The Arosenius Fund.
- 2012
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In: Haemophilia. - : Wiley. - 1351-8216. ; 18, s. 41462-41462
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Journal article (peer-reviewed)
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42. |
- Astermark, Jan, et al.
(author)
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The B-Natural study—The outcome of immune tolerance induction therapy in patients with severe haemophilia B
- 2021
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In: Haemophilia. - : Wiley. - 1351-8216 .- 1365-2516. ; 27:5, s. 802-813
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Journal article (peer-reviewed)abstract
- Introduction: Inhibitors develop less frequently in haemophilia B (HB) than haemophilia A (HA). However, when present, the success of tolerization by immune tolerance induction (ITI) therapy is lower and the risk of complications higher. Aim: To evaluate the use and outcome of ITI in patients with HB and inhibitors. Methods: Subjects include singletons or siblings with a current/history of inhibitors enrolled in B-Natural—an observational study designed to increase understanding of clinical management of patients with HB. Patients were followed for 6 months and information on demographics, medical and social history, and treatment were recorded. Results: Twenty-nine patients with severe HB and inhibitors were enrolled in 24 centres. Twenty-two underwent one or more courses of ITI with or without immune suppression. Eight patients (36.4%) were successfully tolerized after the first course of ITI. One of these successes (12.5%) experienced allergic manifestations, whereas the corresponding number for the 10 treatment failures was five (50%). One of seven (14.2%) patients with large deletions and three of eight (37.5%) with nonsense mutations were tolerized at the first attempt, and all patients experiencing nephrosis either failed or were on-going. At study end, 11 (50%) were considered successfully tolerized after one or more ITI courses, three were unsuccessful, and eight were still undergoing treatment. Conclusion: Our data underscore the possibilities and difficulties of achieving tolerization in patients with HB with inhibitors. The type of mutation and complications appear to correlate with ITI outcome, but more accurate definitions of successful ITI are warranted.
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43. |
- Astermark, Jan, et al.
(author)
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The Malmo International Brother Study (MIBS): further support for genetic predisposition to inhibitor development in hemophilia patients
- 2001
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In: Haemophilia. - : Wiley. - 1351-8216. ; 7:3, s. 267-272
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Journal article (peer-reviewed)abstract
- The issue of factors predisposing for inhibitor development in haemophilia patients is still largely unresolved. In an attempt to address this problem, we initiated a registry in 1996 of siblings with haemophilia and with or without a history of inhibitors. Four hundred and sixty families have accrued, of whom 388 suffer from haemophilia A and 72 haemophilia B. Twenty-five of the brother pairs are twins. The inhibitor incidence in all families with severe haemophilia A was 31.7%. The corresponding figure in the caucasian patients was 27.4%, whereas a higher incidence of inhibitors was reported in the black subjects (55.6%). Twins were reported in six of the 100 inhibitor families, for whom monozygocity was confirmed in three cases. In 32 families (32%), at least two brothers had a history of inhibitors. In 22 (69%) of these families, the inhibitor was also of the same type, i.e. either high- or low-responding. The overall concordance within the severe haemophilia A families was found to be 78.3% (195/249) compared to an expected figure of 68.0% and 58.0% using an inhibitor incidence of 20 and 30%, respectively (P < 0.0001). The corresponding figure for the twins was 88.2% (15/17). Moreover, the risk for inhibitor development in families with a previous inhibitor history was found to be 48% (95% confidence interval [CI] 35-62%), whereas the risk in families with no previous known inhibitor was only 15% (95% CI 11-21%) corresponding to a relative risk of 3.2 (95% CI 2.1-4.9). Immune-tolerance induction was reported in 24 families, of whom 13 siblings were successfully treated. Our data clearly support the concept that a genetic predisposition for inhibitor development exists. However, the markers of this predisposition remain to be elucidated and we believe that the MIBS registry will be useful for this purpose.
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44. |
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45. |
- Astermark, Jan
(author)
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Why do inhibitors develop? Principles of and factors influencing the risk for inhibitor development in haemophilia.
- 2006
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In: Haemophilia. - 1351-8216. ; 12 Suppl 3, s. 52-60
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Journal article (peer-reviewed)abstract
- The formation of inhibitory alloantibodies is, in the postinfectious era, the most severe and costly complication of replacement therapy in patients with haemophilia. The complexity of the immune response to the infused factor becomes more and more obvious as knowledge in the area increases. Antibodies develop as a result of a complex multi-factorial interaction between antigen-presenting cells, T- and B-lymphocytes. Genetic susceptibility of cell surface molecules, such as the major histocompatibility complex, the T-cell receptor and cytokine receptors, as well as various immunomodulatory molecules have a major impact on the outcome. In addition, environmental factors probably influence the risk of inhibitor development. The current concept of inhibitor development is reviewed. A better understanding of the pathophysiological mechanisms involved will facilitate improvement of therapy in the future, and hopefully provide an opportunity to prevent this complication of treatment.
