Increased burden on caregivers of having a child with haemophilia complicated by inhibitors.

INTRODUCTION: Having a child with a chronic disease often increases the burden in the family with more hospital visits, treatment administration, and increased worries for the ill child. A cross-sectional, international, multi-centre study in caregivers of children <18 years with haemophilia and inhibitor was performed at Haemophilia Treatment Centres in Sweden, UK, and Canada to evaluate caregivers' burden and their health-related quality of life (HRQoL) compared to that of caregivers of children on prophylaxis without inhibitors and caregivers of healthy children. METHODS: Caregivers of children with haemophilia completed several questionnaires (SF-36, Visual Analogue Scale of Interference (VAS), Caregivers' Burden Scale and Impact on Family Scale (IOF). Caregivers of healthy children completed only the SF-36. In addition, socio-demographic data were collected. RESULTS: In total, 143 caregivers were included in the study. Comparing the two haemophilia groups with caregivers of healthy children revealed significant differences for all SF-34 domains except 'pain' and 'general health'. In Caregivers' Burden Scale, caregivers of children with inhibitors reported higher impact of haemophilia (P < 0.0001) and higher impact on VAS (P < 0.0001) compared to caregivers of children without inhibitors. In IOF, caregivers of children with inhibitors reported significant negative impact of the disease, except for aspect of coping. CONCLUSION: Caregivers of children with inhibitors reported higher impact of the disease compared to caregivers of children with no inhibitors. No differences between mothers and fathers in the two groups for SF-36, Caregivers' Burden Scale, VAS and IOF, except for domain pain in SF-36 where mothers reported higher impairments.

Bleeding complications of targeted oral anticoagulants: what is the risk?

The vitamin K antagonists (VKAs) are a widely used class of agent to prevent thromboembolism. In recent years, numerous alternatives to VKAs have been developed, the target-specific oral anticoagulants (TSOACs), which are available in clinical practice. Currently available agents target thrombin and factor Xa. The most significant side effect of these agents, as with VKAs, is the development of bleeding complications. In this review, the risks of major bleeding complications with the TSOACs will be discussed. Data from meta-analyses, randomized controlled trials, and observational studies will be used to highlight bleeding complications associated with TSOACs and warfarin. We highlight the most common causes of major bleeding, GI and intracranial hemorrhage.

Guidance on the emergent reversal of oral thrombin and factor Xa inhibitors.

The new oral anticoagulants dabigatran, rivaroxaban and apixaban have advantages over warfarin which include no need for laboratory monitoring, less drug-drug interactions and less food-drug interactions. However, there is no established antidote for patients who are bleeding or require emergent surgery and there is a paucity of evidence to guide the clinical care during these situations. Members of thrombosis and anticoagulation groups participating in the Thrombosis and Hemostasis Summit of North America formulated expert opinion guidance for reversing the anticoagulant effect of the new oral anticoagulants and suggest: routine supportive care, activated charcoal if drug ingestion was within a couple of hours, and hemodialysis if feasible for dabigatran. Also, the pros and cons of the possible use of four factor prothrombin complex concentrate are discussed.

Thrombin generation in haemophilia A patients with factor VIII inhibitors after infusion of recombinant factor VIIa.

BACKGROUND: Development of factor VIII inhibitors is a serious complication in haemophilia A patients. Recombinant factor VIIa (rVIIa) is clinically effective, but its effects on haemostatic system need still to be fully elucidated. MATERIAL AND METHODS: In an open controlled study, we measured thrombin generation (peak thrombin) in venous blood and prothrombin fragment F1 + 2 (F1 + 2) and D-dimer in venous and in shed blood in five haemophilia A patients with inhibitors before and after rVIIa infusion. A total of five healthy individuals who did not receive rVIIa served as controls. RESULTS: At baseline, patients had lower mean (min-max) peak thrombin levels than controls [0.12 (0.0-0.6) vs. 186.9 (116.0-254.4) nM, P = 0.001]. After infusion, peak thrombin levels increased in average to 40.7 (28.3-51.6) nM, which translates into 80.2% (95% CI 65.4-88.6%) lower levels compared to that of controls. Mean (min-max) F1 + 2 levels in venous blood did not differ significantly between patients and controls [160.7 (89.8-331.3) vs. 160.8 (104.4-242.3) pmol L(-1)], but increased in average (min-max) by 39.4% (14.1-58.5%) after infusion. In blood emerging from incisions made to determine the bleeding (shed blood), F1 + 2 levels were lower in patients than controls [1383.3 (906.4-2044.6) vs. 2981.7 (1610.0-4539.6) pmol L(-1); P = 0.04], but were not affected by rVIIa; D-dimer levels were significantly higher in haemophiliacs than in controls and remained unchanged after infusion. CONCLUSIONS: Haemophilia A patients with factor VIII inhibitors have low thrombin generation. After rVIIa, the extent of coagulation activation as measured by levels of F1 + 2 is increased, but thrombin generation is restored to only 20%. Peak thrombin levels could reflect the effects of rVIIa on coagulation mechanisms, and their relevance with regard to the clinical coagulation defect of haemophilia A patients with factor VIII inhibitors might be evaluated.

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.

Health-related quality of life and productivity impact in haemophilia patients with inhibitors.

