Search

Background: Valoctocogene roxaparvovec, an adeno-associated virus-mediated gene therapy for severe hemophilia A, enables endogenous factor (F)VIII expression and provides bleed protection., Objectives: Determine valoctocogene roxaparvovec durability, efficacy, and safety 4 years after treatment., Methods: In the phase 3 GENEr8-1 trial, 134 adult male persons with severe hemophilia A without inhibitors and previously using FVIII prophylaxis received a 6 × 10 13 vg/kg infusion of valoctocogene roxaparvovec. Efficacy endpoints included annualized bleed rate, annualized FVIII infusion rate, FVIII activity, and the Haemophilia-Specific Quality of Life Questionnaire for Adults. Adverse events and immunosuppressant use were assessed. Change from baseline was assessed after participants discontinued prophylaxis (scheduled for week 4)., Results: Median follow-up was 214.3 weeks; 2 participants discontinued since the previous data cutoff. Declines from baseline in mean treated annualized bleed rate (-82.6%; P  < .0001) and annualized FVIII infusion rate (-95.5%; P  < .0001) were maintained from previous years in the primary analysis population of 112 participants who enrolled from a noninterventional study. During year 4, 81 of 110 rollover participants experienced 0 treated bleeds. Week 208 mean and median chromogenic FVIII activity were 16.1 IU/dL and 6.7 IU/dL, respectively, in 130 modified intention-to-treat participants. Seven participants resumed prophylaxis since the previous data cutoff. Mean change from baseline to week 208 in Haemophilia-Specific Quality of Life Questionnaire for Adults Total Score ( P  < .0001) remained clinically meaningful for modified intention-to-treat participants. Alanine aminotransferase elevation was the most common adverse event during year 4 (56/131 participants); none required immunosuppressants., Conclusion: Valoctocogene roxaparvovec provides persistent FVIII expression, hemostatic control, and health-related quality of life improvements with no new safety signals., (© 2024 The Authors.)

Background: Congenital thrombotic thrombocytopenic purpura (TTP) results from severe hereditary deficiency of ADAMTS13. The efficacy and safety of recombinant ADAMTS13 and standard therapy (plasma-derived products) administered as routine prophylaxis or on-demand treatment in patients with congenital TTP is not known., Methods: In this phase 3, open-label, crossover trial, we randomly assigned patients in a 1:1 ratio to two 6-month periods of prophylaxis with recombinant ADAMTS13 (40 IU per kilogram of body weight, administered intravenously) or standard therapy, followed by the alternate treatment; thereafter, all the patients received recombinant ADAMTS13 for an additional 6 months. The trigger for this interim analysis was trial completion by at least 30 patients. The primary outcome was acute TTP events. Manifestations of TTP, safety, and pharmacokinetics were assessed. Patients who had an acute TTP event could receive on-demand treatment., Results: A total of 48 patients underwent randomization; 32 completed the trial. No acute TTP event occurred during prophylaxis with recombinant ADAMTS13, whereas 1 patient had an acute TTP event during prophylaxis with standard therapy (mean annualized event rate, 0.05). Thrombocytopenia was the most frequent TTP manifestation (annualized event rate, 0.74 with recombinant ADAMTS13 and 1.73 with standard therapy). Adverse events occurred in 71% of the patients with recombinant ADAMTS13 and in 84% with standard therapy. Adverse events that were considered by investigators to be related to the trial drug occurred in 9% of the patients with recombinant ADAMTS13 and in 48% with standard therapy. Trial-drug interruption or discontinuation due to adverse events occurred in no patients with recombinant ADAMTS13 and in 8 patients with standard therapy. No neutralizing antibodies developed during recombinant ADAMTS13 treatment. The mean maximum ADAMTS13 activity after recombinant ADAMTS13 treatment was 101%, as compared with 19% after standard therapy., Conclusions: During prophylaxis with recombinant ADAMTS13 in patients with congenital TTP, ADAMTS13 activity reached approximately 100% of normal levels, adverse events were generally mild or moderate in severity, and TTP events and manifestations were rare. (Funded by Takeda Development Center Americas and Baxalta Innovations; ClinicalTrials.gov number, NCT03393975.)., (Copyright © 2024 Massachusetts Medical Society.)

Background: Severe hemophilia A (HA) negatively impacts health-related quality of life (HRQOL)., Objectives: We aimed to analyze HRQOL in adult men with severe HA without inhibitors after valoctocogene roxaparvovec gene transfer in the phase 3 trial GENEr8-1., Methods: Participant-reported outcomes were the hemophilia-specific quality of life questionnaire for adults (Haemo-QOL-A), the EQ-5D-5L instrument, the Hemophilia Activities List (HAL), and the Work Productivity and Activity Impairment Questionnaire: Hemophilia Specific (WPAI+CIQ:HS). Participants completed the questionnaires at baseline and through 104 weeks postinfusion with 6 × 10 13 vg/kg of valoctocogene roxaparvovec. Scores were analyzed per participant characteristics and outcomes., Results: For 132 HIV-negative participants, mean change from baseline in Haemo-QOL-A Total Score met the anchor-based clinically important difference (CID: 5.5) by week 12; the mean (SD) increase was 7.0 (12.6) at week 104. At week 104, improvement in Consequences of Bleeding, Treatment Concern, Worry, and Role Functioning domain scores exceeded the CID (6). EQ-5D-5L Utility Index scores improved above the CID at week 52, but not at week 104. EQ-5D-5L visual analog scale and HAL scores increased from baseline to week 104. Participants reported less activity and work impairment at week 104 than baseline. Participants with problem joints had lower mean baseline Haemo-QOL-A Total and domain scores than those without them, but improved over 104 weeks, except for 11 participants with ≥3 problem joints. Participants with 0 bleeds during the baseline prophylaxis period reported Haemo-QOL-A score improvements above the CID, including in the Consequences of Bleeding domain., Conclusion: Valoctocogene roxaparvovec provided clinically meaningful HRQOL improvement for men with severe HA., Competing Interests: Declaration of competing interests B.O.M. reports consulting fees from BioMarin Pharmaceutical Inc and Freeline. A.L.D. reports research funding from Sanofi, Takeda, Freeline, BioMarin Pharmaceutical Inc, and the American Thrombosis and Hemostasis Network; consulting fees from BioMarin Pharmaceutical Inc, Genentech/Roche, Kedrion, CSL Behring, and uniQure; and service on the board of the World Federation of Hemophilia USA. A.D.L. reports consulting or advisory panel fees from BioMarin Pharmaceutical Inc, Dova, CSL Behring, Merck, Catalyst, and HEME Biologics; and participation as a clinical trial investigator in trials sponsored by BioMarin Pharmaceutical Inc, Sangamo, and Pfizer. F.P. reports honoraria as a speaker for educational symposia by Grifols, Sanofi, and Takeda and as an advisory member for Sanofi and Roche. M.C.O. reports consulting fees from Bayer, BioMarin Pharmaceutical Inc, Novo Nordisk, Pfizer, Roche, Sanofi, and Takeda; research grants from Pfizer, Roche, and Takeda; service as a clinical trial investigator for BioMarin Pharmaceutical Inc, Novo Nordisk, Pfizer, Roche, Sanofi, and Takeda; speaker honoraria from Bayer, BioMarin Pharmaceutical Inc, Novo Nordisk, Roche, and Takeda; travel support from Novo Nordisk, Roche, and Takeda; and participation in grant reviewing for Grifols. J.M. reports consulting fees from Baxalta, CSL Behring, Catalyst Biosciences, Freeline, LFB, Novo Nordisk, and Spark; research grants from and service as a clinical trial investigator for BioMarin Pharmaceutical Inc, CSL Behring, Novo Nordisk, Pfizer, Sobi, Roche, Novartis, Sanofi, and Unique; and speaker fees from Novo Nordisk, Pfizer, Sanofi, Sobi, Shire, Roche, Takeda, the International Society on Thrombosis and Haemostasis, and the World Federation of Hemophilia. K.P. reports consulting fees and research grants from Sobi, Octapharma, Novo Nordisk, and Pfizer; and served as a clinical trial investigator for uniQure, BioMarin Pharmaceutical Inc, and Roche. J-D.W. reports consulting fees from Bayer, Novo Nordisk, Pfizer, Chugai, Sanofi, Takeda, and Sobi; speaker fees from Bayer, CSL Behring, Novo Nordisk, Pfizer, Chugai, Sanofi, and Takeda; and service as a clinical trial investigator for Bayer, BioMarin Pharmaceutical Inc, Novo Nordisk, Pfizer, Roche/Chugai, and Sanofi. G.L. has received honoraria for participating in educational events from Novartis, LEO, Sobi, Alexion, Takeda, Novo Nordisk, and Sanofi; and consulting fees from UCB. A.G. reports honoraria for service on advisory boards from BioMarin Pharmaceutical Inc, Genentech, Pfizer, Bayer, ATHN, Novo Nordisk, uniQure, and Sanofi Genzyme; and travel grants from BioMarin Pharmaceutical Inc. E.C. reports consulting fees from Genentech, BioMarin Pharmaceutical Inc, Novo Nordisk, Takeda, Sanofi, HEMA Biologics, and CSL Behring; and speaker fees from Genentech. D.P. reports a travel grant from Pfizer. H.C. reports consulting fees from Bayer, BioMarin Pharmaceutical Inc, Roche, and Sobi; served as a clinical trial investigator for BioMarin Pharmaceutical Inc, Bioverativ, CSL Behring, LFB, Octapharma, Roche, Pfizer, Sobi, and Takeda; reports speaker fees from BioMarin Pharmaceutical Inc, Pfizer, Roche, and Sobi; and reports travel grants from BioMarin Pharmaceutical Inc, CSL Behring, Octapharma, Roche, and Sobi. M.F.L.F. reports participation in advisory boards and receiving speaking fees from Shire/Takeda, Amgen, CSL Behring, Novo Nordisk, Bayer, LFB, Pfizer, and Sobi. E.M. reports consulting fees and travel support from BioMarin Pharmaceutical Inc and served as a clinical trial investigator for BioMarin Pharmaceutical Inc. M.W.S. reports consulting fees from Bayer, BioMarin Pharmaceutical Inc, Pfizer (DMC), Roche/Genentech, Sanofi, Spark (DMC), and Takeda; and research grants from BioMarin Pharmaceutical Inc, Freeline, Roche, Takeda, and uniQure. R.Klamroth reports consulting fees from Bayer, Biotest, BioMarin Pharmaceutical Inc, Novo Nordisk, Octapharma, Pfizer, Roche/Chugai, Sanofi, Takeda/Shire, and Sobi; research grants from Bayer and LEO; speaker fees from Bayer, Biotest, BioMarin Pharmaceutical Inc, CSL Behring, Daiichi Sankyo, LEO, Novo Nordisk, Octapharma, Pfizer, Roche/Chugai, Sanofi, Takeda/Shire, and Sobi; travel support from Bayer, Biotest, BioMarin Pharmaceutical Inc, CSL Behring, Daiichi Sankyo, LEO, Novo Nordisk, Octapharma, Pfizer, Roche/Chugai, Sanofi, Takeda/Shire, and Sobi; and service as a clinical trial investigator for Bayer, BioMarin Pharmaceutical Inc, CSL Behring, Novo Nordisk, Octapharma, Pfizer, Roche/Chugai, Sanofi, Takeda/Shire, Sobi, and uniQure. S.W.P. reports consulting fees from Apcintex, ASC Therapeutics, Bayer, BioMarin Pharmaceutical Inc, CSL Behring, HEMA Biologics, Freeline, Novo Nordisk, Pfizer, Roche/Genentech, Sanofi, Spark Therapeutics, Takeda, and uniQure; and service as a clinical trial investigator for BioMarin Pharmaceutical Inc, Freeline, Genentech/Roche, Sanofi, and uniQure. J.Q. is a former employee of BioMarin Pharmaceutical and may hold stock. H.Y., T.M.R., and W.Y.W. are employees and stockholders of BioMarin Pharmaceutical Inc. C.W.T., H.T., R.Kazmi, and T-L.K. have no competing interests to disclose., (Copyright © 2023 International Society on Thrombosis and Haemostasis. Published by Elsevier Inc. All rights reserved.)

