Pathogenesis of haemophilic synovitis: experimental studies on blood-induced joint damage

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.

[Orthopedic treatment of musculoskeletal disorders in hemophilic patients]

Objective: To study the orthopedic treatment strategy for hemophilia complicated with musculoskeletal disorders as well as the peri-operative consumption of clotting factor. Methods: Total 338 orthopedic surgeries were performed for 261 patients, average age of 30.6 y (6-65 y) , with hemophilia between January 1996 and December 2019 at our institute. Two hundred and twenty-six patients presented with bleeds within the joints. Sixty-one patients presented with intramuscular bleeds, 45 presented with hemophilic pseudotumors, and six presented with miscellaneous complaints. Strategy of clotting factor replacement therapy was designed as per differences in the level of the operation procedure. Information regarding clinical manifestation, operative strategy, clotting factor consumption, and re-operation for complications was retrospectively recorded. The costs for multiple joint procedure and single joint procedure were studied. Results: We found that 270 of the 338 surgical procedures were major surgical procedures (79.9%) . There were 203 procedures of joint arthroplasty (60%) . Fourteen patients underwent reoperations for local recurrence (4.2%) . The average factor Ⅷ consumption before the surgery was 44.4 ± 8.1 IU/kg. The average FⅧ consumption within postoperative 2 weeks was 40 962 IU (647±177 IU/kg) . Seven type A hemophilic patients developed F Ⅷ inhibitor following the surgical procedure, with an average level of 13.7±11.2 BU/mL. Sixty-eight patients underwent multiple joint procedures under one anesthesia session (26%) . There was no significant difference in the factor consumption between the multiple joint procedure and single joint procedure. Conclusions: Surgical treatment was found to be effective for hemophilic arthropathy and lesion of the musculoskeletal apparatus, with the clotting factor replacement therapy. Multiple joint procedures under one anesthesia were more cost effective for patients with hemophilia, with less factor consumption than staged single joint procedure.

Effect of Pulsed Electromagnetic Fields on Clinical Signs and Quality of Life in Patients with Hemophilic Arthropathy of the Knee Joint: A Randomized Controlled Trial

BACKGROUND

Hemophilic arthropathy (HA) causes severe joint damage and impairs the quality of life (QoL) of hemophiliacs. This study was undertaken to evaluate the effect of pulsed electromagnetic fields (PEMFs) on the clinical signs and QoL of patients with severe hemophilia A experiencing moderate HA in the knee joint.

MATERIALS AND METHODS

Thirty-six severe hemophiliacs with HA of the knee joint were randomly assigned into the PEMF (n = 20) or placebo (n = 16) groups. The PEMF group received 60 min of PEMF (2 Hz, 25 Gauss for 30 min and 70 Hz, 30 Gauss for 30 min) on the knee joint, three times per week for 6 weeks. The clinical signs, QoL, and pain intensity were measured by the Hemophilia Joint Health Score, A36 Hemofilia-QoL Questionnaire, and visual analog scale, respectively, before and after treatment.

RESULTS

In the PEMF group, a significant difference before and after intervention in terms of clinical signs, QoL, and pain intensity (P < 0.05) was founded. Between-group analysis showed a significant improvement in clinical signs (except for atrophy, strength, and swelling duration), QoL, and pain intensity in the PEMF versus control group (P < 0.05).

CONCLUSIONS

PEMF can improve the clinical signs, QoL, and pain intensity of severe hemophilia A patient with moderate knee hemophilic arthropathy.

Morphological characteristics and clinical significance of the distal femur in patients with hemophilia-related knee arthritis

This retrospective study aimed to define the morphological characteristics of the distal femur in patients with hemophilia-related knee arthritis (HA) and develop precise femoral component installation during total knee arthroplasty (TKA) using a reference axis.Computed tomography (CT) was performed in 75 patients [HA group: 34 patients, 48 knees; osteoarthritis (OA group): 41 patients, 48 knees] during 2017-2019. CT scans were constructed into three-dimensional models. We measured the medial (MPC) and lateral (LPC) posterior condyle widths, lateral anteroposterior (LAP) height, medial anteroposterior (MAP) height, mediolateral epicondyle (ML) width, and depths of the anterior patellar groove (X2) and the intercondylar notch (X4). Also, angles were measured between the posterior condylar line (PCL) and surgical transepicondylar axis (STEA) (PCA angle), anteroposterior axis (APA angle) and STEA (APSA angle), anterior condylar line (ACL) and STEA (ACA angle), and clinical transepicondylar axis (CTEA) and PCL (CTA angle). ML/MAP, ML/LAP, X4/LAP, X2/LAP, and LPC/ML ratios were calculated.There were no significant differences in any angles between the HA and OA groups (P > .05). However, the HA group had a smaller MPC (P < .05) and larger X4 than the OA group (P < .05). ML, ML/LAP, X2, MAP, and LAP showed no significant differences between the 2 groups.ML, ML/LAP, and PCA showed no significant differences between the 2 groups. During TKA in hemophilia-related knee arthritis patients, the femoral component can be installed with PCL as the reference axis, although individual differences should be considered.

