Unexpected connections of the IL-23/IL-17 and IL-4/IL-13 cytokine axes in inflammatory arthritis and enthesitis.

The IL-23/IL-17 cytokine axis is related to spondyloarthropathy (SpA) pattern diseases that target the skin, eye, gut and joints. These share overlapping target tissues with Th2 type or allergic diseases, including the skin, eye and gut but SpA diseases exhibit distinct microanatomical topography, molecular characteristics, and clinical features including uveitis, psoriasis, apical pulmonary involvement, lower gastrointestinal involvement with colitis, and related arthritides including psoriatic arthritis and ankylosing spondylitis. Inflammatory arthritis is conspicuously absent from the Th2 diseases which are characterised IL-4/IL-13 dependent pathway activation including allergic rhino-conjunctivitis, atopic eczema, allergic asthma and food allergies. This traditional understanding of non-overlap of musculoskeletal territory between that atopic diseases and the IL-17 -mediated SpA diseases is undergoing a critical reappraisal with the recent demonstration of IL-4/IL-13 blockade, may be associated with the development of SpA pattern arthritis, psoriasiform skin disease and occasional anterior uveitis. Given the known plasticity within Th paradigm pathways, these findings suggest dynamic Th2 cytokine and Th17 cytokine counter regulation in vivo in humans. Unexpected, this is the case in peripheral enthesis and when the IL-4/13 immunological brake on IL-23/17 cytokines is removed, a SpA phenotype may emerge. We discuss hitherto unexpected observations in SpA, showing counter regulation between the Th17 and Th2 pathways at sites including the entheses that collectively indicate that the emergent reverse translational therapeutic data is more than coincidental and offers new insights into the "Th paradigms" in atopy and SpA.

Efficacy and safety of pharmacological treatment of psoriatic arthritis: a systematic literature research informing the 2023 update of the EULAR recommendations for the management of psoriatic arthritis.

OBJECTIVES: To obtain an overview of recent evidence on efficacy and safety of pharmacological treatments in psoriatic arthritis (PsA). METHODS: This systematic literature research (SLR) investigated the efficacy and safety of conventional synthetic (cs), biological (b) and targeted synthetic (ts) disease-modifying antirheumatic drugs (DMARDs) in patients with PsA. A systematic database search using Medline, EMBASE, Cochrane CENTRAL was conducted to identify relevant articles published since the previous update in 2019 until 28 December 2022. Efficacy was assessed in trials while for safety observational data were also considered. Adverse events of special interest were infections (including herpes zoster, influenza and tuberculosis), malignancies, major adverse cardiovascular events, venous thromboembolisms, liver disease, laboratory changes and psychiatric adverse events. No meta-analyses were performed. RESULTS: For efficacy, of 3946 articles screened, 38 articles (30 trials) were analysed. The compounds investigated included csDMARDs (leflunomide, methotrexate), bDMARDs inhibiting IL17 (bimekizumab, brodalumab, ixekizumab, izokibep, secukinumab,), IL-23 (guselkumab, risankizumab, tildrakizumab), IL-12/23 (ustekinumab) as well as TNF (adalimumab, certolizumab-pegol, etanercept, infliximab, golimumab) and Janus Kinase inhibitors (JAKi) (brepocitinib, deucravacitinib, tofacitinib, upadacitinib). The compounds investigated were efficacious in improving signs and symptoms of PsA, improving physical functioning and quality of life. For safety, 2055 abstracts were screened, and 24 articles analysed: 15 observational studies and 9 long-term follow-ups of trials, assessing glucocorticoids, TNFi, IL-17i, JAKi, IL-12/23i and PDE4i (apremilast). Safety indicators were generally coherent with the previous SLR in 2019. CONCLUSION: The results of this SLR informed the task force responsible for the 2023 update of the European Alliance of Associations for Rheumatology recommendations for pharmacological management of PsA.

EULAR recommendations for the management of psoriatic arthritis with pharmacological therapies: 2023 update.

