Adherence to prophylaxis and quality of life in children and adolescents with severe haemophilia A.

Treatment adherence in adolescents with chronic diseases is around 50%, and failure is more common in preventive therapy. In haemophilia, contradictory results are reported by the published studies. The objective of this study was to evaluate adherence with factor VIII (FVIII) prophylaxis in Spanish patients with severe haemophilia A between age 6 and 20 years. Data were collected retrosp-ectively in the previous 2 years. The primary endpoint was the absolute adherence index (AAI), and the endpoints were related to clinical status, age, prophylaxis regimen, responsibility for factor administration and quality of life (QoL), assessed by the Haemo-QoL questionnaires. A total of 78 patients from 14 Spanish hospitals were recruited. Adherence ranged between -64.4 and 66.7 (mean -3.08). No differences were observed between children and adolescents (7.11 vs. 6.39; P = 0.809). A statistically significant association (P < 0.010) between infra adherent group and target joint was found, as was a statistically significant difference (P < 0.010) between the number of bleeding episodes experienced by the adherent group (mean 1.4) and by infra adherents (mean 4.5). There was no significant difference between AAI and prophylactic regimen (6.35 vs. 6.96, P = 0.848), neither between AAI and the person responsible for factor administration (5.57 vs. 8.79, P = 0.326). The Haemo-QoL scores (8-12 years) were related to adherence level (P < 0.05). Adherence was approximately ideal and patients perceived a high QoL. Because of the repercussions for compliance, it is essential to work during puberty on emotional and self-acceptance aspects of the disease, as well as coping, and the patient's family, school and health team relationships.

Inhibitor development after switching of FVIII concentrate in multitransfused patients with severe haemophilia A.

Switching between different therapeutic FVIII concentrate types has been postulated as a possible cause of inhibitor development in patient with haemophilia A. In this single-centre, retrospective study, the incidence, titre and duration of inhibitor development in multitransfused patients, defined as patients with more than 150 exposure days (ED), were analysed from January 1970 to December 2007 in relation to ED and the number of switches between different products. Inhibitor titre was assessed by Bethesda assay (before 1998) or Nijmegen assay (after 1998). Medical records of 167 patients were screened, of which 97 patients met the inclusion criteria. Fourteen products of plasmatic origin (different purities) and five recombinant (three generations) were used. Nine patients (9%) developed inhibitors, all transient, low-titre (1.41 ± 0.54 BU) after 323 ± 287 ED in average. Seventeen patients had no product switches of which four patients (23%) developed inhibitors (97 ED in average), whereas 13 patients (77%) did not (ED: 230). Fifty patients switched between plasmatic products only (median: 10 changes) of which five patients (10%) developed inhibitors (ED: 503), whereas 45 patients did not (ED: 932). Five patients switched between recombinant products only (seven changes) of which no patient developed inhibitors (748 ED). Twenty-five patients switched between plasmatic and recombinant products (13 changes) of which no patient developed inhibitors (ED: 1654). No statistically significant differences between patient groups were observed. Neither the number of different FVIII products administered nor the switching of products influenced the incidence of inhibitor in multitransfused patients.

Secondary prophylaxis vs. on-demand treatment to improve quality of life in severe adult haemophilia A patients: a prospective study in a single centre.

BACKGROUND: Retrospective publications show a decrease in the bleeding frequency and an improvement in the quality of life (QoL) in severe adult haemophilia A (SAHA) after switching from the on-demand treatment (DT) to secondary prophylaxis (SP). But there are no prospective studies which demonstrate, using a haemophilia-specific questionnaire, an improvement in the QoL after such treatment change. The main objective of this study is to prospectively compare the QoL and the musculoskeletal assessment after switching from DT to SP in SAHA using the A36 Hemofilia-QoL(®) . As secondary objective, we compare the haemarthrosis frequency and factor VIII consumption in DT and SP during a similar period of time (12 months) after switching. MATERIALS AND METHODS: We have designed a prospective study including SAHA who have been under DT and were changed to a protocol, which combines SP (biweekly administration of factor VIII) with individualized physiotherapy programme. RESULTS: Twelve months after switching to SP, the QoL was significantly improved (P = 0·005). Musculoskeletal assessment of pathologic irreversible joints and joints with a reversible alteration was generally improved, although in only a few joints, this improvement was statistically significant. Haemarthrosis was strongly reduced (12·60-1·42, P < 0·001). CONCLUSIONS: This prospective study has demonstrated a statistically significant improvement in the QoL after 1 year from switching patients from DT to SP. The musculoskeletal assessment after 1 year was maintained similar or slightly improved. When we compared retrospective DT and prospective SP, haemarthrosis where strongly reduced requiring a slight increase in the consumption of factor VIII concentrates.

