Real‐world comparative analysis of bleeding complications and health‐related quality of life in patients with haemophilia A and haemophilia B

Introduction

Clinical severity and impact of haemophilia on quality of life have been generally considered to be lower for haemophilia B (HB) compared with haemophilia A (HA) patients.

Aims

To compare annual bleeding rate (ABR), target joint development and health‐related quality of life (HRQoL) between adult (≥18 years) severe HA and HB patients using recent data from the Cost of Haemophilia in Europe: a Socioeconomic Survey (CHESS) study.

Methods

Multivariate generalized linear models (GLM) were constructed to assess the relationship between haemophilia type, ABR, HRQoL (derived from EQ‐5D index scores) and the presence of target joints while controlling for covariates.

Results

Of the 1225 patients included, 77% (n = 949) had HA and 23% (n = 278) had HB. Of the 514 patients who completed the EQ‐5D, 78% (n = 405) had HA, and 22% (n = 110) had HB. Unadjusted mean ABR was 3.79 in HA and 4.60 in HB. The presence of ≥1 target joint was reported in 59% and 54% of patients with HA and HB, respectively. Unadjusted mean EQ‐5D index score was 0.78 in HA and 0.76 in HB. Haemophilia type was not a significant predictor of ABR, target joints or HRQoL when adjusted for confounding factors such as BMI, age and replacement therapy regimen.

Conclusion

Data suggest comparable ABR, incidence of target joints and HRQoL between patients with HB and HA indicating comparable clinical severity and disease impact on patient quality of life.     

Adherence to prophylaxis is associated with better outcomes in moderate and severe haemophilia: results of a patient survey

Severe haemophilia is associated with bleeding into joints and development of arthropathy. Prophylactic treatment with infusion of replacement clotting factor is known to prevent bleeding, preserve joint functioning and result in higher health‐related quality of life (HRQoL) than episodic treatment; however, adhering to standard prophylaxis schedules can be difficult, and little is known about the relationship between adherence to prophylactic treatment and outcomes. The aim of this study was to assess the relationship between self‐reported adherence to prophylaxis and health outcomes, including HRQoL and bleeding episodes. Adults with haemophilia (n = 55) and caregivers of children with haemophilia (n = 55) in Australia, Canada, and the United States completed an online questionnaire which included measures of HRQoL (SF‐12v2 for adults and SF‐10 for caregivers of children), self‐reported bleeding episodes, and the VERITAS‐Pro measure of adherence to prophylaxis in haemophilia. Regression analysis was used to test the association between VERITAS‐Pro total score and outcomes. Poorer adherence (higher VERITAS‐Pro scores) was associated with a greater number of self‐reported bleeding episodes in the past year among adults (p < 0.01), more days of work/school missed among paediatric patients (p < 0.01), and lower physical health status scores among paediatric patients (p < 0.05). This study highlights the benefits of adherence to prophylaxis among those with severe haemophilia and provides evidence for the utility of the VERITAS‐Pro by demonstrating a relationship between adherence and outcomes.     

Social determinants and health‐related dimensions of quality of life in adult patients with haemophilia

The availability of safe and effective factor replacement therapies, in persons with haemophilia (PWH), has in some countries answered the basic need for treatment of these patients. The findings suggest that adult patients who have always been on prophylaxis reported significantly better physical functioning, and thus better quality of life. This study is designed to evaluate the QoL in adult PWH, by focusing on social determinants of QoL and their relationship with health‐related dimensions, in Tabriz, Iran. The survey instrument was a self‐report 36 items questionnaire, ‘A36 Hemofilia – QoL’, which is a disease‐specific questionnaire for the assessment of the health‐related QoL in adults living with haemophilia. A total of 100 haemophilia A and B patients, aged over 17 years participated in this study within 1 year. QoL total score was 71.88 (±26.89 SD). Patients who treat in our Hemophilia Treatment Center, had better QoL score (P = 0.000), and education has a significant impact on the social aspects of QoL (P = 0.18). The QoL was very poor in urban area in contrast to patients who lived in the city (54.45 vs. 74.21 respectively). Single patients have a better QoL than married patients (76.56 vs. 68.50 respectively). Our results showed that low education and lack of awareness of the diseases among PWH lead to reduce of QoL and more disease complications. More and wider treatment and psychological care for improving quality of life of these patients are seriously recommended.     

