Pathological mechanism of joint destruction in haemophilic arthropathy.

Haemophilic arthropathy (HA), caused by intra-articular haemorrhage, is one of the most common complications in patients with haemophilia. Factor replacement therapy provides missing coagulation factors to prevent children with haemophilia from joint bleeding and decreases their risk for HA. However, haemophilia patients in developing countries are still suffering from HA due to insufficient replacement therapy. Symptoms such as pain and activity limitations caused by HA seriously affect the functional abilities and quality of life of patients with HA, causing a high disability rate in the haemophilia cohort. The pathological mechanism of HA is complicated because the whole pathological mainly involves hypertrophic synovitis, osteopenia, cartilage and bone destruction, and these pathological changes occur in parallel and interact with each other. Inflammation plays an important role in the whole complex pathological process, and iron, cytokines, growth factors and other factors are involved. This review summarizes the pathological mechanism of HA to provide background for clinical and basic research.

Dysregulated Inflammatory Response Related to Cartilage Degradation after ACL Injury.

PURPOSE: Elevated synovial fluid (SF) concentrations of proinflammatory cytokines, degradative enzymes, and cartilage breakdown markers at the time of anterior cruciate ligament (ACL) reconstruction are associated with worse postoperative patient-reported outcomes and cartilage quality. However, it remains unclear if this is due to a more robust or dysregulated inflammatory response or is a function of a more severe injury. The objective of this study was to evaluate the association of the molecular composition of the SF, patient demographics, and injury characteristics to cartilage degradation after acute ACL injury. METHODS: We performed a cluster analysis of SF concentrations of proinflammatory and anti-inflammatory cytokines, and biomarkers of cartilage degradation, bony remodeling, and hemarthrosis. We evaluated the association of biomarker clusters with patient demographics, days between injury, Visual Analogue Scale pain, SF aspirate volumes, and bone bruise volumes measured on magnetic resonance imaging. RESULTS: Two clusters were identified from the 35 patients included in this analysis, dysregulated inflammation and low inflammation. The dysregulated inflammation cluster consisted of 10 patients and demonstrated significantly greater concentrations of biomarkers of cartilage degradation (P < 0.05) as well as a lower ratio of anti-inflammatory to proinflammatory cytokines (P = 0.053) when compared with the low inflammation cluster. Patient demographics, bone bruise volumes, SF aspirate volumes, pain, and concomitant injuries did not differ between clusters. CONCLUSIONS: A subset of patients exhibited dysregulation of the inflammatory response after acute ACL injury which may increase the risk of posttraumatic osteoarthritis. This response does not appear to be a function of injury severity.

Successful immune tolerance induction with low-dose coagulation factor VIII in a patient with hemophilia A from a developing country.

Inhibitor development is the most frequent and serious complication of the treatment in patients with hemophilia. Immune tolerance induction (ITI) is the only option of treatment for the eradication of factor VIII (FVIII) inhibitor. We would like to present our case with hemophilia whose FVIII inhibitor eradication was done by a low-dose ITI regimen. Our patient has been applied on-demand therapy until 8 years of age. Secondary prophylaxis was began because of having hemophilic arthropathy. A low titer of FVIII inhibitor (4.2 BU/ml) was detected in the fifth month of the prophylaxis. The peak inhibitor titer of patient was 4.6 BU/ml, and there was no decrease in inhibitor titer in the follow-up duration. The low-dose ITI (50 IU/kg, 3 days a week) was started. His inhibitor level was detected negative and the recovery test was ameliorated in the 15th of the ITI therapy. High-dose regimen ITI could not be given particularly in developing countries such as Turkey in view of the high cost of treatment. Patients who had good risk factors might be successfully treated by using low-dose ITI regimen as effective as high-dose ITI regimen.

[THE ROLE OF THE COMBINATION OF INFLAMMATORY PROCESSES IN THE JOINTS AND ALTERED REGIONAL MICROCIRCULATION IN THE DEVELOPMENT OF HEMOPHILIC ARTHROPATHY].

AIM: To study the role of the combination of inflammatory processes in the joints and altered regional microcirculation as well as factors influencing them in the development of hemophilic arthropathy in 82 patients with recurrent hemarthrosis of the knee and ankle joints by computed IR thermography, laser Doppler flowmetry, and bioimpedancometry for determining fatty and muscle tissue mass. It was shown that deviation of body mass from the normal value were pathogenetically associated with different variants of hemophilic arthropathy. Its risk factors in the patients with continuously recurrent hemarthrosis include epiarticular perfusion, elevated body temperature, low BMI, and muscle mass deficit in excess of 2 kg. 12% of the patients with the history of hemarthrosis-free joints experienced a rise in epiarticular temperature and 6% suffered enhanced perfusion due to latent post-hemorrhagic inflammation.

Various regimens for prophylactic treatment of patients with haemophilia.

