| 1. |
- Brown, S A, et al.
(författare)
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Unresolved issues in prophylaxis
- 2002
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Ingår i: Haemophilia. - : Wiley. - 1351-8216. ; 8:6, s. 817-821
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Tidskriftsartikel (refereegranskat)
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| 2. |
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| 3. |
- Astermark, Jan, et al.
(författare)
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Arandomized comparison of bypassing agents in hemophilia complicated by an inhibitor: the FEIBA NovoSeven Comparative (FENOC) Study.
- 2009
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Ingår i: Gematologiâ i Transfuziologiâ. - 0234-5730. ; 54:5, s. 35-35
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Tidskriftsartikel (refereegranskat)abstract
- Arandomized comparison of bypassing agents in hemophilia complicated by an inhibitor: the FEIBA NovoSeven Comparative (FENOC) Study. J. Astermark(1), Sh. M. Donfield(2), D. M. DiMichele(3), A. Gringeri(4), S. A. Gilbert(2), J. Waters(2), E. Berntorp(1), for the FENOC Study Group. Department for Hematology and Coagulation Disorders, Malmo, University Hospital, Malmo, Sweden(1); Department of Biostatistics, Rho, Chapel Hill, NC2; Department of Pediatrics, Weill Medical College, Cornell University, New York, NY3; Angelo Bianchi Bonomi Hemophilia and Thrombosis Center, University of Milan, Italy(4). The development of inhibitory antibodies to factor VIII is a serious complication of hemophilia. FEIBA (factor VIII inhibitorbypassing activity), an activated prothrombin complex concentrate (aPCC), and NovoSeven, recombinant factor Vila (rFVIIa), are used as hemostatic bypassing agents in treating patients with inhibitors. The FENOC study was designed to test equivalence of the products in the treatment of ankle, knee, and elbow joint bleeding. A prospective, open-label, randomized, crossover, equivalency design was used. The parameters of interest were the percentage of patients who reported efficacy in response to FEIBA and the percentage that reported efficacy in response to NovoSeven. A difference in these percentages of no more than 15% was determined to be a clinically acceptable magnitude for equivalence of the 2 products. The primary outcome was evaluation 6 hours after treatment. Data for 96 bleeding episodes contributed by 48 participants were analyzed. The criterion for declaring the 2 products equivalent at 6 hours was not met; however, the confidence interval of the difference in percentages of efficacy reported for each product only slightly exceeded the 15% boundary (11.4-15.7%); p = 0.059. FEIBA and NovoSeven appear to exhibit a similar effect on joint bleeds, although the efficacy between products is rated differently by a substantial proportion of patients. This trial was registered at www.clinicaltrials.gov.
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| 4. |
- Donfield, S. M., et al.
(författare)
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Value added: increasing the power to assess treatment outcome in joint haemorrhages
- 2008
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Ingår i: Haemophilia. - : Wiley. - 1351-8216 .- 1365-2516. ; 14:2, s. 276-280
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Tidskriftsartikel (refereegranskat)abstract
- Subject reports of efficacy of treatment of haemophilia-related joint bleeding are by definition subjective, yet are often the primary outcome in studies comparing therapies. Verbal descriptors such as effective, partially effective, poorly effective, not effective are treated as dichotomous or categorical variables in analyses, lowering the statistical power relative to that which might be achieved with a continuous variable. The aims of this study were to examine reports of pain recorded on a 100-mm visual analogue scale (VAS) during the course of joint bleeding; determine whether pain varied by treatment period among pairs reporting discordant outcomes on a verbal scale (one product effective, the other not effective); test whether the two products under study were equivalent with respect to VAS scores; and evaluate their relationship to verbal reports of efficacy. Data from the international, prospective, randomized, crossover FEIBA NovoSeven Comparative study of two bypassing agents used for treatment of 96 bleeding episodes in 48 participants were examined. VAS scores were associated with verbal descriptors of efficacy at every time point, and were equivalent between treatment periods. There were differences in mean scores at time points at which participants rated one treatment effective, the other not effective. As a continuous variable, the VAS score may have more power than a dichotomous variable and when used with verbal descriptions of efficacy can improve the overall accuracy of assessment. This report highlights an important consideration in the selection of outcome measurement that can be generalized to other haemophilia treatment research.
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| 5. |
- Osooli, Mehdi, et al.
(författare)
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Joint comorbidities among Swedish carriers of haemophilia: A register-based cohort study over 22 years
- 2019
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Ingår i: Haemophilia. - : Wiley. - 1351-8216 .- 1365-2516. ; 25:5, s. 845-850
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Tidskriftsartikel (refereegranskat)abstract
- Background A significant fraction of women with an impaired factor VIII or IX gene in the X chromosome, carriers of haemophilia, will have clotting factor activities corresponding to those seen in males with non-severe haemophilia, hence, experience an increased bleeding tendency. Data describing the long-term joint outcomes among carriers are limited. We compared the age at onset, frequency of joint-related diagnoses as well as joint surgery and related hospitalizations among carriers of haemophilia with sex- and birthdate-matched controls from the general population. Methods Carriers of haemophilia born 1941-2008 were identified through the haemophilia treatment centres' (HTCs) databases and the National Patient Register of Sweden. For each carrier, we included up to five individuals using the Swedish population register as comparisons. Data for the period 1987-2008 were obtained. Results Among 539 potential carriers identified, 213 had a known factor activity. Carriers with reduced factor activity and those with unknown factor activity had received their first joint-related diagnosis at a significantly earlier age than their comparisons. The same subgroups showed an overall 2.3- and 2.4-fold higher hazard for joint-related diagnoses compared with the general population. In addition, the hazards of joint-related outpatient hospitalization were 3.2-fold (95% CI: 1.2, 9.1) and 2.5-fold (95% CI: 1.6, 3.7). This was not observed for those with normal factor activity. Conclusion Carriers of haemophilia suffer a significant risk for joint comorbidities. This risk seems to correlate to the factor activity. Our findings underline the importance of regular clinical follow-up of carriers at HTCs.