Yttrium-90 radiosynovectomy in knees and ankles (25 joints in 22 hemophilic patients). Short-term results

Introduction

The radiosynovectomy (RS) is one treatment option for recurrent hemarthrosis in patients with hemophilia (PWH). A prospective cohort study was designed to evaluate the effects of the RS on the synovial membrane volume in the ankles and knees of PWH and patient characteristics related to the RS outcome.

Methods

In a one-year follow-up, 25 joints of 22 PWH who presented 3 bleeds or more in the same joint over the last 6 months (target joints) were subjected to the RS. Two groups were compared: those who retained target joints following the RS and those who did not (less than 3 bleeds/6 months after the RS). The groups were analyzed according to age, hemophilia type/severity, joint, body mass index (BMI), inhibitor and Hemophilia Joint Health Score 2.1 (HJHS). The magnetic resonance images (MRI) of six ankles and six knees were acquired prior to, and 6 months after, the RS. The synovial membrane volume and arthropathy MRI scale were accessed and volumes were compared and correlated with the Yttrium-90 dose injected.

Results

Patients with a mean age of 12 years and a mean HJHS of 6.7 (p < 0.05) retained target joints after the RS. The inhibitor, joint, type/severity of disease and BMI showed no significant differences between groups. The synovial membrane volume had a significant reduction after the RS (p = 0.03), but no correlation with the Yttrium-90 dose. In proportion to the synovial membrane volume, doses injected to the ankles were larger than those injected to the knees.

Conclusion

The synovial membrane volume is reduced after the RS, regardless of the effective 90Y dose.

Joint scores in hemophilic arthropathy in children: Developing country perspectives

OBJECTIVE

Hemophilia is a common X-linked recessive coagulopathy causing recurrent bleeding into the synovial joints and results in articular and periarticular abnormalities. To our knowledge, this is the first comprehensive study aimed at studying the clinico-radiological joint score evaluation in hemophilic arthropathy in children from a developing country and its possible impact on the quality of life.

METHODS

In this hospital-based, prospective, descriptive study, all children presenting to the pediatric rheumatology clinic were studied. The joint physical examination was scored using the Hemophilia Joint Health Score 2.1 (HJHS 2.1). The patients were then subjected to imaging of the most affected joint using ultrasonography (USG) and magnetic resonance imaging (MRI). Detailed USG and MRI radiological evaluation was recorded in the predesigned proforma using the Hemophilia Early Arthropathy Detection with Ultra Sound (HEAD-US) score and MRI DENVER score. The physical quality of life as per Functional Independence Score in Hemophilia (FISH) was noted. The clinical, radiological, and functional scores were analyzed with an appropriate statistical measure.

RESULTS

The mean age at presentation was 7.4 years (interquartile range 4.9-10), with the knee being the most common joint involved. All of the USG score, MRI score, and FISH score have a significant correlation (p<0.05), with the HJHS 2.1 score with correlation coefficients of 0.7086, -0.8916, and 0.8607, respectively. USG and MRI had a correlation coefficient of -0.7145 and -0.8326 with FISH, respectively.

CONCLUSION

The degree of association between HJHS 2.1 score was found to be maximum with HEAD-US score, whereas a negative correlation was seen evaluating FISH score with both HEAD-US and MRI DENVER scores. Use of these scores, specifically HEAD-US score, will result in consistent assessment of hemophilic joints, optimizing the management of the destructive changes.

Current perspectives on biological approaches for osteoarthritis

Musculoskeletal injuries that disrupt the structure and function of diarthrodial joints can cause permanent biomechanical alterations and lead to a more severe, chronic condition. Despite advancements that have been made to restore tissue function and delay the need for joint replacement, there are currently no disease-modifying therapies for osteoarthritis (OA). To reduce the risk of OA, innovative preventive medicine approaches have been developed over the last decade to treat the underlying pathology. Several biological approaches are promising treatment modalities for various stages of OA owing to their minimally invasive nature and actively dynamic physiological mechanisms that attenuate tissue degradation and inflammatory responses. Individualized growth factor and cytokine therapies, tissue-engineered biomaterials, and cell-based therapies have revolutionary potential for orthopedic applications; however, the paucity of standardization and categorization of biological components and their counterparts has made it difficult to determine their clinical and biological efficacy. Cell-based therapies and tissue-engineered biologics have become lucrative in sports medicine and orthopedics; nonetheless, there is a continued effort to produce a biological treatment modality tailored to target intra-articular structures that recapitulates tissue function. Advanced development of these biological treatment modalities will potentially optimize tissue healing, regeneration, and joint preservation strategies. Therefore, the purpose of this paper is to review current concepts on several biological treatment approaches for OA.

