Limited value of testing for factor XIII and α2-antiplasmin deficiency in patients with a bleeding disorder of unknown cause.

INTRODUCTION: In patients with an increased bleeding tendency, extensive diagnostic blood testing is often performed. When results of tier 1 assays of primary haemostasis are normal, protocols recommend additional testing to rule out rare disorders including coagulation factor XIII (FXIII) and α2-antiplasmin (α2AP) deficiency. AIM: To evaluate the added diagnostic value of FXIII and α2AP levels in patients with a bleeding disorder of unknown cause (BDUC). METHODS: A retrospective monocentre cohort study between August 2011 and August 2023 was conducted. In all patients with bleeding tendencies and normal diagnostic tests for von Willebrand disease and platelet function, FXIII and α2AP were measured. RESULTS: We included 158 consecutive patients; mean ISTH-BAT scores were 8.2 (SD ± 3.7) in children, 6.2 (SD ± 2.1) in men and 10.6 (SD ± 3.3) in women. Median age was 37 (range 5-79) years, 88.6% of patients were female. Patients displayed median FXIII activity of 111% (IQR = 97-131) and median α2AP activity of 112% (IQR = 103-119). Three (1.9%) patients had FXIII levels < 50%, respectively 43%, 45% and 46%. Corresponding ISTH-BAT scores were 7, 12 and 14. No α2AP levels < 60% was observed. No significant association was found between FXIII levels and ISTH-BAT scores. CONCLUSION: In our cohort of BDUC patients, no clinical relevant FXIII deficiencies were detected; absolute values were well above the 30% cutoff considered adequate for normal haemostasis. No α2AP deficiencies were detected. These data suggest that in BDUC patients, measuring FXIII or AP activity is of limited value.

Efficacy of a 1:1 ratio VWF/FVIII concentrate in patients with von Willebrand disease.

INTRODUCTION: Patients with von Willebrand disease (VWD) require administration of von Willebrand factor (VWF) concentrates peri-operatively. Concerns about FVIII accumulation after repetitive injections of a 1:1 ratio VWF/FVIII clotting factor concentrate (CFC) led this study to explore the recovery and FVIII accumulation over time. METHODS: This monocentre study examined patients with VWD receiving perioperative 1:1 ratio CFC infusions. CFC dosing was based on body weight and endogenous VWF/FVIII activity. FVIII and VWF activity was monitored at T0 (baseline), T1 (15 min postinfusion), and trough levels at T2-T6 (24-120 h). RESULTS: We included 125 patients, undergoing 125 procedures (63 major surgeries, 62 minor), with a median of two CFC infusions (IQR 1-3). With a mean administered dose of 35.7 IU/kg CFC, recovery rates of FVIII and VWF were 2.6 IU/dL per IU/kg and 2.4 IU/dL per IU/kg, respectively. Mean FVIII levels at T0 were 62 (SD 51.9), T1: 164 (SD 80.4), T2: 155 (SD 62.8), T3: 162 (SD 59.8), T4: 124 (SD 78.4), and T5: 120 (SD 65.3) IU/dL. Mean VWF activity levels at T0 were 29 (SD 25.0), T1: 133 (SD 43.7), T2: 92 (SD 37.2), and T3: 86 (SD 37.5) IU/dL. Subgroup analysis in 47 patients with more than three infusions, showed no accumulation of mean FVIII levels. CONCLUSION: This perioperative study demonstrated excellent FVIII and VWF recovery of a 1:1 ratio VWF product in patients with VWD. Stable FVIII and VWF activity levels were observed after repeated infusions, without accumulation. Most major surgeries required only three CFC infusions.

A clinical practice guideline for primary care physiotherapy in patients with haemophilia.

