Inhibitor incidence in an unselected cohort of previously untreated patients with severe haemophilia B: a PedNet study.

The incidence of FIX inhibitors in severe hemophilia B (SHB) is not well defined. Frequencies of 3-5% have been reported but most studies to date were small, including patients with different severities, and without prospective follow-up for inhibitor incidence. Study objective was to investigate inhibitor incidence in patients with SHB followed up to 500 exposure days (ED), the frequency of allergic reactions, and the relationship with genotypes. Consecutive previously untreated patients (PUPs) with SHB enrolled into the PedNet cohort were included. Detailed data was collected for the first 50 ED, followed by annual collection of inhibitor status and allergic reactions. Presence of inhibitors was defined by at least two consecutive positive samples. Additionally, data on factor IX gene mutation was collected. 154 PUPs with SHB were included; 75% were followed until 75 ED, and 43% until 500 ED. Inhibitors developed in 14 patients (7 high-titre). Median number of ED at inhibitor manifestation was 11 (IQR 6.5-36.5). Cumulative inhibitor incidence was 9.3% (95%CI 4.4-14.1) at 75 ED, and 10.2% (5.1-15.3) at 500 ED. Allergic reactions occurred in 4 (28.6%) inhibitor patients. Missense mutations were most frequent (46.8%) overall but not associated with inhibitors. Nonsense mutations and deletions with large structural changes comprised all mutations among inhibitor patients and were associated with an inhibitor risk of 26.9% and 33.3%, respectively. In an unselected, well-defined cohort of PUPs with SHB, cumulative inhibitor incidence was 10.2% at 500 ED. Nonsense mutations and large deletions were strongly associated with the risk of inhibitor development. The PedNet Registry is registered at clinicaltrials.gov; identifier: NCT02979119.

Recombinant factor VIII products and inhibitor development in previously untreated patients with severe haemophilia A: Combined analysis of three studies.

INTRODUCTION: Standard treatment of congenital haemophilia A is based on replacement therapy with coagulation factor VIII (FVIII) products. A major complication of FVIII therapy is the occurrence of IgG alloantibodies (inhibitors) that neutralize FVIII activity. AIM: The aim of the analysis was estimating the risk of high-titre inhibitor associated with the second-generation full-length product compared to third-generation full-length product and other recombinant FVIII (rFVIII). METHODS: We conducted a combined analysis of individual patient data from three large studies in previously untreated patients (PUPs) with severe haemophilia A. RESULTS: A total of 1109 PUPs were treated from 1993 to 2013 including 787 PUPs treated from 2004 onwards (primary analysis cohort). A total of 322 patients (29.0%) developed an inhibitor, of which 192 (17.3%) a high-titre inhibitor. In the primary analysis set, 29.9% of patients developed an inhibitor and 17.2% a high-titre inhibitor. The combined analysis indicated a lower risk of high-titre inhibitor development for the third-generation rFVIII product compared to the second-generation rFVIII product (primary analysis: adjusted hazard ratio (HR) = 0.72, 95% CI: 0.49 to 1.06). Adjusted HR for all inhibitor development was significantly lower for the third-generation product compared to the second-generation product. CONCLUSION: The trend of an increased risk of inhibitor development in PUPs for one recombinant product illustrates that extrapolation from one recombinant factor VIII product to other products might not be justified.

Are routine preoperative liver function tests in patients with uncomplicated symptomatic gallstone disease necessary?

BACKGROUND: The aim of this study was to evaluate the value of preoperative liver function tests (LFTs) in patients with uncomplicated gallstone disease and scheduled for laparoscopic cholecystectomy. METHODS: All 1112 patients who underwent a laparoscopic cholecystectomy for symptomatic gallstone disease during a 6-year cohort were retrospectively reviewed. Only patients who presented with uncomplicated disease were selected. Preoperative LFTs, pre-, and postoperative endoscopic retrograde cholangio pancreaticographies (ERCPs) and postoperative complications were collected. RESULTS: A total of 697 patients were included. There were 629 (90.2%) patients with (group I) and 68 (9.8%) patients without (group II) preoperative LFTs. The incidence of ERCPs, ERCPs positive for bile duct stones, and postoperative complications were not significantly different between groups. Second, Group I patients were divided into four groups: 360 patients with normal LFTs (I-A1), 269 patients with at least one LFT > normal value (I-A2), 531 patients with all LFTs <2× normal (I-B1), and 98 patients with at least one LFT >2× normal (I-B2). More ERCPs were performed in group I-A2 (10%) than in group I-A1 (2.2%) and more in group I-B2 (18.4%) than I-B1 (3.2%), as a consequence of significantly more ERCPs performed preoperatively. No differences were detected between groups regarding ERCPs positive for bile duct stones or postoperative complications. CONCLUSIONS: Preoperative LFTs do not influence the occurrence of postoperative complications nor the total rate of ERCPs in patients undergoing cholecystectomy for uncomplicated gallstone disease. Preoperative determination of LFTs seems to cause a slight shift from post- to preoperative ERCPs without further clinical consequences.

