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OBJECTIVE: Contrast-enhanced ultrasound (CEUS) is advantageous for evaluating microcirculation, and has been applied to assess arthritis in previous studies. However, CEUS examinations have not been studied for hemophilia arthritis. Hemophilia arthritis is different from other arthritis, because it is induced by spontaneous joint bleeding. Hence, CEUS may have special value in evaluating hemophilia arthritis. The present study assessed the value of CEUS in evaluating synovial hypertrophy and predicting recurrent joint bleeding in severe hemophilia A patients. METHODS: From August 2016 to January 2017, 81 severe hemophilia A patients, who were referred to our hospital for ultrasound joint assessment with conventional ultrasound, were enrolled. Among these 81 patients, 46 patients consented for CEUS examinations on the same day. RESULTS: Compared to color Doppler flow imaging (CDFI), four more joints presented with a blood flow signal under CEUS mode. In addition, the synovial hypertrophy measured by CEUS was thicker than that measured by conventional ultrasound. The ultrasound scores (including the total grey-scale ultrasound score, joint effusion/hemarthrosis, synovial hypertrophy, CDFI semi-quantitative score, and CEUS semi-quantitative score) were significantly higher in the joint bleeding group than in the no joint bleeding group (P<0.05). Furthermore, these ultrasound scores were positively correlated with the joint bleeding frequency, and had the highest correlation with the CEUS score (r=0.620, P<0.05). CONCLUSION: CEUS can more accurately assess the degree of synovial hypertrophy and vascularization, and diagnose synovitis, when compared to conventional ultrasound. In addition, CEUS appears to be essential for evaluating the possibility of recurrent joint bleeding, and providing more reliable evidence for individualized treatment.
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Artritis , Hemofilia A , Sinovitis , Artritis/complicaciones , Artritis/diagnóstico por imagen , Hemartrosis/diagnóstico por imagen , Hemartrosis/etiología , Hemofilia A/complicaciones , Hemofilia A/diagnóstico por imagen , Hemorragia/etiología , Humanos , Sinovitis/complicaciones , Sinovitis/diagnóstico por imagen , Ultrasonografía/métodosRESUMEN
INTRODUCTION: In countries with restricted access to clotting factor concentrates, early implementation of low-dose prophylaxis is recommended over episodic treatment. OBJECTIVE: The objective of this 1-year prospective secondary prophylaxis study was to evaluate the efficacy of a dose/frequency escalating protocol in young boys with hemophilia A in China. METHODS: Boys were started on a low-dose protocol (minimum 10-15 IU/kg of factor VIII [FVIII] twice weekly). Escalation was based on index joint bleeding, swelling/persistent joint swelling, and serial ultrasound (gray scale and color Doppler) examinations of index joints. RESULTS: Thirty-three boys, median age 4.8 years (interquartile range, 3.8-6.1) were enrolled in a 3-month observation period that preceded a 1-year prophylaxis phase. A significant reduction in total bleeding events (43.0%, P = .001), index joint bleeds (53.2%, P = .002), and target index joint bleeds (70.0%, P = 0.02) was observed during the prophylaxis phase. During the prophylaxis period, 40% of target joints resolved. The percentage of boys with zero index joint bleeds increased significantly (P = .004) from 51.5% during the observation phase to 81.8% in last quarter of the prophylaxis phase (months 10-12). There was no progression of arthropathy based on physical examination (Hemophilia Joint Health Score), X-ray, and ultrasound obtained at entry into the prophylaxis phase and at study exit. The median FVIII consumption over the prophylaxis phase was 1786 IU/kg/y. CONCLUSION: A low-dose, individualized prophylaxis protocol, guided by individual bleeding profiles and serial assessment of joint status, enables escalation of treatment intensity in boys with severe hemophilia A, leading to a significant reduction in bleeding events and reduction in target joint bleeding.
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BACKGROUND: Prophylaxis reduces the frequency of bleeds in boys with severe hemophilia and is the standard care for their management in resource-abundant countries. The effect of prophylaxis on Health-Related Quality of Life (HRQoL) has not been established, because the sample sizes of most studies are too small to explore the relationship of multiple factors that influence HRQoL. METHODS: The aim of this study was to assess the impact of hemophilia severity and treatment regimen on HRQoL and to establish the minimum important difference (MID) using the international level of score distributions. HRQoL data were pooled from 7 studies across 9 countries. HRQoL was measured using the Canadian Hemophilia Outcomes-Kids' Life Assessment Tool (CHO-KLAT). A mixed-effect linear regression analysis was employed to assess the impact of prophylaxis on the CHO-KLAT score. RESULTS: Data from 401 boys with hemophilia were analyzed (57.6% severe hemophilia and 57.6% receiving prophylaxis). The model revealed that receiving prophylaxis was significantly associated with higher HRQoL (regression coefficient 8.5, 95% confidence interval [CI] 3.9-13.1). Boys with severe hemophilia had a significantly lower HRQoL as compared to boys with moderate and mild hemophilia whose CHO-KLAT scores were 7.0 and 6.6 points higher, respectively. There was a significant interaction between treatment and disease severity (P = 0.023), indicating prophylaxis has the most significant impact in boys with severe hemophilia. Based on these pooled data, the MID of the CHO-KLAT was established at 6.5. CONCLUSIONS: This study confirms the positive effect of prophylaxis on HRQoL in boys with hemophilia in a real-world setting and provides initial benchmarks for interpreting HRQoL scores based on use of the CHO-KLAT instrument.