Comparison of a new chemiluminescent immunoassay for von Willebrand factor activity with the ristocetin cofactor-induced platelet agglutination method.

Measuring von Willebrand factor (VWF) activity is essential for the diagnosis of von Willebrand disease (VWD). The VWF activity is usually assessed based on measurement of the ristocetin cofactor (VWF:RCo). However, that test is technically challenging and has high intra- and inter-assay variabilities. A new automated chemiluminescent immunoassay VWF activity has recently become commercially available (HemosIL AcuStar von Willebrand Factor Ristocetin Cofactor Activity). The main objective of this study was to evaluate this new method and to compare it with the VWF:RCo assay as the reference method. We studied 91 samples, 18 healthy volunteers samples and 73 samples from patients (VWF:RCo level <50 IU dL(-1) ): 29 type 1 VWD, 13 type 2A, 5 type 2B, 5 type 2M, 3 type 2N, 5 type 3, 4 type 3 under treatment, 5 type 3 carriers and 4 samples with other pathologies. The HemosIL AcuStar VWF:RCo assay was 96% sensitive and 100% specific for detecting VWF abnormalities. The good analytical performance, and the sensitivity and specificity of HemosIL AcuStar VWF:RCo to detect VWF deficiency renders it a suitable method for VWD screening.

Head-to-head comparison of the pharmacokinetic profiles of a high-purity factor IX concentrate (AlphaNine®) and a recombinant factor IX (BeneFIX®) in patients with severe haemophilia B.

Head-on comparative studies of factor IX (FIX) concentrates performed under standardized conditions are rarely conducted regardless of being a valuable instrument guiding health care providers towards better informed and cost-effective decisions. This study is an extension of a multicentre study that assessed the efficacy, safety and pharmacokinetics (PK) of AlphaNine(®) in 25 previously treated patients with severe haemophilia B (FIX:C ≤ 2%). After a washout period ≥ 7 days following the last PK performed with AlphaNine(®) after a dose of 65-75 IU kg(-1) , an identical PK study was performed with BeneFIX(®) on 22 of the same patients. Venous blood samples for analysis were taken at baseline and at 0.25, 0.5, 1, 3, 6, 9, 24, 48, 72 and 74 h post infusion. The outcomes of the comparison of the PK parameters were as follows: Mean (± SD) in vivo recovery (IVR) was 1.3 ± 0.4 IU dL(-1) per IU kg(-1) for AlphaNine(®) and 1.0 ± 0.3 IU dL(-1) per IU kg(-1) for BeneFIX(®) (P < 0.01). Mean terminal half-life, mean residence time, area under the curve, clearance and volume of distribution of BeneFIX(®) were 36.0 ± 12.8 h, 39.3 ± 13.9 h, 1631 ± 467 IU h dL(-1) , 0.046 ± 0.01 dL kg(-1) min(-1) and 1.75 ± 0.52 mL kg(-1) respectively. These values were not significantly different to those observed in AlphaNine(®), although BeneFIX(®) displayed higher than expected IVR values and lower than expected clearance values. In conclusion, AlphaNine(®) showed a comparable half-life, but an IVR significantly higher than that of BeneFIX(®). This dissimilarity may have implications on dosing requirements for on-demand treatment regimes affecting optimal resource allocation.

Assessment of the thrombin generation assay in haemophilia: comparative study between fresh and frozen platelet-rich plasma.

The severity of haemophilia A has traditionally been classified by the dosage of factor VIII (FVIII) by one-step coagulation tests. However, an homogeneous group of patients with similar FVIII levels show clinical heterogeneity and 10-15% of the patients classified as severe haemophilia do not have a severe bleeding phenotype. Traditional tests used for measuring FVIII are not capable of detecting other prohaemorrhagic or prothrombotic factors. Global tests as the thrombin generation assay (TGA) may detect these haemostatic factors. So TGA may be an additional tool for classifying the actual severity of haemophilia. Our group is carrying out correlation tests between FVIII and TGA in platelet-poor and -rich plasmas (PPP and PRP, respectively). PRP has the inconvenience that must be done freshly soon after blood extraction. Our aim is to study the differences between TGA performed with fresh and frozen PRP and PPP and its implementation in multicenter studies. We included 70 patients with severe haemophilia A in prophylactic treatment. Venous blood drawing was obtained prior to administration of FVIII, at the trough levels. FVIII measurement and TGA were performed in fresh and frozen PRP and PPP. The platelet absence caused a significant decrease in TGA although PPP and PRP correlated well. Frozen samples gave different results in PPP, but there were no significant differences between fresh and frozen PRP. This fact enables using frozen PRP in multicenter studies with a TGA-specialized laboratory for reclassifying haemophilia severity and for pharmacokinetic studies with TGA.