Effect of radiosynoviorthesis on the progression of arthropathy and haemarthrosis reduction in haemophilic patients

INTRODUCTION

Repeated haemarthrosis is widely accepted as the triggering cause of synovitis and haemophilic arthropathy. A first-line treatment of chronic synovitis is radiosynoviorthesis (RS). The aim of this study was to evaluate the RS effects on the progression of arthropathy and on a reduction in bleeding in patients with haemophilia.

METHODS

An observational-retrospective study was performed. Bleeding episodes in the 12 months following and in the 12 months preceding RS was compared. The arthropathy was clinically and radiologically analysed by age range, joint and subject, comparing those undergoing RS (Radiosynoviorthesis Group, RSG) against those not undergoing this treatment (Non-Radiosynoviorthesis Group, Non-RSG).

RESULTS

One hundred and seventy-four RS were performed in 71 patients (⁹⁰ Y in Knees and ¹⁸⁶ Re in elbows/ankles/shoulder). RS resulted in significant reduction in bleeding (582 preintervention and 168 postintervention, P < .001). In general, the level of arthropathy measured clinically and radiologically was greater with age increase in both groups (RSG and Non-RSG), especially in the 25-40 age range. A significant increase (P < .05) in the progression of arthropathy was also observed, both globally by patient and specifically for each joint, in non-RSG and RSG group.

CONCLUSION

RS is an effective method to reduce the number of haemarthrosis episodes in chronic synovitis. Moreover, RS can positively affect arthropathy by slowing down its progression. However, the results obtained suggest that arthropathy may be conditioned by the subject's age, regardless of whether or not the joint has undergone RS.

Ultrasound for Early Detection of Joint Disease in Patients with Hemophilic Arthropathy

Joint bleeding represents the most commonly reported type of hemorrhage in patients affected by hemophilia. Although the widespread use of prophylaxis has been able to significantly reduce the onset of arthropathy, it has been shown that a non-negligible percentage of patients develop degenerative changes in their joints despite this type of treatment. Thus, periodic monitoring of the joint status in hemophilia patients has been recommended to identify early arthropathic changes and prevent the development or progression of hemophilic arthropathy. Ultrasound (US) has proven able to detect and quantify the most relevant biomarkers of disease activity (i.e., joint effusion and synovial hypertrophy) and degenerative damages (i.e., osteo-chondral changes) by means of scoring scales of increasing disease severity. In the present review, we have detailed major literature evidence about the use of US to assess joint status in hemophilia patients, focusing on signs of disease activity and degenerative damages. In particular, we have discussed recent evidence about "point-of-care" use patients with hemophilia.

Insights into cryotherapy and joint bleeding: cryotherapy and hemophilia

: There is some controversy over the use of cryotherapy. Low temperatures (Temp) could interfere with coagulation and increase the risk of bleeding. We sought to examine the effect of cryotherapy on joint swelling, temperature, friction, and inflammatory condition after experimental hemarthrosis. The left knee of 23 albino rabbits, 10 in heparin Ice, five in citrate Ice, four in heparin control, and four in citrate control were injected intraarticularly with 1 ml of blood. In total, four animals were considered to be in normal control group. Joint diameter, Temp, and ultrasonography were assessed before the blood injection. One day after the intraarticular blood injection, cryotherapy was applied 4 times per day for 4 consecutive days. Joint diameter and Temp were measured twice a day. After cessation of the protocol, joint diameter and Temp were assessed and sonography performed, animals euthanized, the friction test was performed and the synovial membrane collected, respectively. Joint diameter and Temp were increased after the intraarticular blood injection. Cryotherapy was capable of reducing the swelling and Temp. Ultrasonography findings approved the positive effect of cryotherapy on joint swelling. The proinflammatory tumor necrosis factor (TNF-α) reduced by cryotherapy in both cryotherapy groups but Interleukin 1β was only reduced in heparin group. Interleukin-4 increased in heparin Ice group that was in comparison with TNF-α reduction. Cryotherapy reduced joint swelling and has a positive effect on controlling joint inflammation and Temp.

A preliminary case series evaluating the safety and immediate to short-term clinical benefits of joint mobilization in hemophilic arthritis of the lower limb

OBJECTIVES

Arthritis resulting from recurrent intra-articular bleeding in individuals with hemophilia can be severely debilitating due to joint pain and stiffness with subsequent loss of mobility and function. Very limited studies have investigated the potential benefits of joint mobilization for this condition. This case series is a preliminary investigation of safety, as well as immediate and short-term clinical benefits, associated with gentle knee and ankle joint mobilization in people with hemophilic arthropathy.

