Ferroptosis: a new target for iron overload-induced hemophilic arthropathy synovitis

Iron deposition is closely related to developing haemophilic arthropathy (HA). Studying the relationship between ferroptosis signal expression and iron overload in HA synovium facilitates understanding the pathogenesis of joint synovial hyperplasia in bloodborne arthritis and the development of new protective methods. The knee synovium was collected from HA and osteoarthritis (OA) patients, and pathological changes were analysed by HE and Prussian blue staining. Ferroptosis phenotypes were examined by immunohistochemistry and western blotting. Moreover, ferric ammonium citrate (FAC)-induced was used to construct an in vitro iron overload model to investigate the relationship between iron overload and ferroptosis in synovial fibroblasts (FLS). Furthermore, the factors influencing ferroptosis in FLS were explored. Iron deposition, cell proliferation, and vascular proliferation in the synovium of HA were more obvious. Ferroptosis in HA synovium appears to inhibit. FLS ferroptosis increased with iron accumulation, malondialdehyde (MDA) in cells, and glutathione (GSH) depletion. TNF-α plays a protective role in this process. Blocking the action of TNF-α and inducing ferroptosis significantly reduced synovial proliferation. TNF-α inhibitors combined with a ferroptosis inducer may be a new therapeutic method for HA synovitis.

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.

In vivo fluorescence molecular tomography of induced haemarthrosis in haemophilic mice: link between bleeding characteristics and development of bone pathology

Background

Haemophilic arthropathy is a chronic and debilitating joint disease caused by recurrent spontaneous joint bleeds in patients with haemophilia. Understanding how characteristics of individual joint bleeds relate to the subsequent development of arthropathy could improve management and prevention of this joint disease. Here, we aimed to explore relations between joint bleed characteristics and development of bone pathology in a mouse model of haemophilic arthropathy by using novel in vivo imaging methodology.

Methods

We characterised induced knee bleeds in a murine model of haemophilic arthropathy by quantitative in vivo fluorescence molecular tomography (FMT) and by measurements of changes in the diameter of the injured knee. Wild-type mice and non-injured haemophilic mice acted as controls. Development of arthropathy was characterised by post mortem evaluation of bone pathology by micro-CT 14 days after bleed-induction. In an in vitro study, we assessed the effect of blood on the quantification of fluorescent signal with FMT.

Results

In most injured haemophilic mice, we observed significant loss of trabecular bone, and half of the mice developed pathological bone remodelling. Development of pathological bone remodelling was associated with significantly increased fluorescent signal and diameter of the injured knee just 1 day after induction of the bleed. Further, a correlation between the fluorescent signal 1 day after induction of the bleed and loss of trabecular bone reached borderline significance. In the in vitro study, we found that high concentrations of blood significantly decreased the fluorescent signal.

Conclusion

Our results add novel insights on the pathogenesis of haemophilic arthropathy and underline the importance of the acute phase of joint bleeds for the subsequent development of arthropathy.

Management of knee flexion contracture in haemophilia with the Ilizarov technique

BACKGROUND

There are limited reports about management of Knee flexion contracture (KFC) in haemophiliacs with Ilizarov technique. The aim of this study was to retrospectively analyzed the results of Ilizarov technique to treat KFC.

METHODS

Six patients with haemophilia A and one with haemophilia B were included in this study, with an average age of 17 years old. The mean preoperative KFC and flexion angle of the knee were 58 ± 21° (mean ± standard deviation) and 127 ± 12°, respectively. Preoperative HSS score (hospital for special surgery knee score) was 51 ± 4. The average time of follow-up was 39.3 ± 23.3 months.

RESULTS

All the patients achieved full correction of flexion contracture at the end of distraction and maintained at the last follow-up. The mean flexion angle at the end of distraction and at the last follow-up were 41 ± 35° and 38 ± 19° respectively, which were significantly lower than preoperative flexion angle. The mean HSS score at the end of distraction and at the last follow-up were 65 ± 4 and 64 ± 2 respectively, which were significantly higher than the preoperative HSS score. One patient suffered from transient numbness of left leg, and all the patients had loss of range of knee flexion at last follow-up.

CONCLUSIONS

Ilizarov is an effective and safe procedure to treat KFC in haemophiliacs. However, loss of knee flexion was the most common complication.

Intra-articular corticosteroid injections in haemophilic arthropathy: are they recommended?

INTRODUCTION

Intra-articular (IA) corticosteroid (CS) injections are commonly used in the treatment of osteoarthritis. However, they are rarely utilized in haemophilic arthropathy. In fact, the efficacy of this method in haemophilic arthropathy is frequently discussed and debated in clinical practice.

AIM

To investigate the effectiveness of IA CS injections in patients with painful haemophilic arthropathy.

METHODS

A review of the literature on the topic was performed.

RESULTS

In osteoarthritis, reports with a high level of evidence state that the efficacy of IA injections of CS is controversial. In haemophilic arthropathy, some low-level evidence reports seem to indicate that short-term pain alleviation can be achieved.

