High serum levels of CXCL13 predict lower response to csDMARDs in both ACPA-positive and ACPA-negative early rheumatoid arthritis.

OBJECTIVES: Increased circulating levels of CXCL13 reflect synovial production and indicate immune dysregulation in patients with rheumatoid arthritis (RA). Here we tested whether CXCL13 predicts response to first-line treatment with methotrexate (MTX) in patients with early RA, independently and in association with anti-citrullinated protein antibodies (ACPA) and IgM-rheumatoid factor (RF). METHODS: A prospective cohort of 243 early RA patients undergoing treat-to-target with MTX was evaluated. CXCL13, ACPA and IgM-RF were determined on baseline sera. Short-term variations of CXCL13 were measured after 2 months. The association of high CXCL13 (≥100 pg/ml) with disease remission after 6 months and escalation to second-line therapies within year 2 was evaluated in the total population and in ACPA-subgroups separately. RESULTS: High levels of CXCL13 were found in 53.6% of ACPA-positive and 31.5% of ACPA-negative patients, with minimal association with disease activity and RF. Serum CXCL13 remained stable after 2 months. High baseline CXCL13 independently predicted failure to achieve remission and more frequent requirement of second-line treatment in ACPA-positive patients, with adjusted ORs in the range of 0.17-0.49 for remission and 6.75 for second-line treatment. In ACPA-negative patients with high CXCL13, remission occurred at the expense of higher doses of MTX, and levels of CXCL13 predicted MTX escalations with an adjusted OR (95% CI) of 2.69 (1.35-5.34). CONCLUSIONS: High serum levels of CXCL13 identify a subgroup of RA patients who are more refractory to first-line treatment with MTX. CXCL13 appears a promising biomarker of response to MTX in both ACPA-positive and -negative early RA.

Effectiveness and safety of filgotinib in rheumatoid arthritis patients: data from the GISEA registry.

OBJECTIVES: The aim of this study was to evaluate the effectiveness and safety profile of filgotinib, a JAK1 preferential inhibitor, in rheumatoid arthritis (RA) patients included in Italian GISEA (Group for the Study of Early Arthritis) registry. METHODS: Data from RA patients treated with filgotinib, recorded in the GISEA registry, were analysed. Disease activity scores and patient-reported outcomes (PROs) were assessed at baseline, as well as during 12-month follow-up. A difficult-to-treat (D2T) RA patient was defined according with EULAR criteria. Retention rate of filgotinib was estimated by the Kaplan-Meier method and factors influencing drug discontinuation were estimated by Cox regression models. RESULTS: 246 RA patients (female 89%, 57.6±12.2 years old) started filgotinib, mostly as second (22%) or further (43.9%) b/tsDMARDs line of treatment. At 3 and 12 months, 18.8% and 27.5% of patients achieved Clinical Diseases Activity Index based remission and 30.1% and 37.7% obtained a visual analogue scale of pain ≤20 (all p<0.01 vs. baseline). Filgotinib survival rate was 84.5% at the 6-month and 75.8% at 12-month follow-up, and was comparable either in monotherapy or combination therapy, and irrespective of glucocorticoid intake. b/tsDMARD naive patients had the lowest hazard ratio (HR) of filgotinib discontinuation (HR 0.29, 95%CI 0.14-0.64), while D2T-RA the highest (HR 1.82, 95%CI 1.01-3.3). Eight patients (3.3%) discontinued filgotinib due to adverse events. CONCLUSIONS: In an Italian real-life setting, filgotinib is confirmed to be safe and with a good effectiveness profile both in monotherapy and without glucocorticoids.

Comorbidities in the Spondyloarthritis GISEA Cohort: an average treatment effect analysis on patients treated with bDMARDs.

