Inhibition of Fenton reaction is a novel mechanism to explain the therapeutic effect of intra-articular injection of PRP in patients with chronic haemophilic synovitis

Intraarticular management of chronic haemophilic arthropathy (Review)

Hemophilia is an inherited X-linked bleeding condition with predominant joint involvement due to intra-articular bleeding, hemosiderin deposition and the synovial hypertrophy that is responsible for cartilage destruction, joint deformity and malalignment, pain and functional restriction. Management of chronic arthropathy includes conservative and surgical approaches. Conservative therapies consist of pain modulation, oral drugs, physiotherapy and intra-articular agents. For the present review, the literature was searched for intra-articular agents and 20 papers on the use of corticosteroids (CS), hyaluronic acid (HA) and platelet-rich plasma (PRP), with different regimes of administration, were included. CS had a longer record of injection, with statistically significant pain reduction and functional improvement in the short-term and moderate persistence in the long-term. HA was able to improve the clinical and functional status of joints with moderate or severe hemophilia. PRP was relatively recently introduced to joint management and the results remain controversial. Different associations between the above-mentioned agents were proposed by studies including a small number of patients, producing comparable results. It was concluded that there is a need for extensive research on intra-articular agents, with stratification according to the severity of joint involvement. The lack of a blinded or placebo-controlled arm due to ethical aspects makes the task challenging.

Material properties of degradable alloy Fe-30Mn-0.6N and its effect on ferroptosis in synoviocytes

Ferroalloy has shown potential as implant materials, but little attention has been paid to their effects on synovial tissue ferroptosis. This study aimed to examine the mechanical properties, degradability and biocompatibility of Fe-30Mn-0.6N alloy and effects of it on synovial tissue ferroptosis. Tensile testing showed that Fe-30Mn-0.6N alloys exhibited tensile strength of 487 ± 18 MPa, yield strength of 221 ± 10 MPa, elongation of 16.9 ± 0.3% and Young's modulus of 37.7 ± 1.3 GPa. In vivo experiments, the cross-sectional area of the Fe-30Mn-0.6N alloys decreased by 73.32 ± 12.73% after 8 weeks of implantation. The results of scanning electron microscopy (SEM) and surface elemental analysis (EDS) showed that the Fe-30Mn-0.6N alloys had more Ca, O, C and P element deposition (p < .05). After 2, 4 and 8 weeks of implantation, no inflammatory response was observed in peri-implant synovial tissue of Fe-30Mn-0.6N and Ti-6Al-4V alloys, and Fe-30Mn-0.6N alloys did not affect the expression of the ferroptosis inhibitory gene Glutathione peroxidase 4 (GPX4). Compared with the control group, 30% Fe-30Mn-0.6N alloy extracts did not affect the cell viability (p > .05) in vitro, and intracellular Fe²⁺ and the reactive oxygen species (ROS) was significantly reduced (p < .05). WB and PCR results showed that the 30% extracts increased the protein activity and mRNA expression of GPX4, FTH1 and SLC7A11 in synoviocytes, but had no effect on PTGS2 and p53. It is concluded that Fe-30Mn-0.6N had degradability and biocompatibility in peri-implant synovial tissue, and did not induce significantly ferroptosis in synoviocytes.

Platelet-rich plasma vs platelet-rich plasma plus hyaluronic acid for haemophilic knee arthropathy treatment

Repeated joint bleeding leads to chronic synovitis, cartilage damage and bone alterations which result in haemophilic arthropathy and are associated with pain, functional impairment and poor quality of life. There are evidence that Hyaluronic Acid (HA) and Platelet-rich Plasma (PRP) have different mechanisms of action in the treatment of arthropathy for this reason we decided to use both components. The aim of this study is to compare, the efficacy, safety and duration of a single intra-articular injection of PRP against PRP+HA for pain, bleeding episodes and joint health, in the same patient with bilateral hemophilic knee arthropathy. Twenty-one men patients (42 knee joints) were treated with intra- articular injections of PRP or PRP+HA. All of them were haemophilia type A severe. The mean age was 36.6 years (21-72). All patients were evaluated for: Haemophilia Joint Health Score (HJHS), pain (VAS), the number of bleeding episodes (BE) in the last 30 days, before treatment, at three and six months after treatment. Statistically significant improvement were shown for both knee joints at three and six months after treatment for VAS and BE (P < 0.00001). The HJHS score did not significantly improve for either knee in the 6-month period after injection. A single PRP or PRP+HA injection is safe and effective in treating haemophilic arthropathy of the knee for up to 6 months follow-up, reducing pain, bleeding episodes and delaying total knee arthroplasty.

Moving toward targeting the right phenotype with the right platelet-rich plasma (PRP) formulation for knee osteoarthritis

Intra-articular injections of platelet-rich plasma (PRP) and other novel blood-derived products developed specifically for osteoarthritis (OA) can provide pain relief and potential benefits in disease progression. Meta-analyses show the clinical superiority of PRP compared with other intra-articular injections, but results are modest and the effect sizes are small. PRP injections in knee OA are performed indiscriminately, but the clinical response varies enormously between patients because of an array of mixed OA phenotypes. Subgroup analyses are scarce; some studies stratify patients according to radiographic severity and found better results in early OA, without consensus for more advanced stages of the condition. Parallel identification of soluble and imaging biomarkers is essential to personalise and leverage PRP therapies. The inflammatory phenotype is most interesting from the PRP perspective because PRPs modulate inflammation by releasing a large pool of chemokines and cytokines, which interact with synovial fibroblasts and macrophages; in addition, they can modulate the innate immune response. No soluble biomarkers have been discovered that have implications for OA research and PRP interventions. Clinical examination of patients based on their inflammatory phenotype and imaging identification of pain sources and structural alterations could help discern who will respond to PRP. Synovial inflammation and bone marrow lesions are sources of pain, and intra-articular injections of PRP combined with subchondral bone injection can enhance clinical outcomes. Further refining ultrasound phenotypes may aid in personalising PRP therapies. Intra-articular delivery combined with injections in altered ligamentous structures, medial and coronal ligaments or premeniscal pes anserinus showed positive clinical outcomes. Although the evidence supporting these approaches are weak, they merit further consideration to refine PRP protocols and target the right OA phenotypes.