OBJECTIVE: New modes of action and more data on the efficacy and safety of existing drugs in psoriatic arthritis (PsA) required an update of the EULAR 2019 recommendations for the pharmacological treatment of PsA. METHODS: Following EULAR standardised operating procedures, the process included a systematic literature review and a consensus meeting of 36 international experts in April 2023. Levels of evidence and grades of recommendations were determined. RESULTS: The updated recommendations comprise 7 overarching principles and 11 recommendations, and provide a treatment strategy for pharmacological therapies. Non-steroidal anti-inflammatory drugs should be used in monotherapy only for mild PsA and in the short term; oral glucocorticoids are not recommended. In patients with peripheral arthritis, rapid initiation of conventional synthetic disease-modifying antirheumatic drugs is recommended and methotrexate preferred. If the treatment target is not achieved with this strategy, a biological disease-modifying antirheumatic drug (bDMARD) should be initiated, without preference among modes of action. Relevant skin psoriasis should orient towards bDMARDs targeting interleukin (IL)-23p40, IL-23p19, IL-17A and IL-17A/F inhibitors. In case of predominant axial or entheseal disease, an algorithm is also proposed. Use of Janus kinase inhibitors is proposed primarily after bDMARD failure, taking relevant risk factors into account, or in case bDMARDs are not an appropriate choice. Inflammatory bowel disease and uveitis, if present, should influence drug choices, with monoclonal tumour necrosis factor inhibitors proposed. Drug switches and tapering in sustained remission are also addressed. CONCLUSION: These updated recommendations integrate all currently available drugs in a practical and progressive approach, which will be helpful in the pharmacological management of PsA.

Subclinical psoriatic arthritis and disease interception-where are we in 2024?

Psoriatic arthritis (PsA) is a chronic rheumatic disease that usually appears in patients with skin psoriasis, making it a model for detection of joint disease in the pre-clinical phases in a setting where therapy for cutaneous disease may ameliorate or prevent arthritis development. Such PsA prevention appears credible due to the increasingly recognized closely shared immunopathology between the skin and joints, especially the entheses. Recently, several initiatives have explored the concept of pre-clinical PsA, and nomenclatures have been developed with the recent EULAR nomenclature proposing a simplified three stages from psoriasis to clinical PsA development, namely at risk of PsA, subclinical PsA and early PsA. A better comprehension of early PsA and the identification of individuals predisposed to its development could enable interventions to 'prevent' the appearance of PsA. Several recent retrospective observational studies have demonstrated disease interception feasibility, i.e. treatment of people with psoriasis may prevent the appearance of PsA, in particular using biologic disease-modifying drugs. However, further data is urgently required due to unexpected findings in some studies where TNF inhibition for psoriasis does not reduce the rate of PsA development. In this review we address the current challenges in early PsA, including comparisons of pre-PsA nomenclature sets, its risk factors, and the potential for disease interception.

Enthesitis in patients with psoriatic arthritis treated with secukinumab or adalimumab: a post hoc analysis of the EXCEED study.

OBJECTIVES: To evaluate enthesitis treatment response, including time to resolution and data from multiple enthesitis instruments, in patients with PsA treated with secukinumab or adalimumab for 52 weeks. METHODS: In this post hoc analysis of the EXCEED study, patients receiving secukinumab 300 mg or adalimumab 40 mg per the label were grouped by presence or absence of baseline enthesitis based on the Leeds Enthesitis Index (LEI) and the Spondyloarthritis Research Consortium of Canada Enthesitis Index (SPARCC). Efficacy was assessed according to several enthesitis-related instruments using non-responder imputation for the achievement of enthesitis resolution (LEI/SPARCC = 0), Kaplan-Meier analysis for time to resolution, and as-observed data for other outcomes. RESULTS: Enthesitis was present at baseline in 498 of 851 patients (58.5%) as assessed by LEI and in 632 of 853 patients (74.1%) as assessed by SPARCC. Patients with baseline enthesitis generally presented with greater disease activity. Similar proportions of patients receiving secukinumab or adalimumab achieved resolution of LEI and SPARCC at weeks 24 (secukinumab: LEI/SPARCC, 49.6%/45.8%; adalimumab: LEI/SPARCC, 43.6%/43.5%) and 52 (secukinumab: LEI/SPARCC, 60.7%/53.2%; adalimumab: LEI/SPARCC, 55.3%/51.4%), with comparable mean time to enthesitis resolution. Improvements were similar for both drugs at individual enthesitis sites. Resolution of enthesitis with secukinumab or adalimumab was associated with improvements in quality of life at week 52. CONCLUSION: Secukinumab and adalimumab showed similar efficacy, including time to resolution, with respect to resolution of enthesitis. Inhibition of IL-17 with secukinumab reduced clinical enthesitis similarly to TNF-α inhibition. TRIAL REGISTRATION: ClinicalTrials.gov, NCT02745080.

