The value of HEAD-US system in detecting subclinical abnormalities in joints of patients with hemophilia

Predictive parameters for spontaneous joint bleeding during emicizumab prophylaxis

ABSTRACT

Emicizumab is approved for prophylaxis of patients with hemophilia A (HA). Despite its efficacy in reducing bleeding, some patients on emicizumab still experience hemarthrosis, but no tool is yet available to identify those at a higher risk of spontaneous joint bleeding. This study aimed to evaluate whether laboratory measurements (global coagulation assays and emicizumab concentration) and/or arthropathy scores can distinguish patients at higher risk of spontaneous joint bleeding while on emicizumab prophylaxis. A thrombin generation assay was performed upon the addition of tissue factor and synthetic phospholipids. Nonactivated thromboelastography was performed on citrated whole blood. Emicizumab concentrations were measured using a modified 1-stage factor VIII assay. The degree of hemophilic arthropathy was assessed using the Hemophilia Joint Health Score and Hemophilia Early Arthropathy Detection with Ultrasound (HEAD-US) score. A Cox proportional hazards model was used to evaluate the association between variables and bleeding. The predictive power of these variables was investigated using receiver operating characteristic (ROC) analysis. Forty patients with severe HA, with or without inhibitors, on emicizumab prophylaxis were enrolled in an observational cohort study. Ten of 40 developed spontaneous joint bleeding. None of the laboratory parameters were able to distinguish patients with a higher risk of spontaneous joint bleeding. ROC analysis showed that during emicizumab prophylaxis, only the presence of synovitis and a higher HEAD-US score were associated with spontaneous joint bleeding (area under the curve, 0.84). A greater degree of arthropathy and the presence of synovitis could help predict the risk of spontaneous joint bleeding in patients with HA on emicizumab prophylaxis.

Outcome measures in hemophilia: current and future perspectives

INTRODUCTION

Hemophilia can detrimentally affect patients' quality of life and likelihood of survival. In the evolving landscape of therapies, the therapeutic gain of each treatment must be understood to accurately position it in the therapeutic armamentarium. Accordingly, appropriate outcomes must be measured with appropriate tools.

AREAS COVERED

Our narrative review (PubMed search for 'hemophilia AND outcome' until June 2023), provides a compendium of outcome measures used in hemophilia clinical research. To define each outcome measure's relative value and applicability, several characteristics are critically discussed.

EXPERT OPINION

Bleeding assessment, first annual/annualized bleeding rate, remains central in evaluating the efficacy and safety of hemophilia treatments. As modern therapies improve clinical outcomes toward zero bleeding events, this endpoint may become less sensitive to detect differences between therapeutic approaches. Technological advancements necessitate the adaptation of outcome measures to address infrequent bleeding events, age-related comorbidities, and laboratory parameters with limited comparability after different treatments. Considerable effort has been dedicated to the development of tools that comprehensively assess coagulation, such as thrombin generation assays. Patient-reported outcome measures are gaining importance although limited by their subjectivity. A definitive set of research outcome measures remains elusive. Outcomes may need to be tailored to different therapeutic interventions.

Self-conducted sonographic monitoring of the knee in patients with haemophilia-A feasibility study

INTRODUCTION/AIM

To evaluate whether patients with haemophilia (PwH) can be enabled to perform ultrasonography (US) of their knees without supervision according to the Haemophilia Early Arthropathy Detection with Ultrasound (HEAD-US) protocol and whether they would be able to recognize pathologies.

METHODS

Five PwH (mean age 29.6 years, range 20-48 years) were taught the use of a portable US device and the HEAD-US protocol. Subsequently, the patients performed US unsupervised at home three times a week for a total of 6 weeks with a reteaching after 2 weeks. All images were checked for mapping of the landmarks defined in the HEAD-US protocol by a radiologist. In a final test after the completion of the self-sonography period, participants were asked to identify scanning plane and potential pathology from US images of other PwH.

RESULTS

On the images of the self-performed scans, 82.7% of the possible anatomic landmarks could be identified and 67.5% of the requested images were unobjectionable, depicting 100% of the required landmarks. There was a highly significant improvement in image quality following reteaching after 2 weeks (74.80 ± 36.88% vs. 88.31 ± 19.87%, p < .001). In the final test, the participants identified the right scanning plane in 85.0% and they correctly identified pathology in 90.0% of images.

CONCLUSION

Appropriately trained PwH can perform the HEAD-US protocol of their knee with high quality and are capable to identify pathologic findings on these standardized images. Asynchronous tele-sonography could enable early therapy adjustment and thereby possibly reduce costs.

Predicting joint involvement through tailored prophylaxis in severe haemophilia A, is it possible?

INTRODUCTION

Tailored prophylaxis is the current treatment regimen for patients with severe haemophilia A. Recently, published guidelines describe two possible approaches, based on clinical characteristics or estimation of pharmacokinetic parameters. However, both have strengths and weaknesses, and their characteristics need to be integrated to optimize treatment appropriately. In this paper, we present a model that considers together the characteristics of prophylaxis and the relevance of each.

METHODS

The age at initiation of prophylaxis, number of bleeding events, treatment regimen, therapeutic adherence, FVIII trough levels, and joint status were analyzed in 59 patients followed at La Paz University Hospital between January 2000 and December 2019.

RESULTS

The mean duration of primary prophylaxis of 113.37 ± 57.79 months. Eighty-three percent (n = 49) had no joint status involvement at the end of follow-up (HJHS and HEAD-US = 0). The median ABR was 0.7 (IQR 0.2 -1.0) and 54.2% presented trough levels of FVIII during follow-up >1 IU/dL. 72,9% engaged in some type of physical activity and overall adherence was over 85% in all patients evaluated. The regression analysis performed, considering all these factors, showed that the initiation of prophylaxis before 21 months of age was the most relevant protective factor against the appearance of joint involvement (OR 88.33 p.031 CI 95% 1.49-5224.40) CONCLUSION: Early initiation of prophylaxis was the most relevant factor in the protection of joint status. More comprehensive analysis models adapted to the characteristics of each population, are needed to adequately individualize treatment.

Joint bleeds in mild hemophilia: Prevalence and clinical characteristics

INTRODUCTION

Joint bleeds are a common and frequent complication associated with hemophilia, increasing the risk of hemophilic arthropathy. It is important to define and characterize the presence of joint complications in mild hemophilia to develop strategies to mitigate disease burden.

AIMS

To characterize the prevalence, clinical characteristics of joint bleeds, and risk factors that may lead to hemarthrosis in people with mild hemophilia.

METHODS

Following Institutional Review Board approval, a retrospective chart review was conducted for patients with mild hemophilia seen at the Yale Hemophilia Treatment Center or Classical Hematology Program.