METHODS

A single intervention of joint mobilization was applied to the affected knees and/or ankles of 16 individuals with severe or moderate hemophilia within a public hospital setting. Adverse events, as well as immediate (pain-free passive joint range, Timed Up and Go Test with maximum pain numerical rating scale) and short-term (Lower Extremity Functional Scale) effects of the intervention were evaluated with a repeated measures ANOVA.

RESULTS

There were no adverse events. An immediate significant increase was observed in pain-free passive ankle joint range of motion (p < 0.05) following the joint mobilization intervention.

DISCUSSION

The findings of this case series suggest that gentle joint mobilization techniques may be safely considered as part of a multimodal management approach for hemophilic arthropathy.

Chemically defined serum-free conditions for cartilage regeneration from human embryonic stem cells

AIMS

The aim of this study was to improve a method that induce cartilage differentiation of human embryoid stem cells (hESCs) in vitro, and test the effect of in vivo environments on the further maturation of hESCs derived cells.

MAIN METHODS

Embryoid bodies (EBs) formed from hESCs, with serum-free KSR-based medium and mesodermal specification related factors, CHIR, and Noggin for first 8days. Then cells were digested and cultured as micropellets in serum-free KSR-based chondrogenic medium that was supplemented with PDGF-BB, TGF β3, BMP4 in sequence for 24days. The morphology, FACS, histological staining as well as the expression of chondrogenic specific genes were detected in each stage, and further in vivo experiments, cell injections and tissue transplantations, further verified the formation of chondrocytes.

KEY FINDINGS

We were able to obtain chondrocyte/cartilage from hESCs using serum-free KSR-based conditioned medium. qPCR analysis showed that expression of the chondroprogenitor genes and the chondrocyte/cartilage matrix genes. Morphology analysis demonstrated we got PG+COL2+COL1-particles. It indicated we obtained hyaline cartilage-like particles. 32-Day differential cells were injected subcutaneous. Staining results showed grafts developed further mature in vivo. But when transplanted in subrenal capsule, their effect was not good as in subcutaneous. Microenvironment might affect the cartilage formation.

SIGNIFICANCE

The results of this study provide an absolute serum-free and efficient approach for generation of hESC-derived chondrocytes, and cells will become further maturation in vivo. It provides evidence and technology for the hypothesis that hESCs may be a promising therapy for the treatment of cartilage disease.

Orthopedic disorders of the knee in hemophilia: A current concept review

The knee is frequently affected by severe orthopedic changes known as hemophilic arthropathy (HA) in patients with deficiency of coagulation factor VIII or IX and thus this manuscript seeks to present a current perspective of the role of the orthopedic surgeon in the management of these problems. Lifelong factor replacement therapy (FRT) is optimal to prevent HA, however adherence to this regerous treatment is challenging leading to breakthrough bleeding. In patients with chronic hemophilic synovitis, the prelude to HA, radiosynovectomy (RS) is the optimal to ameliorate bleeding. Surgery in people with hemophilia (PWH) is associated with a high risk of bleeding and infection, and must be performed with FRT. A coordinated effort including orthopedic surgeons, hematologists, physical medicine and rehabilitation physicians, physiotherapists and other team members is key to optimal outcomes. Ideally, orthopedic procedures should be performed in specialized hospitals with experienced teams. Until we are able to prevent orthopedic problems of the knee in PWH will have to continue performing orthopedic procedures (arthrocentesis, RS, arthroscopic synovectomy, hamstring release, arthroscopic debridement, alignment osteotomy, and total knee arthroplasty). By using the aforementioned procedures, the quality of life of PWH will be improved.

The effect of chemically defined medium on spontaneous calcium signaling of in situ chondrocytes during long-term culture

Chemically defined serum-free medium has been shown to better maintain the mechanical integrity of articular cartilage explants than serum-supplemented medium during long-term in vitro culture, but little is known about its effect on cellular mechanisms. We hypothesized that the chemically defined culture medium could regulate the spontaneous calcium signaling of in situ chondrocytes, which may modulate the cellular metabolic activities. Bovine cartilage explants were cultured in chemically defined serum-free or serum-supplemented medium for four weeks. The spontaneous intracellular calcium ([Ca(2+)]i) signaling of in situ chondrocytes was longitudinally measured together along with the biomechanical properties of the explants. The spontaneous [Ca(2+)]i oscillations in chondrocytes were enhanced at the initial exposure of serum-supplemented medium, but were significantly dampened afterwards. In contrast, cartilage explants in chemically defined medium preserved the level of calcium signaling, and showed more responsive cells with higher and more frequent [Ca(2+)]i peaks throughout the four week culture in comparison to those in serum medium. Regardless of the culture medium that the explants were exposed, a positive correlation was detected between the [Ca(2+)]i responsive rate and the stiffness of cartilage (Spearman's rank correlation coefficient=0.762). A stable pattern of [Ca(2+)]i peaks was revealed for each chondrocyte, i.e., the spatiotemporal features of [Ca(2+)]i peaks from a cell were highly consistent during the observation period (15 min). This study showed that the beneficial effect of chemically defined culture of cartilage explants is associated with the spontaneous [Ca(2+)]i signaling of chondrocytes in cartilage.