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BACKGROUND: Although much attention has been paid to the pharmacokinetics (PKs) of different factor VIII (FVIII) concentrates in persons with hemophilia A (HA), limited information is available in young boys with severe HA. In this study, we aimed to assess the PK parameters of FVIII products in boys with severe HA in China. METHODS: A total of 36 boys (plasma-derived [pd]-FVIII, n = 15; recombinant [r] FVIII, n = 21) were enrolled between January 2015 and May 2016 in Beijing Children's Hospital. PK characteristics of FVIII products were studied according to a reduced 4-sampling time point design (1 h, 9 h, 24 h, and 48 h postinfusion). RESULTS: The mean FVIII half-life (t1/2) was 10.99 ± 3.45 h (range 5.52-20.02 h), the mean in vivo recovery (IVR) was 2.01 ± 0.42 IU/dl per IU/kg (range 1.24-3.02 IU/dl per IU/kg) and mean clearance (CL) of FVIII is 4.34 ± 1.58 ml·kg-1·h-1 (range 2.29-7.90 ml·kg-1·h-1). We also analyzed the influence of several parameters that potentially modulate FVIII PK. The age was closely associated with FVIII half-life (R2 = 0.32, P < 0.01). The t1/2of FVIII increased by 0.59 h per year. Besides age, von Willebrand factor antigen (VWF:Ag) also was associated with FVIII half-life (R2 = 0.52, P < 0.01). Patients with blood Group O had a shorter FVIII half-life than patients with non-O blood group (9.40 ± 0.68 h vs. 12.3 ± 0.79 h, t = 2.70, P = 0.01). The FVIII IVR correlated with age (R2 = 0.21, P < 0.01) and VWF:Ag level (R2 = 0.28, P < 0.01). CL rates were faster in young patients and in those with low-VWF:Ag levels. CL rates of FVIII are higher in blood Group O versus non-blood Group O persons (5.02 ± 0.38 vs. 4.00 ± 0.32 ml·kg-1·h-1, t = 2.53, P = 0.02). CONCLUSIONS: Chinese boys with severe HA have similar PK values to other ethnic groups and large differences in FVIII PK between individual patients. Age, blood group, and VWF:Ag levels are important determining factors for FVIII CL.
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Factor VIII/farmacocinética , Hemofilia A/tratamiento farmacológico , Adolescente , Pruebas de Coagulación Sanguínea , Niño , Preescolar , China , Humanos , Masculino , Factor de von WillebrandRESUMEN
INTRODUCTION: Currently full dose prophylaxis is the standard of care in the treatment of hemophilia (World Federation of Hemophilia). However, the high costs prevent the use of standard or intermediate dose prophylaxis in China and other developing countries. Low dose prophylaxis would be a viable alternative treatment. At present global research data on the use of low dose prophylaxis is limited. Areas covered: Since 2007, China has been developing low dose prophylaxis as a high priority (90 % of moderate and severe hemophilia boys suffer joint disease by age 6 - 9). 11 studies were successfully conducted and published results showing evidence of the benefits of low dose prophylaxis to reduce joint bleeding. This new knowledge has been implemented into clinical practice in China. However the long-term outcome of arthropathy remains unclear and obstacles in execution exist. Expert commentary: In 2016, the first phenotype-based individualized prophylaxis study using four escalating low dose regimens on severe Chinese hemophilia A boys (China Individualized Prophylaxis Study (CHIP China)) launched. Using the previously published and imminent CHIP data, the goal for China is to establish an effective escalating low dose prophylaxis protocol for use in China as a standard of care.
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Hemofilia A/tratamiento farmacológico , Adolescente , Niño , Preescolar , China , Hemofilia A/epidemiología , HumanosRESUMEN
BACKGROUND: Quality of life (QoL) is increasingly recognized as an important outcome measure in clinical trials. The Canadian Hemophilia Outcomes-Kids Life Assessment Tool (CHO-KLAT) shows promise for use in China. OBJECTIVE: To adapt the CHO-KLAT version 2.0 for use in clinical trials in China. METHODS: Forward and back translations of the CHO-KLAT2.0 were completed in 2008. Between October 2009 and June 2010, a series of 3 focus groups were held with 20 boys and 31 parents in rural and urban China to elicit additional concepts, important to their QoL, for the Chinese CHO-KLAT2.0. All of the items identified by boys and parents were reviewed by a group of experts, resulting in a Chinese version of the CHO-KLAT2.0. This version underwent a detailed cognitive debriefing process between October 2010 and June 2011. Thirteen patient-parent pairs participated in this cognitive debriefing process until a stable and clearly understood Chinese version of the CHO-KLAT2.0 was obtained. RESULTS: The initial back translation of the Chinese CHO-KLAT2.0 was slightly discrepant from the original English version on 12 items. These were all successfully adjudicated. The focus groups identified 9 new items that formed an add-on Socio-Economic Context (SEC) module for China. Linguistic improvements were made after the 2nd, 5th, 7th and 13th cognitive debriefings pairs and affected a total of 18 items. The result was a 35 item CHO-KLAT2.0 and a SEC module in Simplified Chinese, both of which have good content validity. CONCLUSION: This detailed process proved to be extremely valuable in ensuring the items were accurately interpreted by Chinese boys with hemophilia ages ≤18 years. The need for the additional SEC module highlighted the different context that currently exists in China with regard to hemophilia care as compared to many Western countries, and will be important in tracking progress within both rural and urban China over time. Changes based on the cognitive debriefings suggest that expert verbatim translation alone is not sufficient. The Chinese version of the CHO-KLAT2.0 is well understood by boys with hemophilia in China. Next steps will be to test its construct validity and reliability in boys with hemophilia in China.