Prophylaxis therapy in haemophilia A: current situation in Spain

Summary. 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.     

The impact of a specific aqua-training for adult haemophilic patients - results of the WATERCISE study (WAT-QoL)

Summary. Sport is increasingly recommended for haemophilic patients due to physical and psychological benefits. ‘WATERCISE’ is a specific aqua‐training programme for haemophiliacs in which endurance, strength, coordination and mobility are trained. In the WAT‐QoL study benefits and risks of regular WATERCISE training sessions were investigated in terms of health‐related quality of life (HRQoL), physical functioning (PF), orthopaedic joint status (OJS), bleeding frequency and factor consumption. Patients in the WATERCISE group attended an aqua‐training programme once a week for 1 h over 12 months, patients in the control group did not. Patients were matched for clinical and demographic data. Information on clinical data, orthopaedic status, PF (HEP‐Test‐Q) and HRQoL were collected in both groups at baseline and at follow‐up (6 and 12 months). Twenty‐eight adult severely affected haemophilic patients (WATERCISE group: 10 haemophilia A (HA), 3 haemophilia B (HB) patients; control group: 12 HA and 3 HB patients) were enrolled (aged 40.68 ± 12.7 years). Baseline data (body mass indices, OJS, sportive activities, HRQoL and PF) were well distributed between groups. After 12 months the WATERCISE group reported a significantly better PF (M_W = 65.22, SD = 11.3; M_C = 52.5, SD = 15.0), especially for endurance (P < 0.004). Although always differently reported by the patients within the WATERCISE group, HRQoL did not prove to be significantly different between groups. WATERCISE seems to have a positive effect on the PF of patients suffering from haemophilia. These study findings need to be further investigated in a larger study group.     

Trends in the epidemiology,diagnosed age and mortality rate of haemophiliacs in Taiwan: a population‐based study, 1997–2009

Many studies on epidemiology and mortality in haemophiliacs have been published in Western countries. However, few have been conducted in Asian countries. The purpose of our study was to investigate the nationwide epidemiology and mortality of haemophiliacs in Taiwan. Population‐based data from the National Health Insurance Research Database between 1997 and 2009 were analysed using SAS version 9.3. The annual prevalence of haemophilia A (HA) and haemophilia B (HB) increased steadily to 7.30 and 1.34 cases per 100000 males, respectively, in 2009. The annual crude incidence of HA and HB averaged 8.73 and 1.73 per 100000 male births respectively. During the study period, the proportion of paediatric haemophiliacs decreased from 41.5% to 28.2% and the proportion of geriatric haemophiliacs increased from 2.5% to 5.7%. Among 493 newly diagnosed cases, the peak diagnostic ages were before 3 and between ages 10 and 40. Of the 76 cases of mortality, most patients died between the ages of 18 and 60. However, an increase in the age of mortality was noted after 2005 (P = 0.033). The overall standardized crude death rate of haemophiliacs was 10.2 per 1000 people, and the standard mortality ratio was 1.98. The annual prevalence of human immunodeficiency virus infection in haemophiliacs grossly declined from 1998 to 2009, with an average of 32.2 per 1000 haemophiliacs. This was a rare population‐based study on the epidemiology and mortality of haemophilia in a Chinese population and Asian countries. The 13‐year trends showed advances in haemophilia care in Taiwan.     

Comparing bleed frequency and factor concentrate use between haemophilia A and B patients

Summary. Haemorrhagic manifestations in patients with haemophilia A and B are considered quite similar for comparable level of factor deficiency. We investigated the bleeding frequency and factor usage between HA and HB patients with comparable disease severities. We collected data on frequency of bleeds and factor concentrate utilization over 3 years, from January 2001 to December 2003. Information was gathered from home infusion logs recorded by patients or their parents, and treatment records from the Hemophilia Clinic or the Hospital Emergency Department. Data were available on 58 patients with severe HA (FVIII < 0.01 U mL^?1), 10 with moderate HA (FVIII < 0.05 U mL^?1), 15 with severe HB, and five with moderate HB who required treatment for episodic bleeds, postoperative haemostasis and for primary or secondary prophylaxis. The HA patients bled more frequently than HB patients (14.4 vs. 8.63 bleeds/patient/year), but used similar amounts of concentrate per year. HA patients underwent surgical procedures 3.2 times more frequently than HB patients to correct musculoskeletal complications. A total of 21 363 409 IU of recombinant FVIII was used by patients with HA (104 722 IU/patient/year) and 6 430 960 IU of recombinant factor IX, by patients with HB (107 182 IU/patient/year). The difference in factor concentrate usage is not statistically significant (P > 0.05). The decrease in bleed frequency in haemophilia B indicates that the conclusions from randomized trials of prophylaxis in HA may not be accurately applied to HB.     