RESULTS

The medical records of 70 patients were reviewed. Eighty one percent were male and 19 percent were female. Twenty individuals with mild hemophilia had a history of joint bleeding, 13 were traumatic bleeds, 7 were spontaneous. The age of first joint bleed ranged from 4 to 58 years old, with an average age of 20.8-years old. Ten patients developed joint bleeds between the ages of 10 and 20 years old. The most common locations of joint bleeding were the knee (n = 11) and ankle (n = 7). Eight of 70 patients had hepatitis C (HCV), 6 experienced joint bleeding.

CONCLUSIONS

In this study, almost one third of patients with mild hemophilia experienced joint bleeding, often without history of trauma. Joint range of motion was abnormal in more than a third of the patients with mild hemophilia regardless. These data highlight the need for ongoing evaluation and characterization of joint health in individuals with mild hemophilia.

HIGHLIGHTS

Twenty-nine percent of individuals with mild hemophilia had history of joint bleed. PwH and mild diseases with previous or current hepatitis C had higher likelihood of joint bleeding. Approximately 15% of PwH and mild diseases had abnormal joint examinations without a confirmed history of joint bleeding.

The value-based healthcare approach to haemophilia: Development of outcome measures for the evaluation of care of people with haemophilia

INTRODUCTION

Considering the advances in haemophilia management and treatment observed in the last decades, a new set of value-based outcome indicators is needed to assess the quality of care and the impact of these medical innovations.

AIM

The Value-Based Healthcare in Haemophilia project aimed to define a set of clinical outcome indicators (COIs) and patient-reported outcome indicators (PROIs) to assess quality of care in haemophilia in high-income countries with a value-based approach to inform and guide the decision-making process.

METHODS

A Value-based healthcare approach based on the available literature, current guidelines and the involvement of a multidisciplinary group of experts was applied to generate a set of indicators to assess the quality of care of haemophilia.

RESULTS

A final list of three COIs and five PROIs was created and validated. The identified COIs focus on two domains: musculoskeletal health and function, and safety. The identified PROIs cover five domains: bleeding frequency, pain, mobility and physical activities, Health-Related Quality of Life and satisfaction. Finally, two composite outcomes, one based on COIs, and one based on PROIs, were proposed as synthetic outcome indicators of quality of care.

CONCLUSION

The presented standard set of health outcome indicators provides the basis for harmonised longitudinal and cross-sectional monitoring and comparison. The implementation of this value-based approach would enable a more robust assessment of quality of care in haemophilia, within a framework of continuous treatment improvements with potential added value for patients. Moreover, proposed COIs and PROIs should be reviewed and updated routinely.

A post hoc comparative real-world analysis of HEAD-US score for joint health assessment of patients with severe haemophilia A and B in Spain

AIM

Joint damage due to haemarthrosis can be effectively monitored with point-of care ultrasound using the Haemophilia Early Arthropathy Detection with US (HEAD-US) scoring system. A post hoc comparative analysis of the joint status of patients with severe haemophilia A (HA) or B (HB) was performed.

METHODS

The databases of two observational, cross-sectional studies that recruited patients with HA or HB from 12 Spanish centres were analysed to compare the status of the elbows, knees and ankles in patients with severe disease according to treatment modality. The HEAD-US score was calculated in both studies by the same trained operators.

RESULTS

Overall, 95 HA and 41 HB severe patients were included, with a mean age of 35.2 ± 11.8 and 32.7 ± 14.2 years, respectively. The percentage of patients who received prophylaxis, over on-demand (OD) treatment, was much higher in HA (91.6%) than in HB (65.8%) patients. With a similar number of target joints, the HEAD-US score was zero in 6.3% HA and 22.0% HB patients (p < .01), respectively. The HA population showed significantly worse HEAD-US scores. Whilst osteochondral damage occurred more frequently in patients OD or tertiary prophylaxis, our data suggest that articular damage is less prominent in primary/secondary prophylaxis, regardless of the type of haemophilia. These latter treatment modalities were also associated with a lower prevalence of synovial hypertrophy, particularly in HB patients.

CONCLUSION

This post hoc analysis indicates that joint status seems to be significantly influenced by haemophilia type (HA or HB) and treatment modality in these severe Spanish populations with severe disease. Continuing HEAD-US monitoring for the early detection and management of intra-articular abnormalities, as well as more efficiently tailored therapies should be warranted.

Age-specific incidence of joint disease in paediatric patients with haemophilia: A single-centre real-world outcome based on consecutive US examination

INTRODUCTION

Joint health is one of the most important factors contributing to a healthy life in patients with haemophilia. Recent study revealed that starting early prophylaxis was not enough to prevent joint disease in most paediatric patients with haemophilia.

AIM

In this study, we aimed to determine the age-specific incidence of acute joint disease during childhood at single haemophilia treatment centre (HTC).

METHOD

The joint health in 48 patients was evaluated based on consecutive US testing for 5 years at annual multidisciplinary comprehensive care.

RESULTS

During the study period, 23 patients (47.9%) had no joint disease since the initial examination, whereas 13 patients (27.0%) showed development from negative to positive findings. The incidence of joint disease increased with age: 0% in preschool, 5.3% in elementary school, 14.3% in junior high school and 35% beyond high school age. Among the 13 patients who developed joint disease, two experienced acquired synovitis that resolved during the follow-up period. Statistical analysis revealed that the patients who routinely underwent follow-up by the HTC exhibited a significantly lower incidence of joint disease than did those followed up at other institutions (p < .001).

CONCLUSION

These results indicated that close check-up, including routine joint examination using US as well as frequent assessment of pharmacokinetic profile at the HTC, might play an important role in avoiding joint disease among paediatric patients with haemophilia.

Hemophilic arthropathy: how to diagnose subclinical bleeding early and how to orthopedically treat a damaged joint

INTRODUCTION

It is important to know the current status of hemophilic arthropathy diagnoses, treatments, complications, and outcomes in developed countries.

AREAS COVERED

A bibliographic search in PubMed for articles published from 1 January 2019 through 12 June 2023 was performed.

EXPERT OPINION

In developed countries with specialized hemophilia treatment centers, primary hematological prophylaxis (started before the age of 2 years and after no more than one joint bleed) has almost completely eliminated the joint-related problems of the disease. The ideal goal of zero hemarthroses can be achieved only with intense and well-dosed prophylaxis: intravenous infusion of coagulation factor - standard half-life or extended half-life; periodic or subcutaneous injections of nonfactor products (emicizumab or fitusiran). However, hemophilic arthropathy continues to occur due to subclinical joint hemorrhages. In one study, 16% of the joints without reported hemarthroses showed signs of previous subclinical bleeding (hemosiderin deposits with/without synovial hypertrophy on magnetic resonance imaging were deemed signs of previous subclinical bleeding), rendering evidence for subclinical bleeding in people with severe hemophilia with lifelong prophylaxis treatment. Subclinical joint hemorrhages can be averted only by employing accurate and tailored prophylaxis.