Kinetics of the interaction between anti-FVIII antibodies and FVIII from therapeutic concentrates, with and without von Willebrand factor, assessed by surface plasmon resonance.

The presence of VWF in plasma-derived FVIII (pdFVIII/VWF) products has been pointed out as a key difference with recombinant FVIII (rFVIII) products with regard to immunogenicity. A Surface Plasmon Resonance (SPR) study was designed to characterize in detail the interaction between anti-FVIII (IgGs) from a severe haemophilia A patient, and FVIII from concentrates of different sources. Full-length rFVIII (preincubated or not with purified VWF), B domain-deleted (BDD)-rFVIII and pdFVIII/VWF were analysed. To ensure reproducible conditions for accurate determination of kinetic constants, a capture-based assay format was developed using protein G surfaces for specific and reversible coupling of endogenous anti-FVIII antibodies. Concentration ranges (nm) of FVIII products tested were 9-0.03 (rFVIII) and 6-0.024 (pdFVIII/VWF). The association with antibodies was monitored for 3-5 min, whereas dissociation of the complex was followed for 5-20-240 min. A strong interaction of rFVIII and BDD-rFVIII with patient's IgG was detected with the K (D) values in the low picomolar range (5.9 ± 3.0 and 12.7 ± 6.9 pm, respectively) and very slow dissociation rates, while pdFVIII/VWF showed only marginal binding signals. The VWF complexed rFVIII displayed reduced binding signals compared with uncomplexed rFVIII, but the K (D) was still in the picomolar range (4.1 ± 1.9 pm) indicating insufficient complex formation. rFVIII, alone or bound to exogenously added VWF, showed high affinity for anti-FVIII IgGs from a severe haemophilia A patient whereas pdFVIII/VWF did not. These results are in agreement with those studies that point towards rFVIII concentrates to be more immunogenic than pdFVIII concentrates.

Is on-demand treatment effective in patients with severe haemophilia?

On-demand therapy enables stopping haemorrhages rapidly, reducing joint pain and restoring joint mobility, but does not prevent the beginning and subsequent development of haemophilic arthropathy. The main objective of this study was to identify the clinical and orthopaedic status of severe haemophilic patients with bleeding phenotype receiving on-demand treatment in Spain. We conducted an epidemiological, observational, retrospective study, recruiting 167 patients from 36 centres (92% of them with haemophilia A), median age at enrolment of 35 years. Forty per cent of the patients received a combination of on-demand and short-term prophylaxis regimen; the rest was under on-demand treatment. One hundred and forty-five patients (87%) reported at least one bleeding episode and 22 (13%) of the biologically severe patients had no bleeding phenotype. Seventy-one per cent of the studied population presented established haemophilic arthropathy, reaching 80% if we exclude patients without bleeding phenotype. Forty-three per cent of these patients had one or two joints affected, 28% of them had three or four affected joints, 20% reported five or six affected joints and 9% more than six injured joints. An increase in established haemophilic arthropathy with age was observed. Forty-six patients underwent orthopaedic surgery at least once. These data show that on-demand therapy is not effective in preventing the development of haemophilic arthropathy in severe haemophilic population with bleeding phenotype. Therefore, we suggest that the optimal treatment in these patients should be based on prophylaxis. We recommend analysing the reasons for ending prophylaxis, in case its reinstatement should be necessary.

Joint protection in haemophilia.