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46. |
- Augustsson, Cecilia, et al.
(author)
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Validation of factor VIII activity for monitoring standard and extended half-life products and correlation to thrombin generation assays
- 2021
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In: Haemophilia. - : Wiley. - 1351-8216 .- 1365-2516. ; 27:3, s. 494-500
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Journal article (peer-reviewed)abstract
- Introduction: Monitoring replacement therapy with standard and extended half-life (EHL) products is challenging, since one-stage assay (OSA) and chromogenic substrate assay (CSA) results may differ significantly. Recent recommendations include local validation of each new product with recovery within 20–30%, depending on activity level. Aim: To validate factor VIII (FVIII) activity for monitoring products in clinical use on Atellica Coag and to correlate it with thrombin generation. Methods: Plasma samples spiked with Advate®, Elocta®, Adynovi®, Nuwiq®, NovoEight® and Afstyla® (0.05, 0.20, 0.50 and 0.80 IU/ml) were analysed using Atellica Coag 360 with CSA-1 (Coatest SP) and CSA-2 (FVIII chromogenic), and OSA (Actin FS). Thrombin generation was performed using two thrombin generation assays (TGA-1 (Thrombinoscope) and TGA-2 (Technothrombin). Results: All products at levels above 0.05 IU/ml, except Adynovi, showed acceptable recovery using CSA-1, whereas measurements using CSA-2 gave more results outside the target level. All products, except Afstyla, showed acceptable recovery using OSA. Correlation between CSA-1 and OSA was excellent (r2=1.0) with biases of 6–32%, depending on FVIII product. A clear dose-response was seen for all thrombin generation parameters and products using both methods, except at low levels for lag time using TGA-1. With CSA-1 as an independent variable, the correlations to thrombin peak (measured with TGA-2) were good (r2 =.8–.9). Conclusion: Our data revealed good correlation and acceptable bias between CSA and OSA using our sets of reagents, methods and analyser in spiked samples. Thrombin generation gave good correlation to CSA-1 factor activity and is a possible complement to factor activity assays.
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47. |
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48. |
- Beeton, K, et al.
(author)
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Recent developments in clinimetric instruments
- 2006
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In: Haemophilia. - : Wiley. - 1351-8216 .- 1365-2516. ; 12:Suppl. 3, s. 102-107
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Journal article (peer-reviewed)abstract
- Assessment of impairment and function is essential in order to monitor joint status and evaluate therapeutic interventions in patients with haemophilia. The improvements in the treatment of haemophilia have required the development of more sensitive tools to detect the more minor dysfunctions that may now be apparent. This paper outlines some of the recent developments in this field. The Haemophilia Joint Health Score (HJHS) provides a systematic and robust measure of joint impairment. The MRI Scoring System has been designed to provide a comprehensive scoring system combining both progressive and additive scales. The Functional Independence Score for Haemophilia (FISH) has been developed to assess performance of functional activities and can be used in conjunction with the Haemophilia Activities List (HAL) which provides a self report measure of function. It is recommended that both measures are evaluated as these tools measure different constructs. Further refinement and testing of the psychometric properties of all of these tools is in progress. More widespread use of these tools will enable the sharing of data across the world so promoting best practice and ultimately enhancing patient care.
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49. |
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50. |
- Berntorp, Erik, et al.
(author)
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A prospective registry of European haemophilia B patients receiving nonacog alfa, recombinant human factor IX, for usual use.
- 2012
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In: Haemophilia. - : Wiley. - 1351-8216. ; 18:4, s. 503-509
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Journal article (peer-reviewed)abstract
- Summary. Nonacog alfa, a recombinant factor IX (FIX) used for the treatment of haemophilia B, was approved in Europe in 1998. In accordance with European Medicines Agency requirements, a registry study was conducted from 2002 to 2009. A reformulated iso-osmotic version was approved for European use in 2007. This study was conducted to evaluate the safety of nonacog alfa in a usual care setting, and provide clinical trial and postmarketing surveillance data support. This open-label, non-interventional, prospective observational cohort study (registry) comprised 52 sites in nine European countries. Patients with haemophilia B receiving nonacog alfa in either formulation for prevention or treatment were followed on a usual care schedule. A total of 218 patients were enrolled, of whom 66 (30.3%) were <18 years of age. Haemophilia severity was evenly distributed, with baseline FIX activity of <1%, 1-5% and >5% in 33.3%, 36.6% and 30.1% of patients, respectively. One hundred thirty-eight patients received the original formulation alone; 80 switched to or received only the new formulation. There was a low incidence of events of special interest (ESIs), with less-than-expected therapeutic effect in five patients (2.2%), inhibitor development in two (0.9%), thrombosis in one (0.5%) and allergic events in eight (3.7%). These accounted for the majority of the 15 serious AEs reported in six patients. Six patients discontinued because of AEs, primarily related to hypersensitivity. Nonacog alfa was shown to be safe for the treatment of haemophilia B, with a low incidence of serious AEs and ESIs.
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