The second Team Haemophilia Education Meeting, 2016, Frankfurt, Germany.

The first Team Haemophilia Education (THE) Meeting was held on 7-8 May 2015 in Amsterdam, The Netherlands. It aimed to promote the optimal care of patients with haemophilia through education of the multidisciplinary treatment team. This was achieved by reviewing the latest developments in haemophilia management, considering how these can be implemented in the clinic to improve patient care and providing a platform for networking and debate for all haemophilia treatment team members. The second THE Meeting was held on 19-20 May in Frankfurt, Germany, and participants included doctors, nurses, physiotherapists, patient representatives and data management staff from 20 different countries. Topics covered the role of the multidisciplinary team in delivering the best haemophilia care, challenges in the management of haemophilia across Europe, available clotting factor treatments, future treatments and the use of genetics in advising carriers of haemophilia. This report is a summary of the key developments in haemophilia care presented by various investigators and healthcare professionals at THE Meeting 2016.

The Fourth Annual Meeting of the International Network for Pediatric Hemophilia: Current Challenges and Recommendations in the Clinical Care of Children with Hemophilia.

The International Network for Pediatric Hemophilia (INPH) comprises a group of physicians committed to the unique care of and challenges facing pediatric hemophilia patients. By collaborating on an international level, extensive experience can be shared on current practice, new trends can be discussed and scientifically valid studies can be developed and performed. The three overall objectives of the group (scientific progress, education and networking) are achieved at each annual meeting starting with a round table on the members' current research and clinical activities, project reports of INPH study initiatives, followed by invited educational presentations and interactive discussions. The meetings close with proposals of new projects, future directions of the group and concluding remarks. The Fourth Annual INPH meeting, held in 2009 in Boston, MA, USA, focused on inhibitor development and hemophilic arthropathy in the clinical care of children with hemophilia.

Aerobic capacity in children with hemophilia.

OBJECTIVE: To determine whether aerobic capacity is normal in boys with different types of hemophilia compared with healthy peers and whether the level of aerobic capacity correlates with the amount of physical activity, joint health status, muscle strength, and anthropometrics. STUDY DESIGN: 47 patients (mean [SD] age, 12.9 [3.2] years; age range, 8.2-17.4 years) from the "Van Creveldkliniek" of the University Medical Center Utrecht, participated. Anthropometry, muscle strength, joint impairment, functional ability, and aerobic capacity were measured. The amount of energy expenditure during daily living was assessed. RESULTS: All boys were able to perform at maximal or near-maximal level on exercise tests, and none of them reported bleeds or other adverse events. Relative peak oxygen, peak heart rate, and peak working capacity were significantly lower compared with healthy control subjects. 30% had Z-scores >2 for weight. Total muscle strength was normal, and almost no joint impairment and no decrease in functional ability were found. CONCLUSION: The aerobic capacity of children with hemophilia is still lower than the normal population, whereas their overall muscle strength is comparable with healthy peers. The functional ability does not differ from healthy peers, and joint health status showed very minor impairments. A substantial proportion of Dutch children with hemophilia was overweight, without showing a reduction in the amount of self-reported physical activities.

Managing the pediatric patient and the adolescent/adult transition.