Haemarthroses (intra-articular haemorrhages) are a frequent finding typically observed in patients with haemophilia. Diagnosis and treatment of these bleeding episodes must be delivered as early as possible. Additionally, treatment should ideally be administered intensively (enhanced on-demand treatment) until the resolution of symptoms. Joint aspiration plays an important role in acute and profuse haemarthroses as the presence of blood in the joint leads to chondrocyte apoptosis and chronic synovitis, which will eventually result in joint degeneration (haemophilic arthropathy). Ultrasonography (US) is an appropriate diagnostic technique to assess the evolution of acute haemarthrosis in haemophilia, although magnetic resonance imaging remains the gold standard as far as imaging techniques are concerned. Some patients experience subclinical haemarthroses, which eventually tend to result in some degree of arthropathy, especially in the ankles. Nowadays, the most effective way of protecting these patients is primary prophylaxis, which in practice changes severe haemophilia into moderate haemophilia, preventing or at least minimizing the occurrence of haemarthrosis. If primary prophylaxis is, for whatever reason not an option, secondary prophylaxis and enhanced on demand treatment should be considered. Two alternatives are available for inhibitor patients: (i) control of haemostasis using by-passing agents (rFVIIa or aPCCs) either as enhanced on demand treatment or secondary prophylaxis, as appropriate, following the same basic principles used for non-inhibitor patients and (ii) immune tolerance induction (ITI) to eradicate the inhibitor.

A clinical study assessing the pharmacokinetics, efficacy and safety of AlphaNine(®) , a high-purity factor IX concentrate, in patients with severe haemophilia B.

Effective treatment with factor IX (FIX) requires a thorough consideration of the properties of the concentrate to be used as replacement therapy, to date, the only available treatment for haemophilia B. The aim of the study was to determine the pharmacokinetics, clinical efficacy and safety in routine clinical use of AlphaNine(®) , a high-purity human FIX concentrate. This open, single-arm, multicentre, non-randomized trial included 25 subjects (age ≥ 12) with moderate/severe haemophilia B. Pharmacokinetics was assessed at baseline and after a 6-month follow-up. The degree of haemostasis control achieved was evaluated during a 12-month follow-up. Safety was evaluated in terms of tolerance, thrombogenicity, immunogenicity and viral safety. Mean recovery was 1.01 ± 0.19 IU dL(-1) per IU kg(-1) at baseline and 1.23 ± 0.34 IU dL(-1) per IU kg(-1) 6 months later. Terminal half-life was 34.5 ± 6.2 h and 33.7 ± 5.4 h, respectively. Ratios of each parameter between the two pharmacokinetic studies were all close to 1. A total of 1,576,890 IU AlphaNine(®) were administered in 889 infusions (mean dose per infusion: 1774 IU; 3.2 infusions per month per patient). The main reasons for infusion were mild/moderate bleeding (62.3%) and prophylaxis (20.5% continuous, 15.6% intermittent). Overall, 93.0% of the efficacy assessments were rated as excellent/good and 88.8% of bleedings resolved after the first infusion. Twenty-one adverse events were reported in eight patients, none of which was considered related to the study medication. AlphaNine(®) showed a pharmacokinetic profile in agreement with that of other plasma-derived FIX concentrates and provides safe and clinically effective substitution therapy for patients with haemophilia B.

Prophylaxis therapy in haemophilia A: current situation in Spain.

The Spanish Epidemiological Study in Haemophilia carried out in 2006 enrolled 2400 patients [2081-86.7% with haemophilia A (HA) and 319-13.3% with haemophilia B]; 465 of them (19.4%) were on prophylaxis. These rates were higher in patients with severe haemophilia (45.4%) and severe paediatric cases (72.5%). On the basis of information recorded in this study, we analysed the current situation of prophylaxis therapy administered to patients with HA in Spain, as well as their orthopaedic status. Prophylaxis was used in 399 (19.2%) patients with HA; such prophylaxis was primary (PP) in 20.3% and secondary (SP) in 75.9% of cases. Among severe HA patients, 313 (45.9%) were on prophylaxis (22.3% on PP and 74.7% on SP). Taking into account the patients' age, 34.7% of severe HA adults were on prophylaxis (6% PP and 92.1% SP), whereas 71.5% of severe HA paediatric patients (40.5% PP and 55.4% SP) received this kind of treatment. Established haemophilic arthropathy (EHA) was detected in 142 from 313 severe HA patients (45.3%) on prophylaxis, but only in 2.9% of patients under PP vs. 59% of patients receiving SP. There was no EHA in adult severe HA patient on PP, whereas 70.4% on SP had joint damage (P < 0.00001). Among paediatric severe HA patients, EHA was detected in 3.3% under PP and 37.8% under SP (P < 0.00001). In conclusion, our data suggest that an early initiation of prophylaxis avoids EHA in the long-term in patients with severe HA. We should emphasize the early onset of prophylaxis regimens.

Pharmacokinetic study of a high-purity factor IX concentrate (Factor IX Grifols) with a 6-month follow up in previously treated patients with severe haemophilia B.