OBJECTIVES: We aimed to investigate the effectiveness of tumour necrosis factor inhibitors (TNFi), anti-interleukin-17 or interleukin-12/23 monoclonal antibodies (anti-IL) on comorbidities in a cohort of patients with spondyloarthritis (SpA), using an average treatment effect (ATE) analysis. METHODS: SpA patients from the multicentre Italian GISEA Registry were divided into groups according to pharmacological exposure: no treatment (G0), TNFi (G1) and non-responders to TNFi switched to anti-IL (G2). In each group, we recorded the prevalence and incidence of infectious, cardiopulmonary, endocrinological, gastrointestinal, oncologic, renal and neurologic comorbidities. Each comorbidity was then fitted for ATE and baseline features were evaluated for importance. RESULTS: The main findings of this study comprising 4458 SpA patients relate to cancer, other gastrointestinal diseases (OGID) and fibromyalgia. ATE showed no increased risk of solid cancer in G1 (0.42 95% CI 0.20-0.85) and G2 (0.26 95% CI 0.08-0.71) vs. G0, with significantly higher incidence in G0 (14.07/1000 patient-years, p=0.0001). Conversely, a significantly higher risk of OGID and fibromyalgia was found in G1 (1.56 95% CI 1.06-2.33; 1.69 95% CI 1.05-2.68, respectively) and G2 (1.91 95% CI 1.05-3.24; 2.13 95% CI 1.14-3.41, respectively) vs. G0. No treatment risk reduction was observed in haematological malignancies, cardiovascular events and endocrinological comorbidities. CONCLUSIONS: Overall, our study confirms the safety of TNFi and anti-IL in SpA patients, albeit with some caveats pertaining to solid cancers, OGID and fibromyalgia. Furthermore, taking into consideration causality with observational data may yield more reliable and relevant clinical information.

Synovial and serum B-cell signature of autoantibody-negative rheumatoid arthritis versus autoantibody-positive rheumatoid arthritis and psoriatic arthritis.

OBJECTIVES: Autoantibody-negative rheumatoid arthritis (RA) differs from autoantibody-positive RA in several clinical aspects, possibly underpinned by pathogenetic differences. At present, the role of adaptive immune responses in autoantibody-negative RA remains unclear. Here, we investigated the synovial and serum immunophenotype indicative of B-lymphocyte involvement across the spectrum of autoantibody-positive and -negative chronic arthritides. METHODS: Ultrasound-guided synovial biopsies were retrieved from 131 patients: 43 autoantibody-positive RA, 35 autoantibody-negative RA, 25 polyarticular psoriatic arthritis (PsA), 28 oligoarticular PsA. Samples were analysed for the degree of histological inflammation, B-lymphocyte infiltration and the distribution of different pathotypes (lympho-myeloid, myeloid, pauci-immune). Serum levels of the B-cell chemoattractant CXCL13 were compared among groups. RESULTS: Synovitis scores and CD68+ sublining macrophage infiltration were comparable irrespective of clinical diagnosis and disease subtype. In contrast, the degree of B-lymphocyte infiltration and the frequency of lympho-myeloid synovitis in autoantibody-negative RA were lower than those of autoantibody-positive RA (mean [SD] 1.8 [1] vs 2.4 [0.6], p = 0.03 and 38.2% vs 62.9%, p = 0.07, respectively), and similar to polyarticular PsA. Oligoarticular PsA had the lowest B-cell scores. Serum CXCL13 was associated with lympho-myeloid synovitis and followed a similar gradient, with the highest levels in autoantibody-positive RA, intermediate and comparable levels in autoantibody-negative RA and polyarticular PsA, and low levels in oligoarticular PsA. CONCLUSIONS: The synovial and serum immunophenotype indicative of B-lymphocyte involvement in autoantibody-negative RA differs from autoantibody-positive RA and more closely resembles that observed in polyarticular PsA. The pathobiological stratification of chronic inflammatory arthritides beyond clinical diagnosis may fuel personalised treatment strategies.

Seronegative rheumatoid arthritis: one year in review 2023.

In the past 20 years, earlier diagnosis and more intensive management have considerably improved the prognosis of rheumatoid arthritis (RA), with milder disease course achieved in particular in seropositive patients. In contrast, seronegative RA has remained largely neglected, and continues to be surrounded by uncertainties regarding its correct diagnosis, clinical phenotype, optimal treatment strategies and relevant outcomes.The purpose of this review is to summarise new insights about the pathogenic, clinical and prognostic peculiarities of seronegative RA that emerged during 2022, and that make this disease subset at least partially different from its seropositive counterpart.