Haemophilia prophylaxis is superior to on-demand treatment to prevent joint damage. 'High-dose prophylaxis' as used in Sweden is more effective in preventing arthropathy than an 'intermediate-dose regimen' (the Netherlands) and the Canadian tailored primary prophylaxis. Prophylaxis may reduce the risk of developing inhibitors. There is no difference in inhibitor risk between plasma derived and recombinant factor VIII (rFVIII) products but the Rodin study showed increased risk with second-generation rFVIII products. MRI is a new and very sensitive tool to detect the symptoms of early arthropathy but some results (soft tissue changes in 'bleed-free joints') still need to be investigated. Ultrasound is a very helpful method to aid diagnosis especially during the acute phase of a bleed. The risk of infection with central venous access remains a matter of debate. A fully implanted central venous access device (CVAD) has a significant lower risk of infection compared to external CVADs. Patient's age under 6 yr and inhibitor presence are additional risk factors for infections. The role of arteriovenous fistulae needs to be investigated because significant complications have been reported. Disease-specific quality of life instruments are complementary to generic instruments evaluating QoL in patients with haemophilia and have become important health outcome measures.

Strategies for reducing inhibitor formation in severe haemophilia.

The greatest barrier to successful haemophilia A care in resource-rich countries is the development of inhibitors to therapeutic factor VIII. Children with inhibitors suffer through increased bleeding and joint damage as well as frequent venepuncture. Costs associated with inhibitors are beyond many healthcare systems. Over the last two decades, there has been no improvement in our ability to reduce inhibitor development. Current strategies based on early prophylaxis and avoidance of immunological danger signals have given rise to conflicting results. Registry data suggest an increasing problem. Our understanding of the immunological systems involved in inhibitor formation should inform efforts to prevent inhibitors. Great efforts with mouse models are being undertaken in this field. However, there is no guarantee of the availability of any new agents arising from experimental work in the near future. Global immunomodulatory agents may be one solution. Compounds with a long history of use in inflammatory conditions have demonstrated efficacy in preventing antibodies to protein therapeutics both in animal models and in humans. As these compounds have a long history of use in humans, including babies, it may be that these agents offer an option for reducing inhibitor formation in previously untreated patients.

Treatment of children with severe haemophilia A and inhibitors: a health economic evaluation for Germany.

BACKGROUND: Decision makers request increasingly for high levels of evidence when allocating resources in medical care. This is hardly feasible for rare diseases. The objective was to analyze clinical and economic aspects of different immune tolerance induction (ITI) strategies for children with severe haemophilia A and inhibitors. METHODS: A decision model, time frame 18 years (base case: 2 year old boy), was constructed from a German statutory health insurance (SHI) perspective. Compared were high-dose (HD) ITI, low-dose (LD) ITI, 'ITI with risk assessment', on-demand (OD) treatment with bypassing agents. Clinical data were derived from structured literature research and expert opinion. Sensitivity analyses were conducted for parameters with wide statistical ranges. RESULTS: Base case analysis: total costs for HD ITI amounted to €3.4 million with 40.9% ITI costs, 51 joint bleeds, 36 hospital days; LD ITI, €2.4 million with 21.4% ITI costs, 74 joint bleeds, 52 hospital days; 'ITI with risk assessment', €2.7 million with 27.6% ITI costs, 53 joint bleeds, 37 hospital days; OD treatment, €1.7 million, 146 joint bleeds, 104 hospital days. Incremental costs per bleed avoided with HD ITI decreased from €1 million to €0.15 million with increase of joint bleeds from 3 to 20 per year, when compared to 'ITI with risk assessment' in sensitivity analysis. CONCLUSION: 'ITI with risk assessment' is cost-saving with comparable outcomes to HD ITI. However, patient-related factors like bleeding frequency have to determine treatment decisions in individual patients. More clinical data is needed to increase the significance of model -calculations.

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-1ß/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.

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.

Discordant antibody response in monozygotic twins with severe haemophilia A caused by intensive treatment.

Both genetic factors and environmental factors are suggested to play a role in the aetiology of inhibitor development in patients with severe haemophilia A. Monozygotic twins are ideal candidates to study the influence of environmental factors. We describe a pair of 3-year-old monozygotic twin brothers with severe haemophilia A. Prenatal diagnosis confirmed the presence of an intron 22 inversion. Other patient-related factors such as birth weight, vaccinations and the duration of breastfeeding were similar. At the age of 7 months, one boy suffered from a spontaneous subdural haematoma, which needed complete correction of haemostasis with continuous infusion of a third-generation recombinant factor VIII. A persistent high-titre inhibitor with severe clinical symptoms developed, that could only be eradicated with high-dose immune tolerance induction (ITI) for 36 months in combination with rituximab therapy. His twin brother first received treatment at 9 months of age with the same FVIII product. After treatment on nine exposure days, he developed a low-titre inhibitor at the age of 14.5 months. Unlike his brother, he was tolerized without difficulties with low-dose ITI within 2 months. The discordant antibody responses were underlined by dissimilar IgG1 and IgG4 levels in their plasma. The discordant immune response to FVIII in this pair of monozygotic twin brothers seemed to be related to intensity of treatment and severity of bleeds. This confirms that these environmental factors play an additional role in the development of inhibitors.