The hidden joint in children with haemophilia on prophylaxis

Prophylaxis is the gold standard treatment for children with haemophilia (CWH). MRI studies revealed joint damage, even with this treatment; this suggests the presence of subclinical bleeding. In the case of children with haemophilia, it is relevant to detect early signs of joint damage, as this allows the medical team to provide the appropriate treatment and follow-up, in order to avoid arthropathy development and its consequences. The aim of this study is to detect the hidden joint in children with haemophilia on prophylaxis (CWHP) and analyse, by age group, which joint is the most affected. We define the hidden joint in CWH on prophylaxis as the joint that presents joint damage secondary to repetitive bleeding episodes and is detected in the joint evaluation, despite being asymptomatic or with mild symptoms. It is most commonly caused by repetitive subclinical bleeding.

METHODS

This was an observational, analytical, cross-sectional study of 106 CWH on prophylaxis treated in our centre. Patients were divided according to age and type of treatment. Joint damage was defined as a HEAD-US score ≥ 1.

RESULTS

Patients' median age was 12 years. All had severe haemophilia. The median age of onset of prophylaxis was 2.7. Forty-seven (44.3 %) patients received primary prophylaxis (PP) and 59 (55.7 %), secondary prophylaxis. Six hundred and thirty-six joints were analysed. Type of prophylaxis and joint involvement showed statistically significant differences (p < 0.001). However, patients on PP had a greater number of damaged joints at older ages. Twenty-two % (140) of the joints scored ≥1 on HEAD-US. Cartilage was most frequently involved, followed by synovitis, and bone damage. We observed a greater frequency and degree of arthropathy in subjects aged 11 and above. Sixty (12.7 %) joints showed a HEAD-US score ≥ 1, with no history of bleeding. The ankle was the most affected joint, representing the hidden joint according to our definition.

CONCLUSION

Prophylaxis is the best treatment for CWH. However, symptomatic or subclinical joint bleeding may occur. The routine evaluation of joint health is relevant, particularly, of the ankle. In our study, early signs of arthropathy according to age and type of prophylaxis were detected by HEAD-US.

The Correlation Between the HEAD-US-C Score and HJHS in Hemophilic Arthropathy of the Knee

OBJECTIVES

We aimed to discuss the correlation between the Hemophilia Early Detection Ultrasound in China (HEAD-US-C) score and the Hemophilia Joint Health Score version 2.1 (HJHS 2.1) of the knee joint in patients with hemophilia.

METHODS

We included 70 male patients with hemophilia admitted to The Second Hospital of Shanxi Medical University; the patients' bilateral knee joints were evaluated using the HEAD-US-C score and HJHS. We analyzed factors influencing hemophilia arthropathy of the knee and examined the correlation between the HEAD-US-C score and HJHS.

RESULTS

The joint injury severity was positively correlated with age and the number of bleeds (P < .001). Further, the HEAD-US-C score and HJHS differed according to the severity (both P < .001), but not type (P = .163 and P = .283, respectively), of hemophilia. There was a significant correlation between the HEAD-US-C score and HJHS (P < .001).

CONCLUSIONS

Overall, all joint lesions observed on ultrasound corresponded to clinical joint functional abnormalities. Therefore, the HEAD-US-C is important for hemophilic arthropathy evaluation and is useful in explaining abnormal joint function.

Clinical Predictors and Prediction Models for rFVIII-Fc Half Life in Real-World People with Severe Hemophilia A

The half life of recombinant factor VIII-Fc (rFVIII-Fc) for people with hemophilia A (PwHA) varies greatly. Understanding the factors influencing the variation and assessment of rFVIII-Fc half life is important for personalized treatment. Eighty-five severe-type PwHA with rFVIII-Fc treatment receiving an evaluation of half life by the Web-Accessible Population Pharmacokinetic (PK) Service—Hemophilia during 2019–2021 were retrospectively enrolled. The 50-patient PK profiles before 2021 were used for analysis and developing prediction models of half life, and the 35-patient PK profiles in 2021 were used for external validation. The patients in the development cohort were aged 8–64, with a median rFVIII-Fc half life of 20.75 h (range, 8.25–41.5 h). By multivariate linear regression analysis, we found two, four, and five predictors of rFVIII-Fc half life for the blood groups non-O, O patients, and overall patients, respectively, including VWF:Ag, BMI, VWF:activity/VWF:Ag ratio, body weight, O blood group, inhibitor history, HCV infection, and hematocrit. The three prediction equations of rFVIII-Fc half life (T) were respectively developed as T for non-O group patients = −0.81 + 0.63 × (BMI, kg/m2) + 6.07 × (baseline VWF:Ag, IU/mL), T for O group patients = −0.68 + 13.30 × (baseline VWF:Ag, IU/mL) + 0.27 × (BW, kg) − 1.17 × (BMI, kg/m2) + 16.02 × (VWF:activity/VWF:Ag ratio), and T for overall patients = −1.76 + 7.24 × (baseline VWF:Ag, IU/mL) − 3.84 × (Inhibitor history) + 2.99 × (HCV infection) − 2.83 × (O blood group) + 0.30 × (Hct, %), which explained 51.97%, 75.17%, and 66.38% of the half life variability, respectively. For external validation, there was a significant correlation between the predicted and observed half lives in the validation cohort. The median half life deviation was +1.53 h, +1.28 h, and +1.79 h for the equations of non-O group, O group, and overall group patients, respectively. In total, eight predictors influencing rFVIII-Fc half life were identified. Prediction equations of rFVIII-Fc half life were developed for the non-O and O blood groups and overall PwHA with a good degree of external validation. The equations could be applied to patients aged 8–64 without the need for PK blood sampling and clinically valuable for personalized therapy.

Screening for subclinical synovial proliferation in haemophilia: A systematic review and meta-analysis comparing physical examination and ultrasound

INTRODUCTION

Ultrasound is increasingly used as addition to physical examination for detection of subclinical joint changes in haemophilia. However, the added value of ultrasound to physical examination for detecting synovial proliferation is not fully established.

AIM

To determine the diagnostic accuracy of swelling at physical examination for ultrasound-detected synovial proliferation in haemophilia.

METHODS

PubMed and EMBASE were searched up to 2 August 2022. Studies reporting original data on occurrence of swelling at physical examination and synovial proliferation on ultrasound of index joints in persons with haemophilia were included. Risk of bias and applicability were assessed using the Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2) tool. Diagnostic accuracy parameters of swelling at physical examination for ultrasound-detected synovial proliferation were determined. Summary sensitivity and specificity were calculated using a bivariate random-effects model.