The identification of inherited antithrombin deficiency (ATD) is critical to prevent potentially life-threatening thrombotic events. Causal variants in SERPINC1 are identified for up to 70% of cases, the majority being single-nucleotide variants and indels. The detection and characterization of structural variants (SVs) in ATD remain challenging due to the high number of repetitive elements in SERPINC1 . Here, we performed long-read whole-genome sequencing on 10 familial and 9 singleton cases with type I ATD proven by functional and antigen assays, who were selected from a cohort of 340 patients with this rare disorder because genetic analyses were either negative, ambiguous, or not fully characterized. We developed an analysis workflow to identify disease-associated SVs. This approach resolved, independently of its size or type, all eight SVs detected by multiple ligation-dependent probe amplification, and identified for the first time a complex rearrangement previously misclassified as a deletion. Remarkably, we identified the mechanism explaining ATD in 2 out of 11 cases with previous unknown defect: the insertion of a novel 2.4 kb SINE-VNTR-Alu retroelement, which was characterized by de novo assembly and verified by specific polymerase chain reaction amplification and sequencing in the probands and affected relatives. The nucleotide-level resolution achieved for all SVs allowed breakpoint analysis, which revealed repetitive elements and microhomologies supporting a common replication-based mechanism for all the SVs. Our study underscores the utility of long-read sequencing technology as a complementary method to identify, characterize, and unveil the molecular mechanism of disease-causing SVs involved in ATD, and enlarges the catalogue of genetic disorders caused by retrotransposon insertions., Competing Interests: None declared., (The Author(s). This is an open access article published by Thieme under the terms of the Creative Commons Attribution-NonDerivative-NonCommercial License, permitting copying and reproduction so long as the original work is given appropriate credit. Contents may not be used for commercial purposes, or adapted, remixed, transformed or built upon. (https://creativecommons.org/licenses/by-nc-nd/4.0/).)

Von Willebrand disease (VWD) is the most frequent inherited bleeding disorder caused by quantitative or qualitative defects of von Willebrand factor (VWF). This protein far from simplicity constitutes a very complex molecular model, remaining unravelled yet many aspects of it, even though the VWF gene (VWF) was cloned already in 1985 and the structure of VWF well defined. VWD diagnosis is difficult to achieve in a significant proportion of patients due to both disease heterogeneity and limitations in existing test processes. The cornerstone of diagnosis relies on interpretation of VWF test results, the presence of clinical manifestations of bleeding, especially mucocutaneous, and (in most cases) a positive family history. However, even with a significant bleeding history, a family history may not be positive due to factors of incomplete penetrance and variable expressivity that affect genetic changes. The laboratory diagnosis of VWD can be difficult, as the disease is heterogeneous and an array of assays is required to describe the phenotype. Basic classification of quantitative (type 1 and 3) and qualitative (type 2 variants) VWD requires determination of VWF antigenic (VWF:Ag) levels and assaying of VWF ristocetin cofactor (VWF:RCo) activity. The latter is required for identifying and subtyping VWD, but the assay is poorly standardized. For that reason, novel VWF activity assays have been developed awaiting more extensive comparison data between different methodologies and requiring validation on larger patient series. The qualitative type 2 VWF deficiency can be further divided into four different subtypes (A, B, M and N) using specific assays that measure other activities or the size distribution of VWF multimers. However, frequently, it may be difficult to correctly classify the VWD phenotype, and genetic analysis is through mutation identification may provide a tool to clarify the disorder., (Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.)

β1-Tubulin plays a major role in proplatelet formation and platelet shape maintenance, and pathogenic variants in TUBB1 lead to thrombocytopenia and platelet anisocytosis (TUBB1-RT). To date, the reported number of pedigrees with TUBB1-RT and of rare TUBB1 variants with experimental demonstration of pathogenicity is limited. Here, we report 9 unrelated families presenting with thrombocytopenia carrying 6 β1-tubulin variants, p.Cys12LeufsTer12, p.Thr107Pro, p.Gln423*, p.Arg359Trp, p.Gly109Glu, and p.Gly269Asp, the last of which novel. Segregation studies showed incomplete penetrance of these variants for platelet traits. Indeed, most carriers showed macrothrombocytopenia, some only increased platelet size, and a minority had no abnormalities. Moreover, only homozygous carriers of the p.Gly109Glu variant displayed macrothrombocytopenia, highlighting the importance of allele burden in the phenotypic expression of TUBB1-RT. The p.Arg359Trp, p.Gly269Asp, and p.Gly109Glu variants deranged β1-tubulin incorporation into the microtubular marginal ring in platelets but had a negligible effect on platelet activation, secretion, or spreading, suggesting that β1-tubulin is dispensable for these processes. Transfection of TUBB1 missense variants in CHO cells altered β1-tubulin incorporation into the microtubular network. In addition, TUBB1 variants markedly impaired proplatelet formation from peripheral blood CD34+ cell-derived megakaryocytes. Our study, using in vitro modeling, molecular characterization, and clinical investigations provides a deeper insight into the pathogenicity of rare TUBB1 variants. These novel data expand the genetic spectrum of TUBB1-RT and highlight a remarkable heterogeneity in its clinical presentation, indicating that allelic burden or combination with other genetic or environmental factors modulate the phenotypic impact of rare TUBB1 variants., (© 2021 by The American Society of Hematology. Licensed under Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0), permitting only noncommercial, nonderivative use with attribution. All other rights reserved.)

