Exploration of the minimum necessary FVIII level at different physical activity levels in pediatric patients with hemophilia A.

Background: Physical activity can increase joint stability and reduce the risk of injury in hemophilia patients. There is limited clinical data on target trough FVIII levels during physical activity in hemophilia A patients. Hence, this study aimed to explore the target trough FVIII level required to avoid bleeding during different physical activities in hemophilia A patients. Methods: Patients with severe or moderate hemophilia A, who underwent pharmacokinetics (PK) tests at our center were enrolled in this study. Physical activities and clinical information such as bleeding were recorded. The FVIII level during physical activity was calculated by the WAPPS-Hemo. Results: A total of 105 patients were enrolled in this study. A total of 373 physical activities were recorded, of which 57.6% (215/373) was low-risk activities and the remaining 42.4% (158/373) was medium-risk activities. Most common physical activities were bicycling (59.0%), swimming (43.8%), running (48.6%), and jumping rope (41.0%). The FVIII trough level of low-risk physical activity was 3.8 IU/dl (AUC = 0.781, p = 0.002) and moderate-risk physical activity was 7.7 IU/dl (AUC = 0.809, p < 0.001). FVIII trough levels [low-risk activities: 6.1 (3.1, 13.2) IU/dl vs. 7.7 (2.3, 10.5) IU/dl, moderate-risk activities: 9.6 (5.8, 16.9) IU/dl vs. 10.2 (5.5, 11.0) IU/dl] were not statistically different between the mild arthropathy group and the moderate-severe arthropathy group. Multiple bleeding risk tended to increase with physical activities classified as moderate-risk (OR [95% CI]: 3.815 [1.766-8.238], p = 0.001). Conclusion: The minimum necessary FVIII level increased with higher risk physical activity, irrespective of arthropathy.

Individualised prophylaxis based on personalised target trough FVIII level optimised clinical outcomes in paediatric patients with severe haemophilia A.

INTRODUCTION: As standard care of severe haemophilia A (SHA), prophylaxis should be individualised. AIM: This study aimed to investigate the effectiveness of this new-proposed individualised prophylaxis protocol. METHODS: Boys with SHA were enrolled and followed a PK-guided, trough-level escalating protocol of prophylaxis after a six-month observational period. In the next 2 years, clinical assessments including joint bleeds, ultrasound (US) scores and Haemophilia Joint Health Score (HJHS) in both sides of ankles, knees and elbows were conducted every 6 months as a scoring system, which determined whether the trough level's escalation. Adjustment of dosing regimen was based on WAPPS-Hemo. RESULTS: Fifty-eight SHA boys were finally analysed. Their age and bodyweight were 5.3(2.8,6.9) years and 21.5(16,25) kg. During the study, 47 escalations were conducted. At study exit, the patient number and proportion of different trough level groups were: < 1 IU/dl, 17.2% (10/58); 1-3 IU/dl, 53.5% (31/58); 3-5 IU/dl, 15.5% (9/58); > 5 IU/dl, 13.8% (8/58). Significantly reduced annualised bleeding rate [4(0,8) to 0(0,2), p < .0001] and annualised joint bleeding rate [2(0,4) to 0(0,.25), p < .0001] was observed at study exit as well as the continuous trend of increased zero bleeding proportion (ZBP) (27.6%-69.0%) and zero joint bleeding proportion (46.5%-81.3%). Besides, 85% (6/7) of the target joints vanished. Statistical improvements of US scores (p = .04) and HJHS (p = .02) were also reported at study exit. CONCLUSION: Our results showed the effectiveness of our protocol based on individualised target trough level and emphasise the importance of personalised prophylaxis.

A semiquantitative color Doppler ultrasound scoring system for evaluation of synovitis in joints of patients with blood-induced arthropathy.

BACKGROUND: Intra-articular bleeds in patients with inherited bleeding disorders lead to active synovitis which may progress to a chronic state over time. We explored the diagnostic value of color Doppler ultrasound in detecting synovitis in boys with bleeding disorders. RESULTS: Sixty boys with hemophilia and 3 boys with type 3 von Willebrand disease aged 5 to 18 years (median 12.3 years) were imaged by gray-scale and color Doppler ultrasound (US) in three centers (Beijing, China [n = 22], Guangzhou, China [n = 12] and Toronto, Canada [n = 29])) in this observational study. Images were independently reviewed by two radiologists blinded to clinical data using a subjective semi-quantitative scoring system and objective measurements of synovial thickness and vascularity. Inter-reader reliability for using subjective versus objective color Doppler US methods for assessing synovial vascularity was excellent for the subjective method and moderate/lower range of substantial for the objective method. Agreement between degree of vascularity on color Doppler and extent of synovial hypertrophy on gray-scale US was overall poor for Canada data and moderate for China data. Correlations between degree of vascularity on color Doppler and synovial hypertrophy on gray-scale US, and clinical constructs (total and itemized HJHS scores and total Pettersson X-ray scores) for assessment of blood-induced arthropathy were all poor. CONCLUSION: Color Doppler US is a valuable scoring method for evaluating reactive synovitis in joints of subjects with inherited bleeding disorders and holds potential for assessing post-bleed reactive synovitis once further information on its association with timing of the joint bleed becomes available in the literature.

Do magnetic resonance imaging manifestations of skeletal system improve after treatment of Gaucher disease?

OBJECTIVES: Skeletal lesions are the most serious complications of Gaucher disease (GD). The pathological changes of skeletal system are complex, which seriously affects the quality of life. The aim was to investigate whether the skeletal system improved in quantitative imaging after treatment with enzyme replacement therapy (ERT). METHODS: Magnetic resonance imaging (MRI) of the vertebrae and femur was performed in 40 patients and 34 healthy volunteers. The scan sequences include iterative decomposition of water and fat with echo asymmetry and least-squares estimation quantitation (IDEAL-IQ) and intravoxel incoherent motion imaging (IVIM). Statistical data were analyzed by using t-test. RESULTS: As for the fat fraction (FF) and R2*, there were significant differences in FF and R2* of vertebrae and left femur. As for the standard apparent diffusion coefficient (sADC), slow apparent diffusion coefficient (D), fast apparent diffusion coefficient (D*) and fraction of fast apparent diffusion coefficient (f) of vertebrae and femur. Only D of vertebrae, sADC and f of left femur and sADC of right femur had statistical difference. CONCLUSION: The quantitative imaging of skeletal system lesions have certain characteristics. The lesions in the skeletal system of patients treated with ERT has been improved to some extent, but it is still different from that in normal people.