Reactogenicity, safety and disease flares following BNT162b2 mRNA COVID-19 vaccine in patients with chronic immune-inflammatory arthritis treated with biological and targeted synthetic disease-modifying anti-rheumatic drugs.

OBJECTIVES: The safety of COVID-19 vaccination in rheumatic patients treated with biological (b) and targeted synthetic (ts) disease-modifying anti-rheumatic drugs (DMARDs) remains poorly explored. METHODS: Reactogenicity, safety and disease flares following each of the two doses of the BNT162b2 mRNA vaccine was evaluated in 186 patients with rheumatoid arthritis, psoriatic arthritis and spondyloarthritis treated with b/tsDMARDs, who discontinued anti-rheumatic treatments around vaccination. A group of 53 healthy controls was used for comparison. RESULTS: The frequency and severity of systemic events was similar to that reported in the general population, and no particular safety concerns emerged. The use of methotrexate reduced systemic reactogenicity (adjORs [95% CI] 0.49 [0.25-0.94] and 0.63 [0.32-0.99] after each vaccine dose), whilst no specific effects of different b/tsDMARDs were seen. Flares around vaccination were reported by 24.5% of the patients. Factors associated with flares were active disease (adjORs [95% CI] 2.8 [1.01-8.09] and 1.86 [0.99-6.03] after each vaccine dose) and use of JAKi (adjORs [95% CI] 3.96 [1.39-11.27] and 3.10 [0.99-7.85]). The percentage of cases requiring change or increase in DMARD therapy due to persistent worsening of disease activity at follow-up visits was low (3.2%). CONCLUSIONS: The safety of mRNA COVID-19 vaccination in arthritis patients on treatment with b/tsDMARDs is reassuring. In a regimen of peri-vaccine drug interruption, transient flares of the disease more commonly occur in association with active arthritis and use of shorter half-life drugs. Most flares do not require treatment escalation or change.

Inflammatory correlates of the Patient Global Assessment of Disease Activity vary in relation to disease duration and autoantibody status in patients with rheumatoid arthritis.

OBJECTIVE: To investigate the associations between the Patient Global Assessment (PGA) and measures of disease activity in patients with rheumatoid arthritis (RA) in relation to disease duration and autoantibody status. METHODS: 1412 patients from three independent cohorts were studied: a prospective cohort of 810 patients with early RA followed up for 24 months; a cross-sectional cohort of 210 patients with established RA in low disease activity; a cross-sectional cohort of 401 patients with established RA in moderate-to-high disease activity. Correlations of the PGA were analysed by Pearson's coefficients and multivariable linear regression at baseline and at months 6, 12 and 24 in the overall populations and after stratification for autoantibody subgroup and remission status (Boolean remission, PGA near remission and non-remission). RESULTS: In patients with early RA in non-remission, swollen joints correlated independently with the PGA; the correlation became progressively weaker but persisted at all time points in autoantibody-positive patients (adjusted r=0.30-0.12) but lost significance after month 12 in autoantibody-negative patients. Swollen joints independently correlated with the PGA also in near remission until month 12 (adjusted r=0.18-0.16) in autoantibody-positive patients. No independent correlations of inflammatory variables were instead found in patients with established RA irrespective of disease activity and autoantibody status. CONCLUSIONS: In the early phases of RA, particularly in autoantibody-positive patients, inflammatory variables directly correlate with the PGA across different disease activity states. The optimal cut-off values of the PGA capable of identifying absence of disease should be better explored in relation to disease duration and autoantibody status.

Cytokine profile, ferritin and multi-visceral involvement characterize macrophage activation syndrome during adult-onset Still's disease.