RESULTS

Fifteen studies reporting on swelling at physical examination and synovial proliferation on ultrasound in 2890 joints of 627 patients were included. Prevalence of subclinical synovial proliferation ranged between 0% and 55%. Sensitivity of swelling was low [summary estimate .34; 95% confidence interval (CI) .24-.46], while specificity was high (summary estimate .97; CI .92-.99). Predictive values varied widely due to inter-study differences in prevalence of synovial proliferation.

CONCLUSION

Joint swelling has low sensitivity for presence of ultrasound-detected synovial proliferation in haemophilia, suggesting underestimation of synovial proliferation by physical examination alone. Consequently, ultrasound screening may generate important information on synovial changes which would otherwise remain undetected.

Synovitis and joint health in patients with haemophilia: Statements from a European e-Delphi consensus study

INTRODUCTION

Synovitis, a common feature in haemophilia, is triggered by the presence of blood in joints, and represents the first step towards the development of chronic arthropathy. Synovitis may be detected early by means of ultrasound or magnetic resonance imaging scan; clinical joint scores are less sensitive in this setting. Regular long-term prophylaxis with clotting factor concentrates, as primary prophylaxis and tailored to individual needs, has high efficacy in preventing synovitis. In general, higher factor levels lower bleeding risk, but no direct correlation between factor levels and synovitis incidence has been demonstrated.

AIM

This study aimed to develop an expert consensus relating to the definition, pathophysiology, diagnosis, prevention, follow-up and treatment of synovitis, recognising its relevance for joint health and taking into account existing knowledge gaps.

METHODS

A Delphi consensus study was designed and performed. An expert group prepared 22 statements based on existing literature; a wider expert panel subsequently voted on these.

RESULTS

Retention of panellists was high. Four statements required amending and consensus on all statements was achieved after three rounds of voting.

CONCLUSION

This e-Delphi consensus study addressed the importance of synovitis in joint health of people with haemophilia and highlighted knowledge gaps in this field. Studies on the natural course of synovitis are lacking and the biological mechanisms underlying this process are not yet fully elucidated. While basic and clinical research proceeds in this field, expert consensus can help guide clinicians in their routine clinical practice, and Delphi methodology is often used to produce best-practice guidelines.

How to assess, detect, and manage joint involvement in the era of transformational therapies: Role of point-of-care ultrasound

BACKGROUND

Patients with haemophilia experience recurring hemarthroses, mainly involving knees, elbows and ankles, which lead to haemophilic arthropathy, the major chronic complication of haemophilia. With new approaches to haemophilia treatment leading to fewer joint bleeds and, in some cases, no bleeding events, assessing whether current outcome assessment tools provide adequate sensitivity and specificity for management and care of patients with haemophilia is needed.

METHODS

An overview of current imaging tools for monitoring joint health, novel osteochondral damage and synovial proliferation biomarkers, and the relationship between assessments for functionality and imaging modalities is provided. Usefulness and sensitivity of point-of-care ultrasound (POCUS) to complement other assessments and use of ultrasound to monitor haemophilic arthropathy are also examined.

RESULTS

This review provides rationale for haemophilia teams to move beyond traditional outcomes in joint imaging, as well as guidance and evidence on assessment of joint health for potential new treatment modalities, such as gene therapy. The role of POCUS in the existing paradigm for haemophilia care and management along with the use of ultrasound as a complement to other outcome assessment tools are also discussed. Finally, the clinical effects of subclinical bleeding on joint function are described, to motivate screening for synovial proliferation.

CONCLUSION

POCUS can facilitate the early detection of joint damage and can monitor disease progression while providing insights into the efficacy of treatment regimens, and should be considered as an essential assessment tool for managing the care of patients with haemophilia.

Long-term impact of primary prophylaxis on joint status in patients with severe hemophilia A

Background

Primary prophylaxis with factor VIII concentrates is the therapeutic gold standard for severe hemophilia A. Although this approach will change substantially with the use of nonsubstitutive therapies, the long-term effects of primary prophylaxis remain unclear. We present information on joint health with tailored primary prophylaxis in a consecutive series at a single center.

Methods

We retrospectively analyzed 60 patients who did not develop early inhibitors. The annual bleeding rate and annual joint bleeding rate, prophylaxis characteristics, physical activity, adherence, and development of inhibitors were compared between those with and without joint involvement at the end of follow-up. Joint involvement was defined as a Hemophilia Joint Health Score or Hemophilia Early Arthropathy Detection with an ultrasound score ≥1.

Results

Among 60 patients with median follow-up of 113 ± 6 months after starting prophylaxis, 76.7% had no joint involvement at the end of the follow-up. Those without joint involvement started prophylaxis at a younger median age (1 [IQR 1-1] year vs 3 [IQR 2-4.3] years). They also had lower annual joint bleeding rate (0.0 [IQR 0-0.2] vs 0.2 [IQR 0.1-0.5]), were more often physically active (70% vs 50%), and had lower trough factor VIII levels. Adherence to treatment was not significantly different between groups.

Conclusion

Initiation of primary prophylaxis at a younger age was the main factor associated with long-term preservation of joint status in patients with severe hemophilia A.

Characteristics of BAY 2599023 in the Current Treatment Landscape of Hemophilia A Gene Therapy

Hemophilia A, a single gene disorder leading to deficient Factor VIII (FVIII), is a suitable candidate for gene therapy. The aspiration is for single administration of a genetic therapy that would allow the production of endogenous FVIII sufficient to restore hemostasis and other biological processes. This would potentially result in reliable protection from bleeding and its associated physical and emotional impacts. Gene therapy offers the possibility of a clinically relevant improvement in disease phenotype and transformational improvement in quality of life, including an opportunity to engage in physical activities more confidently. Gene therapy products for hemophilia A in advanced clinical development use adeno-associated viral (AAV) vectors and a codon-optimized B-domain deleted FVIII transgene. However, the different AAV-based gene therapies have distinct design features, such as choice of vector capsid, enhancer and promoter regions, FVIII transgene sequence and manufacturing processes. These, in turn, impact patient eligibility, safety and efficacy. Ideally, gene therapy technology for hemophilia A should offer bleed protection, durable FVIII expression, broad eligibility and limited response variability between patients, and long-term safety. However, several limitations and challenges must be overcome. Here, we introduce the characteristics of the BAY 2599023 (AAVhu37.hFVIIIco, DTX 201) gene therapy product, including the low prevalence in the general population of anti-AAV-hu37 antibodies, as well as other gene therapy AAV products and approaches. We will examine how these can potentially meet the challenges of gene therapy, with the ultimate aim of improving the lives of patients with hemophilia A.