Introduction: Type 2N von Willebrand disease (VWD) is characterized by a decreased affinity of von Willebrand factor (VWF) for factor VIII (FVIII). Abnormal binding of FVIII to VWF (VWF:FVIIIB), results in low FVIII plasma levels, which can lead to a misdiagnosis of mild haemophilia A. Accurate diagnosis of type 2N VWD is essential for appropriate genetic counselling and therapy. This disease can be distinguished from haemophilia A by in vitro assays (measurement VWF:FVIIIB activity) and/or genetic analysis., Aim: To identify the current challenges in the diagnosis and treatment of this type of VWD and provide an in-depth description of the phenotypes and mutations identified., Results: Twenty-eight patients had at least one type 2N mutation, and 13 of these had a type 2N mutation combined with other variations. Three type 2N mutations were detected: p.Arg816Trp, p.Arg854Gln, and p.Arg763Ser. Two of these are the most frequently described mutations worldwide. This mutational spectrum differs from the broad spectrum seen in neighbouring France, where at least eight distinct 2N mutations have been found. In the PCM-EVW-ES cohort, 11 asymptomatic type 2N carriers with borderline FVIII plasma levels would probably have been excluded if the evaluation had been based on clinical and laboratory data only. Likewise, three patients with a severe phenotype would have been classified as homozygous for a 2N mutation if only the phenotype study had been performed., Conclusion: The high detection yield and affordability of next-generation sequencing support the use of this technology as a first-line diagnostic tool in this setting., (© 2021 John Wiley & Sons Ltd.)

Introduction: Current guidelines recommend prophylactic treatment of hemophilia B with the missing coagulation factor IX, either with standard half-life or extended half-life products. Extended half-life products have half-lives three to six times longer than the former, allowing a reduction in the number of weekly injections and therefore, potentially impacting on treatment adherence and quality of life. Albutrepenonacog alfa is an extended half-life fusion protein of coagulation factor IX with recombinant human albumin, indicated for both on-demand and prophylactic treatment for bleeding in patients with hemophilia B of all ages. Areas covered: The authors review the clinical and pharmacokinetic characteristics of albutrepenonacog alfa, as well as the available information regarding trough levels and real-world evidence. Given the availability of other factor IX products in the market, indirect comparisons of clinical and pharmacokinetic characteristics are presented. Expert opinion: The authors exhibit their expert opinion on which patient profiles are candidates for prophylactic treatment with albutrepenonacog alfa, and on the management of patients in terms of dosing, regimens of administration and protocols for switching the treatment.

Introduction: Adherence is a cornerstone of factor VIII prophylactic treatment. Information regarding the factors with potential influence on adherence is limited, particularly in adult patients., Aim: To assess adherence in adult patients with severe haemophilia A receiving prophylactic treatment in a real-life setting, and investigate the factors influencing adherence., Methods: Observational, prospective study including adult patients receiving factor VIII therapy in 15 Spanish centres. Patients recorded infusion doses on a logbook and answered various questionnaires to assess their health beliefs. Adherence rate was the percentage of infused doses over the prescribed ones. Self-perceived adherence was assessed using the VERITAS-Pro questionnaire, the psychometric properties of which were validated in the Spanish population. The relationship between adherence rate and treatment, clinical and demographic characteristics, health beliefs and perceived self-efficacy was investigated., Results: A total of 66 patients were followed up for 12 months. Mean adherence rate at the end of follow-up was 82.5%. Most of the study patients (n = 53, 80.3%) showed a moderate-to-high adherence rate (>70%). The VERITAS-Pro revealed a high perception of adherence. Multivariate analyses to predict treatment adherence identified the knee as a target joint and longer treatment duration as variables with significant (negative) influence on adherence. Adherence rate was not influenced by the patient's health beliefs or perceived self-efficacy., Conclusion: Most adult patients receiving factor VIII prophylactic treatment in Spain have moderate-to-high treatment adherence. Treatment duration and the knee as a target joint are factors with a moderate negative influence on treatment adherence., (© 2020 John Wiley & Sons Ltd.)

Objectives: This study estimated the cost of prophylaxis with activated prothrombin complex concentrate (aPCC) and recombinant activated factor VIIa (rFVIIa) in surgical patients with haemophilia A and inhibitors in Spain., Methods: A decision-analytic model was developed to estimate the cost to the Spanish National Health System of providing haemostatic coverage in this haemophilia population, with age distribution and average weight derived from the literature, and the annual number of surgeries (0.33 per patient) from local data. Drug costs were calculated from official ex-factory prices with a 7.5% mandatory deduction and recommended dosing regimens., Results: The estimated average costs per patient were €10 100.73 (aPCC) and €14 265.89 (rFVIIa) for dental extraction, €24 043.88 (aPCC) and €62 301.08 (rFVIIa) for minor surgery and €126 595.81 (aPCC) and €347 731.09 (rFVIIa) for major surgery. Assuming an estimated 23 annual surgeries in this population (N = 69), distributed as 19% dental extraction, 50% minor surgery and 31% major surgery, the total annual cost of prophylaxis was €1 209 682.35 with aPCC and €3 221 929.28 with rFVIIa., Conclusions: aPCC costs were 62.5% lower than rFVIIa. Assuming potential clinical equivalence, aPCC is a potentially cost-saving option for surgical patients with haemophilia A and inhibitors., (© 2020 The Authors. European Journal of Haematology Published by John Wiley & Sons Ltd.)

The clinical diagnosis of von Willebrand disease (VWD), particularly type 1, can be complex because several genetic and environmental factors affect von Willebrand factor (VWF) plasma levels. An estimated 60% of the phenotypic variation is attributable to hereditary factors, with the ABO blood group locus being the most influential. However, recent studies provide strong evidence that nonsynonymous single nucleotide variants (SNVs) contribute to VWF and factor VIII phenotypic variability in healthy individuals. This study aims to investigate the role of common VWF SNVs on VWD phenotype by analyzing data from 219 unrelated patients included in the "Molecular and Clinical Profile of von Willebrand Disease in Spain project." To that end, generalized linear mixed-effects regression models were fitted, and additive and epistatic analyses, and haplotype studies were performed, considering five VWD-related measures (bleeding score, VWF:Ag, VWF:RCo, factor VIII:C, and VWF:CB). According to these analyses, homozygotes: for p.Thr789Ala(C) would be expected to show 39% higher VWF:Ag levels; p.Thr1381Ala(C), 27% lower VWF:Ag levels; and p.Gln852Arg(C), 52% lower VWF:RCo levels. Homozygotes for both p.Thr789Ala(C) and p.Gln852Arg(T) were predicted to show 185% higher VWF:CB activity, and carriers of two copies of the p.Thr1381Ala(T)/p.Gln852Arg(T) haplotype would present a 100% increase in VWF:RCo activity. These results indicate a substantial effect of common VWF variation on VWD phenotype. Although additional studies are needed to determine the true magnitude of the effects of SNVs on VWF , these findings provide new evidence regarding the contribution of common variants to VWD, which should be taken into account to enhance the accuracy of the diagnosis and classification of this condition. ClinicalTrials.gov identifier: NCT02869074., Competing Interests: None declared., (Georg Thieme Verlag KG Stuttgart · New York.)

Diagnosis of von Willebrand disease (VWD) depends on personal and family history of bleeding and confirmatory laboratory testing. Currently available phenotypic tests for VWD contain potential sources for error that may distort results. Despite an exponential growth of information about the von Willebrand factor gene ( VWF ), the role of molecular diagnosis in VWD is still controversial. Due to the complexity and high cost of conventional molecular analyses, some investigators have recommended limiting this approach to distinguish suspected type 2N VWD from hemophilia A, type 2B from platelet-type VWD, and the exploration of type 3 VWD. New genetic methodologies and approaches are becoming available, but there is still some reluctance for their implementation in VWD diagnosis. This article discusses the pros and cons of molecular testing in VWD considering the experience obtained through the multicenter project "Molecular and Clinical Profile of VWD in Spain (PCM-EVW-ES).", Competing Interests: Dr. Batlle reports grants and personal fees from Shire and Ministerio de Economía y Competitividad during the conduct of the study., (Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.)