The impact of haemarthropathy on the QoL of Korean severe haemophilia A patients: the critical level of haemarthropathy for the QoL

The minimum goal of secondary prophylaxis may be to delay the progression of haemarthropathy below a critical level over which it has a great impact on the QoL of haemophilia patients. However, the critical level of haemarthropathy may be different across countries. For these reasons, the impact of haemarthropathy on the QoL in Korean haemophilia A patients was investigated. Depending on observed Pettersson scores of 27 severe haemophilia A patients, they were divided into three groups, P (Pettersson score) ≤10, P11~19 and P ≥ 20 groups. The QoL of each patient, assessed by the SF36, was compared between the groups. In addition, the changes in the QoL of the patients were observed according to the changes of Pettersson scores to find out the critical level of arthropathy. None of the scores of the SF36 scales were different between the P ≤ 10 and P11~19 groups. In contrast, the scores of PF and MH scales were significantly different between the P11~19 and P ≥ 20 groups. When changes in the scores of each scale in the SF36 were observed according to changes in Pettersson scores, the average P score of 13.0 ± 2.7 was thought to be the critical level of haemarthropathy because above that level, haemarthropathy and physical and mental health of the patients rapidly deteriorated. The progression of haemarthropathy to the critical level should be delayed as long as possible to prevent or to delay a rapid deterioration of the QoL of Korean patients with haemophilia.     

Goal Attainment Scaling for haemophilia (GAS‐Hēm): testing the feasibility of a new patient‐centric outcome measure in people with haemophilia

Introduction

To address the need for a patient‐reported outcome that can measure clinically and personally meaningful change in people with haemophilia (PwH) on prophylaxis, an approach based on Goal Attainment Scaling (GAS) was developed: the GAS‐Hēm.

Aim

To establish real‐world feasibility of GAS‐Hēm in PwH.

Methods

Patients aged 5‐65 years were enroled from four North American centres for a 12‐week study. The primary outcome was the proportion of participants who completed GAS‐Hēm interviews at baseline, 6 and 12 weeks. GAS‐Hēm scores were obtained by subject‐ and clinician‐rated goal attainment at Weeks 6 and 12, and compared with quality of life (QoL) measures and annualized bleed rate (ABR) for construct validity. Goals were evaluated qualitatively for content validity. Responsiveness was calculated using standardized response means (SRM).

Results

Forty‐two participants set 63 goals. Participants preferred to define (37/63) their own goals or further individualize (23/63) from the GAS‐Hēm menu. Thirty of the 37 self‐defined goals were matched to goals on the GAS‐Hēm menu. The most common goal areas were: weight, exercise and nutrition (n = 17); leisure activities (n = 8); and joint problems (n = 7). Both participant‐ and clinician‐rated GAS‐Hēm scores at 6 weeks (n = 40) and 12 weeks (n = 41) demonstrated satisfactory goal attainment (SRM [subject‐rated] at 12 weeks for adult and paediatric groups was 1.25 and 1.16, respectively). Correlations of GAS‐Hēm scores with QoL measures and ABR were uniformly small.

Conclusion

GAS‐Hēm was feasible and tapped constructs not captured by ABR or QoL measures.     