INTRODUCTION: As a result of centralisation of haemophilia care to a limited number of intramural settings, many persons with haemophilia have to travel long distances to attend their haemophilia specialised treatment centre. However, regular physiotherapy treatment can be provided by primary care physiotherapists in the person's own region. Due to the rarity of the disease most primary care physiotherapists have limited experience with this population. This study aims to provide a clinical practice guideline for primary care physiotherapists working with persons with bleeding disorders. METHOD: A list of the most urgent key-questions was derived from a previous study. Literature was summarised using the grading of recommendations assessment, development, and evaluation (GRADE) evidence-to-decision framework. Recommendations were drafted based on four 90 min consensus meetings with expert physiotherapists. Recommendations were finalised after feedback and >80% consensus of all stakeholders (including PWH, physiotherapists, haematologists and the corresponding societies). RESULTS: A list of 82 recommendations was formulated to support primary care physiotherapists when treating a person with a bleeding disorder. These recommendations could be divided into 13 categories: two including recommendations on organisation of care, six on therapy for adult patients with bleeding disorders and five on therapy adaptations for paediatric care. Therapy recommendations included treatment after a joint- or muscle bleed, haemophilic arthropathy, chronic synovitis, non-haemophilia related conditions and orthopaedic surgery. CONCLUSION: An evidence-based practice guideline, based on current evidence from literature and clinical expertise, has been developed for primary care physiotherapists treating a person with haemophilia. To improve care, the recommendations should be implemented in daily practice.

Quantitative MRI assessment of joint effusion using T2-relaxometry at 3 Tesla: a feasibility and reproducibility study.

OBJECTIVE: T2-relaxometry could differentiate between physiological and haemorrhagic joint effusion (≥ 5% blood) in vitro. Are quantitative T2-relaxation time measurements of synovial fluid feasible and reproducible in vivo in clinically bleed-free joints of men with haemophilia? MATERIALS AND METHODS: In this cross-sectional study, we measured T2-relaxation times of synovial fluid in clinically bleed-free ankles, knees or elbows of men with severe haemophilia A using a T2-mapping sequence (duration ≤ 7 min) at 3 Tesla MRI. Manual and circular regions of interest (ROI) were drawn in the synovial fluid of each joint by two independent observers to measure T2-relaxation times. Measurement feasibility was expressed as the success rate of the measurements by both observers. The interobserver and intraobserver reproducibility of the measurements were evaluated by the intraclass correlation coefficient of absolute agreement (ICC) and the limits of agreement (LoA) from Bland Altman analysis. RESULTS: We evaluated 39 clinically bleed-free joints (11 ankles, 12 knees, 16 elbows) of 39 men (median age, 24 years; range 17-33) with severe haemophilia A. The success rate of the T2-measurements was ≥ 90%. Interobserver reliability was good to excellent (manual ROI: ICC = 0.92, 95% CI 0.76-0.97; circular ROI: ICC = 0.82, 95% CI 0.66-0.91) and interobserver agreement was adequate (manual ROI: LoA = 71 ms; circular ROI: LoA = 146 ms). Intraobserver reliability was good to excellent (manual ROI: ICC = 0.78, 95% CI - 0.06-0.94; circular RO: ICC = 0.99, 95% CI 0.98-0.99) and intraobserver agreement was good (manual ROI: LoA = 63 ms; circular ROI: LoA = 41 ms). CONCLUSION: T2-relaxometry of synovial fluid in haemophilia patients is feasible with good interobserver and intraobserver reproducibility.

Monitoring recovery of joints after bleeding: Physical examination and ultrasound are complementary.

AIM: Traditionally, recovery after a joint bleed in people with bleeding disorders is evaluated by clinical symptoms. Following a bleed, however, asymptomatic joints may still show synovial hypertrophy and effusion on ultrasound. We evaluated the duration of full recovery from a joint bleed. Additionally, we determined how recovery differed when assessed by physical examination and ultrasound. METHODS: In this retrospective cohort study, we investigated joint bleeds in elbows, knees and ankles of people with haemophilia or Von Willebrand disease who attended the Van Creveldkliniek between 2016 and 2021. Physical examination (warmth, swelling, range of motion and gait) and ultrasound (effusion and synovial hypertrophy) were performed within 7 days after the onset of the bleed, 1 week after the first examination and monthly thereafter until patients had recovered fully. Joint bleeds were treated in line with the current international treatment guidelines. RESULTS: We evaluated 30 joint bleeds in 26 patients. The median recovery time was 1 month (range 0.3-5 months). In 47% of the joint bleeds, the recovery took longer than 1 month. The moment of recovery based on physical examination and ultrasound differed in 27% of bleeds. Both persistent abnormalities at physical examination in joints with normalized ultrasounds and persistent ultrasound findings in clinically recovered joints occurred. CONCLUSION: Joint bleed recovery can take long and recovery times differed per bleed. Recovery differed when assessed by physical examination or ultrasound. Therefore, both should be used to closely monitor recovery of joint bleeds and offer personalized care.