Association of the clinical components in the distal interphalangeal joint synovio-entheseal complex and subsequent response to ixekizumab or adalimumab in psoriatic arthritis.

OBJECTIVES: To assess the frequency of simultaneous distal interphalangeal (DIP) joint disease and adjacent nail psoriasis (finger unit) among patients with psoriatic arthritis (PsA) and compare the efficacy of the interleukin (IL)-17A antagonist ixekizumab (IXE) and the tumour necrosis factor (TNF)-α inhibitor adalimumab (ADA). METHODS: This post hoc analysis evaluated the simultaneous occurrence of DIP joint involvement (tenderness and/or swelling) and adjacent nail psoriasis among patients with PsA from the SPIRIT-H2H (NCT03151551) trial comparing IXE to ADA. Among patients with simultaneous DIP joint involvement and adjacent nail psoriasis in ≥ 1 digit at baseline, treatment effects were assessed through week 52 for each affected finger unit; 'finger unit' defines the connected DIP joint and adjacent nail of an individual digit. RESULTS: A total of 354 patients had simultaneous DIP joint involvement and adjacent nail psoriasis in ≥ 1 finger unit at baseline. Among them, 1309 (IXE = 639, ADA = 670) finger units had baseline DIP joint tenderness and/or swelling and adjacent nail psoriasis. Proportions of affected finger units achieving complete resolution were significantly higher with IXE vs ADA as early as week 12 (38.8% vs 28.4%, p< 0.0001) and at all post-baseline assessments through week 52 (64.9% vs 57.5%, p= 0.0055). CONCLUSIONS: In this study cohort, patients with DIP joint involvement almost always had adjacent nail psoriasis. Greater resolution of DIP joint tenderness, swelling, and adjacent nail psoriasis was achieved at all timepoints over 52 weeks through targeting IL-17A with IXE than TNF-α with ADA, which is noteworthy given prior comparable musculoskeletal outcomes for both drug classes.

Effects of upadacitinib on enthesitis in patients with psoriatic arthritis: a post hoc analysis of SELECT-PsA 1 and 2.

OBJECTIVES: To characterize the effect of upadacitinib 15 mg once daily (UPA15) on enthesitis in patients with psoriatic arthritis from the SELECT-PsA Phase 3 trials. METHODS: Patients with an inadequate response/intolerance to ≥ 1 non-biologic DMARD (SELECT-PsA 1) or ≥ 1 biologic DMARD (SELECT-PsA 2) received UPA15, adalimumab 40 mg every other week or placebo (weeks 0-24) switched to UPA15 (week 24 onward). The Leeds Enthesitis Index (LEI) and Spondyloarthritis Research Consortium of Canada (SPARCC) index were used to assess improvement in enthesitis, enthesitis resolution, maintenance of enthesitis resolution, and protection from enthesitis development through week 56. RESULTS: Data from 639 patients receiving UPA15 and 635 patients receiving placebo (including 317 patients who switched from placebo to UPA15) were analysed. UPA15 led to higher rates of enthesitis resolution vs placebo at week 24 (LEI: 59.8% vs 38.0%; SPARCC index: 50.6% vs 31.5%, respectively) and greater improvements in the LEI (-1.7 vs -1.0) and SPARCC index (-3.4 vs -1.9); improvements were maintained through week 56. Improvements were observed after 12 weeks of UPA15 treatment. Over 90% of patients without enthesitis (LEI = 0) at baseline receiving UPA15 were enthesitis-free at week 56, and UPA15 prevented recurrence of enthesitis at week 56 in > 80% of patients with enthesitis at baseline who achieved resolution (LEI = 0) at week 24. CONCLUSIONS: UPA15 is associated with a comprehensive improvement in enthesitis, with improvements observed after 12 weeks of treatment. Additionally, treatment with UPA15 was associated with maintaining an enthesitis-free state after resolution and protection against new-onset enthesitis. CLINICALTRIALS.GOV IDENTIFIERS: NCT03104400 (SELECT-PsA 1) and NCT03104374 (SELECT-PsA 2).

GRAPPA 2023 Debate: Is Psoriatic Disease Really a Primary Enthesitis That Drives Joint Synovitis? The Enthesitis Hypothesis 25 Years On.