Long‐term outcomes in haemophilic synovitis after radiosynovectomy using rhenium‐186: a single‐centre experience

Radiosynovectomy has been performed successfully for more than 10 years in our hospital. This study investigated the long‐term outcome in the context of time to progression (TTP) analysis and the factors influencing TTP following radiosynovectomy with Re‐186 in patients with haemophilic synovitis. Radiosynovectomy performed in 165 joints (81 elbows, 74 ankles, 8 shoulder and 2 hip joints) of 106 patients (median age was 18.0 ± 7.5 years; 91 haemophilia A, 13 haemophilia B and 2 von Willebrand's disease between June 2001 and July 2011. The mean follow‐up was 48 months (range: 9–120 months). This study revealed that patients' mean TTP after primary radiosynovectomy was satisfactory for both the ankle and elbow joints. There was no TTP differences between the ankle and elbow joint groups (67 vs. 72 months respectively; P = 0.22). We did not find a relationship between the TTP and the following variables: age, type and severity of haemophilia, the presence or absence of inhibitor, the radiological score, range of motion (ROM) status of joints and the pretreatment bleeding frequency. In this study, 18–20% of the treated joints had improved ROM and 82–79% of the treated joints had unchanged ROM after treatment both the ankle and elbow joints respectively. In this report including TTP analysis in the largest series with long‐term follow‐up, we demonstrated long‐term effectiveness of Re‐186 radiosynovectomy in haemophilic synovitis. In our experience, the main predictor of outcome following radiosynovectomy is the number of joint bleeding within 6 months after therapy.     

Quadriceps strength,inter‐extremity difference (IED) and joint status in adult persons with severe haemophilia in different age stages

Quadriceps weakness seems to be a hallmark in adult persons with severe haemophilia (PWH). The purpose of this study was to compare PWH and non‐haemophilic controls in different age stages with reference to joint status and quadriceps strength. Further aims were to examine the extent of strength‐specific inter‐extremity‐difference (IED) and the prevalence of abnormal IED (AIED). A total of 106 adults with severe haemophilia (H) and 80 controls (C) had undergone an orthopaedic examination for classification of knee and ankle status using the WFH score. Quadriceps strength was evaluated unilaterally as well as bilaterally with a knee extensor device. Each group was divided into four age‐related subgroups (HA/CA: 18–29, HB/CB: 30–39, HC/CC: 40–49, HD/CD: 50–70; in years). H presented a worse knee and ankle status than C indicated by higher WFH scores (P < 0.01). Regarding the age‐matched subgroups only HB showed higher knee scores than CB (P < 0.05). The ankles were clinically more affected in HB‐HD compared with those in age‐matched controls (P < 0.05). H showed lower quadriceps strength than C (P < 0.05). In addition, all subgroups of H presented lower strength (HA: 10–17, HB: 19–23, HC: 35–36, HD: 53–61; in%, P < 0.05). IED was higher in H than in C [H: 12.0 (5.3/32.2) vs. C: 7.1 (2.9/10.9); Median (quartiles) in%, P < 0.001] and increased with age in H. We discovered an AIED in 35% of H. These findings highlight the importance for the early implementation of preventive and rehabilitative muscle training programmes in the comprehensive treatment of PWH.     

Prophylaxis with FEIBA in paediatric patients with haemophilia A and inhibitors

The benefits shown with factor VIII (FVIII) prophylaxis relating to joint health and quality of life (QoL) provide the rationale for FEIBA prophylaxis in haemophilia A patients with persistent FVIII inhibitors. FEIBA has previously shown efficacy in preventing bleeds in inhibitor patients who failed to respond to, or were ineligible for immune tolerance induction (ITI). The study examined the outcome of paediatric patients undergoing long‐term FEIBA prophylaxis. A retrospective chart review included severe haemophilia A patients with persistent inhibitors aged ≤13 years at the start of FEIBA prophylaxis. Baseline characteristics captured dose, frequency of prophylaxis, history of inhibitor development, including baseline titre, historical peak titre and history of ITI. Outcome measurements included annual bleed rate before and during FEIBA prophylaxis, joint status and school days missed. Sixteen cases of FEIBA prophylaxis from two centres are presented. The mean age of subjects at prophylaxis initiation was 7.5 ± 3.6 years and median baseline inhibitor titre was 23 (range 3.1–170) BU. Prior to prophylaxis initiation, median annual joint bleeds among all patients was 4 (0–48), which dropped significantly after the first year of prophylaxis, to a median annual joint bleed rate of 1 (0–7; P = 0.0179). Subsequent years (median = 9) of prophylaxis therapy demonstrated similarly low annual joint bleed rates. There were no life‐threatening bleeds, no viral seroconversions or thrombotic events during FEIBA prophylaxis treatment. FEIBA prophylaxis was effective for preventing joint bleeds and subsequent joint damage, delaying arthropathy and improving outcomes in children with haemophilia A and inhibitors to FVIII, who failed or were ineligible for ITI.     

