Evaluation of the utility of the ISTH-BAT in haemophilia carriers: a multinational study.

INTRODUCTION: There has been increasing recognition in recent years that female carriers of haemophilia manifest abnormal bleeding; however, data on the use of bleeding assessment tools in this population are lacking. AIM: Our objective was to validate the ISTH-BAT in haemophilia carriers to describe bleeding symptoms and allow for comparisons with factor levels and other patient groups. METHODS: This was a prospective, observational, cross-sectional study performed by members of Global Emerging HEmostasis Panel (GEHEP). Unselected consecutive haemophilia carriers were recruited and a CRF and the ISTH-BAT were completed by study personnel. RESULTS: A total of 168 haemophilia carriers were enrolled: 155 haemophilia A and 13 haemophilia B. The mean age was 40 years (range: 20-82). Carriers had higher mean bleeding scores (BS) compared with age-matched controls (n = 46; 5.7 vs. 1.43; P < 0.0001) and Type 3 VWD OC (n = 32; 3.0; P = 0.009), but lower BS compared with women with Type 1 VWD (n = 83; 8.7; P < 0.0001). Fifteen carriers reported haemarthrosis, and of those six had normal FVIII/FIX levels. There was a significant but weak negative correlation between BS and factor level (Spearman's r2  = -0.36, P < 0.001). CONCLUSION: Our results show that haemophilia carriers experience abnormal bleeding, including haemarthrosis. Overall, BS in women with Type 1 VWD > haemophilia carriers > Type 3 VWD OC > controls. Understanding the performance of the ISTH-BAT in this population is a critical step in future research aimed at investigating the underlying pathophysiology of abnormal bleeding, with the ultimate goal of optimizing treatment.

Presentation and management of acute coronary syndromes among adult persons with haemophilia: results of an international, retrospective, 10-year survey.

Sparse data are available on presentation and management of acute coronary syndromes (ACS), including unstable angina and non-ST- and ST-elevation myocardial infarction, among persons with haemophilia (PWH). The aim of this study was to determine demographics, bleeding disorder characteristics, cardiovascular risk factors (CRFs), interventions, haemostatic protocol, revascularization outcomes and complications among PWH with ACS. Members of an international consortium comprising >2000 adult PWH retrospectively completed case report forms for episodes of ACS in a >10-year follow-up period (2003-2013). Twenty ACS episodes occurred among 19 patients [rate, 0.8% (95% CI 0.4, 1.2)]. Seven patients (37%) were aged <50 years; 10 (53%) had ≥3 CRFs. In 5/20 episodes (25%), the initial ACS management protocol was altered because of the bleeding disorder. None of the eight patients with severe haemophilia underwent coronary artery bypass grafting (CABG), compared with 54.5% of patients with non-severe disease (P = 0.02). Revascularization with percutaneous coronary intervention (PCI) or CABG was rated successful in 13/13 cases, with no excessive bleeding during initial management. During chronic exposure to antiplatelet agents, secondary haemophilia prophylaxis was more prevalent in patients with severe haemophilia compared with non-severe haemophilia (85.7% vs. 30%, P = 0.05). No ACS-related deaths occurred during initial management, but one patient with severe haemophilia A died of undetermined cause 36 months after the ACS event while on aspirin therapy. ACS occurs even among relatively younger PWH, typically in association with multiple CRFs. Revascularization with PCI/CABG is feasible, and antiplatelet agents plus secondary prophylaxis appears to be well tolerated in selected PWH with ACS.

Neonatal circumcision in severe haemophilia: a survey of paediatric haematologists at United States Hemophilia Treatment Centers.

Neonatal circumcision in patients with severe haemophilia has not been well studied. We performed a survey of paediatric haematologists from Hemophilia Treatment Centers (HTC) across the United States to better understand the attitudes toward and management of neonatal circumcision in haemophilia patients. Response rate to our survey was 40% (n = 64/159). Thirty-eight percent of respondents (n = 24) said that they would allow this procedure in the newborn period but in many cases this was against medical advice. The most reported concern regarding neonatal circumcision in haemophilia patients was the risk of development of an inhibitor (n = 25; 39%) followed by the concern for bleeding (n = 22; 34%) and issues related to vascular access in the neonate (n = 11; 17%). All respondents recommended at least one preprocedure dose of factor replacement. Twenty-two percent (n = 14) of respondents did not use more than one dose of factor replacement but 32% (n = 21) used 1-2 postoperative doses. The remainder of paediatric haematologists surveyed recommended between 3-5 (16%; n = 10) and 6-10 (3%, n = 2) additional days postoperatively. There was wide variation in both techniques of circumcision as well as adjuvant haemostatic agents used. Only 22% of respondents said that they had an established protocol for management of circumcision in the newborn haemophilia patient. These survey results highlight the need for evidence-based guidelines regarding the optimal management of circumcision in neonates with severe haemophilia.

Thromboelastography identifies children with rare bleeding disorders and predicts bleeding phenotype.