Presently, no data on the molecular basis of hereditary protein C (PC) deficiency in Spain is available. We analyzed the PC gene ( PROC ) in 109 patients with symptomatic PC deficiency and in 342 relatives by sequencing the 9 PROC exons and their flanking intron regions. In 93 probands, we found 58 different mutations (26 novel). Thirty-seven consisted of a nucleotide change, mainly missense mutations, 1 was a 6-nucleotide insertion causing the duplication of 2 amino acids, and 4 were deletions of 1, 3, 4, and 16 nucleotides. Nine mutations caused type II deficiencies, with the presence of normal antigen levels but reduced anticoagulant activity. Using a PC level of 70% as lowest normal limit, we found no mutations in 16 probands and 25 relatives with PC levels ≤ 70%. On the contrary, 4 probands and 12 relatives with PC levels > 70% carried the mutation identified in the proband. The spectrum of recurrent mutations in Spain is different from that found in the Netherlands, where the most frequent mutations were p.Gln174* and p.Arg272Cys, and is more similar to that found in France, where the most frequent were p.Arg220Gln and p.Pro210Leu. In our study, p.Val339Met (9 families), p.Tyr166Cys (7), p.Arg220Gln (6), and p.Glu58Lys (5) were the most prevalent. This study confirms the considerable heterogeneity of the genetic abnormality in PC deficiencies, and allowed genetic counseling to those individuals whose PC levels were close to the lower limit of the normal reference range., Competing Interests: F.E. reports grants from Spanish Society of Thrombosis and Haemostasis, during the conduct of the study; P.M. reports grants from Spanish Society of Thrombosis and Haemostasis, during the conduct of the study; S.N. reports grants from Spanish Society of Thrombosis and Haemostasis, during the conduct of the study. Other authors report no conflict of interest., (Georg Thieme Verlag KG Stuttgart · New York.)

: Prophylaxis with factor VIII concentrates is the cornerstone of treatment for severe hemophilia A. In children, early onset of primary and secondary prophylaxis is the gold standard in most of countries with adequate financial resources. In adults, it is reasonable to continue the prophylactic treatment initiated during childhood to preserve joint functionality. Adults with advanced hemophilic arthropathy can also benefit from tertiary prophylaxis, showing reductions in bleeding episodes, target joints and missed days from work. The long-term evolution of hemophilic patients usually depends on how successfully prophylaxis can prevent bleeding in both children and adults. For prophylaxis to be efficient it is essential to consider the resources available (factor concentrate use and trough levels) and the patient's bleeding phenotype and clinical situation (levels of activity required, presence of chronic synovitis and arthropathy), and to define the annual number of bleeds (particularly into joints) acceptable for each patient.

Introduction: Rurioctocog alfa pegol (BAX 855, TAK-660) is a PEGylated, full-length, recombinant factor VIII (rFVIII) with extended half-life developed from unmodified rFVIII (antihaemophilic factor [recombinant])., Aim: To determine the perioperative haemostatic efficacy and safety of rurioctocog alfa pegol in male previously treated patients (PTPs) with severe haemophilia A., Methods: This multicentre, single-arm, phase III study included PTPs who were to undergo major or minor elective or minor emergency surgical, dental or other invasive procedures. Rurioctocog alfa pegol dose and frequency were individualized based on patients' pharmacokinetic profiles for major surgeries and by rurioctocog alfa pegol incremental recovery for minor surgeries. Haemostatic efficacy was assessed using the Global Haemostatic Efficacy Assessment score., Results: Twenty-one patients aged 16-61 years underwent 21 major and five minor surgeries. For all 24 evaluable surgeries, overall haemostatic efficacy was rated as excellent and blood loss comparable to that expected in non-haemophilic patients. No blood transfusions were required intraoperatively but were administered postoperatively for four surgeries in three patients. Five injury-related postoperative bleeding episodes occurred in five patients, of which two required additional rurioctocog alfa pegol treatment. Two non-serious adverse events of mild severity (increased ALT level and headache) were considered possibly related to rurioctocog alfa pegol. There were no deaths or treatment-related serious adverse events. No patients developed inhibitory antibodies to FVIII or persistent IgG- or IgM-binding antibodies to FVIII, PEG-FVIII or PEG., Conclusion: Rurioctocog alfa pegol was well tolerated and effective for perioperative use in patients with haemophilia A and showed no signs of immunogenicity., (© 2019 The Authors Haemophilia Published by John Wiley & Sons Ltd.)

: We hypothesized that inhibitor specificity may predict the outcome of antifactor VIII autoantibodies eradication treatment in acquired hemophilia A. Our objective was to analyze the association between factor VIII domains recognized by inhibitors and outcome of the immunosuppressive therapies (ISTs) in a prospective, observational study. 16 patients were recruited. Inhibitor specificities were assessed at diagnosis and throughout the study. Their association with IST outcome was addressed. First-line IST succeeded in 56% of patients. Inhibitors reacted mainly with light chain domains (69%) and/or the A2 domain (44%). 31% inhibitors recognized more than one domain. Significantly, the number of patients whose inhibitors recognized the light chain was significantly higher in the group of those who did not reach complete remission after first line IST when compared with those who did [6/7 (85.7%) vs. 4/9 (44.4%), P < 0.05]. Therefore, inhibitor specificity could predict the success of IST in acquired hemophilia A.

Large studies in von Willebrand disease patients, including Spanish and Portuguese registries, led to the identification of >250 different mutations. It is a challenge to determine the pathogenic effect of potential splice site mutations on VWF mRNA. This study aimed to elucidate the true effects of 18 mutations on VWF mRNA processing, investigate the contribution of next-generation sequencing to in vivo mRNA study in von Willebrand disease, and compare the findings with in silico prediction. RNA extracted from patient platelets and leukocytes was amplified by RT-PCR and sequenced using Sanger and next generation sequencing techniques. Eight mutations affected VWF splicing: c.1533+1G>A, c.5664+2T>C and c.546G>A (p.=) prompted exon skipping; c.3223-7&#95;3236dup and c.7082-2A>G resulted in activation of cryptic sites; c.3379+1G>A and c.7437G>A) demonstrated both molecular pathogenic mechanisms simultaneously; and the p.Cys370Tyr missense mutation generated two aberrant transcripts. Of note, the complete effect of three mutations was provided by next generation sequencing alone because of low expression of the aberrant transcripts. In the remaining 10 mutations, no effect was elucidated in the experiments. However, the differential findings obtained in platelets and leukocytes provided substantial evidence that four of these would have an effect on VWF levels. In this first report using next generation sequencing technology to unravel the effects of VWF mutations on splicing, the technique yielded valuable information. Our data bring to light the importance of studying the effect of synonymous and missense mutations on VWF splicing to improve the current knowledge of the molecular mechanisms behind von Willebrand disease. clinicaltrials.gov identifier:02869074 ., (Copyright© 2019 Ferrata Storti Foundation.)

Inherited platelet disorders are a heterogeneous group of rare diseases, caused by inherited defects in platelet production and/or function. Their genetic diagnosis would benefit clinical care, prognosis and preventative treatments. Until recently, this diagnosis has usually been performed via Sanger sequencing of a limited number of candidate genes. High-throughput sequencing is revolutionizing the genetic diagnosis of diseases, including bleeding disorders. We have designed a novel high-throughput sequencing platform to investigate the unknown molecular pathology in a cohort of 82 patients with inherited platelet disorders. Thirty-four (41.5%) patients presented with a phenotype strongly indicative of a particular type of platelet disorder. The other patients had clinical bleeding indicative of platelet dysfunction, but with no identifiable features. The high-throughput sequencing test enabled a molecular diagnosis in 70% of these patients. This sensitivity increased to 90% among patients suspected of having a defined platelet disorder. We found 57 different candidate variants in 28 genes, of which 70% had not previously been described. Following consensus guidelines, we qualified 68.4% and 26.3% of the candidate variants as being pathogenic and likely pathogenic, respectively. In addition to establishing definitive diagnoses of well-known inherited platelet disorders, high-throughput sequencing also identified rarer disorders such as sitosterolemia, filamin and actinin deficiencies, and G protein-coupled receptor defects. This included disease-causing variants in DIAPH1 (n=2) and RASGRP2 (n=3). Our study reinforces the feasibility of introducing high-throughput sequencing technology into the mainstream laboratory for the genetic diagnostic practice in inherited platelet disorders., (Copyright© 2018 Ferrata Storti Foundation.)