Managing haemophilia for life: 4th Haemophilia Global Summit

The 4th Haemophilia Global Summit was held in Potsdam, Germany, in September 2013 and brought together an international faculty of haemophilia experts and delegates from multidisciplinary backgrounds. The programme was designed by an independent Scientific Steering Committee of haemophilia experts and explored global perspectives in haemophilia care, discussing practical approaches to the optimal management of haemophilia now and in the future. The topics outlined in this supplement were selected by the Scientific Steering Committee for their relevance and potential to influence haemophilia care globally. In this supplement from the meeting, Jan Astermark reviews current understanding of risk factors for the development of inhibitory antibodies and discusses whether this risk can be modulated and minimized. Factors key to the improvement of joint health in people with haemophilia are explored, with Carlo Martinoli and Víctor Jiménez-Yuste discussing the utility of ultrasound for the early detection of haemophilic arthropathy. Other aspects of care necessary for the prevention and management of joint disease in people with haemophilia are outlined by Thomas Hilberg and Sébastian Lobet, who highlight the therapeutic benefits of physiotherapy and sports therapy. Riitta Lassila and Carlo-Federico Perno describe current knowledge surrounding the risk of transmission of infectious agents via clotting factor concentrates. Finally, different types of extended half-life technology are evaluated by Mike Laffan, with a focus on the practicalities and challenges associated with these products.

Radiosynovectomy: review of the literature and report from two haemophilia treatment centers

Haemophilic arthropathy occurs due to recurrent bleeding into joints leading to swelling, inflammation, destruction of cartilage and bone, and development of arthritis. Although prophylactic replacement therapy assists in preventing arthropathy, it is not always adequate or affordable. Radiosynovectomy is a minimally invasive intervention for treatment of synovitis in haemophilic joints. The procedure utilises locally injected radioisotopes (Y, P, Rh) to ablate abnormal synovium with the goal of decreasing bleeding, slowing progression of cartilage and bone damage and preventing arthropathy. The objective of this review is to summarize the radiosynovectomy literature and to present patient outcomes associated with radiosynovectomy over the past 17 years from two haemophilia treatment centers (HTCs), one in the United States and one in Spain. Articles from these two centers support the current literature. A retrospective medical records review was performed by the two reporting HTCs on patients who underwent radiosynovectomy prior to 2009. Data review included: site of procedure, isotope utilized, bleeding frequency, and procedure complications. Radiosynovectomy is a cost-effective, minimally invasive, well tolerated procedure. As the paradigm for care in haemophilia shifts towards prevention of joint disease, the number of target joints with synovitis will likely decrease, except in patients who develop inhibitors. We propose early consideration of radiosynovectomy for patients with haemophilic synovitis prior to appearance of articular cartilage damage.

The effect of secondary prophylaxis versus episodic treatment on the range of motion of target joints in patients with haemophilia

This study prospectively compared the effect of secondary prophylaxis to episodic treatment on target joint (TJ) range of motion (ROM), number of joint haemorrhages and new TJ development in patients with moderate or severe haemophilia. Two-hundred and eighty-six males, 17% in prophylaxis, 83% in episodic treatment group, participating in the Centers for Disease Control and Prevention's Universal Data Collection project, fulfilled inclusion criteria: age >2 years at enrollment, free of TJs at enrollment, developed at least one TJ after enrollment, and received either prophylaxis or episodic treatment continuously for two follow-up visits after TJ development. The outcomes of interest - percentage change in TJ ROM, number of joint haemorrhages and new TJ development, were modelled using multivariate linear, Poisson and logistic regression techniques respectively. Individuals who received secondary prophylaxis in comparison to episodic treatment were younger at TJ development (P < 0.01); there was no difference in the decrease in TJ ROM between the two groups (P = 0.9). Factors significantly associated with a higher rate of haemarthroses included episodic treatment, severe haemophilia, age >5 years at TJ development, obesity and inhibitor negative status. Secondary prophylaxis significantly decreased haemarthroses but was not associated with a significant improvement in TJ ROM or with new TJ development.

Management of joint bleeding in hemophilia

Hemarthrosis, the hallmark of severe hemophilia, is the major cause of serious bleeding events, disability and reduced quality of life in patients with factor VIII or factor IX deficiency. Joint bleeding is one of the greatest challenges confronting individuals treating hemophilia, and its economic impact is enormous. This article reviews the current management of hemophilic joint bleeding and discusses the potential impact of novel therapies.