Rare bleeding disorders (RBDs) comprise 3-5% of all congenital bleeding disorders. They can evade typical coagulation screening tests and there is a poor correlation between laboratory results and bleeding phenotype. Thromboelastography (TEG) measures coagulation globally in whole blood samples. The aims of this study were to evaluate the utility of TEG as an adjunct to the routine screening tests employed for the diagnosis of RBDs and to correlate TEG results with the bleeding phenotype in RBDs. TEG parameters and clot kinetics were compared to bleeding phenotypes (asymptomatic, mild, moderate and severe) in 26 RBD patients and 30 normal controls. Clot kinetics correlated strongly with RBDs and with the severity of bleeding phenotype with mean maximum rate of thrombus generation (MRTG) 15.4 mm min(-1) in controls vs. 6.0 in RBDs (P < 0.0001, Wilcoxin). The mean MRTG was 7.7 in mildly symptomatic, 5.5 in moderately symptomatic and 4.1 in severely symptomatic patients (P < 0.0001, Kruskal-Wallis). Disorders that are often missed by conventional screening tests, dysfibrinogenaemia and platelet disorders displayed a distinctive TEG curve with markedly decreased maximum amplitude (MA) and low MRTG values. Factor XIII and PAI deficient patients displayed increased fibrinolysis in addition to low MRTGs. All patients with RBDs, but none of the normal controls, had abnormal clot kinetics suggesting that TEG may be an effective screening test for RBDs.

Use of recombinant activated factor VII in patients with Glanzmann's thrombasthenia: a review of the literature.

Glanzmann's thrombasthenia (GT) is a rare bleeding disorder characterized by a quantitative or qualitative defect of glycoprotein IIb/IIIa on the platelet membrane. Managing bleeding episodes is often difficult, and a variety of modalities have been used, including platelet transfusions, recombinant factor VIIa (rFVIIa), and other supportive care. The aim of this review was to present the clinical experience with rFVIIa bolus infusion (rFVIIa BI) for treatment of bleeding episodes and prevention of bleeding during surgical procedures in patients with GT. A literature search was performed to identify rFVIIa-treated patients with GT. Overall, one international survey, one open-label study, and 40 case reports identified 172 bleeding episodes treated with rFVIIa and 62 procedures covered with rFVIIa. In the international survey, rFVIIa BI was used for 96 bleeding episodes in 59 patients. Recombinant FVIIa was effective in 76 bleeding episodes (79%). Of 34 surgical procedures, 25 procedures received rFVIIa BI with 92% bleeding-prevention efficacy. The open-label study reported 28 patients with 28 rFVIIa BI-treated bleeds, and 26 (93%) bleeding episodes responded to rFVIIa. Published case reports revealed that 25 (69%) of 36 bleeds and 27 (96%) of 28 surgeries responded to rFVIIa BI treatment. Overall, 26 adverse events were reported in 19 patients, including five thromboembolic events in two patients where a possible relationship with rFVIIa could not be excluded. Two large studies and 40 case reports provide a literature base to support the efficacy and safety of rFVIIa BI in patients with GT.

Therapeutic and prophylactic ethanol lock therapy in patients with bleeding disorders.

Obtaining a reliable venous access is a limiting factor for early initiation of clotting factor prophylaxis and immune tolerance induction. To circumvent this issue, central venous access devices (CVADs) are increasingly being used. Catheter-related infections (CRIs) remain the primary complication of insertion of CVAD. Thus, newer strategies for treatment and prevention of CRI are needed. Ethanol lock therapy (ELT) has been used to treat and prevent CRI in non-bleeding disorder patients. The aim of this study was to assess the efficacy of ELT in treating and preventing CRI in bleeding disorder patients. The medical charts of patients with bleeding disorders who underwent ELT for antimicrobial resistant CRIs were reviewed and data were analysed. ELT was effective in catheter salvage in 87% of patients with antimicrobial resistant CRI by a wide variety of pathogens. Prophylactic therapy with ethanol lock was associated with catheter dysfunction especially in mediports. ELT should be considered prior to removal of catheters in bleeding disorder patients with resistant CRIs. Further studies are needed for using prophylactic ethanol lock in prevention of CRIs in bleeding disorder patients.

Standardization of thromboelastography: a report from the TEG-ROTEM working group.