The Limitations and Unmet Needs of the Five Cornerstones to Guarantee Lifelong Optimization of Prophylaxis in Hemophilia Patients

Prophylaxis to prevent bleeding is highly recommended for hemophilia patients. The development of new drugs and tools for modeling personalized prophylaxis provides the means for people with hemophilia to lead active lives with a quality of life comparable to that of nonhemophilic individuals. The choice of regimens must be made on a highly individual basis. Unfortunately, reference guides neither always concur in their recommendations nor provide directions to cover all possible scenarios. In this review, a group of experts identify the significant limitations and unmet needs of prophylaxis, taking advantage of their clinical experience in the disease, and supported by a rigorous literature update. To perform a more systematic and comprehensive search for gaps, the main cornerstones that influence decisions regarding prophylactic patterns were first identified.

Bleeding phenotype, joint status, physical activity, pharmacokinetics/medication properties, and adherence to treatment were considered as the primary mainstays that should allow physicians guiding prophylaxis to secure the best outcomes. Several challenges identified within each of these topics require urgent attention and agreement. The scores to assess severity of bleeding are not reliable, and lead to no consensus definition of severe bleeding phenotype. The joint status is to be redefined in light of new, more efficient treatments with an agreement to establish one scale as the unique reference for joint health. Further discussion is needed to establish the appropriateness of high-intensity physical activities according to patient profiles, especially because sustaining trough factor levels within the safe range is not always warranted for long periods. Importantly, many physicians do not benefit from the advantages provided by the programs based on population pharmacokinetic models to guide individualized prophylaxis through more efficient and cost-saving strategies. Finally, ensuring correct adherence to long-term treatments may be time-consuming for practitioners, who often have to encourage patients and review complex questionnaires.

In summary, we identify five cornerstones that influence prophylaxis and discuss the main conflicting concerns that challenge the proper long-term management of hemophilia. A consensus exercise is warranted to provide reliable guidelines and maximize benefit from recently developed tools that should notably improve patients' quality of life.

Past, present and future of orthopedic surgery in hemophilia: looking to a world without bleeding and arthropathy in the near future

INTRODUCTION

The purpose of this article is to review the literature on orthopedic surgery in people with hemophilia (PWH), to better understand its past and present and attempt to predict the future.

AREAS COVERED

A Cochrane Library and PubMed (MEDLINE) search of studies related to orthopedic surgery in PWH was analyzed. A downward trend in orthopedic surgery in PWH has been observed. Patients on continuous prophylaxis are less likely to require orthopedic surgery. In patients with hemophilia, the risk of major bleeding remains high after total joint arthroplasty, even with factor replacement. Cases of acute compartment syndrome, pseudotumors and even limb amputations are still observed in PWH.

EXPERT OPINION

Orthopedic surgery for PWH should always be performed in specialized centers with multidisciplinary expertise in the correct management of hemophilia. It is paramount to perform an accurate preoperative coagulation screening before surgery. The availability of prophylaxis through replacement and the recent non-replacement therapy in the well-developed countries will diminish substantially or hopefully abolish completely the need for surgery in the treatment of PWH. Therefore, we are looking to a world without bleeding and arthropathy in the next future. Unfortunately, this is not true for the under-development countries.

Treatment Individualization Using Pharmacokinetic Studies and Joint Ultrasound Imaging in Pediatric Patients With Hemophilia

Hemophilia is characterized by bleeding diathesis, primarily affecting the joints. Prophylactic use of missing factor aims at limiting the number of bleeds and, in the long term, the risk of permanent joint damage. However, standard prophylactic regimens are usually applied empirically, not adjusting for variations in bleeding phenotype or drug metabolism. Aim of the present study was to evaluate the need for individualizing prophylaxis, with guidance of pharmacokinetic (PK) studies and joint ultrasound in a setting of everyday clinical practice. To evaluate adequacy of applied regimens, joint status was assessed using the Hemophilia Joint Health Score as well as ultrasound imaging, while PK studies were performed using the Web-Accessible Population Pharmacokinetic Service-Hemophilia. Imaging results were consistent with early joint damage in a large proportion of pediatric patients, whereas PK measures were indicative of inadequate prophylaxis in many cases-despite the limited number of bleeds reported by patients. The study revealed the need for prophylaxis adjustment in the majority of patients. Real world data confirm that traditional prophylaxis is often unable to achieve therapeutic goals, while an individualized approach, guided by the use of novel modalities, may be of great benefit to young hemophilia patients.

The value of ultrasonography in detecting early arthropathic changes and contribution to the clinical approach in patients of hemophilia

PURPOSE\AIM: Hemophilia affects the blood clotting process, is a genetic disease characterized by recurrent bleeding. The hemophilia early arthropathy detection with ultrasound (HEAD-US) procedure and scoring method were designed for the detection of early changes in affected joints of patients. In this article, it was aimed to detect early arthropathic changes in the joints of hemophilia patients with the HEAD US scoring system and to investigate its clinical contribution. It was aimed to investigate the effectiveness of HEAD-US scoring in showing early joint damage in subclinical hemophilia cases and its contribution to treatment.

METHODS

The present study included 50 hemophilia patients who were admitted to Departments of Pediatric and Adult Hematology for routine follow-up. During routine follow-up controls, patients were scored by physical examination and HJHS 2.1 and by ultrasonography and HEAD US. Statistical tests were used to analyze joint health status and the results of US examination in the patient group.

RESULTS

A total of 294 joints (elbow n = 100, knee n = 94, ankle n = 100) were evaluated by ultrasonography. The mean HJHS and HEAD-US scores of the patients were 14.94 ± 15.18 and 15.6 ± 12.6, respectively.

CONCLUSIONS

HEAD-US is accepted to be more sensitive than HJHS in detecting early signs of arthropathy. Detection of early abnormalities by ultrasonography will enable the development of individualized treatment protocols and to the prevention of arthropathy development.

Joint status and related risk factors in patients with severe hemophilia A: a single-center cross-sectional study

OBJECTIVES

Hemophilic arthropathy is the most common complication of severe hemophilia A. This study aims to investigated joint status and related risk factors in patients with severe hemophilia A (PWSHA).

METHODS

This single-center study included 31 patients. Six index joints (both elbows, knees, and ankles) were evaluated using the Hemophilia Early Arthropathy Detection with UltraSound in China (HEAD-US-C) and Hemophilia Joint Health Score (HJHS). Treatment adherence was measured using the Validated Hemophilia Regimen Treatment Adherence Scale-Prophylaxis (VERITAS-Pro). We analyzed the influence of age, treatment delay (the interval between diagnosis and the initiation of treatment), prophylaxis, and treatment adherence on joint outcomes.