OBJECTIVES: To multidimensionally characterize macrophage activation syndrome (MAS) complicating adult-onset Still's disease (AOSD) considering cytokine profile, inflammatory markers and multi-visceral involvement of the disease. To perform a high-dimensional phenotypic analysis of circulating immune cells in AOSD patients with and without MAS. To assess interferon (IFN)-related pathways in AOSD synovial tissues by a bulky RNA sequencing. METHODS: Clinical and biologic data were collected and compared in AOSD patients with and without MAS. Sera biomolecules were analysed by Luminex multiplexing technology. Mass cytometry (CyTOF) was used to characterize circulating immune cells. A bulky RNA sequencing was performed in AOSD synovial tissues. RESULTS: Forty consecutive AOSD patients were assessed, 14 complicated with MAS. Paralleling with increases of systemic score and ferritin, MAS patients showed higher levels of IL-1α, IL-1ß, IL-1Ra, IL-2Ra, IL-6, IL-10, IL-17A, IFN-γ, G-CSF, MCP-1, MIP-1α and SCF. Combining the discriminatory ability of these data in identifying MAS, the best model was composed by systemic score, ferritin, IFN-γ and IL-10. By CyTOF analysis, MAS patients showed an increase of circulating 'classical monocytes' and a reduction of total NK cells. Our assessment showed 3477 IFN-related genes (IRGs) were differently expressed in AOSD synovial tissues. CONCLUSIONS: A multidimensional characterization of AOSD patients suggested that IFN-γ, IL-10, ferritin and systemic score discriminated the occurrence of cytokine storm syndrome associated with MAS. The inflammatory milieu of AOSD and MAS may be related to a signature of circulating immune cells. Finally, our results about IRGs reinforced the role of IFN-γ in these patients.

Adult-onset Still's disease with elderly onset: results from a multicentre study.

OBJECTIVES: In this study, we aimed at describing the clinical characteristics, life-threatening complications occurrence, and mortality of adult-onset Still's disease (AOSD) patients with elderly onset. METHODS: A multicentre retrospective study of prospectively followed-up AOSD patients included in Gruppo Italiano di Ricerca in Reumatologia Clinica e Sperimentale (GIRRCS) cohort was performed. RESULTS: Out of 221 assessed patients, 37 (16.7%) had an onset of the disease aged over 60 years. When compared with younger patients, these were characterised by a higher prevalence of pericarditis (p=0.008), comorbidities (p<0.0001), and mortality (p=0.023). Age predicted the presence of serositis in both univariate (HR: 1.02, 95%CI: 1.01-1.03, p=0.007) and multivariate analyses (HR: 1.02, 95%CI: 1.01-1.04, p=0.007). Age was also a significant predictor of parenchymal lung disease in both univariate (HR: 1.03, 95%CI: 1.01-1.05, p=0.017) and multivariate analyses (HR: 1.03, 95%CI: 1.00-1.05, p=0.048). Furthermore, age resulted to be a negative predictor of polycyclic pattern only in univariate analysis (HR: 0.99, 95%CI: 0.97-1.00, p=0.048). Finally, age significantly predicted the mortality in both univariate (HR: 1.03, 95%CI: 1.00-1.06, p=0.034) and multivariate analyses (HR: 1.05, 95%CI: 1.01-1.08, p=0.012). CONCLUSIONS: Clinical features of AOSD patients in the elderly were described in our cohort. Although the main clinical characteristics were similar comparing older and younger patients, patients aged over 60 years at disease onset were characterised by an increased prevalence of serositis, comorbidities, mostly cardiometabolic, and a higher mortality rate. Age predicted the presence of parenchymal lung disease and mortality, and it could be considered a negative prognostic factor in AOSD.

The Genetic, Environmental, and Immunopathological Complexity of Autoantibody-Negative Rheumatoid Arthritis.

Differences in clinical presentation, response to treatment, and long-term outcomes between autoantibody-positive and -negative rheumatoid arthritis (RA) highlight the need for a better comprehension of the immunopathogenic events underlying the two disease subtypes. Whilst the drivers and perpetuators of autoimmunity in autoantibody-positive RA have started to be disclosed, autoantibody-negative RA remains puzzling, also due its wide phenotypic heterogeneity and its possible misdiagnosis. Genetic susceptibility appears to mostly rely on class I HLA genes and a number of yet unidentified non-HLA loci. On the background of such variable genetic predisposition, multiple exogeneous, endogenous, and stochastic factors, some of which are not shared with autoantibody-positive RA, contribute to the onset of the inflammatory cascade. In a proportion of the patients, the immunopathology of synovitis, at least in the initial stages, appears largely myeloid driven, with abundant production of proinflammatory cytokines and only minor involvement of cells of the adaptive immune system. Better understanding of the complexity of autoantibody-negative RA is still needed in order to open new avenues for targeted intervention and improve clinical outcomes.