Can motor proficiency testing predict sports injuries and sports-induced bleeds in people with haemophilia?

INTRODUCTION: Predicting the risk of sports injuries and sports-induced bleeds (SIBs) in people with haemophilia (PWH) may support clinical counselling. AIM: To assess the association between motor proficiency testing and sports injuries and SIBs and to identify a specific set of tests for predicting injury risk in PWH. METHODS: In a single centre, prospective study male PWH aged 6-49 playing sports ≥1x/week were tested for running speed and agility, balance, strength and endurance. Test results below -2Z were considered poor. Sports injuries and SIBs were collected for 12 months while 7 days of physical activity (PA) for each season was registered with accelerometers. Injury risk was analysed according to test results and type of physical activity (%time walking, cycling, running). Predictive values for sports injuries and SIBs were determined. RESULTS: Data from 125 PWH (mean [± SD] age: 25 [± 12], 90% haemophilia A; 48% severe, 95% on prophylaxis, median factor level: 2.5 [IQR 0-15]IU/dl) were included. Few participants (n = 19, 15%) had poor scores. Eighty-seven sports injuries and 26 SIBs were reported. Poor scoring participants reported 11/87 sports injuries and 5/26 SIBs. The current tests were poor predictors of sports injuries (Range PPV: 0%-40%), or SIBs (PPV: 0%-20%). PA type was not associated with season (activity seasonal p values > .20) and type of PA was not associated with sports injuries or SIBs (Spearman's rho < .15). CONCLUSION: These motor proficiency- and endurance tests were unable to predict sports injuries or SIBs in PWH, potentially due to few PWH with poor results and low numbers of sports injuries and SIBs.

Pre-operative synovial hyperaemia in haemophilia patients undergoing total knee replacement and the effects of genicular artery embolization: A retrospective cohort study.

AIM: Haemophilia is characterized by recurrent joint bleeding caused by a lack of clotting factor VIII or IX. Due to repeated joint bleeding, end-stage arthropathy occurs in relatively young patients. A total knee replacement (TKR) can be a solution. However, TKR may be complicated by perioperative and postoperative bleeds despite clotting factor therapy. The aim of this study was to evaluate the prevalence of pre-operative synovial hyperaemia and the effects of Genicular Artery Embolization on synovial hyperaemia and 3-month postoperative joint bleeding. METHODS: In this retrospective cohort study, all patients with haemophilia who underwent periarticular catheter angiography between 2009 and 2020 were evaluated after written informed consent. Synovial hyperaemia on angiography was scored by an interventional radiologist. RESULTS: Thirty-three angiography procedures in 24 patients were evaluated. Median age was 54.4 years (IQR 48.4-65.9). Preoperative synovial hyperaemia was observed in 21/33 joints (64%). Moderate and severe synovial hyperaemia was observed in 10/33 joints (30%). Synovial hyperaemia decreased in 13/15 (87%) joints after embolization. Three-month postoperative joint bleeding occurred in 5/32 joints: in 2/18 joints (11%) without synovial hyperaemia and in 3/14 joints (21%) with mild synovial hypertrophy. Non-embolized and embolized joints did not differ regarding 3-month postoperative bleeding (P = .425). No complications were observed after embolization. CONCLUSION: One-third of patients with haemophilia requiring a TKR had moderate or severe synovial hyperaemia which can be reduced safely by Genicular Artery Embolization prior to TKR. Three-month postoperative bleeding appears to occur independently of the presence of residual mild synovial hyperaemia.