Nuclear factor (NF)-κB and its associated pathways are major molecular regulators of blood-induced joint damage in a murine model of hemophilia

BACKGROUND

The present study was designed to investigate the molecular signaling events from onset of bleeding through the development of arthropathy in a murine model of hemophilia A.

METHODS AND RESULTS

A sharp-injury model of hemarthrosis was used. A global gene expression array on joint-specific RNA isolated 3 h post-injury revealed nuclear factor-kappa B (NF-κB) as the major transcription factor triggering inflammation. As a number of genes encoding the cytokines, growth factors and hypoxia regulating factors are known to be activated by NF-κB and many of these are part of the pathogenesis of various joint diseases, we reasoned that NF-κB-associated pathways may play a crucial role in blood-induced joint damage. To further understand its role, we screened NF-κB-associated pathways between 1 h to 90 days after injury. After a single articular bleed, distinct members of the NF-κB family (NF-κB1/NF-κB2/RelA/RelB) and their responsive pro-inflammatory cytokines (IL-1β/IL-6/IFNγ/TNFα) were significantly up-regulated (> 2 fold, P < 0.05) in injured vs. control joints at the various time-points analyzed (1 h/3 h/7 h/24 h). After multiple bleeds (days 30/60/75/90), there was increased expression of NF-κB-associated factors that contribute to hypoxia (HIF-1α, 3.3-6.5 fold), angiogenesis (VEGF-α, 2.5-4.4 fold) and chondrocyte damage (matrix metalloproteinase-13, 2.8-3.8 fold) in the injured joints. Micro RNAs (miR) that are known to regulate NF-κB activation (miRs-9 and 155), inflammation (miRs-16, 155 and 182) and apoptosis (miRs-19a, 155 and 186) were also differentially expressed (-4 to +13-fold) after joint bleeding, indicating that the small RNAs could modulate the arthropathy phenotype.

CONCLUSIONS

These data suggest that NF-κB-associated signaling pathways are involved in the development of hemophilic arthropathy.

Hemophilic chronic synovitis: therapy of hemarthrosis using endovascular embolization of knee and elbow arteries

PURPOSE

Congenital hemophilia is a hereditary bleeding disorder that affects 1 in 5,000 males and is characterized by repetitive musculoskeletal bleeding episodes. Selective embolization of the knee and elbow arteries can prevent bleeding episodes. To evaluate the long-term efficacy of these procedures, we assessed the outcomes of 30 procedures performed in our center.

METHODS

We performed 30 procedures in 27 hemophilic patients, including 23 knee, and 7 elbow procedures. To evaluate the efficacy of selective embolization of knee and elbow arteries in people with hemophilia, we analyzed the number of bleeding episodes during 12 months before the procedure compared with the amount of episodes that occurred 3, 6, and 12 months after embolization.

RESULTS

Twenty-nine of 30 procedures were classified as successful. The median of 1.25 episodes per month (range 0-3) observed before the procedure was reduced to 0 (range 0-1.67; p < 0.001) at 3 months, 0.17 (range 0-1.67; p < 0.001) at 6 months, and 0.33 (range 0-1.67; p = 0.024) at 12 months. Three patients remained free of bleeding events for more than 6 months. Additionally, after the procedure there was a significant reduction in factor FVIII usage that sustained up to 12 months after the procedures. No serious adverse events were observed.

CONCLUSIONS

Selective angiographic embolization of knee and elbow arteries is a feasible procedure that can prevent repetitive bleedings, which would translate in better joint outcomes for these patients.

The clotting system - a major player in wound healing

Wound healing involves a complex series of interactions between coagulation, inflammation, angiogenesis, and cellular migration and proliferation. Our laboratory has developed an excisional dermal wound model in mice in order to study some of these processes and to determine how coagulation defects affect wound healing. In contrast to wild type mice, haemophilia B mice typically show delayed healing, signs of bleeding into the wound, and significant wound expansion. The difference in wound size may result from limited fibrin deposition in haemophilic animals and the subsequent inability to anchor the platelet plug to the surrounding tissues, thus allowing wound expansion through oedema. Haemophilic mice also demonstrate impaired wound healing times. However, while pre-treatment with factor IX or human activated factor VII improves some wound characteristics in haemophilia B animals, the time to wound healing is still delayed and signs of ongoing bleeding are evident. Haemophilic mice also show a deficient initial inflammatory response and increased angiogenesis, which, in turn, leads to increased bleeding: in the absence of robust haemostasis, these fragile, newly sprouted vessels have a tendency to bleed. Taken together, these observations suggest that ongoing haemostasis is necessary for normal wound healing. If this is correct, then optimal wound healing in haemophilia would require therapy until at least the point that vessel formation is stabilized. The goal of such treatment would be to avoid a feedback cycle in which bleeding tends to lead to further bleeding. Once initiated, this cycle may be difficult to control.