The enthesitis hypothesis posits that enthesitis is a primary lesion and that inflammation at the enthesis initiates the musculoskeletal symptoms of psoriatic arthritis (PsA) and spondyloarthropathies (SpA). The hypothesis suggested that inflamed entheseal tissue near the synovium could trigger cytokine-mediated synovitis, that enthesis bone anchorage could explain osteitis, and that the location of entheses at the soft tissue interface could explain dactylitis. Advances in imaging techniques that allow better visualization of enthesitis lesions and the development of animal models have allowed evolution of the concept of enthesitis as a central mechanistic driver of musculoskeletal symptoms in PsA and SpA. A debate between Drs. Dennis McGonagle and Bruce Kirkham at the Group for Research on Psoriasis and Psoriatic Arthritis (GRAPPA) 2023 annual meeting discussed the data supporting and refuting this hypothesis in PsA and SpA, respectively. The major points of this debate are summarized in this article.

Systematic Review and Metaanalysis of Pharmacological Interventions in Adult-Onset Still Disease and the Role of Biologic Disease-Modifying Antirheumatic Drugs.

OBJECTIVE: To conduct a systematic review of the effectiveness and safety of pharmacological treatments for adult-onset Still disease (AOSD). METHODS: Six databases, 2 trial registries, and conference abstracts were searched from January 2012 to February 2023 for studies of pharmacological interventions in people with AOSD. Outcomes were rates of remission and response, discontinuation of concurrent treatments, complications of AOSD, and treatment-related adverse events. Risk of bias was assessed with the Cochrane risk of bias tool and the Joanna Briggs Institute tool for case series. RESULTS: Forty-four studies evaluated treatments, including nonsteroidal antiinflammatory drugs (NSAIDs), corticosteroids (CS), conventional synthetic disease-modifying antirheumatic drugs (DMARDs), and biologic DMARDs (bDMARDs). For bDMARDs, tocilizumab (TCZ), anakinra (ANK), and canakinumab (CNK) had the most available data. Although 3 randomized controlled trials did not show statistically significant benefits of bDMARDs, metaanalyses showed high rates of complete remission and CS discontinuation. Complete remission was 80% (95% CI 59-92%, I 2 36%), 73% (95% CI 58-84%, I 2 66%), and 77% (95% CI 29-97%, I 2 82%) and CS discontinuation was 57% (95% CI 29-81%, I 2 66%), 47% (95% CI 18-78%, I 2 79%), and 34% (95% CI 6-81%, I 2 59%), respectively, for TCZ, ANK, and CNK. Studies with a higher proportion of patients previously treated with bDMARDs showed a trend toward lower rates of CS discontinuation (P = 0.05). The analyses had high clinical heterogeneity, largely because treatments were prescribed as different lines of therapy. CONCLUSION: Evidence supports TCZ, ANK, and CNK therapy for AOSD. However, the magnitude of effect and comparative effectiveness of treatments is uncertain.

Soluble low affinity nerve growth factor receptor (sLNGFR) may regulate pain in knee osteoarthritis.

OBJECTIVES: Nerve growth factor ß (ß-NGF) is a protein which is important to the development of neurons particularly those involved in the transmission of pain and is central to the experience of pain in osteoarthritis (OA). Direct NGF antagonism has been shown to reduce OA pain but is associated with rapidly progressive OA. The aim of the study is to investigate the ability of soluble neurotrophin receptors in the NGF pathway to modulate pain in OA. METHODS: Synovial fluid (SF) was obtained from the knee joints of 43 subjects who underwent total knee arthroplasty. Visual analogue scale (VAS) pain scores were obtained prior to surgery. Customised-automated-ELISAs and commercial-ELISAs and LEGENDplex™ were used to measure soluble low-affinity nerve growth factor (LNGFR), soluble tropomyosin receptor kinase (TrkA), proNGF, ß-NGF, other neurotrophins (NT) and cytokines including inflammatory marker TNF-α. RESULTS: The VAS score positively correlated with ß-NGF (r=0.34) and there was positive association trend with neurotrophin-3 (NT-3), BDNF and negative association trend with ProNGF. sLNGFR positively correlated with VAS (r=0.33). The ß-NGF/soluble TrkA ratio showed a strong positive correlation with VAS (r=0.80). In contrast, there was no correlation between pain and the ß-NGF/sLNGFR ratio (r=-0.08). TNF-α positively correlated with ß-NGF (r=0.83), NT-3 (r=0.66), and brain-derived neurotrophic factor (BDNF) (r=0.50) and negatively with ProNGF (r= -0.74) and positively correlated with both soluble TrkA (r=0.62), sLNGFR (r=0.26). CONCLUSIONS: This study suggests that endogenous or cleaved sLNGFR, but not soluble TrkA may participate in OA pain modulation thus supporting further research into soluble LNGFR as a therapeutic target in OA.

