The synovium is the major target tissue of inflammatory arthritides such as rheumatoid arthritis (RA). The study of synovial tissue has advanced significantly over a number of decades from arthroplasty, blind needle biopsy and more recently facilitated by arthroscopic and ultrasonographic technology that allows easier visualisation and improves the reliability of obtaining synovial biopsies. The potential for study of pathogenesis, patient stratification, discovery of biomarkers and novel targets, as well as validation of therapy, have all been progressed rapidly in the last decade, facilitated by increasingly diverse and sophisticated analytical and technological approaches. In this review we describe clinical and translational developments in the field of synovial tissue research, outlining current and novel investigative technologies, and highlight their application to advance our understanding of the aforegoing imperatives.3

This study shows for the first time that IL-38 overexpression attenuates the severity of experimental arthritis. IL-38 may exert its anti-inflammatory effects by decreasing the production of proinflammatory cytokines by macrophages and synovial fibroblasts. This effect can lead to the development of novel treatment strategies in arthritis.

ObjectivesPerform a systematic literature review (SLR) on risk and prognosis of SARS-CoV-2 infection and vaccination against SARS-CoV-2 in patients with rheumatic and musculoskeletal diseases (RMDs).MethodsLiterature was searched up to 31 May 2021, including (randomised) controlled trials and observational studies with patients with RMD. Pending quality assessment, data extraction was performed and risk of bias (RoB) was assessed. Quality assessment required provision of (1) an appropriate COVID-19 case definition, and (2a) a base incidence (for incidence data) or (2b) a comparator, >10 cases with the outcome and risk estimates minimally adjusted for age, sex and comorbidities (for risk factor data).ResultsOf 5165 records, 208 were included, of which 90 passed quality assessment and data were extracted for incidence (n=42), risk factor (n=42) or vaccination (n=14). Most studies had unclear/high RoB. Generally, patients with RMDs do not face more risk of contracting SARS-CoV-2 (n=26 studies) or worse prognosis of COVID-19 (n=14) than individuals without RMDs. No consistent differences in risk of developing (severe) COVID-19 were found between different RMDs (n=19). Disease activity is associated with worse COVID-19 prognosis (n=2), possibly explaining the increased risk seen for glucocorticoid use (n=13). Rituximab is associated with worse COVID-19 prognosis (n=7) and possibly Janus kinase inhibitors (n=3). Vaccination is generally immunogenic, though antibody responses are lower than in controls. Vaccine immunogenicity is negatively associated with older age, rituximab and mycophenolate.ConclusionThis SLR informed the July 2021 update of the European Alliance of Associations for Rheumatology recommendations for the management of RMDs in the context of SARS-CoV-2.

The first EULAR provisional recommendations on the management of rheumatic and musculoskeletal diseases (RMDs) in the context of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), largely based on expert opinion, were published in June 2020. Since then, an unprecedented number of clinical studies have accrued in the literature. Several SARS-CoV-2 vaccines have been approved for population-wide vaccination programmes in EULAR-affiliated countries. Studies regarding vaccination of patients with (inflammatory) RMDs have released their first results or are underway.EULAR found it opportune to carefully review to what extent the initially consensus expert recommendations stood the test of time, by challenging them with the recently accumulated body of scientific evidence, and by incorporating evidence-based advice on SARS-CoV-2 vaccination. EULAR started a formal (first) update in January 2021, performed a systematic literature review according to EULAR’s standard operating procedures and completed a set of updated overarching principles and recommendations in July 2021. Two points to consider were added in November 2021, because of recent developments pertaining to additional vaccination doses.