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.     

Improvement in health‐related quality of life with recombinant factor IX prophylaxis in severe or moderately severe haemophilia B patients: results from the BAX326 Pivotal Study

Little is known about the health‐related quality of life (HRQoL) burden of haemophilia B. The aim of this study was to assess HRQoL burden of haemophilia B, the benefit of recombinant factor IX (rFIX) prophylaxis and the HRQoL benefit of achieving a zero annual bleed rate. Subjects receiving rFIX (BAX326) prophylaxis or on‐demand completed the SF‐36 survey. Baseline SF‐36 scores were compared to the general US population scores to understand the HRQoL burden. Changes in SF‐36 scores between baseline and follow‐up were tested using t‐tests. Subgroup analysis was conducted to examine SF‐36 change among subjects who switched to BAX326 prophylaxis. SF‐36 scores were also compared between those with zero bleeds and those who bled during the study. Compared to the US norms, subjects reported lower average scores in all physical and several mental HRQoL domains. At follow‐up, prophylaxis subjects reported statistically significant and clinically meaningful improvements in overall physical HRQoL, as measured by the Physical Component Score (PCS) (mean change 2.60, P = 0.019), Bodily Pain (BP) (3.45, P = 0.015) and Role Physical (RP) domains (3.47, P = 0.016). Subjects who switched to prophylaxis from intermittent prophylaxis or on‐demand experienced more pronounced improvements not only in the PCS (3.21, P = 0.014), BP (3.71, P = 0.026), RP (4.43, P = 0.008) but also in Vitality (3.71, P = 0.04), Social Functioning (5.06, P = 0.002) and General Health domains (3.40, P = 0.009). Subjects achieving zero bleeds reported lower BP (P = 0.038). Prophylaxis with BAX326 significantly improved HRQoL in patients with moderately severe or severe haemophilia B by reducing bleeds.     

Progression of haemophilic arthropathy in children: a Lithuanian – Danish comparative study

Recurrent bleeding into joints initiates a sequence of events leading to a progressive joint damage in people with severe haemophilia. This is a continuous process during childhood and adolescence, therefore joint abnormalities may be minimal on physical examination in very young children – even those receiving on‐demand treatment. The aim of our study was to quantify the burden of arthropathy in Lithuanian patients who had been treated exclusively by on‐demand substitution and compare their physical joint health with age‐matched Danish patients who received prophylaxis from an early age. Boys, aged 4–17 years, with severe haemophilia and no signs of inhibitors were included in the study. Joint outcome based on the Haemophilia Joint Health Score (HJHS) was analysed in two different treatment groups and compared within the matched pairs. In total, 32 (16 in each treatment group) patients were enroled. A total of 192 joints were evaluated. Joint status according to treatment strategy was strikingly different: 27.4 for on‐demand vs. 3.3 for prophylaxis (<0.001) group. Significance of the difference in joint status comparing different treatment strategies was equally strong both in younger (4–9 years) and older (10–17 years) patient groups: 2.2 vs. 12.5 (P = 0.0002) and 3.9 vs. 36.3 (P < 0.0001) respectively. The results further demonstrate the unequivocal effect of prophylaxis on joint status and give an insight into early and late manifestations of joint impairment based on the HJHS in haemophilia patients with treatment on‐demand compared with joint changes that may develop over the time with the preventative treatment.     

Influence of medical insurance schemes and charity assistance projects on regular prophylaxis treatment of the boys with severe haemophilia A in China

Objective

To explore the influence of medical insurance policy and charity assistance projects on the uptake and discontinuation of regular prophylaxis treatment in Chinese severe haemophilia A children.

Methodology

This retrospective study was conducted on children with severe haemophilia A, who received FVIII prophylaxis treatment at 12 haemophilia centres in China from 1 November 2007 to 31 May 2013.