Liver-related complications before and after successful treatment of chronic hepatitis C virus infection in people with inherited bleeding disorders.

INTRODUCTION: With availability of direct-acting antivirals (DAA), most persons with inherited bleeding disorders are currently cured of hepatitis C virus (HCV) infection. The risk of liver-related complications following HCV cure has not been reported for this population. AIM: Reporting liver-related complications during long-term chronic HCV infection and following sustained virological response (SVR) in this population. METHODS: Retrospective follow-up of a prospective single-centre cohort of HCV antibody-positive persons with inherited bleeding disorders. Primary endpoint was liver-related complications [hepatocellular carcinoma (HCC), decompensated cirrhosis, bleeding gastroesophageal varices]. Liver-related complications were reported separately during chronic HCV and following SVR, stratified for interferon-based and DAA-based SVR. RESULTS: In total 309/381 (81%) HCV antibody-positive individuals developed chronic HCV infection. Median follow-up was 44 years [interquartile range (IQR): 34-50]. Liver-related complications occurred in 36/309 (12%) of individuals with chronic HCV infection after median 31 years of chronic infection. Of 199 individuals with SVR, 97 were cured with interferon-based regimens and 102 with DAA after median infection durations of 29 and 45 years, respectively. At end of follow-up, respectively, 21% and 42% had advanced fibrosis or cirrhosis. Post-SVR, seven (4%) individuals had a liver-related complication, mainly HCC (n = 4). Incidence of liver-related complications per 100 patient-years post-SVR follow-up was .2 for interferon-cured and 1.0 for DAA-cured individuals (p = .01). CONCLUSION: Successful HCV treatment does not eliminate the risk of liver-related complications in persons with inherited bleeding disorders. Due to higher baseline risk, incidence was higher after DAA than interferon-based SVR. We advise continuing HCC surveillance post-SVR in all with advanced fibrosis or cirrhosis.

Subclinical synovial proliferation in patients with severe haemophilia A: The value of ultrasound screening and biochemical markers.

AIM: Subclinical bleeding and inflammation play a role in progression of haemophilic arthropathy. Synovial proliferation is predictive of joint bleeding and its early detection may guide treatment changes and prevent arthropathy progression. This study evaluated the prevalence of active and inactive subclinical synovial proliferation and investigated potential biochemical blood/urine markers to identify patients with active subclinical synovial proliferation. METHODS: This cross-sectional study included patients with severe haemophilia A born 1970-2006 who were evaluated during routine clinic visits. Patients with (a history of) inhibitors or recent joint bleeding were excluded. Elbows, knees and ankles were examined for subclinical synovial proliferation by ultrasound and physical examination. Active synovial proliferation was distinguished from inactive synovial proliferation using predefined criteria. Blood/urine biochemical markers (serum osteopontin, sVCAM-1, Coll2-1, COMP, CS846, TIMP, and urinary CTX-II) were compared individually and as combined indexes between patients with and without active synovial proliferation. RESULTS: This cohort consisted of 79 patients with a median age of 31 years (range 16.5-50.8 years) with 62/79 (78%) of the patients using continuous prophylaxis. The annualized joint bleeding rate over the last 5 years was .6 (.2-1.1). Active (17/79, 22%) and inactive subclinical synovial proliferation (17/79, 22%) were both prevalent in this cohort. Biochemical markers were not correlated with active subclinical synovial proliferation. CONCLUSION: Subclinical synovial proliferation, both active and inactive, was prevalent in patients with severe haemophilia A with access to prophylaxis and would be overlooked without routinely performed ultrasounds. Biochemical markers were unable to identify patients with active subclinical synovial proliferation.

Structural changes after ankle joint distraction in haemophilic arthropathy: an explorative study investigating biochemical markers and 3D joint space width.