RESULTS

All patients were male (median age, 22 years). The median age at diagnosis was 1 year; that at initial treatment was 5 years. All patients experienced joint bleeding. HEAD-US-C and HJHS scores were positively correlated (R = 0.70, P < 0.0001). Median [range] HEAD-US-C and HJHS scores were 15 [0-36] and 32 [2-49], respectively. Age was positively correlated with both HEAD-US-C (P = 0.002) and HJHS scores (P < 0.0001). The difference of HEAD-US-C scores between groups with ≤1 year and >1 year treatment delay was close to significant (P = 0.055). HJHS scores were significantly different between these two groups (P = 0.03). Joint assessment scores were not significantly different between on-demand and low-dose prophylaxis groups. VERITAS-Pro scores were correlated with both HEAD-US-C and HJHS scores (P = 0.046 and P = 0.005, respectively).

CONCLUSIONS

Hemophilic arthropathy was pervasive in PWSHA. Age and poor adherence were significantly correlated with joint damage. Prompt treatment and adherence improvement may reduce severity.

The EANM guideline for radiosynoviorthesis

Purpose

Radiosynoviorthesis (RSO) using the intraarticular application of beta-particle emitting radiocolloids has for decades been used for the local treatment of inflammatory joint diseases. The injected radiopharmaceuticals are phagocytized by the superficial macrophages of the synovial membrane, resulting in sclerosis and fibrosis of the formerly inflamed tissue, finally leading to reduced joint effusion and alleviation of joint pain.

Methods

The European Association of Nuclear Medicine (EANM) has written and approved these guidelines in tight collaboration with an international team of clinical experts, including rheumatologists. Besides clinical and procedural aspects, different national legislative issues, dosimetric considerations, possible complications, and side effects are addressed.

Conclusion

These guidelines will assist nuclear medicine physicians in performing radiosynoviorthesis. Since there are differences regarding the radiopharmaceuticals approved for RSO and the official indications between several European countries, this guideline can only give a framework that must be adopted individually.

Clinical assessment and point of care ultrasonography: How to diagnose haemophilic synovitis

BACKGROUND

The ability of clinical tools to identify early joint changes is limited. Synovitis is a fundamental finding in understanding haemophilia activity and the response to its therapies; thus, there is a need for sensitive methods to better diagnose subclinical synovitis early.

PURPOSE

Our aim was to compare the frequency with which clinical assessment and ultrasound detected synovial hypertrophy in the most frequently affected joints in patients with haemophilia (elbows, knees and ankles).

METHODS

We analysed patients with haemophilia older than 16 years who came to the haemophilia centre for routine follow-up. From the clinical assessment carried out in the consultation, the swelling, pain and history of haemarthrosis were evaluated and compared with the findings of synovial hypertrophy detected by ultrasound. This comparison was also analysed independently for elbows, knees and ankles.

RESULTS

A total of 203 joints of 66 patients with haemophilia (mean age 34 years), most of them on secondary, tertiary prophylaxis or on demand treatment, were included. In joints with swelling, pain and history of haemarthrosis, 78% of the joints showed synovial hypertrophy on ultrasound. However, in joints with no swelling, no pain and no history of haemarthrosis, 40% presented subclinical synovial hypertrophy on ultrasound. This percentage was higher in elbows than in knees and ankles.

CONCLUSION

In adults with haemophilia, physical examination and point-of-care ultrasound study provide complementary data on their joint disease. However, without ultrasound, the ability to detect subclinical synovitis is considerably reduced, especially in the elbows.

Hemophilic arthropathy: a teaching approach devoted to hemophilia treaters in under-development countries

INTRODUCTION

Arthropathy is the characteristic injury of hemophilia, primarily occurring in the elbows, knees, and ankles. The aim of this review is a teaching approach devoted to hemophilia treaters in under-development countries.

AREAS COVERED

Current major challenges include the absence of the following therapeutic tools for all people with hemophilia (PWH) worldwide: hematological prophylaxis; well-coordinated multidisciplinary teams in specialized centers; joint aspiration of acute hemarthrosis; point-of-care ultrasonography (POC-US); exercise; treatment of synovitis by means of radiosynovectomy; treatment of mild hemophilic arthropathy with analgesics, anti-inflammatory agents, and rehabilitation medicine; intra-articular injections of corticosteroids, hyaluronic acid, platelet-rich plasma, and mesenchymal stem cells; and treatment of severe hemophilic arthropathy by surgical treatment. The future scenario in under-development countries should include all the aforementioned treatment tools plus the possibility of performing total joint arthroplasty in PWH with inhibitors; concomitant use of bypassing agents with emicizumab for PWH with inhibitors undergoing orthopedic surgery; and telemedicine.

EXPERT OPINION

Primary hematological prophylaxis is now the gold standard for the management of hemophilia. Acute hemarthrosis needs intense hematological management and articular aspiration; the articular situation should be scrutinized by POC-US. Synovitis can be controlled by radiosynovectomy. In cases of severe articular degeneration, surgical procedures might be required.

Clinical and ultrasound evaluation of patients with haemophilia on prophylaxis

INTRODUCTION

Primary prophylaxis is the current gold standard in haemophilia care for the prevention of bleeding and ensuing joint damage. Early detection of joint bleeding, whether symptomatic or subclinical, preferably during childhood, helps prevent joint deterioration and subsequent disability. The aim of this study is to evaluate the level of agreement between the Haemophilia Joint Health Score and the Haemophilia Early Arthropathy Detection with Ultrasound tools in children with severe haemophilia on primary and secondary prophylaxis.

MATERIALS AND METHODS

All patients were followed up regularly at our centre. Elbows, knees and ankles were evaluated by physical examination using the Haemophilia Joint Health Score 2.1 (HJHS 2.1), and by ultrasound with HEAD-US score.

RESULTS

A total of 80 children with haemophilia on prophylaxis were included in this study. Mean age was 10.8 years (range 4-18). We evaluated 480 joints, of which 423 (88.1%) were concordant with both tools, whereas 57 (11.9%) were discordant; 377 (78.5%) joints scored 0 on HJHS, 370 (77%) on HEAD-US and 345 (72%) on both tools. The overall Kappa concordance coefficient was .656. For elbows, knees and ankles the respective values were .783, .522 and .589. For HJHS scores greater than 3, all joints scored ≥1 on HEAD-US.

CONCLUSION

HJHS and HEAD-US are used to assess joint health in children with haemophilia on prophylaxis. In this study, the level of agreement between both tools was consistent with literature values only for the elbow joint.