Results

The average duration of prophylaxis treatment received by haemophilia children significantly increased from 16.7 weeks in 2008 to 32.8 weeks in 2012 (P < .001). The main reason for prophylaxis acceptance included dissatisfaction with previous “on‐demand” regimens, availability of improved local medical insurance policies and patient/family awareness of haemophilia. The main reason for subsequent discontinuation of prophylaxis was economic instability. The upper limit of insurance was up to RMB 150 000/y (~USD: 22 000/y) for 80.1% of the insured patients and would be sufficient to cover the continuous low‐dose prophylaxis regimen. However, for many patients the burden of out‐of‐pocket copayment cost represented a risk for poor adherence to regular prophylaxis. In about two third of the patients, the annual out‐of‐pocket copayment cost amounted to >50% of their average annual disposable income. Many patients therefore required assistance from the charity assistance projects, but nonadherence remained prevalent.

Conclusion

Medical insurance policy and charity assistance projects helped haemophilia children to accept and continue prophylaxis regimens. It was the proportion of the out‐of‐pocket copayment cost rather than the upper limit of insurance reimbursement that restricted long‐term regular low‐dose prophylaxis in China.     

LRP1/CD91 is up‐regulated in monocytes from patients with haemophilia A: a single‐centre analysis

The low‐density lipoprotein receptor‐related protein 1 (LRP1) is an ubiquitously expressed endocytic receptor that, among its several functions, is involved in the catabolism of coagulation factor VIII (FVIII) and in the regulation of its plasma concentrations. Although LRP1/CD91 polymorphisms have been associated with increased FVIII levels and a consequent thrombotic risk, no data are available on LRP1/CD91 expression in patients with inherited FVIII deficiency. With the aim of elucidating this issue, 45 consecutive patients with haemophilia A (HA) (18 severe, 5 moderate and 22 mild HA) were enrolled in this cross‐sectional, single‐centre survey. The LRP1/CD91 mean fluorescence intensity (MFI) in monocytes from HA patients was significantly higher than that detected in 90 healthy blood donors (105 vs. 67, P < 0.001). This over‐expression was independent of hepatitis C virus infection status and varied according to the severity of the haemophilia, being higher in patients with more severe FVIII deficiency. In conclusion, our study documents for the first time that LRP1/CD91 is over‐expressed on monocytes from HA patients, with the intensity of expression varying according to the severity of the FVIII deficiency. Further studies are needed to assess the clinical implications of these findings.     

Break‐through bleeding in relation to pharmacokinetics of Factor VIII in paediatric patients with severe haemophilia A

Introduction

As the pharmacokinetics (PK) of factor VIII (FVIII) is individualized in children with haemophilia A (HA), PK parameters may be indicators of patients' bleeding phenotype and instruction for their personalized replacement program.

Aim

The aim of this study was to investigate the possible relationship between PK/FVIII level and bleeding frequency in Chinese paediatric patients with severe (HA).

Methods

A total of 24 patients were enrolled in Beijing Children's Hospital from February to October 2015, all of whom were given 50 IU/kg of FVIII concentrates after a 72‐hours washout period. Samples' activities (FVIII:C) were tested at 5 time points, using WinNonlin software for PK testing, and then the individual half‐life(t_1/2) and the time (h) of FVIII concentrations <1 IU/dL within a week during prophylaxis were calculated. Baseline and the annual bleeding rate (ABR), annual joint bleeding rate (AJBR) were recorded and analyzed.

Results

The mean t_1/2 of FVIII was 10.20 ± 2.72 hours and the mean time of FVIII <1 IU/dL in 1 week was 44.7 hours (?38.56 to 102.33 hours). A significant relationship between t_1/2 of FVIII and ABR₀/AJBR₀ (baseline bleeding) was found (R² = 0.75 and 0.62, P < .001). Besides, baseline and the annual bleeding rate during prophylactic treatment of haemophilia had a positive correlation with the time (hours) of FVIII <1 IU/dL in 1 week (R² = 0.67 and 0.52, P < .001).

Conclusion

t_1/2 was an important indicator to prevent bleeding in severe HA; the frequency of bleeding will be reduced with the increased of t_1/2 of FVIII. The data also demonstrates that increasing the time with a FVIII<1 IU/dL is associated with an increased rate of bleeding during prophylaxis.