INTRODUCTION: Ankle joint distraction (AJD) is a promising treatment for patients with severe haemophilic ankle arthropathy (HAA). However, some patients showed no clinical improvement after AJD and these differences may be related to structural differences. AIM: Primarily to quantify the structural changes after AJD in patients with HAA by the use of 3D joint space width (JSW) measurements and biochemical markers and secondarily to correlate these findings with clinical pain/function. METHODS: Patients with haemophilia A/B who underwent AJD were included for this study. Bone contours on MRI (performed before and 12 and 36 months after AJD) were drawn manually and percentage change in JSW was calculated. Blood/urine (before and 6, 12, 24 and 36 months after AJD) was collected for biomarker measurement (COMP, CS846, C10C, CALC2, PRO-C2, CTX-II) and combined indexes of markers were calculated. Mixed effects models were used for analyses on group level. Structural changes were compared with clinical parameters. RESULTS: Eight patients were evaluated. On group level, percentage changes in JSW showed a slight decrease after 12 months followed by a non-statistically significant increase in JSW after 36 months compared to baseline. Biochemical marker collagen/cartilage formation also showed an initial decrease, followed by a trend towards net formation 12, 24 and 36 months after AJD. On individual patient level, no clear correlations between structural changes and clinical parameters were observed. CONCLUSION: Cartilage restoration activity on group level in patients with HAA after AJD was in concordance with clinical improvements. Correlating structural modifications with clinical parameters in the individual patient remains difficult.

Clotting factor activity levels and bleeding risk in people with haemophilia playing sports.

BACKGROUND: Improved treatment options for people with haemophilia (PWH) have increased the possibilities for sports participation, but the risk of sports-induced bleeding (SIB) is still considered considerable by many. AIM: To assess sports associated injury- and bleeding risk in PWH and to assess clotting levels associated with safe sports participation. METHODS: Sports injuries and SIBs were prospectively collected for 12 months in PWH aged 6-49 without inhibitors playing sports at least once weekly. Injuries were compared according to factor levels, severity, joint health, sports risk category and sports intensity. Factor activity at the time of injury was estimated using a pharmacokinetic model. RESULTS: 125 participants aged 6-49 (41 children, 90% haemophilia A; 48% severe, 95% severe on prophylaxis) were included. Sports injuries were reported by 51 participants (41%). Most participants (62%) reported no bleeds at all and only 16% reported SIBs. SIBs were associated with factor levels at time of injury (OR: 0.93/%factor level (CI 0.88-0.99); p = .02), but not with haemophilia severity (OR: 0.62 (CI 0.20-1.89); p = .40), joint health, sports risk category or sports intensity. PWH with factor levels <10% during sports injury had a bleeding risk of 41% versus 20% in those with higher (>10%) factor levels. CONCLUSION: The results of this study emphasize the importance of clotting factor levels in prevention of bleeds. This information is vital for patient counselling and tailoring prophylactic treatment with clotting factors and non-replacement therapy.

Transition readiness among adolescents and young adults with haemophilia in the Netherlands: Nationwide questionnaire study.

INTRODUCTION: Care for adolescents with haemophilia is transferred from paediatric to adult care around the age of 18 years. Transition programs help to prepare adolescents for this transfer and prevent declining treatment adherence. Evaluating transition readiness may identify areas for improvement. OBJECTIVE: Assess transition readiness among Dutch adolescents and young adults with haemophilia, determine factors associated with transition readiness, and identify areas of improvement in transition programs. METHODS: All Dutch adolescents and young adults aged 12-25 years with haemophilia were invited to participate in a nationwide questionnaire study. Transition readiness was assessed using multiple-choice questions and was defined as being ready or almost ready for transition. Potential factors associated with transition readiness were investigated, including: socio-demographic and disease-related factors, treatment adherence, health-related quality of life, and self-efficacy. RESULTS: Data of 45 adolescents and 84 young adults with haemophilia (47% with severe haemophilia) were analyzed. Transition readiness increased with age, from 39% in 12-14 year-olds to 63% in 15-17 year-olds. Nearly all post-transition young adults (92%, 77/84) reported they were ready for transition. Transition readiness was associated with treatment adherence, as median VERITAS-Pro treatment adherence scores were worse in patients who were not ready (17, IQR 9-29), compared to those ready for transition (11, IQR 9-16). Potential improvements were identified: getting better acquainted with the adult treatment team prior to transition and information on managing healthcare costs. CONCLUSIONS: Nearly all post-transition young adults reported they were ready for transition. Improvements were identified regarding team acquaintance and preparation for managing healthcare costs.