Molecular diagnosis of patients with von Willebrand disease is pending in most populations due to the complexity and high cost of conventional molecular analyses. The need for molecular and clinical characterization of von Willebrand disease in Spain prompted the creation of a multicenter project (PCM-EVW-ES) that resulted in the largest prospective cohort study of patients with all types of von Willebrand disease. Molecular analysis of relevant regions of the VWF , including intronic and promoter regions, was achieved in the 556 individuals recruited via the development of a simple, innovative, relatively low-cost protocol based on microfluidic technology and next-generation sequencing. A total of 704 variants (237 different) were identified along VWF , 155 of which had not been previously recorded in the international mutation database. The potential pathogenic effect of these variants was assessed by in silico analysis. Furthermore, four short tandem repeats were analyzed in order to evaluate the ancestral origin of recurrent mutations. The outcome of genetic analysis allowed for the reclassification of 110 patients, identification of 37 asymptomatic carriers (important for genetic counseling) and re-inclusion of 43 patients previously excluded by phenotyping results. In total, 480 patients were definitively diagnosed. Candidate mutations were identified in all patients except 13 type 1 von Willebrand disease, yielding a high genotype-phenotype correlation. Our data reinforce the capital importance and usefulness of genetics in von Willebrand disease diagnostics. The progressive implementation of molecular study as the first-line test for routine diagnosis of this condition will lead to increasingly more personalized and effective care for this patient population., (Copyright© 2017 Ferrata Storti Foundation.)

Background: The natural history and its modulation by treatments administered for immune thrombocytopenia (ITP) in the clinical practice remains unknown. In addition, little information is available on the characteristics and management of ITP in Spain., Methods: We conducted an observational, multicenter, registry in 70 Hematology Services from Spain between 2009 and 2011, which included children from 2 months of age and adults with primary ITP or another ITP diagnosed within the last 6 months (platelet count [PC] < 100 × 10 9 /l). Patients were followed-up at 6 and 12 months., Results: 484 patients were included (median [Q1, Q3] age 52 [29,74] years, 87.6% adults), 56% women, 10.5% with secondary ITP. Median (Q1, Q3) PC at diagnosis was 12 × 10 9 /l (4, 32); 72% of patients had bleeding symptoms (62% cutaneous bleeding, 29% oral cavity bleeding, 18% epistaxis). 81% of patients with primary ITP received first-line treatment, mainly with corticosteroids (>6 weeks in 59% of cases), either alone (41%) or associated with intravenous immunoglobulin (33%). The response (≥30 × 10 9 /L) to first-line treatment was 92%. A total of 19% of patients received second-line treatment and 6% additional treatments. At 12 months, 74% of primary ITP patients maintained a PC ≥ 100 × 10 9 /L in absence of treatment (10% still had hemorrhagic manifestations)., Conclusions: Characteristics of Spanish ITP patients are comparable to those from other countries. Although a high response rate to first-line treatments is observed, at 1 year, the disease persists in around one quarter of patients. Overall therapeutic management in Spain conforms to current recommendations, except for an excessive duration of corticosteroids therapy.

Introduction: The bleeding propensity in von Willebrand disease (VWD) is usually moderate or mild and patients with VWD do not need continuous treatment, but do require extra increased haemostatic cover when undergoing dental or surgical procedures. Desmopressin can be effective in certain patient groups and this has been considered in a previous publication., Aim: This paper now seeks to evaluate current knowledge and practice in the use of factor concentrate in the management of VWD patients undergoing invasive procedures., Methods: A literature search was performed on the use of factor concentrates to cover invasive procedures and a survey of current practice in a number of specialist haematology centres across Europe represented by the European Haemophilia Strategy Board was conducted., Results: Our review of the literature and the results of the survey showed considerable heterogeneity in treatment regimens, and a lack of consistency in reporting of the variables that determine factor concentrate dosing and monitoring., Conclusion: By analysing the literature, examining guidelines and using consensus deliberation, this survey allowed the group to develop recommendations for management of VWD patients undergoing invasive procedures., (© 2016 John Wiley & Sons Ltd.)

Introduction: Recombinant factor IX fusion protein (rIX-FP) has been developed to improve the pharmacokinetic (PK) profile of factor IX (FIX), allowing maintenance of desired FIX activity between injections at extended intervals, ultimately optimizing haemophilia B treatment., Aim: To determine the efficacy and safety of rIX-FP in the perioperative setting., Methods: Subjects were adult and paediatric patients with severe to moderately severe haemophilia B (FIX ≤ 2%) participating in three Phase III clinical trials and undergoing a surgical procedure. PK profiles were established prior to surgery for each patient. Haemostatic efficacy was assessed by the investigator for up to 72 h after surgery. Safety measurements during the study included adverse events and inhibitors to FIX. FIX activity was monitored during and after surgery to determine if repeat dosing was required., Results: Twenty-one, both major and minor, surgeries were performed in 19 patients. Haemostatic efficacy was rated as excellent (n = 17) or good (n = 4) in all surgeries. A single preoperative dose maintained intraoperative haemostasis in 20 of 21 surgeries. Nine major orthopaedic surgeries were conducted in eight patients with a mean of 7 (range: 6-12) rIX-FP injections during surgery and the 14-day postoperative period. Median rIX-FP consumption for orthopaedic surgeries was 87 IU kg(-1) preoperatively and 375 IU kg(-1) overall. No subject developed inhibitors to FIX or antibodies to rIX-FP., Conclusion: Recombinant factor IX fusion protein was well tolerated and effectively maintained haemostasis during and after surgery. Stable FIX activity was achieved with a prolonged dosing interval and reduced consumption compared to conventional or currently available long-acting recombinant FIX., (© 2016 The Authors. Haemophilia Published by John Wiley & Sons Ltd.)

Prophylaxis with the blood clotting factor, factor VIII (FVIII) is ineffective for individuals with haemophilia A and high-titre inhibitors to FVIII. Prophylaxis with the FVIII bypassing agents activated prothrombin complex concentrates (aPCC; FEIBA® Baxalta) or recombinant activated factor VII (rFVIIa; Novo-Seven®, Novo Nordisk) may be an effective alternative. It was our aim to develop evidence -and expert opinion- based guidelines for prophylactic therapy for patients with high-titre inhibitors to FVIII. A panel of nine Spanish haematologists undertook a systematic review of the literature to develop consensus-based guidance. Particular consideration was given to prophylaxis in patients prior to undergoing immune tolerance induction (ITI) (a process of continued exposure to FVIII that can restore sensitivity for some patients), during the ITI period and for those not undergoing ITI or for whom ITI had failed. These guidelines offer guidance for clinicians in deciding which patients might benefit from prophylaxis with FVIII bypassing agents, the most appropriate agents in various clinical settings related to ITI, doses and dosing regimens and how best to monitor the efficacy of prophylaxis. The paper includes recommendations on when to interrupt or stop prophylaxis and special safety concerns during prophylaxis. These consensus guidelines offer the most comprehensive evaluation of the clinical evidence base to date and should be of considerable benefit to clinicians facing the challenge of managing patients with severe haemophilia A with high-titre FVIII inhibitors.

Introduction: Patients with severe haemophilia and inhibitors against factor VIII who require surgery need a prophylactic approach to prevent bleeding complications. Scientific evidence to decide the best prophylactic treatment is very limited and mainly based on retrospective or case series., Aims: To develop evidence- and expert opinion-based guidelines for prophylactic therapy for patients with haemophilia and inhibitors undergoing surgery., Methods: A panel of nine Spanish haematologists undertook a systematic review of the literature and selected publications providing relevant information regarding the prophylactic management of patients with haemophilia and inhibitors undergoing dental extraction, minor surgery or major surgery., Results: Although evidence is very limited, the panel considers that it seems advisable that prophylaxis should be given in most cases with a bypassing agent (aPCC or rFVIIa) and should start immediately before minor or major surgery. Patients should be closely monitored to enable dose/product modification as needed., Conclusion: It is necessary to communicate clinical experience in a detailed way in order to ensure optimal schemes of prophylaxis for patients with haemophilia and inhibitors. Development of objective outcomes to evaluate efficacy is crucial., (© 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

The diagnosis of von Willebrand disease (VWD) remains difficult in a significant proportion of patients. A Spanish multicentre study investigated a cohort of 556 patients from 330 families who were analysed centrally. VWD was confirmed in 480. Next generation sequencing (NGS) of the whole coding VWF was carried out in all recruited patients, compared with the phenotype, and a final diagnosis established. A total of 238 different VWF mutations were found, 154 were not included in the Leiden Open Variation Database (LOVD). Of the patients, 463 were found to have VWF mutation/s. A good phenotypic/genotypic association was estimated in 96.5% of the patients. One hundred seventy-four patients had two or more mutations. Occasionally a predominant phenotype masked the presence of a second abnormality. One hundred sixteen patients presented with mutations that had previously been associated with increased von Willebrand factor (VWF) clearance. RIPA unavailability, central phenotypic results disagreement and difficult distinction between severe type 1 and type 3 VWD prevented a clear diagnosis in 70 patients. The NGS study facilitated an appropriate classification in 63 of them. The remaining seven patients presented with a VWF novel mutation pending further investigation. In five patients with a type 3 and two with a type 2A or 2B phenotype with no mutation, an acquired von Willebrand syndrome (AVWS) was suspected/confirmed. These data seem to support NGS as a first line efficient and faster paradigm in VWD diagnosis.