Healthcare management of the developing child with hemophilia presents several difficulties. Determining the optimum medication dose is complicated by the difficulty of performing pharmacokinetic studies in children and the fact that extrapolation from data collected in adults is generally unsatisfactory. Even when pediatric pharmacokinetic data are available, accumulating evidence suggests that there can be wide interindividual differences; age and size are important contributing factors. Achieving the venous access necessary for blood factor administration is frequently difficult in the small child. Preliminary results suggest that an arteriovenous fistula may be an appropriate option in some patients. Finally, there is the question of whether prophylactic therapy should be discontinued as patients enter adulthood. This article provides insights for managing this challenging patient population.

Cost effectiveness of haemophilia treatment: a cross-national assessment.

The aim of this study was to assess the incremental cost effectiveness of on-demand versus prophylactic haemophilia therapy in Germany, Sweden, the United Kingdom and The Netherlands from the third-party payers' perspective. Using a decision tree model, the cost effectiveness of on-demand versus prophylactic therapy was analysed by extrapolating data from the European Haemophilia Economic Study to a 1-year analytic time horizon. Five hundred and six patients with severe haemophilia A and B, without inhibitors and at least 14 years of age, were enrolled in this study. Patients treated prophylactically had fewer bleeds than patients treated on-demand. With prophylactic treatment, the incremental cost per avoided bleeding ranged from 6,650 Euro dollars for patients 30 years of age or younger in Germany to 14,140 Euro dollars for patients over 30 years old in Sweden. If quality of life was taken into account, patients receiving prophylactic treatment had higher mean utilities than patients on on-demand therapy. The incremental effectiveness ratios in Germany were 1.2 million Euro dollars per quality-adjusted life year gained for patients 30 years or younger and HIV-positive and 2.2 million Euro dollars for patients 30 years or younger and HIV-negative. In the group aged over 30 years and HIV-positive the on-demand treatment strategy was dominant, whereas in the over 30 years/HIV-negative group the incremental cost-utility ratio was 4.7 million Euro dollars per quality-adjusted life year. Based on our decision analysis, the use of prophylactic treatment was overall more effective than on-demand therapy in young haemophiliacs, but at extremely high cost.

Use of implantable venous access devices in children with severe hemophilia: benefits and burden.

BACKGROUND AND OBJECTIVES: Since venous access in small children can be difficult to obtain, implantable venous access devices (IVAD) are used to administer clotting factor in such patients with severe hemophilia. The aim of our study was to evaluate how many children in our center needed an IVAD in order to be able to start early prophylaxis, what the differences were between children who needed an IVAD and those who did not and what the complications of the IVAD were. DESIGN AND METHODS: All 70 patients with severe hemophilia born between January 1987 and October 2000 treated at our center before they were 6 years old were studied. RESULTS: An IVAD was placed in 23 children (33%). Children with an IVAD started prophylactic treatment at a mean age of 2 years (SD 1.3), those without at a mean age of 3.6 years (SD 1.6) (p< 0.001). Home treatment was feasible at a mean age of 2.8 years (SD 1.3) in children with an IVAD and at 4.5 years in those without an IVAD (SD 1.8) (p = 0.001). Infection was the most frequent complication; the mean number of infections per IVAD was 0.61. Thrombosis was more common than initially thought (15%). The infection rate in children with inhibitory antibodies was 3.1 per 1000 patient-days; in children without an inhibitor it was 0.72 per 1000 patient-days. INTERPRETATION AND CONCLUSIONS: In 33% of the children in our cohort an IVAD was needed in order to start early prophylaxis. IVAD are needed more frequently when prophylaxis is started at an early age, but have the advantage that home treatment is feasible earlier. Infection is the most common complication, particularly in children with inhibitors.

Short-term exposure of cartilage to blood results in chondrocyte apoptosis.