Laboratory evaluation of bleeding disorders has been performed with the standard clotting assays such as the PT and PTT for several decades. Our improved understanding of the process of blood coagulation has now revealed the important role played by the cellular elements such as platelets, monocytes and red blood cells. The need for a test that can assess clotting in a more 'global' manner, beyond the initiation of clot formation, has led to greater interest in assays such as thrombin generation and thromboelastography. Even though there are several publications using thromboelastography it remains a research tool as the methodology is not standardized. In an attempt to show reproducibility and consistency using thromboelastography, a group of investigators from different countries joined hands to form the TEG-ROTEM Working Group. Two studies were performed using PRP and FVIII deficient plasma and an intrinsic pathway activator. This article summarizes the results of the first international effort at standardization of thromboelastography. Both of the instruments using this technology (TEG(®) and ROTEM(®)) were used. Nine laboratories from countries around the globe participated in this effort. The results showed a significant inter-laboratory variance with CV's greater than 10%. Although these results were not satisfactory, this has been the first effort to standardize this methodology and significant work remains to be done to improve reliability and reproducibility. These studies were performed on PRP and the results may be more reliable when preformed on whole blood samples. We believe that it is important to continue this work so that we may investigate the usefulness and potential applications of thromboelastography in the evaluation of bleeding and thrombosis.

Immune tolerance induction in 31 children with haemophilia A: is ITI less successful in African Americans?

Inhibitor development continues to be a major problem in the treatment of haemophilia. Immune tolerance induction (ITI) continues to be the most effective approach to managing this complication. This study reviews the practice and outcome of ITI at a single centre over a 17-year period. All 31 inhibitor patients have haemophilia A. Two patients with haemophilia A underwent two trials of ITI and a third patient underwent three trials of ITI for a total of 35 courses of ITI in these 31 patients. Most patients had high responding inhibitors, 22 of 31. Seventy-one percent of haemophilia patients achieved tolerance. Courses of ITI in African American (AA) patients with haemophilia A were much less likely to achieve tolerance compared with non-AAs, 57.9% and 92% (P = 0.04) respectively. Most trials of ITI were carried out with recombinant products (25 of 35). While ITI continues to be an effective therapy for patients with inhibitors, it is less effective in AA patients, and patients with higher inhibitor titres. In this refractory group of patients, new approaches are needed.

Tests of global haemostasis and their applications in bleeding disorders.

SUMMARY: There is a potential for significant paradigm shift in the assessment of haemostasis from the conventional plasma recalcification times, such as prothrombin time (PT) and activated partial thromboplastin time (APTT), which correspond to artificially created compartments of haemostasis to tests that assess the entire process in a more physiological and holistic manner. These include the thrombin generation test, thromboelastogram and the clot wave form analysis. While these tests have been described many years ago, there is renewed interest in their use with modified technology for assessing normal haemostasis and its disorders. Although early data suggest that they can provide much greater information regarding the overall haemostasis process and its disorders, many challenges remain. Some of them are possible only on instruments that are proprietary technology, expensive and are not widely available. Furthermore, these tests need to be standardized with regard to their reagents, methodology and interpretation, and finally, much more data need to be collected regarding clinical correlations with the parameters measured.

Ethanol lock therapy for the treatment of catheter-related infections in haemophilia patients.

Central venous access devices (CVAD) are increasingly being used for optimal delivery of clotting factor concentrates in patients with haemophilia with poor peripheral venous access. The utility of CVAD is particularly well recognized in young patients starting factor prophylaxis and in patients with inhibitors undergoing immune tolerance induction (ITI). A catheter-related infection (CRI) remains the most common complication of CVAD in haemophilia patients and is the most frequent indication for its removal. Additionally, in some patients the infection results in significant morbidity and mortality and also contributes to failure of the ITI regimen. Ethanol-lock therapy (ELT) is a treatment modality that has been used to treat CRI in patients with indwelling catheters for home parenteral nutrition and chemotherapy. The aim of this study was to report the success in treating CRI in haemophilia patients using ELT. Three severe haemophilia A patients undergoing ITI regimen who developed CVAD infections resistant to conventional management with antibiotics were treated by ELT according to the institutional technique. All three patients responded well to ELT with clearance of the CVAD infection. There were no adverse side effects. To our knowledge, this is the first report of ELT in patients with haemophilia. The role of ELT needs to be investigated in larger studies for treatment of CRI in patients with bleeding disorders.

Inhibitors in factor IX deficiency a report of the ISTH-SSC international FIX inhibitor registry (1997-2006).

Haemophilia B is an X-linked disorder resulting in coagulation factor IX deficiency. Patients with severe deficiency (<1% factor IX activity) may have significant bleeding complications similar to patients with haemophilia A or factor VIII deficiency. The development of inhibitory antibodies to the missing coagulation factor is a major complication in patients with haemophilia. While the incidence of inhibitors in patients with haemophilia A is higher than that in haemophilia B, the occurrence of allergic and or anaphylactic reactions with the development of inhibitors is unique to haemophilia B patients. Since haemophilia B is a rare bleeding disorder and the incidence of inhibitors is an even rarer entity, a registry was established by Dr Indira Warrier under the auspices of the FVIII/FIX subcommittee of the International Society of Thrombosis and Haemostasis, to gather information on the occurrence and characteristics of patients with inhibitors and also the incidence of allergic and anaphylactic reactions in this group of patients. This is the first report from this registry and helps us to gather some insight on haemophilia B patients with inhibitors and complications related to inhibitor development and difficulties with immune tolerance.