CONCLUSIONS

Considering that pain relief after IA injections of CS is controversial and that the cost of the haematologic treatment required to perform the procedure is high in haemophilic arthropathy, we do not recommend the routine use of CS IS injections in haemophilia. Moreover, point of care (POC) ultrasound (US)-guided injections are not advised, because the injection procedure is so simple that the use of POC-US will unnecessarily prolong the duration of the procedure.

Long-term results of total knee arthroplasty in haemophilic patients: an 18-year follow-up

PURPOSE

Total knee arthroplasty (TKA) for patients with end-stage haemophilic arthropathy is considered to be a successful procedure with satisfying mid- to long-term results. It was the purpose of this study to provide clinical and radiological long-term results of TKAs implanted in a consecutive cohort of haemophilic patients.

METHODS

Primary TKA was performed in 43 consecutive knees in 30 haemophilic patients. After a mean of 18 (SD ± 4) years, 15 patients (21 knees) with a mean age of 58 (SD ± 8) years were available for follow-up. The outcome was assessed using the Knee Society score, WOMAC, SF-36, Kaplan-Meier survivorship analysis as well as radiographic evaluation of radiolucency.

RESULTS

In 13 (30%) of the 43 consecutive knees, revision surgery was necessary due to infection or aseptic loosening, among which eight (19%) due to aseptic loosening and five (12%) due to haematogenous infection. The calculated 20-year survival rates with revision for any reason or infection as the end points were 59 and 82%, respectively. All patients with the primary TKA in situ observed progressive radiolucent lines around the implants at the final follow-up. The Knee Society clinical and functional score significantly improved from pre- (36 points; SD ± 16 and 62 points; SD ± 19) to post-operatively (73 points; SD ± 15 and 78 points; SD ± 18; p < 0.001). Eighty-six per cent rated their result as either good or excellent. Whereas flexion did not improve, flexion contracture could be reduced significantly from 18° (SD ± 12) to 6° (SD ± 5; p < 0.001) post-operatively.

CONCLUSION

Total knee arthroplasty in haemophilic patients is associated with high revision, loosening and infection rates after 18 years. However, if revision can be avoided, joint replacement in haemophilic patients helps to relieve pain, achieve higher subjective satisfaction and to restore knee function. Level of evidence IV.

A cohort study of the usefulness of primary prophylaxis in patients with severe haemophilia A

Primary prophylaxis is a method of haemostatic management to prevent bleeding and arthropathy in patients with severe haemophilia. The aim of this study was to evaluate the usefulness of primary prophylaxis in patients with severe haemophilia A. This study included 15 patients with haemophilia A who received primary prophylaxis at our institution for a minimum of 5 years. We evaluated the annualized bleeding ratio of joints or other sites, current joint function, and X-ray images and MRI scans taken when patients were 6 years old. The range of patients' ages at the end of the study was 6.2-16.8 years, and at the start of primary prophylaxis it was 0.8-2.4 years. Factor VIII concentrates (25-40 units kg(-1) dose(-1)) were administered 3 times/week or every other day, according to the Swedish protocol. Mean joint and non-joint annualized bleeding ratios were 0.49 ± 0.5 and 1.54 ± 1.69, respectively. At the final evaluation, all patients displayed a normal range of motion for both elbows, knees, and ankles. The radiography and MRI findings at the age of 6 were unremarkable in all patients. Overall, primary prophylaxis for patients with severe haemophilia A was performed safely, reduced the number of bleeding events, and prevented progression to arthropathy.

Autologous chondrocytes as a novel source for neo-chondrogenesis in haemophiliacs

Haemophilic arthropathy is the major cause of disability in patients with haemophilia and, despite prophylaxis with coagulation factor concentrates, some patients still develop articular complications. We evaluate the feasibility of a tissue engineering approach to improve current clinical strategies for cartilage regeneration in haemophiliacs by using autologous chondrocytes (haemophilic chondrocytes; HaeCs). Little is known about articular chondrocytes from haemophilic patients and no characterisation has as yet been performed. An investigation into whether blood exposure alters HaeCs should be interesting from the perspective of autologous implants. The typical morphology and expression of specific target genes and surface markers were therefore assessed by optical microscopy, reverse transcription plus the polymerase chain reaction (PCR), real-time PCR and flow-cytometry. We then considered chondrocyte behaviour on a bio-hybrid scaffold (based on polyvinyl alcohol/Wharton's jelly) as an in vitro model of articular cartilage prosthesis. Articular chondrocytes from non-haemophilic donors were used as controls. HaeC morphology and the resulting immunophenotype CD44(+)/CD49c(+)/CD49e(+)/CD151(+)/CD73(+)/CD49f(-)/CD26(-) resembled those of healthy donors. Moreover, HaeCs were active in the transcription of genes involved in the synthesis of the extracellular matrix proteins of the articular cartilage (ACAN, COL1A, COL2A, COL10A, COL9A, COMP, HAS1, SOX9), although the over-expression of COL1A1, COL10A1, COMP and HAS was observed. In parallel, the composite scaffold showed adequate mechanical and biological properties for cartilage tissue engineering, promoting chondrocyte proliferation. Our preliminary evidence contributes to the characterisation of HaeCs, highlighting the opportunity of using them for autologous cartilage implants in patients with haemophilia.