In anecdotal reports, some patients with immune thrombocytopenia (ITP) maintained platelet counts after discontinuing romiplostim. Here, we examined rates of platelet response (≥50 × 10(9) /l), remission, splenectomy and adverse events in patients with primary ITP duration ≤6 months who were treated with romiplostim for ≤12 months. The starting dose of romiplostim was 1 μg/kg; concomitant and rescue treatments were permitted to maintain platelet counts. Patients with platelet counts ≥50 × 10(9) /l at the end of 12 months entered a dose taper in which the romiplostim dose was decreased as long as platelet counts were maintained. Remission (platelet count ≥50 × 10(9) /l for 24 consecutive weeks with no ITP treatments) was evaluated in patients once romiplostim was discontinued. Over the 12 months, a high response rate (>90%) was observed. Platelet response occurred quickly (median, ~2 weeks) and was observed for a cumulative median of 11 months. Remission was observed in 24 patients (32%); there were no significantly predictors of remission. Most (20/24) patients had remission start before the forced taper. No new safety signals were identified. Thus, in patients with early-stage ITP, romiplostim was well tolerated and induced rapid responses, with remission occurring in approximately one-third of patients (NCT01143038, Amgen 20080435)., (© 2015 John Wiley & Sons Ltd.)

Introduction: Desamino D-arginine vasopressin (DDAVP or desmopressin) is a useful and effective haemostatic treatment for patients with von Willebrand Disease (VWD). However, there are still issues regarding in which subtypes of VWD DDAVP is appropriate and little consensus on its use in different surgical settings. We also lack information concerning the appropriate laboratory parameters that should be monitored., Aim: The European Haemophilia Therapy Strategy Board (EHTSB) wished to investigate published information and clinical use of DDAVP in VWD patients., Methods: We conducted a literature survey on management of VWD during surgical interventions and undertook a survey of specialist haematologist centres across Europe to assess current management of VWD patients., Results: DDAVP is ineffective in type 3 VWD and its use in type 2B remains controversial due to the possibility of thrombocytopenia. It can, however, be used effectively to cover minor surgery and dental procedures in most other VWD patients. For major surgery there is wider use of factor concentrate in preference to DDAVP depending on the subtype of VWD. We give consensus recommendations on the use of DDAVP for surgical interventions in VWD including laboratory parameters that denote an adequate response and contraindications to its use., Conclusions: DDAVP can be recommended to cover invasive procedure in selected patients with VWD, however, we need more information and systematic recording of adverse events associated with DDAVP use in VWD. A companion paper will be published covering the use of factor concentrates in VWD patients., (© 2015 John Wiley & Sons Ltd.)

Congenital thrombotic thrombocytopenic purpura (TTP), also known as Upshaw-Schulman syndrome, is associated with an inherited deficiency of ADAMTS13, a von Willebrand factor-cleaving protease. It is a rare, life-threatening disorder characterized by thrombocytopenia, hemolytic anemia, neurological symptoms, renal dysfunction, and fever resulting from formation of platelet thrombi within the microvasculature. Patients have initial episodes mainly during infancy or early childhood, and are conventionally treated with fresh frozen plasma. However, a more appropriate approach based on recombinant ADAMTS13 is slated to begin shortly. Mutations throughout the ADAMTS13 have been identified in congenital TTP patients. The prevalence of this entity is probably underestimated because it is often not suspected, the clinical course is usually heterogeneous and most of the symptoms are common to other diseases. The present review summarizes our current knowledge about Upshaw-Schulman syndrome., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

Diagnostics of von Willebrand disease (VWD) includes assessment of factor VIII (FVIII) coagulant activity, von Willebrand factor (VWF) antigen (VWF:Ag) and VWF ristocetin cofactor activity (VWF:RCo), and more specific tests as multimeric and genetic analyses are necessary for the correct VWD classification. The ACL AcuStar analyzer introduces chemiluminescence (CL) technology in detection of VWD with automated VWF:Ag and VWF:RCo assays. Compare VWF:Ag-ELISA and VWF:RCo by aggregometry conventional assays with new CL VWF:Ag-IL and VWF:RCo-IL assays, investigate the ability to make accurate VWD diagnosis and concordance with multimeric and genetic analyses. 146 patients with congenital VWD (51 Type 1; 34 Type 2A; 16 Type 2B; 31 Type 2M; 5 Type 2N; 9 Type 3) and 30 healthy normal subjects were included. A comparison was made between CL and conventional methods. Diagnostic evaluation included: VWF:RCo/VWF:Ag ratio, multimeric distribution (sodium dodecyl sulfate [SDS]-agarose gel) of VWF and genetic analysis in 110 of 146 patients. CL and conventional methods revealed good correlation. Kappa test agreement diagnosis was >0.8. CL diagnostic sensitivity was 100% and specificity 97%. Multimeric and genetic analysis were of help in clarifying 13 discrepancies of diagnosis between methods, of which six discrepancies were explained by lack of conventional methods′ sensibility. CL methodology can detect VWD and discriminate between type 1, 3 and variant forms and offers an automated, faster, sensitive and less cumbersome method when compared to conventional assays, in particular VWF:RCo by aggregometry. In some cases, even with all phenotype and genetic analyses, discrepancies exist in the classification of VWD.

Background: Of patients with severe aortic stenosis, 15-25% present with bleeding episodes possibly attributable to acquired von Willebrand syndrome (AVWS). AVWS associated with mitral valve prosthesis leakage has not been reported., Methods and Results: Five patients receiving appropriate oral anticoagulation showed mitral valve prosthesis leakage and bleeding episodes; all of them required hospitalization and two blood transfusions, and a von Willebrand factor (VWF) analysis was performed. Two patients with normal functioning metallic prosthesis valves were included as controls. Before surgery, after cessation of acenocumarol, the patients had prolonged activated partial thromboplastin time; four had prolonged closure time (CT) from the platelet function analyzer. Factor VIII procoagulant activity (FVIII:C), VWF ristocetin cofactor activity (VWF:RCo), and VWF collagen binding (VWF:CB) were considerably elevated, while VWF antigen (VWF:Ag) was most elevated. Disproportionate VWF:RCo/VWF:Ag and VWF:CB/VWF:Ag ratios were seen with the loss of large VWF multimers. Following surgery, all parameters were markedly increased and the ratios, CT, and multimeric VWF profile became normal., Conclusions: Acquired VWF qualitative alterations in mitral valve prosthesis leakage may be associated with or contribute to bleeding diathesis. AVWS should be taken into consideration in patients with mitral valve prosthesis leakage with bleeding diathesis not explained by excessive oral anticoagulation., (© 2011 John Wiley & Sons A/S.)

Some 10-20% of bleeding events in haemophilia patients with high-responding inhibitors cannot be controlled with bypassing agents. However, sequential combined bypassing therapy (SCBT) has been reported to be successful in five children. To extend this observation, a survey was undertaken by the European Haemophilia Treatment Standardisation Board (EHTSB) in children and adults. Data were collected from all centres belonging to the EHTSB network by a retrospective medical record review. SCBT courses were defined as the administration of both recombinant activated factor VIIa (rFVIIa) and activated prothrombin complex concentrate (APCC) within 12 h. A web-based database was prepared to collect data on SCBT courses in a standardized and anonymous manner from patients' files. Eleven inhibitor patients underwent SCBT (nine haemophilia A; two haemophilia B). Two children had refractory knee haemarthrosis and one, an unresponsive calf haematoma. Five adults had significant bleeds following major surgery, one had lower limb compartmental syndrome and one a post-traumatic upper limb haematoma and haemarthrosis. SCBT administration alternated one APCC dose to 1-3 rFVIIa doses: dosing intervals ranged between 3 and 6 h; APCC (20-80 U kg(-1) ) was given every 8-12 h; rFVIIa (90-270 μg kg(-1) ) was given every 3-12 h. Bleeding control was achieved in 12-24 h in all patients. SCBT was discontinued after 1-15 days. No clinical adverse events were observed, but a significant increase in D-dimer levels was seen in three/five patients who were assessed. SCBT was efficacious without adverse events; nevertheless, due to potential risks, it remains a salvage treatment. A prospective clinical trial is needed to provide further evidence., (© 2011 Blackwell Publishing Ltd.)