Management of musculoskeletal complications in patients with hemophilia: literature review and expert recommendations

In people with hemophilia, hematological prophylaxis during childhood and adolescence could elude the occurrence of musculoskeletal complications (in joints and muscles) if the concentration of the defective factor is averted from decreasing under 1% of normal. Prompt management is of capital significance as the juvenile skeleton is hypersensitive to the adverse events of the disease; intense structural defects might appear rapidly. Important articular bleeds and inveterate hypertrophy of the articular synovial membrane must be treated vigorously to preclude joint degeneration (hemophilic arthropathy). At the moment that extreme joint disease is in place with intense affliction, the goal must be to reestablish activity whilst at the same time reducing the peril to the patient. Articular debridement is an efficacious surgical technique to accomplish this goal, particularly around the knee or ankle, and may be contemplated to be a backup to ankle arthrodesis or ankle or knee replacement in patients of younger age. Eventually joint replacement can commonly reestablish both articular mobility and function in an unhealthy articulation.

Asymptomatic Joint Bleeding and Joint Health in Hemophilia: A Review of Variables, Methods, and Biomarkers

Joint health is a key contributor to quality of life in patients with hemophilia. However, variables that impact long-term joint outcomes have not been comprehensively defined. A systematic literature search identified publications relating to joint health in patients with hemophilia. Studies clearly show that early, sustained prophylaxis with factor replacements improves long-term joint outcomes. However, a subset of patients appear to develop arthropathy despite maintaining excellent bleeding outcomes, which suggests possible recurrent asymptomatic bleeding into the joints in these patients. Furthermore, limited data are available on how long-acting factor VIII and factor IX replacement therapies could impact long-term joint outcomes. Many variables were identified as potential indicators that a patient may develop hemophilic arthropathy, including genetic mutations, endogenous factor VIII and IX levels, bone health, and physical activity levels. Tools for the diagnosis and monitoring of hemophilic arthropathy are critical to detect early joint damage, so that management can be adjusted accordingly. Imaging techniques, particularly magnetic resonance imaging, can detect synovial changes, a strong predictor for the future development of hemophilic arthropathy. In addition, several biomarkers associated with cartilage and bone formation, vascularization, and angiogenesis could potentially identify the onset and progression of early joint damage. Since the development of hemophilic arthropathy is complex, a comprehensive therapeutic approach is necessary for the effective prevention of arthropathy in patients with hemophilia.

Ultrasound evaluation of joint damage and disease activity in adult patients with severe haemophilia A using the HEAD-US system

INTRODUCTION

The Haemophilia Early Arthropathy Detection with Ultrasound (HEAD-US) system and scoring scale has proven to be an accurate and time-efficient imaging method for identifying joint damage in patients with haemophilia.

AIM

Observational, multicentre, cross-sectional study conducted in 8 centres in Spain that assessed the joint status of adult patients with severe haemophilia A (SHA) using HEAD-US.

METHODS

Joint status of the elbow, knee and ankle was evaluated in adults with SHA receiving on-demand (OD) treatment, or primary (PP), secondary (SP), tertiary (TP) or intermittent (IP) prophylaxis.

RESULTS

Of the 95 patients enrolled, 87 received prophylaxis (6.3% PP, 38.9% SP, 43.2% TP and 3.2% IP). Mean age was 35.2 years, and 59% of patients had not undergone image testing in the last year. The HEAD-US score was 0 in all joints in 6.3% of patients. The ankle was the most affected joint, regardless of treatment regimen. Patients receiving OD treatment, TP or IP had the overall worst scores, mainly in the ankles and elbows; a similar but milder profile was observed in patients on SP; and patients on PP had the best score in all joints.

CONCLUSION

Joint function may be effectively preserved in patients with SHA on PP, but OD treatment or later initiation of prophylaxis does not seem to prevent progression of arthropathy. Disease worsening was observed in patients OD, TP or IP, most often affecting ankles and elbows. Closer ultrasound imaging monitoring may improve management of these patients.

Haemophilia early arthropathy detection with ultrasound and haemophilia joint health score in the moderate haemophilia (MoHem) study

INTRODUCTION

Detection of early arthropathy is crucial for the management of haemophilia, but data on moderate haemophilia are limited. Therefore, we evaluated joint health and treatment modalities in Nordic patients with moderate haemophilia A (MHA) and B (MHB).

AIM

To explore and compare the Haemophilia Early Arthropathy Detection with Ultrasound (HEAD-US) and Haemophilia Joint Health Score (HJHS) to detect early arthropathy in moderate haemophilia.

METHODS

A cross-sectional, multicentre study covering Nordic patients with MHA and MHB. Arthropathy was evaluated by HEAD-US and HJHS 2.1.

RESULTS

We assessed 693 joints in 118 patients. HEAD-US scores (medians [interquartile ranges]) were as follows: elbows 0 points (0-0), knees 0 (0-0) and ankles 0 (0-1). Respectively, by HJHS: elbows 0 (0-1), knees 0 (0-1) and ankles 0 (0-1). Cartilage (14%) and bone (13%) were most commonly affected by HEAD-US. Frequent HJHS findings were crepitus on motion in knees (39%), and loss of flexion (23%) and extension (13%) in ankles. HEAD-US correlated strongly with HJHS (elbows r = .70, knees r = .60 and ankles r = .65), but 24% had discordant scores. Joints with HJHS zero points, 5% captured HEAD-US ≥1 point. Moreover, 26% had HJHS findings without HEAD-US pathology. Notably, 31% of knees had crepitus on motion and normal HEAD-US.

CONCLUSION

Overall, the joints attained low scores implying good joint health. HEAD-US correlated strongly with HJHS. In 5%, HEAD-US detected subclinical pathology. Crepitus on motion was frequently reported despite normal HEAD-US, thus not necessarily reflecting arthropathy. HEAD-US therefore improves the joint assessment in moderate haemophilia.

Detection and evaluation of haemophilic arthropathy: Which tools may be considered more reliable

INTRODUCTION

Progressive arthropathy is the main cause of morbidity in patients with severe haemophilia. Diagnostic imaging can detect even subclinical arthropathy and impact prophylactic treatment. However, in most clinical settings the regular joint evaluation and follow-up are based on clinical evaluation and patient's personal reporting of problems, while diagnostic imaging is not regularly employed.

AIM

The aim of our prospective study was to assess how ultrasound (US), clinical examination, patient's subjective assessment and certain laboratory biomarkers correlate with magnetic resonance imaging (MRI) for detection and evaluation of haemophilic arthropathy in order to determine which tool is the most reliable.