Risk factors for psoriatic arthritis development in psoriasis patients: myths, pitfalls, and pearls.

Psoriatic arthritis (PsA) predominantly emerges in individuals previously diagnosed with psoriasis (PsO), offering a unique opportunity to study the transition from PsO to PsA. This progression provides a window to identify characteristics of PsO patients who may develop PsA, facilitating early intervention and potentially informing prevention and treatment strategies. This review evaluates a wide array of research focusing on various risk factors for PsA development. These factors span demographic characteristics, concomitant diseases and habits, characteristics of skin and nail psoriatic disease, and symptoms and imaging abnormalities associated with PsA. By summarising the existing literature, this review critically examines each risk factor, highlighting the strengths and limitations inherent in the studies. Each section of the review not only summarises the current state of knowledge but also includes an expert opinion, culminating in a final concluding remark. This integration allows physicians to utilise the confluence of established literature and ongoing clinical experience, facilitating a rationalised decision-making process that is deeply informed by both empirical evidence and practical insights.

Hidradenitis suppurativa associated telomere-methylome dysregulations in blood.

BACKGROUND: Hidradenitis suppurativa (HS) is a chronic debilitating disease with a significant burden of both organic and psychological comorbidities. It has been shown that certain telomere-related genes (TRGs) affect a wide range of diseases, including HS and its associated comorbidities, but their exact role in HS pathogenesis is still unknown. OBJECTIVES: To determine whether TRG methylomes can be used as biomarkers in HS. METHODS: Using the Illumina HumanMethylation450 BeadChip array, we examined methylation variations associated with TRGs in HS cases and age-, sex- and ethnicity-matched healthy controls. The study utilized integrated bioinformatics statistical methods, such as a false discovery rate (FDR), the area under the receiver operating characteristic curve (AUC) and principal component analysis. RESULTS: There were a total of 585 different differentially methylated CpG sites identified in 585 TRGs associated with HS (474 hypomethylated and 111 hypermethylated) (FDR p-value < 0.05). A number of these CpGs have been identified as being involved in increased pain sensitivity including EPAS1, AHR, CSNK1D, DNMT1, IKBKAP, NOS3, PLCB1 and PRDM16 genes; GABRB3 as a potential alcohol addiction marker; DDB1, NSMCE2 and HNRNPA2B1 associated with cancers. Pathway analysis identified 67 statistically significant pathways, including DNA repair, telomere maintenance, mismatch repair and cell cycle control (p < 0.001). CONCLUSION: The disruption of TRGs leads to the shortening of telomeres, which is associated with HS progression, ageing, cellular senescence and an increased risk of various diseases, including cancer and associated comorbidities, such as metabolic syndrome, cardiovascular disease and inflammatory disorders. Further research is necessary to better understand the underlying mechanisms and establish causal links between TRGs and HS. The present study is the first effort to comprehend potential pathomechanisms of sporadic HS cases concentrating on PBMC methylome since ours.

ICON 2023: International Scientific Tendinopathy Symposium Consensus - the core outcome set for Achilles tendinopathy (COS-AT) using a systematic review and a Delphi study of professional participants and patients.

To develop a core outcome set for Achilles tendinopathy (COS-AT) for use in clinical trials we performed a five-step process including (1) a systematic review of available outcome measurement instruments, (2) an online survey on truth and feasibility of the available measurement instruments, (3) an assessment of the methodological quality of the selected outcome measurement instruments, (4) an online survey on the outcome measurement instruments as COS and (5) a consensus in-person meeting. Both surveys were completed by healthcare professionals and patients. The Outcome Measures in Rheumatology guidelines with a 70% threshold for consensus were followed. We identified 233 different outcome measurement instruments from 307 included studies; 177 were mapped within the International Scientific Tendinopathy Symposium Consensus core domains. 31 participants (12 patients) completed the first online survey (response rate 94%). 22/177 (12%) outcome measurement instruments were deemed truthful and feasible and their measurement properties were evaluated. 29 participants (12 patients) completed the second online survey (response rate 88%) and three outcome measurement instruments were endorsed: the Victorian Institute of Sports Assessment-Achilles questionnaire, the single-leg heel rise test and evaluating pain after activity using a Visual Analogue Scale (VAS, 0-10). 12 participants (1 patient) attended the final consensus meeting, and 1 additional outcome measurement instrument was endorsed: evaluating pain during activity/loading using a VAS (0-10). It is recommended that the identified COS-AT will be used in future clinical trials evaluating the effectiveness of an intervention. This will facilitate comparing outcomes of intervention strategies, data pooling and further progression of knowledge about AT. As COS-AT is implemented, further evidence on measurement properties of included measures and new outcome measurement instruments should lead to its review and refinement.

