Early Oligoarthritis

Clinical effectiveness of symptomatic therapy compared with standard step-up care for the treatment of low-impact psoriatic oligoarthritis: the two-arm parallel group randomised POISE feasibility study

Introduction

In psoriatic arthritis (PsA), treatment recommendations support first-line use of disease-modifying antirheumatic drugs (DMARDs). There are few treatment strategy trials, and no previous studies have investigated tailored treatment choice by disease severity. Studies in oligoarthritis (<5 inflamed joints) are limited but have suggested that some can be managed without DMARDs, preventing unnecessary side effects. This study aimed to assess the feasibility and acceptability of a study comparing standard DMARD treatment against symptomatic therapy in patients with mild psoriatic oligoarthritis.

Methods

This trial was embedded within the MONITOR-PsA cohort, which uses a Trials Within Cohorts (TWiCs) design. Patients with newly diagnosed psoriatic oligoarthritis, with low disease activity (PASDAS ⩽ 3.2) and the absence of poor prognostic factors [C reactive protein (CRP) < 5 mg/dL, HAQ < 1, no radiographic erosions] were randomised open-label to either standard care with 'step-up' DMARD therapy or to symptomatic therapy with nonsteroidal anti-inflammatory drugs (NSAIDs) and local corticosteroid injections to inflamed joints. Key outcomes were the proportion of eligible cohort patients, consent and study completion rate.

Results

Over the 15-month study period, only one eligible patient was randomised. Although oligoarthritis patients represented 45% of patients in this early PsA cohort, the majority did not have mild disease (24% raised CRP, 51% moderate disease activity, 13% radiographic damage and/or poor function). Of those meeting trial inclusion criteria, many patients refused treatment in the observational cohort prior to an invitation into the trial as they did not wish to be treated with DMARDs.

Conclusion

The study was not feasible as designed. Oligoarthritis represents around half of initial PsA presentations, but the majority starting therapy have high-impact disease. A small proportion have mild oligoarticular disease but many are not keen on treatment with DMARDs, given the potential side effects of these medications. Further research is needed to support evidence-based treatment in this subgroup.

Trial registration number

- ClinicalTrials.gov (NCT03797872) and EudraCT (2018-001085-42).

Expression of immune response genes in the stifle joint of dogs with oligoarthritis and degenerative cranial cruciate ligament rupture

Dysregulation of immune responses within joints plays an important role in development of inflammatory arthritis. We determined expression of a panel of immune response and matrix turnover genes in synovial fluid collected from a group of dogs with stifle oligoarthritis and associated degenerative cranial cruciate ligament (CCL) rupture (n=27). We also studied synovial fluid gene expression in dogs affected with other forms of degenerative arthritis (n=9) and in the stifle joint of healthy dogs with intact CCL (n=14). After collection, synovial cells were pelleted and RNA was isolated. Relative expression of cathepsin K, cathepsin S, tartrate-resistant acid phosphatase (TRAP), matrix metalloproteinase-9 (MMP-9), invariant chain (li), toll-like receptor-2 (TLR-2), and TLR-9 was determined using real-time quantitative RT-PCR. Data were normalized to peripheral blood mononuclear cells (PBMC) as an internal control. Relative expression of cathepsin K, MMP-9, TRAP, and li was increased in the stifle synovial fluid of dogs with oligoarthritis, when compared with the stifles of healthy dogs (P<0.05). In contrast, relative expression of all of the genes-of-interest in synovial fluid from joints affected with other forms of arthritis was not significantly different from the stifles of healthy dogs. TRAP expression was also significantly increased in the stifle joints of dogs with oligoarthritis, when compared to joint expression of TRAP in dogs with other forms of degenerative arthritis (P<0.05). In the dogs with stifle oligoarthritis, expression of both matrix turnover and immune response genes was increased in stifle synovial fluid, when compared with the internal PBMC control, whereas in healthy dogs and dogs with other forms of arthritis, only expression of matrix turnover genes was increased in synovial fluid, when compared with the internal PBMC control (P<0.05). Taken together, these findings suggest that antigen-specific immune responses within the stifle joint may be involved in the pathogenesis of persistent synovitis and associated joint degradation in dogs with oligoarthritis and degenerative CCL rupture.