To measure health-related quality of life (HRQL), its determinants, and its association with patient and caregiver productivity among a sample of haemophilia patients with inhibitors in the United States (US). Data on demographical and clinical characteristics, treatment patterns, HRQL (SF-12v2), and productivity outcomes were reported for 53 patients. Mean SF-12v2 domain and mental (MCS) and physical (PCS) component summary scores were assessed and compared with US norms. Regression analyses explored the association of patient and treatment factors with HRQL and productivity. Patients' mean age was 20.7 years (SD = 18.8), 88.5% were type A, and 39.6% received on-demand therapy as their only mode of treatment. Mean PCS was significantly lower than the US norm (PCS, 39.9, P < 0.01) and mean MCS showed no significant difference (MCS, 49.9, P = ns). On-demand treatment (B = -0.336, P < 0.05) and number of haemorrhages (B = -0.366, P < 0.05) were negatively associated with PCS; and PCS was associated with patients' missed work or school days [incidence rate ratio (IRR) = 0.93, P < 0.001] and perceived impact on daily activities (OR = 0.72, P < 0.05). Younger age (IRR = 0.91, P < 0.01), lower PCS (IRR = 0.94, P < 0.01), more haemorrhages (IRR = 1.05, P < 0.05), and surgery (IRR = 2.74, P < 0.05) were associated with fewer patients' productive days. Physical functioning among inhibitor patients in the US is compromised and is negatively associated with their daily activities and productivity. These data suggest a positive association of prophylactic and immunotolerance therapy with HRQL, specifically physical impairment.

Efficacy of recombinant activated factor VII vs. activated prothrombin complex concentrate for patients suffering from haemophilia complicated with inhibitors: a Bayesian meta-regression.

The optimal on-demand treatment of joint bleeds in haemophilia patients with inhibitors is a source of debate, with studies reporting various efficacy levels for different drugs and dosage regimens. To analyse, in a unified Bayesian meta-regression model, the published efficacy of recombinant activated factor VII (rFVIIa) and/or activated prothrombin complex concentrate (aPCC) as on-demand treatments for joint bleeds in haemophilia patients with inhibitors. A systematic search was carried out to identify studies reporting on dosage and efficacy of rFVIIa and aPCC in the treatment of joint bleeds in the target patient population. Data were abstracted and included in the model and adjusted for potential sources of heterogeneity. Pooled efficacy levels for typical rFVIIa and aPCC regimens were estimated. Seventeen studies, collectively reporting on >2000 joint bleeds, were included. Medication type combined with dosage was the only significant explanatory parameter. The model predicts that a typical regimen of 90 microg kg(-1) rFVII repeated every 3 h if needed results in cumulative joint bleed resolution of 66%, 88% and 95% after 12, 24 and 36 h, respectively. In comparison, a typical regimen of 75 IU kg(-1) aPCC repeated every 12 h if needed results in cumulative joint bleed resolution of 39%, 62% and 76%, respectively. These differences were statistically significant and were also robust in sensitivity analyses. This analysis suggests that a typical rFVIIa regimen will resolve joint bleeds more effectively than a typical aPCC regimen after 12, 24 and 36 h.

Side-effects and venous access issues with immune tolerance therapy.

Immune tolerance therapy (ITT) is the most effective approach to eradicate inhibitors in patients with haemophilia who develop high-titre inhibitors. Yet ITT is associated with many adverse side-effects. Rarely, adverse side-effects arise from the various factor concentrates that patients on ITT receive or from adjuvant immunosuppressive agents used during ITT. Most adverse side-effects of ITT are related to the need for frequent and repetitive venous access, which often results in the need for central venous access devices (CVAD). These devices greatly facilitate the ability to give repeated doses of factor concentrates to patients and are particularly useful in young children who often have small and poorly functioning peripheral veins. These devices can become infected, can malfunction or can lead to venous thrombosis. These complications, although rarely causing mortality, may lead to significant morbidity including the need to have the devices removed and new ones inserted. As well, such CVAD complications may lead to reduced effectiveness of ITT through interruptions in ITT.

Delays in maturation among adolescents with hemophilia and a history of inhibitors.

Inhibitory antibodies to factors VIII or IX have the potential to affect a broad range of outcomes among people with hemophilia; however, their possible effect on growth and maturation has not been explored. We evaluated skeletal maturation (bone age), pubertal progression, serum testosterone levels, height velocity, and stature in the multicenter Hemophilia Growth and Development Study. A total of 333 children and adolescents (mean age, 12.4 years) were enrolled from 1989 to 1990 and followed for 7 years. Of these, 18% (n = 60) had a history of inhibitors. Bone age among HIV(-) adolescents with a history of inhibitors lagged 9 or more months behind those without inhibitors at every age from 12 to 15 years. Those with a history of inhibitors were older at every Tanner stage transition, attained a lower maximum growth velocity, and their serum testosterone levels were significantly lower compared with those without inhibitors. Delays were greater among HIV(+) patients with a history of inhibitors compared with those without inhibitors; however, the differences were generally small and not statistically significant. The results of this investigation underscore the importance of monitoring the growth and maturation of children and adolescents with hemophilia, particularly those with inhibitors.