The pathogenesis of rheumatoid arthritis.

Significant recent progress in understanding rheumatoid arthritis (RA) pathogenesis has led to improved treatment and quality of life. The introduction of targeted-biologic and -synthetic disease modifying anti-rheumatic drugs (DMARDs) has also transformed clinical outcomes. Despite this, RA remains a life-long disease without a cure. Unmet needs include partial response and non-response to treatment in many patients, failure to achieve immune homeostasis or drug free remission, and inability to repair damaged tissues. RA is now recognized as the end of a multi-year prodromal phase in which systemic immune dysregulation, likely beginning in mucosal surfaces, is followed by a symptomatic clinical phase. Inflammation and immune reactivity are primarily localized to the synovium leading to pain and articular damage, but is also associated with a broader series of comorbidities. Here, we review recently described immunologic mechanisms that drive breach of tolerance, chronic synovitis, and remission.

A multiparametric risk table for loss of clinical remission status in patients with rheumatoid arthritis: A starter study post-hoc analysis.

OBJECTIVE: This post-hoc analysis was carried out on data acquired in the longitudinal Sonographic Tenosynovitis/arthritis Assessment in Rheumatoid Arthritis Patients in Remission (STARTER) study. Its primary aim was to determine the predictive clinical and MSUS features factors for disease flare in RA patients in clinical remission, whilst its secondary aim was to evaluate the probability of disease flare based on clinical and MSUS features. METHODS: The analysis included a total of 389 RA patients in DAS28-defined remission. All patients underwent a MSUS examination according to OMERACT guidelines. Logistic regression and results presented as OR and 95%CI were used for the evaluation of the association between selected variables and disease flare. Significant clinical and MSUS features were incorporated into a risk table to predict disease flare within 12 months in RA remission patients. RESULTS: Within 12 months, 137(35%) RA patients experienced a disease flare. RA patients who experienced a flare disease differed from persistent remission for ACPA positivity (75.9%vs62.3%; p= 0.007), percentage of sustained clinical remission at baseline (44.1%vs68.5%; p= 0.001) and synovium PD signal presence (58.4%vs33.3%; p< 0.001). Based on these results, the three features were considered in a predictive model of disease flare with adjOR 3.064(95%CI 1.728-5.432). Finally, a risk table was constructed including the three significant predictive factors of disease flare within 12 months from the enrolment. CONCLUSION: An adaptive flare prediction model tool, based on data available in outpatient setting, were developed as a multiparametric risk table. If confirmed by the external validation, this tool might support the definition of therapeutic strategies in RA patients in DAS28-defined remission status.

B-Cell Activation Biomarkers in Salivary Glands Are Related to Lymphomagenesis in Primary Sjögren's Disease: A Pilot Monocentric Exploratory Study.

Primary Sjögren's disease is primarily driven by B-cell activation and is associated with a high risk of developing non-Hodgkin's lymphoma (NHL). Over the last few decades, microRNA-155 (miR-155) has arisen as a key regulator of B-cells. Nevertheless, its role in primary Sjögren's disease remains elusive. Thus, the purpose of this study was (i) to explore miR-155, B-cell activating factor (BAFF)-receptor (BAFF-R), and Interleukin 6 receptor (IL-6R) expression in the labial salivary glands (LSG) of patients with primary Sjögren's disease, aiming to identify potential B-cell activation biomarkers related to NHL development. Twenty-four patients with primary Sjögren's disease, and with available tissue blocks from a LSG biopsy performed at diagnosis, were enrolled. Among them, five patients developed B-cell NHL during follow-up (7.3 ± 3.1 years). A comparison group of 20 individuals with sicca disease was included. Clinical and laboratory parameters were recorded and the LSG biopsies were evaluated to assess local inflammation in terms of miR-155/BAFF-R and IL-6R expression. Stratifying the primary Sjögren's disease cohort according to lymphomagenesis, miR-155 was upregulated in primary Sjögren's disease patients who experienced NHL, more so than those who did not experience NHL. Moreover, miR-155 expression correlated with the focus score (FS), as well as BAFF-R and IL-6R expression, which were increased in primary Sjögren's disease patients and in turn related to neoplastic evolution. In conclusion, epigenetic modulation may play a crucial role in the aberrant activation of B-cells in primary Sjögren's disease, profoundly impacting the risk of NHL development.

COVID-19 illness: Different comorbidities may require different immunological therapeutic targets.