Validation of the pedHALshort and HALshort in Dutch children and adults with haemophilia.

INTRODUCTION: The Haemophilia Activities List (HAL) and paediatric HAL assess self-reported limitations in various daily activities. To reduce patient burden, shorter versions of the pedHAL (22 items) and HAL (18 items) have been developed. AIM: This study aimed to determine the agreement between the pedHAL/HALfull and pedHAL/HALshort and construct validity and internal consistency of the pedHAL/ HALshort in persons with haemophilia (PWH). METHODS: A cross-sectional secondary analysis of the Hemophilia in the Netherlands-6 national survey was performed. Adult and paediatric PWH completed the original pedHAL/HALfull , from which pedHAL/ HALshort were derived. Score differences between the original and short versions were calculated. Construct validity was studied by testing hypotheses regarding the relationship of the pedHAL/HALshort with the pedHAL/HALfull , Haemophilia & Exercise Project Test-Questionnaire (HEP-Test-Q), Canadian Haemophilia Outcomes-Kids' Life Assessment Tool (CHO-KLAT) and RAND 36-item Health Survey (RAND-36) (convergent/discriminant validity) as well as its ability to discriminate between subgroups (known-group validity). Internal consistency was assessed with Cronbach's α. RESULTS: We included 113 children (median 10y [range 4-17], 53% severe haemophilia) and 691 adults (median 51y [range 18-88], 35% severe). Scores of the pedHAL/HALfull and pedHAL/HALshort were similar with high correlations (>0.9). Construct validity was confirmed for the pedHAL/HALshort . The HALshort was able to discriminate between different disease severities and ages. Cronbach's α of the pedHAL/HALshort was 0.95-0.97. CONCLUSION: This study confirmed the agreement between the pedHAL/HALfull and the pedHAL/HALshort and the construct validity of the pedHAL/HALshort . The next step is to study construct validity of the pedHAL/HALshort when administered as short forms.

Ankle joint distraction is a promising alternative treatment for patients with severe haemophilic ankle arthropathy.

INTRODUCTION: Haemophilic ankle arthropathy (HAA) causes major morbidity. When conservative treatment fails, major surgical interventions are indicated. An alternative treatment to maintain joint mobility and postpone these interventions is desired. AIM: To gather prospective data on clinical/structural changes after ankle joint distraction (AJD) in HAA. METHODS: This study includes patients with severe HAA insufficiently responding to conservative treatment. AJD was performed during 8-10 weeks by use of an external frame. Questionnaires, physical examination and radiology were used to evaluate pain, function and structural changes before and 6, 12, 24 and 36 months after distraction. Mixed effect models were used for analysis. RESULTS: This study includes eight cases (21-53 years). The fixed effects estimates of the visual analogue score (0-10) improved from 7.5 at baseline to 3.4 (p = .023) 3 years after distraction. The Haemophilia Activities List (HAL, 0-100) for basic/complex lower extremities functions improved from respectively 29.6 and 31.5 to 54.3 (p = .015) and 50.7 (p = .031). Joint mobility was maintained. Magnetic resonance imaging (MRI) showed thickened cartilage and reduced bone marrow oedema and subchondral cysts. Pin tract infections (n = 6) were effectively treated and no adverse bleeding events occurred. At 3-year follow-up, in none of the patients the originally indicated arthrodesis was performed. CONCLUSION: This first prospective study showed that AJD in HAA results in decreased pain, improved function and decreased arthropathy-related MRI findings in the majority of patients for prolonged time. Although the study population is small and follow-up is relatively short, AJD may be promising to postpone invalidating interventions and might be a breakthrough treatment.

Synovitis and synovectomy in haemophilia.