Interleukin-23 pathway at the enthesis: The emerging story of enthesitis in spondyloarthropathy.

The inflammatory disorders collectively termed the seronegative spondyloarthropathies (SpA) include ankylosing spondylitis (AS), psoriatic arthritis (PsA), reactive arthritis, the arthritis associated with inflammatory bowel disease including Crohn's disease and ulcerative colitis, the arthritis related to anterior uveitis, and finally, somewhat controversially Behcet's disease. All of these diseases are associated with SNPs in the IL-23R or the interleukin-23 (IL-23) cytokine itself and related downstream signaling JAK pathway genes and the interleukin-17 (IL-17) pathway. In rheumatoid arthritis, the target of the immune response is the synovium but the SpA disorders target the tendon, ligament, and joint capsule skeletal anchorage points that are termed entheses. The discovery that IL-23R-expressing cells were ensconced in healthy murine enthesis, and other extraskeletal anchorage points including the aortic root and the ciliary body of the eye and that systemic overexpression of IL-23 resulted in a severe experimental SpA, confirmed a fundamentally different immunobiology to rheumatoid arthritis. Recently, IL-23R-expressing myeloid cells and various innate and adaptive T cells that produce IL-17 family cytokines have also been described in the human enthesis. Blockade of IL-23 pathway with either anti-p40 or anti-p19 subunits has resulted in some spectacular therapeutic successes in psoriasis and PsA including improvement in enthesitis in the peripheral skeleton but has failed to demonstrate efficacy in AS that is largely a spinal polyenthesitis. Herein, we discuss the known biology of IL-23 at the human enthesis and highlight the remarkable emerging story of this unique skeletal tissue.

EULAR points to consider for the definition of clinical and imaging features suspicious for progression from psoriasis to psoriatic arthritis.

BACKGROUND: The transition from psoriasis (PsO) to psoriatic arthritis (PsA) and the early diagnosis of PsA is of considerable scientific and clinical interest for the prevention and interception of PsA. OBJECTIVE: To formulate EULAR points to consider (PtC) for the development of data-driven guidance and consensus for clinical trials and clinical practice in the field of prevention or interception of PsA and for clinical management of people with PsO at risk for PsA development. METHODS: A multidisciplinary EULAR task force of 30 members from 13 European countries was established, and the EULAR standardised operating procedures for development for PtC were followed. Two systematic literature reviews were conducted to support the task force in formulating the PtC. Furthermore, the task force proposed nomenclature for the stages before PsA, through a nominal group process to be used in clinical trials. RESULTS: Nomenclature for the stages preceding PsA onset, 5 overarching principles and 10 PtC were formulated. Nomenclature was proposed for three stages towards PsA development, namely people with PsO at higher risk of PsA, subclinical PsA and clinical PsA. The latter stage was defined as PsO and associated synovitis and it could be used as an outcome measure for clinical trials evaluating the transition from PsO to PsA. The overarching principles address the nature of PsA at its onset and underline the importance of collaboration of rheumatologists and dermatologists for strategies for prevention/interception of PsA. The 10 PtC highlight arthralgia and imaging abnormalities as key elements of subclinical PsA that can be used as potential short-term predictors of PsA development and useful items to design clinical trials for PsA interception. Traditional risk factors for PsA development (ie, PsO severity, obesity and nail involvement) may represent more long-term disease predictors and be less robust for short-term trials concerning the transition from PsO to PsA. CONCLUSION: These PtC are helpful to define the clinical and imaging features of people with PsO suspicious to progress to PsA. This information will be helpful for identification of those who could benefit from a therapeutic intervention to attenuate, delay or prevent PsA development.

