Oligoarticular onset juvenile idiopathic arthritis as the most common cause of disability of children and young adults

Intra-articular delivery of AAV vectors encoding PD-L1 attenuates joint inflammation and tissue damage in a mouse model of rheumatoid arthritis

Objective

Rheumatoid arthritis (RA) is the most common form of autoimmune inflammatory arthritis. Intra-articular gene delivery to block proinflammatory cytokines has been studied in pre-clinical models and human clinical trials. It has been demonstrated that the level of programmed death-ligand 1 (PD-L1) is associated with rheumatoid arthritis (RA). This study examined the therapeutic role of PD-L1 by intra-articular delivery via adeno-associated virus (AAV) vectors in the mouse collagen-induced arthritis (CIA) model.

Methods

Mice were intra-articularly injected with AAV5 vectors encoding human PD-L1 on day 0 and immunized with bovine type II collagen to induce CIA simultaneously. On day 49 post AAV administration, joints were collected for histo-pathological and cytokine analysis. Additionally, the systemic impacts of intra-articular injection of AAV5/PD-L1 vectors were also studied. To study the therapeutic effect of PD-L1, AAV5/PD-L1 vectors were administered into the joints of RA mice on day 21.

Results

After administration of AAV5/PD-L1 vectors, strong PD-L1 expression was detected in AAV transduced joints. Joints treated with PD-L1 at the time of arthritis induction exhibited significantly less swelling and improved histopathological scores when compared to untreated joints. Additionally, the infiltration of T cells and macrophages was decreased in joints of CIA mice that received AAV5/PD-L1 vectors (P<0.05). The levels of pro-inflammatory cytokines, including IL-1, IL-6, IL-17 and TNFα, were lower in AAV5/PD-L1 treated than untreated joints (P<0.05). Furthermore, the administration of AAV5/PD-L1 vectors into the joints of CIA mice did not impact serum cytokine levels and the antibody titers to type II collagen. Biodistribution of AAV vectors after intra-articular injection showed undetectable AAV genomes in other tissues except for a low level in the liver. Similar to the results of AAV5/PD-L1 vector administration on day 0, decreased joint swelling and lower histopathological damage were observed in joints treated with AAV5/PD-L1 vectors on day 21.

Conclusion

The results from this study demonstrate that local AAV mediated PD-L1 gene delivery into the joints is able to prevent the development and block the progression of arthritis in CIA mice without impacting systemic immune responses. This study provides a novel strategy to effectively treat inflammatory joint diseases using local AAV gene therapy by interference with immune checkpoint pathways.

Synovectomy in juvenile idiopathic arthritis: A systematic review and meta-analysis

BACKGROUND

Juvenile idiopathic arthritis (JIA) is an inflammatory arthropathy with onset in children younger than 16 years. Treatment is primarily medical; however, surgical interventions, such as arthroscopic or open synovectomy, can be beneficial. Many studies have investigated synovectomy in JIA, but the results of these studies have not been synthesized to our knowledge. Therefore, we performed a systematic review of the literature reporting synovectomy as a treatment for JIA to provide clinical recommendations regarding its risks and benefits.

METHODS

On March 8, 2022, we searched the Cochrane Library, Embase, PubMed, Scopus, and Web of Science for studies evaluating clinical outcomes of open or arthroscopic synovectomy to treat JIA in patients younger than 18 years. We included only studies published in English and excluded studies of synovectomy to treat other arthropathies, septic arthritis, hemophilia, or foreign body arthropathy. The level of evidence for included studies was determined by using the Oxford Centre for Evidence-Based Medicine criteria. We qualitatively analyzed clinical outcomes data, including patient-reported pain relief, rates of symptom recurrence, and postoperative complications.

RESULTS

Of 428 articles assessed, 14 were included in our analysis. One was a randomized trial, 1 was a case-control study, and all others were case-series. Studies consistently reported that synovectomy was associated with improved function and decreased pain postoperatively. However, comparisons with modern medical therapy were lacking. Rates of arthritis recurrence varied, with increasing symptom recurrence with longer follow-up and re-synovectomy rates up to 15%. Oligoarticular disease and early disease course were associated with better response to synovectomy, whereas systemic and polyarticular disease were associated with poor response. Stiffness requiring manipulation under anesthesia was the most common complication (4% of all included patients).

CONCLUSION

Although synovectomy is associated with positive functional outcomes and pain reduction postoperatively, there was inadequate comparison thus inadequate evidence to recommend it over modern medical therapy. The current literature suggests that synovectomy should be offered only to patients for whom medical management has failed, while noting the risks of decreased range of motion and symptom recurrence over time.

Fifteen-minute guide to managing oligoarticular juvenile idiopathic arthritis

Juvenile idiopathic arthritis (JIA) is the most common chronic rheumatic disease affecting children and young people today. However, it is not a single disease entity, but an umbrella term that gathers together a heterogeneous collection of complex, chronic inflammatory conditions with oligoarticular JIA the most common form in both Europe and North America. Due to its relative rarity in daily practice and potential to mimic other conditions, oligoarticular JIA can present a diagnostic and management challenge to healthcare professionals in both primary care and general paediatrics. The aim of this article is to provide a summary of the key aspects of diagnosis, investigation and management of this condition, with the hopes of building clinicians' confidence when facing a possible case of oligoarticular JIA.

Response to treatment with intra-articular triamcinolone hexacetonide and triamcinolone acetonide in oligo articular juvenile idiopathic arthritis

BACKGROUND

Oligo-articular juvenile idiopathic arthritis (Oligo JIA) is the most common subtype of juvenile idiopathic arthritis. Intra-articular corticosteroid (IAC) injection is a mainstay treatment of oligo JIA providing pain relief, improving mobility and preventing further joint destruction in the majority of patients. In 2015, production of triamcinolone hexacetonide (TH) an intra-articular corticosteroid was discontinued in the United States leading to use of triamcinolone acetonide (TA) as an alternative. In this study, we compared response to treatment in children with oligo JIA who underwent therapy with intra-articular TA and TH injection.

METHODS

Our study is a retrospective chart review of children with oligo JIA who were treated with IAC injections with TH between January 2012 and June 2015 and TA between J uly 2015 and December 2018. The two groups were followed at John R. Oishei Children's Hospital of Buffalo and were evaluated for response to treatment, side effects and predictors of response including duration of disease before treatment, erythrocyte sedimentation rate (ESR), and c-reactive protein (CRP). Response to treatment was defined as at least 6 months follow up without evidence of active arthritis in injected joints. Patients were considered to be non-responders if they continued to show active arthritis during their first follow up after joint injection. The primary objective was to evaluate whether there was a significant difference in rate of response between TH and TA.

RESULTS

Forty-nine patients, 38 female and 11 male with oligo JIA were included in the study. The average age was 6.7 years. A total of 111 joints were injected includin g 78 knees, 13 ankles, 9 wrists, 4 hips, 4 elbows, 2 TMJ and one subtalar joint. In the TA group, 49% (29/59) did not show response to injection compared to 27% (14/52) in the TH group. After 6 months, response rates were better for individuals injected with TH compared to TA (73% vs. 51%). In general, response to intra-articular TH was superior to TA with P = .016 using chi-square test of independence. This difference in outcome was not influenced by other variables such as duration of illness before treatment (P value 0.784) or elevated ESR and CRP. No difference in side effects between the two groups were noted.

CONCLUSION

Our results in conjunction with prior published data suggests that TH intra-articular joint injection in oligo JIA is superior to TA, although future controlled trials are necessary for confirmation. An effective, long lasting treatment can have a great impact on the outcome of these children.