Joint bleeds cause major morbidity in haemophilia patients. The synovial tissue is responsible for removal of blood remnants from the joint cavity. But blood components, especially iron, lead to a series of changes in the synovial tissue: inflammation, proliferation and neovascularization. These changes make the synovium vulnerable to subsequent bleeding and as such a vicious cycle of bleeding-synovitis-bleeding may develop leading to chronic synovitis. The initial step in the treatment is adequate clotting factor supplementation and immediate physiotherapeutic involvement. If these measures fail, synovectomy may be indicated. Non-surgical options are chemical and radioactive synovectomy. This is a relatively non-invasive procedure to do synovectomy, leading to a reduction in pain and joint bleeds. Radioactive synovectomy seems more effective than chemical synovectomy in larger joints. Surgical options are open and arthroscopic synovectomy. Open synovectomy has been found to decrease the incidence of breakthrough bleeds but at the cost of loss of joint motion. Use of arthroscopic synovectomy has been advocated to reduce bleeding episodes with less morbidity to extra-articular tissue and preservation of joint motion. Use of a continuous passive motion (CPM) machine and early mobilization can decrease the postoperative stiffness and promote early recovery. This review addresses the current understanding of synovitis and its treatment options with specific emphasis on chemical and radioactive synovectomy and surgical options.

On-demand treatment with the iron chelator deferasirox is ineffective in preventing blood-induced joint damage in haemophilic mice.

INTRODUCTION: Early intervention in the devastating process of haemophilic arthropathy (HA) is highly desirable, but no disease-modifying therapy is currently available. Considering the pivotal role of iron in the development of HA, iron chelation is considered a promising therapeutic approach. A previous study in haemophilic mice demonstrated that treatment with the iron chelator deferasirox (DFX) 8 weeks before joint bleed induction, attenuated cartilage damage upon blood exposure. However, in haemophilia patients this approach is not opportune given the unpredictable occurrence of hemarthroses. AIM: To evaluate the effectiveness of on-demand DFX treatment, initiated immediately after joint bleed induction. METHODS: A joint bleed was induced in 66 factor VIII-deficient mice by infra-patellar needle puncture. Mice were randomly assigned to treatment with either placebo (drinking water) or DFX (dissolved in drinking water) throughout the study. Five weeks after joint bleed induction, inflammation and cartilage damage were assessed histologically. Joints of ten bleed naive haemophilic mice served as controls. RESULTS: A joint bleed resulted in significant inflammation and cartilage damage in the blood-exposed joint compared with those of control animals, in both the placebo and DFX group (all p = <.05). No differences in tibiofemoral or patellar inflammation (p = .305 and p = .787, respectively) nor cartilage damage (p = .265 and p = .802, respectively) were found between the blood-exposed joints of both treatment groups. CONCLUSION: On-demand treatment with DFX does not prevent joint damage following blood exposure in haemophilic mice. DFX seems unable to reach the joint in time to exert its effect before the irreversible harmful process is initiated.

Similar sports participation as the general population in Dutch persons with haemophilia; results from a nationwide study.

INTRODUCTION: Although sports participation is advocated in people with haemophilia (PWH), detailed data concerning sports participation in Dutch PWH is lacking. AIM: to assess sports participation in Dutch PWH (6-65 years) compared to the Dutch general population (GP). METHODS: Data from a nationwide, cross-sectional study in PWH were analysed. Sports participation (type, duration, frequency) was assessed by the Modifiable Activities Questionnaire (MAQ), limitations in activities using the (Paediatric) Haemophilia Activities List ((Ped)HAL). Sports in the two highest categories according to the National Hemophilia Foundation classification were considered high-risk sports. Groups were compared using Chi-square testing. RESULTS: A total of 524 Adult PWH (median age: 45 (IQR: 30-55); 37% severe) and 126 paediatric PWH (median age: 11 (IQR: 8-14); 52% severe) were included. Sports participation was higher in adults (70%) than the GP (58%) and similar to the GP in children (PWH: 68%, GP: 72%). High-risk sports participation decreased with age in PWH: from 65% (6-12 years) to 17% (50-65 years), which was also observed in the GP. Sports participation in children was independent of severity (non-severe: 67% vs. severe: 65%; P = 0.97), but not in adults (non-severe: 75%, severe: 62%; P < 0.01). Non-severe PWH played more high-risk sports than severe PWH: children at 65% vs. 48% (P = 0.05), adults at 25% vs. 15% (P = 0.07). DISCUSSION: These results suggest that sports participation in PWH was comparable to the GP. Sports participation was dependent of haemophilia severity in adults. Children were more involved in high-risk sports than adults. More studies on sports-related injury-risk are needed for adequate counselling.