METHODS

The study included 30 patients with severe haemophilia (age range 16-49 years). MRI (IPSG), US (HEAD-US), clinical examination (HJHS 2.1) and patient's subjective assessment of elbows, knees and ankles were performed; additionally, blood samples for laboratory analysis were taken (s-25-OH vitamin D, s-ferritin, s-C-terminal telopeptide of type I collagen, s-N-terminal propeptide of type I procollagen and s-cartilage oligomeric matrix protein). MRI results were used as a reference standard for joint status. Pearson's r was used to assess correlation of other methods with MRI.

RESULTS

The correlation with MRI was the highest for US (r = .92), considerably higher than for clinical evaluation (r = .62) and patient's subjective assessment (r = .66). There was no correlation between the presence or degree of haemophilic arthropathy and any of the laboratory biomarkers.

CONCLUSION

The results of our study warrant the inclusion of US into the regular follow-up of patients with severe haemophilia, where the equipment and staffing permit.

HJHS 2.1 and HEAD-US assessment in the hemophilic joints: How do their findings compare?

: In hemophilic patients methods are needed to better diagnose joint damage early, so that treatments can be adjusted to slow the progression of hemophilic arthropathy. The aim of this study is to investigate the relationship between the Hemophilia Joint Health Score version 2.1 (HJHS 2.1) and hemophilia early arthropathy detection with ultrasound (HEAD-US) scales, as well as each of their individual items, to better understand the value each provides on the joint condition of patients with hemophilia. The study included data from patients with hemophilia older than 16 years of age, who attended a routine check-up. HJHS 2.1 and HEAD-US assessments were performed on the elbows, knees and ankles. We studied the correlations and agreements between the two scales and analyzed the relationship between the various items of the HJHS 2.1 (inflammation, duration, atrophy, crepitation, flexion deficit, extension deficit, pain, strength, gait) and HEAD-US (synovitis, cartilage and bone). The study included 203 joints from 66 patients with hemophilia (mean age, 34 years). We found a good correlation between the two scales (r = 0.717). However, HJHS 2.1 revealed only 54% of the cases with synovitis and 75% of the cases with osteochondral damage. HEAD-US detected several relevant physical and functional aspects in less than 53% of the cases. HJHS 2.1 and HEAD-US provide complementary data on joint disease in adults with hemophilia; both assessments should therefore, be made available. HEAD-US presented the added value of detecting early joint changes (synovitis and osteochondral damage), while HJHS 2.1 showed the added value of detecting relevant physical and functional changes.

Prophylaxis for hemophilia A without inhibitors: treatment options and considerations

INTRODUCTION

Hemophilia A is a bleeding disorder traditionally managed with standard half-life (SHL) factor (F) VIII concentrates. Extended half-life (EHL) FVIII products and emicizumab-kywh, a nonfactor therapy, are newer treatment options. Additional nonfactor agents and gene therapy are expected to reach the market in the near future.

AREAS COVERED

A PubMed (MEDLINE) search from 1962 to April 2020 related to hemophilia A, its management, and the products currently available for prophylaxis was performed to comprehensively review these topics and analyze the benefits and drawbacks of each therapeutic.

EXPERT OPINION

Prophylaxis with SHL FVIII concentrates remains the standard of care for patients with severe hemophilia A and may also be considered for selected individuals with moderate disease. Several years of real-world experience with EHL FVIII, emicizumab-kywh, and other agents in development will be necessary to determine their ultimate roles in the prevention of bleeding and its complications. Gene therapy may not provide a permanent cure for hemophilia A.

Changes in Muscle Activity Patterns and Joint Kinematics During Gait in Hemophilic Arthropathy

Hemophilic arthropathy is the result of repetitive intra-articular bleeding and synovial inflammation. In people with hemophilic arthropathy (PWHA), very little is known about the neural control of individual muscles during movement. The aim of the present study was to assess if the neural control of individual muscles and coordination between antagonistic muscle pairs and joint kinematics during gait are affected in PWHA. Thirteen control subjects (CG) walked overground at their preferred and slow velocity (1 m/s), and 14 PWHA walked overground at the preferred velocity (1 m/s). Joint kinematics and temporal gait parameters were assessed using four inertial sensors. Surface electromyography (EMG) was collected from gluteus maximus (GMAX), gluteus medius (GMED), vastus medialis (VM), vastus lateralis (VL), rectus femoris (RF), medial gastrocnemius (MG), lateral gastrocnemius (LG), soleus (SOL), tibialis anterior (TA), semitendinosus (ST), and biceps femoris (BF). Waveforms were compared using the time-series analysis through statistical parametric mapping. In PWHA compared to CG, EMG amplitude during the stance phase was higher for LG (for both velocities of the CG), BF (slow velocity only), and ST (preferred velocity only) (p < 0.05). Co-contraction during the stance phase was higher for MG-TA, LG-TA, VL-BF, VM-ST, LG-VL, and MG-VM (both velocities) (p < 0.05). MG and LG were excited earlier (preferred velocity only) (p < 0.05). A later offset during the stance phase was found for VL, BF, and ST (both velocities), and BF and GMAX (preferred velocity only) (p < 0.05). In addition, the range of motion in knee and ankle joints was lower in PWHA (both velocities) and hip joint (preferred velocity only) (p < 0.05). In conclusion, the neural control of individual muscles and coordination between antagonistic muscles during gait in PWHA differs substantially from control subjects.

Merging into the mainstream: the evolution of the role of point-of-care musculoskeletal ultrasound in hemophilia

Bleeding with resultant hemophilic arthropathy constitutes the largest cause of morbidity in patients with hemophilia. It results from repeated bleeding episodes in the joint and is characterized by synovial hypertrophy and cartilage and bony destruction. Hemophilic arthropathy assessment is a continually evolving process and is particularly challenging in children and young adults in whom joint disease may be missed or underestimated as obtaining serial "baseline" magnetic resonance imaging scans of multiple clinically asymptomatic or nearly asymptomatic joints may be unjustifiable and cost-ineffective. Musculoskeletal ultrasound-particularly, point-of-care musculoskeletal ultrasound-has emerged as a promising imaging modality for the early detection and management of hemophilic arthropathy, and for the evaluation of hemarthrosis and painful musculoskeletal episodes in patients with hemophilia. This review summarizes currently available data on the emerging role of this new imaging modality, its limitations, and gaps in knowledge. The review also raises unanswered questions, highlights the need for consolidated research efforts, and delineates future directions expected to advance this technology and optimize its use in this patient population.

Nano-evidence for joint microbleeds in hemophilia patients

The concept of joint microbleeding in hemophilia patients was first proposed over 10 years ago. This was based on unexpected abnormalities found in medical imaging studies of asymptomatic joints. Since then, there have been no published studies confirming the presence of joint microbleeds. This critique will review the evidence for and against joint microbleeding in hemophilia patients and the potential implications.