Continuous infusion (CI) of factor VIII (FVIII) is an effective method for replacement therapy in haemophilia. Recently, concerns have been raised regarding association of CI with the development of inhibitors. The aim of this study was to gain information on the current practices in Europe regarding CI and the true inhibitor incidence after this mode of therapy. In a cross sectional study performed in 22 Comprehensive Care Centres (CCCs), we evaluated CI techniques, treatment protocols, efficacy, safety and complications of CI including inhibitors. Thirteen (59%) CCCs reported a total of 1079 CI treatments, given peri-operatively or for major bleeds, in 742 patients. Most centres used 'adjusted dose' CI aimed at median target FVIII level of 0.8 IU mL(-1). CI was haemostatically very effective with a low incidence of complications: median incidence of postoperative bleeding was 1.8%, six centres observed phlebitis in 2-11% of CI treatments. Only nine (1.2%) patients developed inhibitors (0.45% of 659 severe and 7.2% of 83 mild haemophilia patients). Additional analysis of inhibitor patients revealed several confounding factors (low number of prior FVIII exposure days, high steady-state factor levels during CI, high-risk genotype). In this unprecedentedly large cohort, CI treatment appears to be an effective and safe treatment that does not increase the risk of inhibitor development in patients with severe haemophilia. Thus, previous small case series reports suggesting that CI may increase inhibitors cannot be confirmed. Inhibitor risk in mild haemophilia could not be evaluated as the influence of other, potentially confounding, risk factors could not be excluded.
[Show abstract][Hide abstract] ABSTRACT: Studies of determinants of the development of inhibitory antibodies in patients with haemophilia indicate that this is a complex process involving several factors. The foundation is characterized by the T- and B-cell repertoire and the antigen presenting cells and to elicit an immune response to the deficient factor, a pre-disposing foundation is needed. Hence, in the absence of a certain set of circumstances, there will be no risk for development of inhibitors. Conversely, in patients fundamentally at risk, genetic and non-genetic factors might add to the risk. These factors may be additive or interactive, and ultimately promote or counteract the immune reaction by modifying immune regulators and the cytokine profile in an individual. In some subjects, only minor inflammatory signals might be needed, whereas in others a more pronounced pro-inflammatory state will be required. Regarding genetic markers other than the type of mutation and the HLA class II molecules, polymorphisms in various immune regulatory genes have been associated with inhibitor risk. These associations have not, however, been consistent across all patient groups. The reason for this is not clear, but could be related to study design or statistical power, family relationships among those studied, the complexity of interacting molecules and ethnic genomic variation. The Hemophilia Inhibitor Genetics Study (HIGS) has identified additional candidates within the intracellular pathways, all of which require additional evaluation to be fully appreciated. In the case of non-genetic factors, the overall view is that immune system challenges might add to the risk. HIGS data suggest that it will be possible to calculate a genetic score to identify patients at high risk for inhibitor development before the start of treatment. By doing so, it may hopefully be possible in the future to prevent the formation of inhibitors in these patients by offering therapeutic options other than the native factor VIII or IX molecule in an inflammatory setting.
[Show abstract][Hide abstract] ABSTRACT: The aims of severe perioperative bleeding management are three-fold. First, preoperative identification by anamesis and laboratory testing of those patients for whom the perioperative bleeding risk may be increased. Second, implementation of strategies for correcting preoperative anaemia and stabilisation of the macro- and microcirculations in order to optimise the patient's tolerance to bleeding. Third, targeted procoagulant interventions to reduce the amount of bleeding, morbidity, mortality and costs. The purpose of these guidelines is to provide an overview of current knowledge on the subject with an assessment of the quality of the evidence in order to allow anaesthetists throughout Europe to integrate this knowledge into daily patient care wherever possible. The Guidelines Committee of the European Society of Anaesthesiology (ESA) formed a task force with members of scientific subcommittees and individual expert members of the ESA. Electronic databases were searched without language restrictions from the year 2000 until 2012. These searches produced 20 664 abstracts. Relevant systematic reviews with meta-analyses, randomised controlled trials, cohort studies, case-control studies and cross-sectional surveys were selected. At the suggestion of the ESA Guideline Committee, the Scottish Intercollegiate Guidelines Network (SIGN) grading system was initially used to assess the level of evidence and to grade recommendations. During the process of guideline development, the official position of the ESA changed to favour the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system. This report includes general recommendations as well as specific recommendations in various fields of surgical interventions. The final draft guideline was posted on the ESA website for four weeks and the link was sent to all ESA members. Comments were collated and the guidelines amended as appropriate. When the final draft was complete, the Guidelines Committee and ESA Board ratified the guidelines.
European Journal of Anaesthesiology 06/2013; 30(6):270-382. DOI:10.1097/EJA.0b013e32835f4d5b · 2.94 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The development of inhibitory antibodies against infused factor VIII (FVIII) is a major challenge in hemophilia treatment. As the antibodies swiftly inactivate administered therapeutic FVIII concentrates, FVIII is no longer effective in controlling bleeding. To achieve adequate hemostasis, bypassing therapies are required, with accompanying clinical challenges and financial expense. Extensive research has aimed to elucidate the multifactorial etiology of inhibitor development. Both genetic and nongenetic causes have been identified. Identification of treatment-related risk factors would offer the possibility to modify treatment strategies in high-risk patients, thereby reducing the risk of inhibitor development. Have we presently gained sufficient knowledge to make a prediction of the inhibitor risk possible and justify changes in treatment regimens for specific patient groups? This review summarizes and evaluates the research findings on nongenetic risk factors of inhibitor development, with special focus on treatment-related factors.
Seminars in Thrombosis and Hemostasis 09/2013; 39(7). DOI:10.1055/s-0033-1354417 · 3.88 Impact Factor
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