EULAR study group on 'MHC-I-opathy': identifying disease-overarching mechanisms across disciplines and borders.

The 'MHC-I (major histocompatibility complex class I)-opathy' concept describes a family of inflammatory conditions with overlapping clinical manifestations and a strong genetic link to the MHC-I antigen presentation pathway. Classical MHC-I-opathies such as spondyloarthritis, Behçet's disease, psoriasis and birdshot uveitis are widely recognised for their strong association with certain MHC-I alleles and gene variants of the antigen processing aminopeptidases ERAP1 and ERAP2 that implicates altered MHC-I peptide presentation to CD8+T cells in the pathogenesis. Progress in understanding the cause and treatment of these disorders is hampered by patient phenotypic heterogeneity and lack of systematic investigation of the MHC-I pathway.Here, we discuss new insights into the biology of MHC-I-opathies that strongly advocate for disease-overarching and integrated molecular and clinical investigation to decipher underlying disease mechanisms. Because this requires transformative multidisciplinary collaboration, we introduce the EULAR study group on MHC-I-opathies to unite clinical expertise in rheumatology, dermatology and ophthalmology, with fundamental and translational researchers from multiple disciplines such as immunology, genomics and proteomics, alongside patient partners. We prioritise standardisation of disease phenotypes and scientific nomenclature and propose interdisciplinary genetic and translational studies to exploit emerging therapeutic strategies to understand MHC-I-mediated disease mechanisms. These collaborative efforts are required to address outstanding questions in the etiopathogenesis of MHC-I-opathies towards improving patient treatment and prognostication.

Increased risk for stroke in patients with familial Mediterranean fever: results from a large population-based study.

OBJECTIVE: The association between chronic inflammatory conditions and cardiovascular disease is well established. Considering FMF, few studies exist investigating the risk of ischaemic heart disease, and none address the risk of stroke. We aimed to evaluate the incidence and risk for stroke in FMF patients compared with the general population. METHODS: A retrospective cohort study using the electronic database of Clalit Health Services (CHS), the largest health organization in Israel. All FMF patients diagnosed between 2000 and 2016 were included and matched with control according to age, gender and place of residence. Follow-up continued until the first diagnosis of stroke or death. The incidence of stroke was compared between the groups using univariate and multivariate models adjusting for cardiovascular risk-factors. RESULTS: A total of 9769 FMF patients and a similar number of controls were followed up for a median period of 12.5 years. The mean age at the beginning of the follow-up was 25.7 years. In total, 208 FMF patients were diagnosed with stroke compared with 148 controls, resulting in an incidence rate (per 10 000 persons-years) of 19.8 (95% CI 17.2, 22.7) and 13.9 (95% CI 11.8, 16.4), respectively, and a crude HR of 1.42 (95% CI 1.15-1.76; P < 0.001). In a multivariate analysis, FMF patients who developed amyloidosis with related or non-related renal failure demonstrated significant stroke risk (HR = 2.16; 95% CI 1.38, 3.38; P < 0.001), as well as for those who did not develop these complications (HR = 1.32; 95% CI 1.04, 1.67; P < 0.05). CONCLUSION: FMF patients are at increased risk for stroke regardless of known complications.

Increased risk of osteoporosis and femoral neck fractures in patients with familial Mediterranean fever-a large retrospective cohort study.

OBJECTIVES: The direct impact of inflammatory conditions and their therapy with corticosteroids both contribute to an increased risk of osteoporosis with associated fractures. Familial-Mediterranean-Fever (FMF) is an autoinflammatory disorder not commonly treated with corticosteroids. Evidence regarding FMF association with osteoporosis and femur fractures is anecdotal. We aimed to evaluate the incidence and risk of osteoporosis and femoral neck fracture in FMF patients compared with the general population. METHODS: A retrospective cohort study using the electronic database of Clalit Health Services of all FMF patients first diagnosed between 2000-2016 and controls was evaluated including age and sex matched controls in 1:1 ratio. Follow-up continued until the first diagnosis of osteoporosis or fracture. Risk for these conditions was compared using univariate and multivariate cox-regression models. RESULTS: 9,769 FMF patients were followed for a median period of 12.5 years. 304 FMF patients were diagnosed with osteoporosis compared with 191 controls, resulting in an incidence rate (per 10 000 persons-years) of 28.8 and 17.8 respectively, and a crude HR of 1.62 (95%CI 1.35-1.93; p< 0.001). Patients were diagnosed with osteoporosis at a considerably younger age than controls (60.1 ± 12.4 vs 62.5 ± 11.0 years; p= 0.028). 56 FMF patients were diagnosed with femoral neck fracture compared with 35 controls, resulting in an incidence rate of 5.3 and 3.3 respectively, and a crude HR of 1.60 (95%CI 1.05-2.44; p< 0.05). CONCLUSION: FMF patients are at increased risk for osteoporosis and consequently femur fracture. Our findings emphasize the importance of considering bone health in the management of FMF patients.