New approaches in the management of inhibitor patients.

The most serious current complication of factor replacement therapy for hemophilia patients is the development of neutralizing antibodies to the factor termed inhibitors. Patients with high-titer inhibitors frequently develop serious bleeding complications which do not respond to standard factor replacement therapy. Therefore, they must be treated with the so-called bypassing agents, recombinant factor VIIa and activated prothrombin complex concentrates, neither of which is as effective as standard factor replacement in patients without inhibitors. Immune tolerance therapy aimed at eradicating inhibitors is successful in a majority of patients; however, a sizable minority will have life-long inhibitors and often develop debilitating joint disease. The ultimate goal is to develop strategies aimed at preventing inhibitor development though these have not been realized yet. Until this is achieved, additional novel approaches are needed to improve the treatment of bleeding episodes and to better treat arthropathy once it develops. Finally, there is no laboratory monitoring device which can predict the clinical response of patients to bypassing agents. Thus another goal of current research is to develop such a tool which will enable the individualization of bypassing agent.

Rapid leukocyte activation following intraarticular bleeding.

The study aims at elucidating the leukocyte activation in the joint fluid of patients with acute traumatic hemarthrosis. Paired samples of peripheral blood and articular effusions after an acute hemorrhage were obtained from 22 patients. Leukocytes were separated and stained with fluorescein isothiocyanate (FITC)-conjugated mouse anti-human CD11a, CD18, and CD97 monoclonal antibodies for flow cytometry. The reactive oxygen species (ROS) production of leukocytes in corresponding samples of peripheral blood and joint effusion was measured via luminol dependent whole blood chemiluminometry. Significant decrease of CD11a density on monocytes, but markedly enhanced expression of CD97 and CD18 on polymorphonuclear neutrophil granulocytes (PMN), and significantly increased proportion of CD97 positive lymphocytes were found in the joint fluids as compared to the corresponding peripheral blood samples. Moreover, significantly decreased lag time and elevated rate of ROS production were revealed by chemiluminometry in case of joint derived leukocytes. Our results provide good evidence for intraarticular leukocyte activation during acute hemarthrosis. Since the activation precedes synovial inflammation, it is suggested that the leukocytes play an important role as an initiator in the pathogenesis of acute hemarthrosis.

Iron deposits and catabolic properties of synovial tissue from patients with haemophilia.

Haemophilic arthropathy is characterised by iron deposits in synovial tissues. We investigated the suggestion that iron plays an important role in synovial changes. We obtained synovial tissue from six patients with haemophilia during arthroplasty, finding that brown haemosideritic tissue was often adjacent to tissue with a macroscopically normal appearance in the same joint. Samples from both types of synovial tissue were analysed histologically and biochemically to determine catabolic activity. Macroscopically haemosideritic synovium showed a significantly higher inflammatory activity than that with a normal appearance. Cultures of abnormal synovial tissue gave a significantly enhanced production of IL-1, IL-6 and TNF alpha compared with cultures of synovial tissue with a normal appearance. In addition, the supernatant fluids from the cultures showed greater catabolic activity from haemosideritic tissue, as determined by the inhibition of the synthesis of articular cartilage matrix. We conclude that in patients with haemophilic arthropathy, local synovial iron deposits are associated with increased catabolic activity.

An unusual haemarthrosis in an HIV-seronegative haemophilia A patient.

We report the case of a severe haemophilia A patient with an anti-factor VIII antibody who presented with a thigh haematoma and 1 year later with an elbow haemarthrosis infected by Salmonella enteritidis. These two infections were treated by antibiotics. The probable origin of these infections seems to be an anal fistula. The occurrence of a septic arthritis due to Salmonella is rare, and to our knowledge has never been reported in HIV-negative haemophilic patients. The differential diagnosis of haemarthrosis and septic arthritis in a haemophilic patient is also discussed.

[Changes in the composition and properties of the joint contents in hemophilic arthropathies during local invasive therapy]. / Izmenenie sostava i svoistv sustavnogo soderzhimogo pri gemofilicheskikh atropatiiakh v protsesse lokal'noi invazivnoi terapii.

An immunological study has been made in 47 hemophiliacs with arthropathies receiving local invasive therapy. Joint contents were examined in 20 patients with acute hemarthrosis, 10 patients with exudative synovitis and 11 ones with proliferative synovitis. Under the protection of cryoprecipitate (5 U/kg) all the patients underwent joint puncture with removal of the contents, lavage of the synovial cavity and intraarticular injection of 50 mg of hydrocortisone. Arthropathy activity proved most active in patients with proliferative synovitis. Introduction of local invasive therapy early in hemarthrosis course arrests immune inflammation. Delayed punctures are less effective. Local immunological responses, as shown by repeated punctures, noticeably reduced, at puncture 3-4 the contents were small, immune complexes and immunoglobulins decreased significantly.