Summary Background: There is currently intense debate as to whether pharmacogenetic algorithms for estimating the initial dose of coumarins provide a more accurate dose than the fixed-dose approach. Recently, it has been suggested that the greatest benefit of pharmacogenetic algorithms is observed in patients with extreme dose requirements., Objectives: To identify clinical and genetic factors that better characterize patients who need extreme acenocoumarol doses for steady anticoagulation state., Patients/methods: We reviewed 9538 patients with a steady acenocoumarol dose from three Spanish hospitals, selecting 83 who took or= 30.00 mg week(-1) (p95). We also selected patients matched by gender and age taking 13.50-14.00 mg week(-1) (p50). We genotyped VKORC1 (rs9923231), CALU (rs1043550), GGCX (rs699664), CYP2C9 (rs1799853; rs1057910), CYP4F2 (rs2108622) and F7 (rs5742910) single-nucleotide polymorphisms (SNPs)., Results: Comparison between p5 and p95 revealed five parameters with significant differences: body surface area (BSA) (P = 0.006), age, VKORC1, CYP2C9 and CYP4F2 genotypes (all P < 0.001). First VKORC1, and second, CYP2C9 SNPs played a strong effect by determining extreme doses, particularly in p95. Only one out of 203 p95 had the VKORC1 A-1639A genotype, but this subject was CYP2C9*1/*1. In contrast, nine out of 83 p5 carried the VKORC1 G-1639G genotype, although six of them were CYP2C9*3 homozygotes and another two were heterozygotes. Surprisingly, CYP4F2 V433M SNP displayed prevalences that suggest that its influence might only be evident when patients are treated with high doses., Conclusion: Two clinical data, age and BSA, and three SNPs in the VKORC1, CYP2C9 and CYP4F2 genes strongly predict outlier patients treated with acenocoumarol.

Background: Mutation C1149R in the von Willebrand factor (VWF) gene has been thought to cause autosomal dominant severe type 1 von Willebrand disease (VWD)., Design and Methods: Eight patients from three unrelated families with this mutation were included in the present study who had distinct VWF abnormalities, not described in earlier studies., Results: The patients showed notably low levels of VWF antigen (VWF:Ag), VWF ristocetin cofactor activity (VWF:RCo), VWF collagen binding (VWF:CB), and a reduced ristocetin-induced platelet aggregation (RIPA). VWF:RCo/VWF:Ag and VWF:CB/VWF:Ag ratios were lower than 0.7. At basal conditions, all the VWF multimers were decreased in plasma, with a clearly lower relative proportion of the high molecular weight VWF multimers (HMWM). In high-resolution agarose gels, a large decrease in the relative proportions of the satellite bands was seen. The patients had a brief good response to desmopressin (DDAVP) administration, but the released VWF half-life was shorter than normal, indicating an accelerated clearance of their VWF. Platelet VWF was abnormal., Conclusions: We conclude from the results obtained in these patients for plasma phenotypic data that this mutation should be classified as a VWD type 2A (IIE). DDAVP therapy may be somewhat helpful for this mutation, at least for mild to moderate bleeding. These data provide evidence that for VWD classification factors other than basal VWF, such as DDAVP response and platelet VWF, should be considered.

Therapy for von Willebrand disease (VWD) aims to restore the hemostatic function conferred by von Willebrand factor (VWF), which facilitates platelet adhesion and aggregation, and serves to increase potentially low coagulation factor VIII (FVIII) in plasma. In patients unresponsive to desmopressin (DDAVP), the preferred treatment is with plasma-derived VWF-containing FVIII concentrates. Only a few of the available VWF/FVIII concentrates have been licensed for use in VWD based on prospective studies. The efficacy of VWF/FVIII concentrates depends on the content and quality of VWF and FVIII. Several studies have demonstrated the variability of the VWF contents, as well as the differences in the VWF multimer patterns (including the high molecular weight VWF multimers that are most effective in restoring hemostasis), among these concentrates. Treating physicians should be aware of these disparities and the potential clinical implications for patients with different VWD subtypes. Dosing has traditionally been calculated based on the FVIII content of the products, although dosing based on VWF functional activity [e.g., VWF ristocetin cofactor activity (VWF:RCo)] addresses the primary protein deficiency in VWD patients. Several clinical studies have demonstrated the efficacy of concentrates dosed according to VWF:RCo. Dosing is generally consistent across VWD subtypes, although patients with severe phenotypes or undergoing major procedures may require more infusions or longer treatment duration. Other considerations for the use of VWF-containing concentrates include laboratory monitoring of efficacy and safety issues such as thrombosis risk and thromboprophylaxis.

The Consensus Document on Alternatives to Allogenic Blood Transfusion (AABT) has been drawn up by a panel of experts from 5 scientific societies. The Spanish Societies of Anesthesiology (SEDAR), Critical Care Medicine and Coronary Units (SEMICYUC), Hematology and Hemotherapy (AEHH), Blood Transfusion (SETS) and Thrombosis and Hemostasis (SETH) have sponsored and participated in this Consensus Document. Alternatives to blood transfusion have been divided into pharmacological and non-pharmacological, with 4 modules and 12 topics. The main objective variable was the reduction of allogenic blood transfusions and/or the number of transfused patients. The extent to which this objective was achieved by each AABT was evaluated using the Delphi method, which classifies the grade of recommendation from A (supported by controlled studies) to E (non-controlled studies and expert opinion). The experts concluded that most of the indications for AABT were based on middle or low grades of recommendation, "C", "D", or "E", thus indicating the need for further controlled studies.

Patients initially diagnosed with type 1 von Willebrand disease (VWD) have been reclassified as type 2 after a more exhaustive analysis in several studies. Our study's objectives were (1) to reanalyze patients that were previously diagnosed as type 1 to achieve a more accurate diagnosis and (2) to compare the von Willebrand factor (VWF) ristocetin cofactor assay (VWF:RCo) and the VWF collagen binding assay (VWF:CB) in order to evaluate the possibility of replacing the former assay with the latter in the diagnosis of VWD. Twenty-one patients from two large unrelated families and 104 normal controls were studied. VWF:Ag, VWF:RCo, FVIII coagulant activity (FVIII:C), bleeding time (BT), PFA(100), and multimeric analysis of VWF were tested. Genetic analysis by sequencing exon 28 on the VWF gene was also carried out. Patients presented lower levels of VWF:Ag and VWF:RCo, a dissociation between VWF:RCo/VWF:Ag, and the presence of all sizes of multimers in plasma VWF. The results for VWF:CB varied depending on the type of collagen used. The genetic analysis showed that the mutation R1374C is responsible for type 2M VWD. A high frequency of the R1374C mutation is observed in northwestern Spain (Galicia). Some types of 2M VWD are misdiagnosed as type 1 VWD. The VWF:CB (with type I collagen) assay was unable to discriminate defective platelet binding of the R1374C VWF. This confirms that VWF:CB cannot substitute for VWF:RCo, and both should be tested when diagnosing VWD.

An analysis was conducted in four members of the same family, two of whom had a history of severe bleeding associated with type 2B von Willebrand's disease (VWD) which, although found to be due to the same mutation, nevertheless exhibited different phenotype patterns in the two subjects involved. Von Willebrand's factor (VWF) multimers were assayed with high- and low-resolution sodium dodecyl sulfate (SDS) agarose gels. The patients were studied before and after intravenous administration of desmopressin (DDAVP) at doses of 0.4 microg/kg body weight. Automatic sequencing techniques were used to analyze VWF gene exon 28. The propositus presented with mild basal thrombocytopenia with ristocetin-induced platelet aggregation (RIPA) at low concentrations of ristocetin. He had a very prolonged bleeding time (BT), and his plasma VWF was found to be lacking in large and intermediate multimers. Thrombocytopenia was observed to intensify transiently after the administration of DDAVP. The propositus' mother, in contrast, presented reduced RIPA while in a basal state, with only partial loss of the high molecular weight VWF multimers. Although she had a very prolonged BT, her platelet count was borderline. Transient correction of BT and a decrease in the platelet count were observed after administration of DDAVP and RIPA was observed at low concentrations of ristocetin. Exon 28 sequencing revealed a G4196A-->Val1316Met mutation in both patients. No other abnormality was detected within this exon. Val1316Met has been reported in type 2B VWD. In conclusion, in the family presented here, the phenotype pattern in one patient was typical of type 2B VWD, whereas the pattern in his mother was closer to type 2A VWD. After administration of DDAVP, however, a type 2B phenotype could be clearly attributed to both, indicating that this drug can be a useful tool for elucidating ambiguous phenotypes.