Optimal replacement treatment in haemophilia B patients requires a good understanding of the pharmacokinetics of factor IX (FIX). The aim of this study was to compare the pharmacokinetic profile of Factor IX Grífols, a highly purified human FIX concentrate with two specific pathogen inactivation/removal steps, to that of available FIX preparations. The study was an open, non-randomized trial including 25 male subjects older than 12 years of age with severe haemophilia B. Pharmacokinetic profile of the FIX preparation regularly used by the subjects was determined as control. Pharmacokinetic profile of Factor IX Grifols was determined twice, one 7-15 days after control assessment and second after a 6 months period had elapsed. Results showed that all products had peak plasma levels of FIX:C within 30 min. Mean recovery was 1.3 +/- 0.3 IU dL(-1) per IU kg(-1) for Factor IX Grifols and 1.0 +/- 0.3 IU dL(-1) per IU kg(-1) for control products (P < 0.001). The mean terminal half-life (t(1/2)) for Factor IX Grifols was 26.7 h and 26.8 h for control product. Pharmacokinetic parameters after 6 months of treatment with Factor IX Grifols did not statistically differ from the parameters obtained with the first infusion. There were no adverse events related to Factor IX Grifols for the duration of the study. In conclusion, Factor IX Grifols has adequated pharmacokinetic properties comparable to the control plasma-derived FIX and these parameters remain stable after 6 months of treatment. Factor IX Grifols can be an effective and safe plasma-derived FIX concentrate for replacement therapy in haemophilia B patients.

Haemophilia in Spain.

To determine the prevalence of haemophilia A and B and their complications in Spain, and to characterize the health care network providing support to haemophiliac patients. The study examines clinical and genetic characteristics, treatment options, and complications observed during the course of the disease. Cross-sectional multi-centre study. The study population were patients with HA and HB in active follow-up at any Spanish hospital by December 2006. We studied 2400 haemophiliacs, 2081 (86.7%) HA and 319 (13.3%) HB patients. Illness was severe in 32.3% of patients, moderate in 16.4%, and mild in 51.3%. Genetic screening was carried out in 32.6% of the patients. Treatment administered in 2006 consisted of coagulation factor concentrates in 60% of patients. Until December 2006, 45.8% of severely ill patients were taking prophylaxis. The mean number of bleeding episodes in 2006 was four for patients not receiving primary prophylaxis and 1.3 for those taking primary prophylaxis. Thirty percent of patients had established haemophiliac arthropathy in at least one joint; 16.8% of patients were HIV-infected and 34.8% HCV-infected. Inhibitors were detected in 10% of severe HA patients and in 6.5% of severe HB patients. Immune tolerance induction therapy was started in 34 patients. This is the first comprehensive study on the epidemiology of haemophilia in Spain. It will enable us to draw comparisons with neighbouring countries, to assess the quality of care provided to haemophiliacs in Spain, and to provide evidence-based guidance for the even provision and improvement of such care.

Exercise and sport in the treatment of haemophilic patients: a systematic review.

In haemophiliacs, the physical condition, muscular strength, aerobic resistance, anaerobic resistance and proprioception have all diminished. Muscle atrophy and instability, being more vulnerable to stressful motor demands, increase the risk of lesion and establish a vicious circle that is hard to break: pain, immobility, atrophy, articular instability and repeated bleeding episodes. In haemophilia, physical and/or sporting activities were not recommended until the seventies. Nowadays, the overall policy is to recommend certain physical activities, especially swimming, to improve the patient's quality of life, thanks to prophylaxis programmes. The objective of this study is to perform a systematic review of the exercise and sporting activities recommended for haemophiliacs. Experimental and observational studies and clinical assays about rehabilitation for haemophiliacs with exercise and sporting activities have been included. The relevant studies were identified in Medline, Cinahl, Embase and SportDiscus, and key words were: haemophilia, exercise and sport (with no language restrictions). Works were independently analysed by reviewers and the following were identified: of 3603 studies, 103 were included in this review: 29 (28.15%) were experimental, 27 (26.21%) were observational and 47 (45.63%) were clinical. Physiotherapy, physical activity and sport are basic elements to improve quality of life and the physical condition, increase strength and resistance and to reduce the risk of musculoskeletal lesions and to prevent haemophilic atrophy. In general, professionals in haemophilia believe that regular exercise and rehabilitation with physiotherapy is fundamental, particularly in countries where replacement therapy is not readily available.