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| 6. |
- Schwarz, J., et al.
(författare)
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F8 haplotype and inhibitor risk: results from the Hemophilia Inhibitor Genetics Study (HIGS) Combined Cohort
- 2013
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Ingår i: Haemophilia. - : Wiley. - 1351-8216. ; 19:1, s. 113-118
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Tidskriftsartikel (refereegranskat)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.
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| 7. |
- Abshire, T, et al.
(författare)
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Prophylaxis Escalation in Severe von Willebrand Disease: A Prospective Study from the von Willebrand Disease Prophylaxis Network.
- 2015
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Ingår i: Journal of Thrombosis and Haemostasis. - : Elsevier BV. - 1538-7933 .- 1538-7836. ; 13:9, s. 1585-1589
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Tidskriftsartikel (refereegranskat)abstract
- Treatment of mucosal bleeding (epistaxis, gastrointestinal and menorrhagia) and joint bleeding remains problematic in clinically severe von Willebrand Disease (VWD). Patients are often unresponsive to treatment (e.g. desmopressin or antifibrinolytic therapy) and may require von Willebrand (VW) factor replacement therapy. There are little data on the use of prophylaxis in VWD and none applied in a prospective, treatment escalation design.
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| 8. |
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| 9. |
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| 10. |
- Donfield, Sharyne M., et al.
(författare)
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Delays in maturation among adolescents with hemophilia and a history of inhibitors
- 2007
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Ingår i: Blood. - : American Society of Hematology. - 1528-0020 .- 0006-4971. ; 110:10, s. 3656-3661
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Tidskriftsartikel (refereegranskat)abstract
- Inhibitory antibodies to factors VIII or IX have the potential to affect a broad range of outcomes among people with hemophilia; however, their possible effect on growth and maturation has not been explored. We evaluated skeletal maturation (bone age), pubertal progression, serum testosterone levels, height velocity, and stature in the multicenter Hemophilia Growth and Development Study. A total of 333 children and adolescents (mean age, 12.4 years) were enrolled from 1989 to 1990 and followed for 7 years. Of these, 18% (n = 60) had a history of inhibitors. Bone age among HIV- adolescents with a history of inhibitors lagged 9 or more months behind those without inhibitors at every age from 12 to 15 years. Those with a history of inhibitors were older at every Tanner stage transition, attained a lower maximum growth velocity, and their serum testosterone levels were significantly lower compared with those without inhibitors. Delays were greater among HIV+ patients with a history of inhibitors compared with those without inhibitors; however, the differences were generally small and not statistically significant. The results of this investigation underscore the importance of monitoring the growth and maturation of children and adolescents with hemophilia, particularly those with inhibitors.
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| 11. |
- Kahle, J., et al.
(författare)
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Anti-factor VIII antibodies in brothers with haemophilia A share similar characteristics
- 2017
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Ingår i: Haemophilia. - : Wiley. - 1351-8216. ; 23:2, s. 292-299
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: The development of neutralizing antibodies (inhibitors) against coagulation factor VIII (FVIII) is currently the most serious complication for patients with haemophilia A undergoing FVIII replacement therapy. Several genetic factors have been acknowledged as risk factors for inhibitor development. Aim: To analyze the influence of genetic factors on the nature of the humoral immune response to FVIII in eight brother pairs with inhibitors. Methods: The domain specificity of FVIII-specific IgG was analysed by antibody binding to FVIII fragments and homologue-scanning mutagenesis (HSM). The FVIII-specific IgG subclasses were measured by direct ELISA. Results: Of the 16 patient analysed with both methods, 12 had A2- and 13 had C2-specific IgG. The presence of A1-, A3- or C1-specific IgG was identified in nine of 14 patients analysed by HSM. IgG1, IgG2 and IgG4 subclasses contributed to the anti-FVIII IgG response, and the amount of FVIII-specific IgG1 (r = 0.66) and IgG4 (r = 0.69) correlated significantly with inhibitor titres. Patients with high concentrations of total anti-FVIII IgG (r = 0.69) or high inhibitor titres (r = 0.52) had a high proportion of FVIII-specific IgG4. Statistical analysis revealed trends/evidence that the subclass distribution (P = 0.0847) and domain specificity to HC/LC (P = 0.0883) and A2/C2 (P = 0.0011) of anti-FVIII IgG were more similar in brothers compared to unrelated subjects. Conclusion: Overall, our data provide a first hint that anti-FVIII IgG characteristics are comparable among haemophilic brothers with inhibitors. Whether genetic factors also influence the nature of patients' antibodies needs to be confirmed in a larger study population.
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