Aspects of current management: orthopaedic surgery in haemophilia

If continuous prophylaxis is not feasible due to expense or lack of venous access, we must aggressively treat major haemarthroses (including arthrocentesis) to prevent progression to synovitis, recurrent joint bleeds, and ultimately end-stage osteoarthritis (haemophilic arthropathy). For the treatment of chronic haemophilic synovitis, radiosynovectomy should always be indicated as the first procedure. If, after three procedures with 6-month interval, radiosynovectomy fails, an arthroscopic synovectomy must be indicated. Between the second and fourth decades, many haemophilic patients develop joint destruction (arthropathy). At this stage possible treatments include alignment osteotomy, arthroscopic joint debridement, arthrodesis (joint fusion) and total joint arthroplasty. For the hip press-fit uncemented components (hemispherical acetabulum, flanged femoral stem, metal-to-polyethylene) are recommended whilst for the knee a posterior-stabilized (PS) cemented design is advised. Muscular problems must not be underestimated in haemophilia due to their risk of developing compartment syndromes (which will require surgical decompression) and pseudotumours (which will require surgical removal or percutaneous treatment). Regarding patients with inhibitors, the advent of APCCs and rFVIIa has made major orthopaedic surgery possible, leading to an improved quality of life for haemophilia patients. Concerning local fibrin seal, it is not always necessary to achieve haemostasis in all surgical procedures performed in persons with haemophilia. However, it could be a good adjunct therapy, mainly when a surgical field potentially will bleed more than expected (i.e. patients with inhibitors), and also in some orthopaedic procedures (mainly the surgical removal of pseudotumours).

Hemophilic synovitis: factor VII and the potential role of extravascular factor VIIa

The initiation of coagulation via tissue factor/factor VIIa is relatively weak in normal synovium and joint tissues, so that hemophilic patients with additional deficiency of the intrinsic pathway of coagulation are especially at risk for joint bleeding and the development of hemophilic synovitis. The inflamed joint that results from recurrent bleeding-induced injury, however, may be an environment in which pharmacologic doses of factor VIIa have potentially greater procoagulant action than in the uninjured joint. There is accumulating evidence suggesting that coagulation factors in the extravascular space, and not only circulating plasma factors, have the potential to contribute to hemostatic protection of joints. The potential role of extravascular factor VIIa is considered.

Biotribological and biomechanical changes after experimental haemarthrosis in the rabbit knee

Changes in articular cartilage after haemarthrosis have not been completely elucidated in haemophilic arthropathy. Insights into the pathophysiological mechanisms of blood-induced joint damage mainly derived from histological, inflammatory and biochemical investigations. A structure-function relationship is another reasonable way to determine the joint overall health status. Cartilage, a viscoelastic connective tissue, is at least a biphasic material that should also work under minimal friction. Pendulum friction tester measures the mechanical aspects of joint lubrication and quantifies the biotribological properties of the joint. Indentation test is an in situ method characterizing the biomechanical properties of the cartilage. Gross, biotribological and biomechanical properties were determined in a rabbit model of experimental haemarthrosis. A sample of 1 mL of fresh autologous blood was injected in the left knee of rabbit's joint twice weekly for four consecutive weeks. The right knee and animals in the control group were left untreated. After 8 days, joint perimeter, biotribological and biomechanical tests were performed. In a consistent manner, all data showed detrimental effects of the blood on the overall cartilage function under loading. Non-weight bearing and early blood aspiration seem wise to be considered after haemarthrosis.

Blood-induced joint disease: the pathophysiology of hemophilic arthropathy

Arthropathy is a frequent and serious complication of repeated joint bleeding in patients with hemophilia, resulting in pain, deformity, and disability. Although the pathogenesis of hemophilic arthropathy has not been fully elucidated, it appears to have similarities with the degenerative joint damage that occurs in osteoarthritis and the inflammatory processes associated with rheumatoid arthritis. This article reviews the potential actions of various blood constituents on joint components that culminate in the development of hemophilic arthropathy.