The aim of this study was to analyze the ability of an alloantibody from a patient with severe von Willebrand disease (vWD) to interfere with the vWF domain for FVIII, to inhibit factor VIII (FVIII), and to compare it with a rabbit polyclonal antibody. The vWF domain for binding to FVIII was assayed by a method previously described but using recombinant FVIII (r-FVIII, Kogenate), which contains no vWF, instead of Hemofil M (HM). Rabbit or human antibodies towards FVIII (FVIII-Ab) were analyzed using microtiter wells with immobilized r-FVIII through a monoclonal anti-FVIII antibody and an ELISA method. IgG from plasma of a patient with hemophilia A and FVIII inhibitor was used as a positive control. Normal human and rabbit IgGs were included as negative controls. Human vWD alloantibody IgG and the rabbit anti-vWF antibody IgG reacted with immobilized normal vWF, inhibiting its binding to r-FVIII in a dose-dependent manner, which suggests that it is specific. Normal human IgG fraction, as well as nonspecific rabbit IgG, did not interfere with this binding at all. The monoclonal antibody used in this assay to immobilize vWF did not alter this interaction at all. Human vWD alloantibody IgG and the rabbit antibody against vWF showed a partial inhibitory activity to plasma FVIII as well as r-FVIII. The inhibition reached a plateau with residual FVIII activity. FVIII-Ab were not detected in human alloantibody or in rabbit antibody preparations. In contrast, hemophiliac FVIII inhibitor showed FVIII-AB. This human vWD alloantibody behaves like polyclonal heterologous antibodies, and their inhibition of FVIII seems to be nonspecific due to a steric hindrance mechanism provided that both have no FVIII antibodies.

Non-neutralizing factor VIII (FVIII) antibodies (FVIII-Ab) in hemophilia A may be associated with an abnormal clinical response to FVIII concentrates. Patients with FVIII inhibitors may develop noncoagulation FVIII-Ab after the induction of immunotolerance. Natural FVIII-Ab may be detected in the plasma of some healthy subjects. The aim of this study was to analyze the presence of FVIII-Ab in the plasma of 53 normal blood donors and 124 patients with hemophilia A (18 patients had a previous history of FVIII inhibitor, but only 12 had inhibitor at the moment this study was performed). FVIIII inhibitor was measured using the Bethesda method. FVIII-Ab were analyzed by a specific ELISA assay using purified FVIII from a monoclonal concentrate and a standard plasma containing 26 Bethesda units (BU) of FVIII inhibitor. Purified FVIII was used to coat wells of a microtiter plate and was incubated with dilutions of plasma to be tested. Bound human IgG FVIII-Ab were detected by incubation with polyclonal sheep anti.human IgG alkaline phosphatase conjugate, and the OD405 was quantitated. A linear fit was obtained (by plotting FVIII-Ab positivity [OD 405nm] versus BU titer) when serial dilutions of this standard inhibitor plasma, containing titers of 0.5 BU or higher, were used. Four different levels of FVIII-Ab positivity [OD 405nm] were distinguished in this assay: Negative levels (-) were obtained with dilutions of the standard inhibitor containing < 0.5 BU. Mild levels (+) were obtained with dilutions of 0.5-5 BU. Moderate levels (+2) were obtained for dilutions ranging from 5-25 BU. Maximum positivity (+3) was obtained for dilutions of titers > 25 BU. FVIII-Ab positivity was detected in eight of the normal subjects (15%): three were found to be moderately positive (+2) and five mildly positive (+). No inhibitory activity was detectable when whole plasma was used. All the hemophilic patients with a presence of FVIII inhibitor at the time of the study were found to be positive for FVIII-Ab. In addition, the level of positivity correlated with the corresponding BU. Four of the six patients who had a history of inhibitory were negative and two positive. Twenty additional patients (16.12%) in whom no inhibitory activity was detected were found to be positive for FVIII-Ab: 16 + and four +2. The mean age of patients with FVII-Ab positivity was significantly higher than that of patients of the FVIII-Ab negative group (p < 0.005). In conclusion, FVIII-Ab positivity in patients with hemophilia A was 17.7% higher than the level of positivity detected by an inhibitory assay. We propose that this method for FVIII-Ab analysis could be used for patients with hemophilia A, at least to complement the functional inhibitor assay. FVIII recovery or half-life should be assessed in patients who test positive for FVIII-Ab and who show no evidence of inhibitor.

To date very few studies that analyze the prevalence of anticardiolipin antibodies (ACA) in healthy subjects have been reported. No data based on a systematic analysis of normal subjects with positive ACA is available. The aim of the present study was to evaluate the prevalence of ACA; its clinical significance and relationship to the lupus anticoagulant (LA) and other autoimmune parameters in an apparently healthy population. 552 normal blood donors from a blood bank were randomly selected. ACA positive donors who consented were monitored over a period of twelve months and tested every three months. ACA (IgG and IgM isotypes) were quantitated by enzyme linked immunoassay (ELISA). The prevalence for IgG ACA in our donor population was estimated to be 6.5%, and 9.4% for IgM ACA, which is similar to the one previously reported for IgG and slightly higher for IgM. It is worth noting that in our study ACA positive donors exhibited a progressive negativization. Eight donors with IgG ACA and seven with IgM ACA remained positive for nine months. Five donors with IgG ACA and four with IgM ACA had family history of thromboembolic disease. One donor with IgG ACA and two with IgM ACA had had unexplained miscarriages in the past. We did not find any relationship between ACA and LA, nor between ACA positivity and the clinical and laboratory data studied. Pseudopositivity for lues was not found. No thrombotic event occurred in donors that were positive for ACA during the 12-month follow-up.

Type IIA von Willebrand disease (vWD) is a heterogeneous disorder for which two different pathogenetic mechanisms have been proposed: increased proteolytic susceptibility of von Willebrand factor (vWF), and/or interference of its post-translational processing. Subunit analysis of vWF in type-IIA vWD has revealed an increased relative proportion of the 176- and 140-kDa subunit-derived fragments, suggesting an augmented fragmentation of vWF, even in the resting state. We analyzed the subunit pattern of vWF in plasma from five previously described patients with type-IIA vWD. All of them showed the above-mentioned pattern. In addition, the presence of a new band with an apparent molecular mass of 200 kDa, not described in normal individuals or in patients with vWD, was repeatedly observed in one of these patients. This patient also exhibited an abnormal vWF multimeric structure in platelets and in plasma, before and after desmopressin administration, when the blood was collected either in the presence or in the absence of proteinase inhibitors. We believe that an abnormal primary structure of vWF could be responsible for this abnormal proteolytic fragmentation pattern, as well as for the abnormal multimerization of vWF. Moreover, an abnormal susceptibility to proteolysis appears to be present, as suggested by the increase in the relative proportion of the 176-kDa fragment observed in the same patient. Future sequencing studies and genetic analysis may clarify whether there are one or two different defects related to the vWF of that patient. Our results indicate that the subunit analysis of vWF may reveal additional defects present in type-IIA vWD that may help our understanding of the pathogenesis of such disease.

Purpose: To evaluate our experience in the treatment of disseminated intravascular coagulation (DIC) associated to AML-M3 with substitution therapy with or without heparin., Patients and Methods: The clinical records of 19 patients diagnosed of AML-M3 in the Hospital Juan Canalejo, in La Coruña, between 1986 and 1991 were revised. DIC was defined by abnormalities in one or more of the following: prothrombin time, activated partial thromboplastic time, thrombin time, fibrinogenaemia, fibrin/fibrinogen degradation products, D-dimers. The treatment given to 13 patients was only substitutive including platelets, fresh-frozen plasma, cryoprecipitates and antithrombin III. Low-dose sodium heparin (Kabi) in continuous intravenous infusion was associated to the treatment of the remaining 6 patients. With regard to the leukaemic therapy, most of the patients received daunorubicin, 2 mg/kg/day x 5 days, and AraC, 100 mg/Kg/day x 7 days., Results: All patients showed haemorrhagic symptoms at diagnosis, and laboratory data of DIC were present in 11 cases (57%). The mean duration of DIC was 6.5 days for the patients receiving substitutive treatment and 9.5 days for those given heparin. Complete remission (CR) of the leukaemia was attained in 12 cases (63%); of the patients treated with heparin, 50% achieved CR whereas 75% of those receiving substitute therapy attained CR. The 24-months survival rate was 30% for the patients treated with substitutive therapy and 16% for those treated with heparin. The incidence of death associated to haemorrhage during induction therapy was 30% for the substitutive treatment group and 50% for the heparin group., Conclusion: Shorter duration of DIC, lesser rate of early death, higher CR rate and longer 2-year survival were found in those AML-M3 patients not receiving heparin.