BACKGROUND: The SARS-CoV-2 pandemic has led to more than 6,870.000 deaths worldwide. Despite recent therapeutic advances, deaths in Intensive Care Units still range between 34 and 72%, comprising substantial unmet need as we move to an endemic phase. The general agreement is that in the first few days of infection, antiviral drugs and neutralizing monoclonal antibodies should be adopted. When the patient is hospitalized and develops severe pneumonia, progressing to a systemic disease, immune modifying therapy with corticosteroids is indicated. Such interventions, however, are less effective in the context of comorbidities (e.g., diabetes, hypertension, heart failure, atrial fibrillation, obesity and central nervous system-CNS diseases) which are by themselves associated with poor outcomes. Such comorbidities comprise common and some distinct underlying inflammatory pathobiology regulated by differential cytokine taxonomy. METHODS: Searching in the PubMed database, literature pertaining to the biology underlying the different comorbidities, and the data from the studies related to various immunological treatments for the Covid-19 disease were carefully analyzed. RESULTS: Several experimental and clinical data have demonstrated that hypertension and atrial fibrillation present an IL-6 dependent signature, whereas diabetes, obesity, heart failure and CNS diseases may exhibit an IL-1a/b predominant signature. Distinct selective cytokine targeting may offer advantage in treating severe COVID-19 illness based on single or multiple associated comorbidities. When the patient does not immediately respond, a broader target range through JAKs pathway inhibitors may be indicated. CONCLUSIONS: Herein, we discuss the biological background associated with distinct comorbidities which might impact the SARS-CoV-2 infection course and how these should to be addressed to improve the current therapeutic outcome.

The Role of Neutrophils in Spondyloarthritis: A Journey across the Spectrum of Disease Manifestations.

Spondyloarthritis (SpA) contemplates the inflammatory involvement of the musculoskeletal system, gut, skin, and eyes, delineating heterogeneous diseases with a common pathogenetic background. In the framework of innate and adaptive immune disruption in SpA, neutrophils are arising, across different clinical domains, as pivotal cells crucial in orchestrating the pro-inflammatory response, both at systemic and tissue levels. It has been suggested they act as key players along multiple stages of disease trajectory fueling type 3 immunity, with a significant impact in the initiation and amplification of inflammation as well as in structural damage occurrence, typical of long-standing disease. The aim of our review is to focus on neutrophils' role within the spectrum of SpA, dissecting their functions and abnormalities in each of the relevant disease domains to understand their rising appeal as potential biomarkers and therapeutic targets.

EULAR points to consider for minimal reporting requirements in synovial tissue research in rheumatology.

BACKGROUND: Synovial tissue research has become widely developed in several rheumatology centres, however, large discrepancies exist in the way synovial tissue is handled and, more specifically, how data pertaining to biopsy procedure, quality check and experimental results are reported in the literature. This heterogeneity hampers the progress of research in this rapidly expanding field. In that context, under the umbrella of European Alliance of Associations for Rheumatology, we aimed at proposing points to consider (PtC) for minimal reporting requirements in synovial tissue research. METHODS: Twenty-five members from 10 countries across Europe and USA met virtually to define the key areas needing evaluation and formulating the research questions to inform a systematic literature review (SLR). The results were presented during a second virtual meeting where PtC were formulated and agreed. RESULTS: Study design, biopsy procedures, tissue handling, tissue quality control and tissue outcomes (imaging, DNA/RNA analysis and disaggregation) were identified as important aspects for the quality of synovial tissue research. The SLR interrogated four databases, retrieved 7654 abstracts and included 26 manuscripts. Three OPs and nine PtC were formulated covering the following areas: description of biopsy procedure, overarching clinical design, patient characteristics, tissue handling and processing, quality control, histopathology, transcriptomic analyses and single-cell technologies. CONCLUSIONS: These PtC provide guidance on how research involving synovial tissue should be reported to ensure a better evaluation of results by readers, reviewers and the broader scientific community. We anticipate that these PtC will enable the field to progress in a robust and transparent manner over the coming years.

High CD14+ peripheral monocytes expression of ALX/FPR2 and BLT1 in low disease activity and remission status in rheumatoid arthritis: a piltot study.

OBJECTIVES: Specialised pro-resolving mediator (SPM) can dampen the acute inflammation through ERV1, ALX/FPR2 and BLT1 cell receptors and it is conceivable that their expression is dysregulated during chronic inflammation. The aim of this study was to evaluate the expression of ERV1, ALX/FPR2 and BLT1 on peripheral blood (PB) cells from rheumatoid arthritis (RA) patients. METHODS: At baseline, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), clinimetric indexes (28-joint disease activity score (DAS28) and clinical disease activity index (CDAI)), and PB samples were collected from 33 RA patients. Based on DAS28, patients were divided into high-moderate (H-Mo/RA, DAS28≥3.2) and low-remission (L-Rem/RA, DAS28<3.2) disease activity group. Cell membrane expression of ERV1, ALX/FPR2 and BLT1 on CD3pos, CD19pos, CD14pos cells and granulocytes was assessed by multi-parametric flow-cytometry analysis. Nine healthy controls (HC) were also studied. RESULTS: Sixteen H-Mo/RA and 17 L-Rem/RA patients were identified. The percentage of BLT1posCD14pos cells was significantly higher in L-Rem/RA (47.17%) than in H-Mo/RA (14.27%) group (p=0.005). Likewise, the percentage ALX/FPR2pos CD14pos cells was significantly higher in L-Rem/RA (33.02%) than in H-Mo/RA (8.77%; p=0.04) patients. An inverse correlation between BLT1posCD14pos cell percentage and DAS28 (r=-0.42; p=0.01), CDAI (r=-0.51; p=0.003), ESR (r=-0.39; p=0.025) and CRP (r=-0.40; p=0.02), ALX/FPR2posCD14pos cell percentage and CRP (r=-0.39; p=0.02) were found, while SPM-receptors mean fluorescence intensity (MFI) was not different between HC and L-Rem/RA patients. CONCLUSIONS: ALX/FPR2 and BLT1 receptors expression mirrors RA disease activity arising as potential biomarkers of inflammatory regulation.