Studies have shown that joint bleeding leads to cartilage degradation independent of concurrent synovitis. We hypothesized that the blood-induced cartilage damage is because of increased chondrocyte apoptosis after short-term exposure of whole blood or isolated mononuclear cells plus red blood cells to cartilage. Human cartilage tissue samples were co-cultured for 4 days with whole blood (50% v/v) or with mononuclear cells plus red blood cells (50% v/v equivalents). Cartilage matrix proteoglycan synthesis ((35)SO(4)(2-) incorporation) was determined after 4 days as well as at day 16 (after a 12-day recovery period in the absence of any additions). To test the involvement of apoptosis a specific caspase-3 inhibitor (acDEVDcho, 0 to 500 micro mol/L) as well as a pan-caspase inhibitor (zVADfmk, 0 to 500 micro mol/L) were added. Chondrocyte apoptosis was evaluated by immunohistochemical staining of single-strand DNA and by terminal dUTP nick-end labeling. Cartilage co-cultured with whole blood as well as mononuclear cells plus red blood cells induced a long-term inhibition of proteoglycan synthesis (74% and 78% inhibition on day 16, respectively). Immunohistochemistry showed a threefold increase in apoptotic chondrocytes in cultures with 50% whole blood as well as with mononuclear cells plus red blood cells. Both the specific caspase-3 inhibitor and the pan-caspase inhibitor partially restored proteoglycan synthesis in the cartilage after blood exposure. This effect was accompanied by a decrease in the number of apoptotic chondrocytes. These data suggest that a single joint hemorrhage (a 4-day exposure of cartilage to 50% v/v blood) results in induction of chondrocyte apoptosis, responsible for the observed inability of the chondrocytes to restore the proteoglycan synthesis during recovery from a short-term exposure to blood. This reduced restoration could eventually lead to cartilage degeneration and ultimately joint destruction.

Blood-induced joint damage: longterm effects in vitro and in vivo.

OBJECTIVE: We previously showed that 4-day in vitro exposure of human cartilage to blood, as well as a single experimental joint bleeding in dogs, resulted in a disturbed cartilage matrix turnover lasting at least 2 weeks. We now evaluate the longterm outcome of the adverse in vitro and in vivo effects of blood on cartilage matrix turnover. METHODS: Human and canine articular cartilage tissue was cultured in the presence of homologous whole blood during 4 days. The in vitro cartilage matrix turnover was analyzed directly after blood exposure or following culture for additional periods of 2, 5, and 10 weeks in the absence of blood. The in vivo longterm effects were determined by injecting autologous blood into the right knee of 12 Beagle dogs. Six dogs were killed shortly after blood injections; the 6 remaining dogs were killed 10 weeks later. Cartilage matrix turnover and the cartilage destructive properties of the synovial tissue were analyzed. RESULTS: Short term (4 days) in vitro exposure of human or canine cartilage to whole blood inhibited proteoglycan synthesis by more than 98% (day 4), an inhibition which lasted until week 10 (70 and 75% inhibition, respectively). Also the in vivo short term exposure of cartilage to blood induced the adverse changes in cartilage proteoglycan turnover seen shortly after exposure. However, in vivo 10 weeks after the last injection, normalization of cartilage matrix turnover was observed. Synovial inflammation was absent and no destructive activity was found. CONCLUSION: These data show a discrepancy between the in vitro and in vivo longterm effects of blood on cartilage. A possible explanation for the in vivo recovery after experimental joint bleeding in dogs could be that the observed changes in cartilage only predispose to acute damage but that additional (e.g., mechanical) factors are needed to induce permanent joint damage.

The effects of postponing prophylactic treatment on long-term outcome in patients with severe hemophilia.

To prevent hemophilic arthropathy, prophylactic treatment of children with severe hemophilia should be started before joint damage has occurred. However, treatment is expensive, and the burden of regular venipunctures in young children is high. With the aim of providing information on starting prophylaxis on the basis of individual patient characteristics, the effect of postponing prophylaxis on long-term arthropathy was studied in a cohort of 76 patients with severe hemophilia born between 1965 and 1985. The median age at first joint bleed was 2.2 years (range, 0.2-5.8). Prophylaxis was started at a median age of 6 years (interquartile range [IQR], 4-9), and the median annual clotting factor use on prophylaxis was 1750 IU/kg/y (31 IU/kg/wk). Hemophilic arthropathy was measured by the Pettersson score (maximum, 78 points). At a median age of 19 years, the median Pettersson score was 7 points (IQR, 0-17). After 2 decades of follow-up, the Pettersson score was 8% higher (95% confidence interval, 1%-16%) for every year prophylaxis was postponed after the first joint bleed. This effect was independent of age at Pettersson score, age at first joint bleed, and prophylactic dose used. In conclusion, most patients have their first joint bleed after the age of 2 years. Patients who start prophylaxis soon after the first joint bleed show little arthropathy in adulthood. The longer the start of prophylaxis is postponed after the first joint bleed, the higher the risk of developing arthropathy.