IL-1 beta, IL-6, KC and MCP-1 are elevated in synovial fluid from haemophilic mice with experimentally induced haemarthrosis

The hallmark of haemophilia is the joint morbidity resulting from haemarthrosis that accounts for the majority of the bleeds. The exact mechanisms underlying changes are not fully elucidated. Cytokines are speculated to be involved in the progression and in vitro studies have confirmed the presence of elevated levels of cytokines in synovial tissue and cartilage from patients with haemophilic synovitis. In this study, the presence of selected cytokines in synovial fluid from haemophilia A mice with experimentally induced haemarthroses treated with rFVIII, rFVIIa and an rFVIIa analogue were investigated. Ten cytokines previously shown to be involved in arthritic syndromes were evaluated. Interleukin (IL)-1 beta, IL-2, IL-4, IL-6, IL-10, IL-17, Tumor Necrosis Factor-alpha (TNF- alpha), keratinocyte-derived chemokine (KC), Regulated upon Activation, Normal T cell Expressed and Secreted (RANTES) and monocyte chemotactic protein-1 (MCP-1) were included. In this article, we demonstrate, for the first time, that bleeding in knee joints of haemophilia A mice resulted in correlated increased levels of the pro-inflammatory cytokines: IL-1 beta, IL-6, KC and the MCP-1 in synovial fluid. These results suggest an important role of MCP-1 in the recruitment of monocytes and furthermore that the inflamed synovium releases IL-1 beta, IL-6 and KC, which in turn might contribute to further progression of the inflammatory process.

Musculoskeletal complications of hemophilia

The most important clinical strategy for management of patients with hemophilia is the avoidance of recurrent hemarthroses by means of continuous, intravenous hematological prophylaxis. When only intravenous on-demand hematological treatment is available, frequent evaluations are necessary for the early diagnosis and treatment of episodes of intra-articular bleeding. The natural history of the disease in patients with poorly controlled intra-articular bleeding is the development of chronic synovitis and, later, multi-articular hemophilic arthropathy. Once arthropathy develops, the functional prognosis is poor. Treatment of these patients should be conducted through a comprehensive program by a multidisciplinary hemophilia unit. Although continuous prophylaxis can avoid the development of the orthopedic complications of hemophilia still seen in the twenty-first century, such a goal has not, so far, been achieved even in developed countries. Therefore, many different surgical procedures such as arthrocentesis, radiosynoviorthesis (radiosynovectomy) (yttrium-90, rhenium-186), tendon lengthenings, alignment osteotomies, joint arthroplasties, removal of pseudotumours, and fixation of fractures are still frequently needed in the care of these patients.

Factor VIII-von Willebrand factor complex inhibits osteoclastogenesis and controls cell survival

Factor VIII-von Willebrand factor (FVIII.vWF) complex, a molecule involved in coagulation, can be physically associated with osteoprotegerin (OPG). OPG is an anti-osteoclastic protein and a soluble receptor for the proapoptotic protein TRAIL (tumor necrosis factor-related apoptosis-inducing ligand), suggesting a potential role of FVIII.vWF complex in bone and cancer biology. We, thus, assessed the effects of FVIII.vWF complex on osteoclastogenesis and cell survival. We first evidenced that FVIII.vWF complex inhibited RANKL-induced osteoclastogenesis and enhanced the inhibitory effect of OPG. Interestingly, we revealed by surface plasmon resonance that FVIII.vWF complex bound to RANKL, whereas recombinant FVIII and vWF did not. By modeling, we showed that the OPG binding domain to the A1 domain of vWF was closely located and partially overlapped to its binding site to RANKL. Then, we demonstrated that FVIII.vWF complex cancelled the inhibitory activity of OPG on TRAIL-induced apoptosis and characterized interactions between these molecules. The present work evidenced a direct activity of FVIII.vWF complex on osteoclasts and on induced cell apoptosis, pointing out its potential involvement in physiological bone remodeling or in bone damages associated with severe hemophilia and cancer development.

Physiopathology of haemophilic arthropathy

Haemophilic arthropathy, which shares some clinical and biological injury characteristics with rheumatoid arthritis, is characterized by two main features: chronic proliferative synovitis and cartilage destruction. It is the consequence of repeated extravasation of blood into joint cavities, but its exact pathogenesis, particularly with regard to early changes in the joint, is still incompletely understood. This review presents recent findings obtained in experiments performed in vitro and using animal models, which have improved our knowledge of the pathogenesis of haemophilic arthropathy. These experimental studies show that haemophilic arthropathy is a multifactorial event in which the deposit of iron in the joints appears to exert a central role. First, iron may promote the apoptosis of chondrocytes by catalysing the formation of oxygen metabolites; this may explain the fact that intra-articular blood exerts a directly harmful effect on cartilage before, and independent of synovial changes. Secondly, iron may also act on the synovial membrane by favouring its proliferation through the induction of proto-oncogenes involved in cellular proliferation and stimulation of inflammatory cytokines as well as abrogation of apoptosis. These two processes, one degenerative and cartilage-mediated, the other inflammatory and synovium-mediated could occur in parallel or sequentially. Overall, it may be expected that these experimental results will yield new therapeutic strategies capable of effectively preventing the occurrence of this still serious and common complication in patients with severe haemophilia.