Asymmetric Flexion Contracture is Associated With Leg Length Inequality in Patients With Knee Osteoarthritis: Data From the Osteoarthritis Initiative.

OBJECTIVE: To evaluate whether knee flexion contracture (FC) was associated with leg length inequality (LLI) and/or morbidity in knee osteoarthritis (OA). DESIGN: We accessed 2 databases: (1) the Osteoarthritis Initiative (OAI) cohort, including participants with, or at-risk of OA, and (2) the Ottawa Knee Osteoarthritis cross-sectional database (OKOA), including participants with primary advanced knee OA. Both included demographics, radiographic data, knee range of motion, leg length, pain, and function scales. SETTING: Tertiary care academic rheumatology and orthopedic clinics. PARTICIPANTS: Patients with or at-risk of primary OA. We included 881 OAI and 72 OKOA participants (N=953). INTERVENTION: Not applicable. MAIN OUTCOME MEASURES: The primary outcome tested the association between the difference in knee extensions of the OA and contralateral knees (the knee extension difference, or KExD) and LLI. This was evaluated using bivariate regression, followed by a multivariable linear regression model. RESULTS: OAI participants had less severe knee OA [Kellgren and Lawrence (KL) score 1.9±1.3] vs OKOA (KL score 3.4±0.6). The KExD correlated with LLI for both databases (OAI: R=0.167; P≤.001; OKOA: R=0.339; P=.004). Multivariable regression showed an effect of KExD on LLI in both databases (OAI: ß=0.37[0.18,0.57]; P<.001, OKOA: ß=0.73[0.20,1.26]; P=.007). When broken down by subgroup, the OAI moderate-severe OA group showed a significant effect of KExD on LLI (ß=0.60 [0.34,0.85]; P<.001). CONCLUSIONS: OA-related loss of knee extension was associated with LLI for those with moderate-severe OA. Because LLI correlates with worse knee OA symptoms, discovering an FC should cue clinicians to evaluate for LLI, an easily-treatable finding that may help reduce OA-associated morbidity for those approaching the need for arthroplasty.

Ankylosing spondylitis is associated with increased prevalence of valvular heart diseases: a cross-sectional population-based study.

BACKGROUND: Ankylosing spondylitis (AS) is a chronic inflammatory arthritis primarily affecting the sacroiliac joint and axial skeleton with associated extra-articular involvement including cardiovascular system disease including aortic valve disease with variable reported prevalence. The aim of this study is to determine the prevalence of heart valve disorders in AS patients. METHODS: This was a retrospective, population-based, cross-sectional study that retrieved data from the Clalit Health Services registry. Cases were defined as having AS, whereas controls were frequency matched by age and sex in a ratio of 5:1. The prevalence of valvular heart diseases was compared between the two groups; a multivariate logistic regression model was applied to estimate the association after controlling for potential confounders. RESULTS: We included 4082 AS patients and 20 397 controls frequency matched by age and sex. AS patients had a significantly higher prevalence of cardiovascular risk factors (P < .001) and a higher prevalence of valvular heart disease. In the multivariate logistic regression model, adjusting for multiple confounding factors, AS was independently associated with aortic stenosis [odds ratio (OR): 2.25, 95% confidence interval (CI): 1.57-3.23, P < 0.001], aortic insufficiency (OR: 2.44, 95% CI: 1.50-3.94, P < 0.001), and mitral insufficiency (OR: 1.75, 95% CI: 1.17-2.61, P < 0.001) but not mitral stenosis (OR: 1.31, 95% CI: 0.60-2.70, P = 0.47). CONCLUSIONS: Our study reports the increased risk of valvular heart diseases in patients with AS, possibly due to the inflammatory milieu associated with the disease process and the result of biomechanical stress affecting the enthesis-like valvular structures.