Treatment of acquired hemophilia A, a balancing act: results from a 27-year Dutch cohort study.

Acquired hemophilia A (AHA) is a severe auto-immune bleeding disorder. Treatment of AHA is burdensome and optimal management is still unresolved. Therefore a retrospective nationwide multi-center cohort study (1992-2018) was performed to evaluate clinical presentation and treatment efficacy and safety of AHA in the Netherlands. Multivariate logistic and Cox regression analysis was used to study independent associations between patient characteristics and clinical outcomes. A total of 143 patients (median age 73 years; 52.4% male) were included with a median follow-up of 16.8 months (IQR 3.6-41.5 months). First-line immunosuppressive treatment was mostly steroid monotherapy (67.6%), steroids/cyclophosphamide (11.9%) and steroids/rituximab (11.9%), with success rates of 35.2%, 80.0% and 66.7% respectively, P < .05. Eventually 75% of patients achieved complete remission (CR). A high anti-FVIII antibody titer, severe bleeding and steroid monotherapy were associated with lower CR rates. Infections, the most important adverse event, occurred significantly more often with steroid combination therapy compared to steroids alone (38.7% vs 10.6%; P = .001). Overall mortality was 38.2%, mostly due to infections (19.2%) compared to 7.7% fatal bleeds. Advanced age, underlying malignancy and ICU admission were predictors for mortality. This study showed that AHA is characterized by significant disease-related and treatment-related morbidity and mortality. A high anti-FVIII titer, severe bleeding and steroid monotherapy were associated with a lower CR rate. The efficacy of steroid combination therapies however, was overshadowed by higher infection rates and infections represented the most important cause of death. The challenging and delicate balance between treatment effectivity and safety requires ongoing monitoring of AHA and further identification of prognostic markers.

Proteoglycan synthesis rate as a novel method to measure blood-induced cartilage degeneration in non-haemophilic and haemophilic rats.

INTRODUCTION: Haemophilic animal models are used to study blood-induced cartilage damage, but quantitative and sensitive outcome measures are needed. AIM: To develop a novel quantitative method for detecting early cartilage degeneration in a haemophilic rat model of blood-induced joint damage. METHODS: The 35 Sulphate incorporation (35 SO4 2- assay) was applied to tibial and patellar cartilage of wild-type rats to quantify baseline proteoglycan synthesis and to evaluate the effect of 4-day blood exposure in vitro. Next, haemarthrosis was induced in 39 FVIII-deficient rats and characterized by changes in knee joint diameter and development of bone pathology (using micro-CT). Four- and 16-day posthaemarthrosis proteoglycan synthesis rate (PSR) was assessed using the 35 SO4 2- assay, with the contralateral knee as control. RESULTS: In vitro, a decrease in PSR in tibial and patellar cartilage was demonstrated following blood exposure. In vivo, joint diameter and development of bone pathology confirmed successful induction of haemarthrosis. In the blood-exposed knee, tibial and patellar PSR was inhibited 4 and 16 days after induced haemarthrosis. Interestingly, at day 16 the proteoglycan synthesis in the contralateral knee was also inhibited to an extent correlating with that of the blood-exposed knee. CONCLUSION: For the first time, early changes in cartilage matrix synthesis upon blood exposure were quantified with the 35 SO4 2- assay in a haemophilic rat model, establishing this assay as a novel method to study blood-induced cartilage damage.