In early inflammatory polyarthritis more intensive management according to the 2010 ACR/EULAR criteria leads to higher rates of clinical remission: comparison of two cohorts treated according to different treat-to-target protocols.

OBJECTIVES: The aim of this study was to compare the 12-month probability of remission in early inflammatory arthritis with a milder treatment based on the 1987 criteria or a more intensive protocol based on the 2010 criteria. METHODS: Patients with rheumatoid arthritis (RA) or undifferentiated arthritis (UA) (2005-2012) were included. Before October 2010, patients fulfilling the 1987 criteria received methotrexate (MTX) and possibly low-dose prednisone, while UA hydroxychloroquine (HCQ) (1987-driven cohort). From October 2010, patients fulfilling the 2010 criteria received higher dose MTX and low-dose prednisone, while UA HCQ (2010-driven cohort). Treatment was increased to achieve DAS28 low disease activity. Clinical remission, defined by DAS28, was evaluated at subsequent visits in the whole population. Hazard ratios (HR) adjusted for age, sex, baseline DAS28, symptoms duration, MTX dose and prednisone were calculated by Cox regression. RESULTS: 677 patients were included (468 in 1987-driven cohort, 209 in 2010-driven cohort), with no significant differences in age, gender, autoantibodies and pain. The 2010-driven cohort had significantly fewer tender and swollen joints, lower acute phase reactants, DAS28 and HAQ and achieved more frequently remission even when the analysis was adjusted for all confounders (adjusted HR (95% CI) 1.73 (1.34, 2.22)) and limited to per protocol patients (adjusted HR (95%CI) 1.49 (1.11, 2.02). CONCLUSIONS: Treating patients with early arthritis according to a more intensive protocol leads to higher remission rate. The results of this study support the use of a strategy led by the 2010 criteria with more intensive treatment strategies in the management of early arthritis.

High expression levels of the B cell chemoattractant CXCL13 in rheumatoid synovium are a marker of severe disease.

OBJECTIVE: The B cell chemoattractant chemokine ligand 13 (CXCL13) is emerging as a new biochemical marker in RA. This study was undertaken to dissect the relationship between CXCL13 expression levels in the synovium and clinico-pathological variables relevant to RA pathogenesis and outcome. METHODS: Synovial tissues from 71 RA patients were evaluated by immunohistochemistry. Thirty paired samples were used for comparative gene expression analysis by quantitative real-time PCR. CXCL13 levels were analysed in relation to cellular, molecular and clinical features of inflammation, lymphocyte activation and joint damage. RESULTS: In patients with early disease (<12 months duration), CXCL13 expression correlated significantly with synovial markers of local disease activity and systemic inflammation. Such correlation was less evident in established RA. Notably, the association with lymphocyte infiltration and with expression of B/T cell-related activation and proliferation genes, such as activation-induced cytidine deaminase, IFN-γ and IL-2, remained highly significant independent of disease duration and local disease activity. Patients featuring the highest levels of CXCL13 were more frequently ACPA positive and IgG ACPA titres were increased in the high CXCL13 expression group. Furthermore, the frequency of erosive disease on radiographs was significantly higher in the upper tertile of CXCL13 expression (P = 0.01 with adjustment for disease duration and ACPA). Accordingly, synovial CXCL13 and the local receptor activator of nuclear factor κB ligand (RANKL)/osteoprotegerin (OPG) ratio significantly co-varied (ρ = 0.52, P < 0.01), independent of the level of local inflammation. CONCLUSION: Synovial CXCL13 appears to be a marker of a more severe pattern of RA disease, characterized by increased lymphocyte activation and bone remodelling beyond the level of conventional markers of inflammation.