Postural control and disability in patients with early rheumatoid arthritis.

OBJECTIVES: Rheumatoid arthritis (RA) may affect the postural control through abnormal sensory inputs and impaired motor responses. Sensory Organization Test (SOT) objectively evaluates contribution of different sensorial afferences in postural control. The aim of the study is to assess mechanisms of postural instability and their relations with disability and disease characteristics in an early RA(ERA) cohort. METHODS: The equilibrium scores were assessed in 30 ERA patients and 30 age- and sex-matched controls. The somatosensory (SOM), visual (VIS) and vestibular (VEST) ratios were computed to assess the use of different sensory and the composite equilibrium score (CES) as a measure of global balance performance. RESULTS: ERA patients had lower CES (78.4±6.0% vs. 83.4±5.0%, p=0.002), SOM ratio (98.5±1.8% vs. 99.6±2.1%, p=0.035), VIS ratio (85.2±7.6% vs. 91.5±6.0%, p=0.001) and VEST ratio (70.8±10.0% vs. 80.3±7.8%, p<0.001) compared to controls. The presence of ankle arthritis correlated negatively to both SOM (r=-0.369, p=0.045) and VIS ratio (r=0.470, p=0.009), pain severity to CES (r=-0.389, p=0.045) and VIS ratio (r=-0.385, p=0.048) and HAQ-DI to CES (r=-0.591, p=0.001), SOM (r=-0.510, p=0.004) and VIS ratio (r=-0.390, p=0.033.). Patients-reported postural instability was associated with lower CES (75.4±5.4% vs. 80.7±5.5%, p=0.016) and VEST ratios (66.5±10.1% vs. 74.1±8.8%, p=0.036). SOT outcomes did not differ according to acute phase reactants, disease activity or autoantibody positivity. CONCLUSIONS: RA patients showed an early impairment of postural control related to the degree of disability and subjective postural instability. Our data suggest that the lack of balance could result from both impaired motor response and abnormal sensory organisation.

Checkpoint inhibitors (CPI) and autoimmune chronic inflammatory diseases (ACIDs): tolerance and loss of tolerance in the occurrence of immuno-rheumatologic manifestations.

Immune related adverse events (irAEs) have been observed with all checkpoint inhibitors and are very frequent. The evidences coming from experimental models of congenital or acquired deficiency of CTLA-4 or from PD-1 knock-out mice, provided all the informations to interpret the organ or systemic manifestations (endocrine, or systemic autoimmune chronic inflammatory diseases-ACIDs) observed in trials as well as in registries of cohorts treated with anti-CTLA-4 or anti-PD-1/PD-L1 inhibitors, or combination therapies. Finally the concern raised by cancers occurring in patients with autoimmune diseases (Systemic Lupus Erythematosus, Myositis, Rheumatoid Arthritis, Psoriatic Arthritis, Vasculitis, Scleroderma, Polymyalgia Rheumatica and others) and how to deal with immunotherapy was discussed. The biological knowledges acquired with the immunotherapy trials, have paved to way to better treat autoimmune diseases in patients developing cancer during the autoimmune illness. Immunotherapy without Autoimmunity is the unmet need within our reach in the future.

Measuring the T-cell down-regulation of TCR-zeta, ZAP-70 and CD28 in arthritis patients: An old tool for new biomarkers.

Low T-cell receptor (TCR)/CD28 signaling lymphocytes are expanded in arthritis. We asked whether the down-expression of TCR-related molecules correlates with specific arthritis characteristics and if it has clinical implications. TCR-ZETA, ZAP-70 and CD28 expression was measured by flow cytometry in synovial fluid (SF) and peripheral blood (PB)-derived T cells. In PB, ZETA-downregulation in CD4+ CD28+ and consequent CD4+ CD28lowZETAlow cell expansion correlate with CRP elevation, leukocyte recruitment into SF and, primarily, disease activity (DAS). In some patients, ZETA-downregulation extends to CD8+ CD28null and/or CD8+ CD28+ cells, and this correlates with enhanced leukocyte recruitment, multiple joint involvement, and disability index (HAQ). ZETA-downregulation in CD4+ CD28+ may also lead to CD4+ CD28+ ZETAnull cell expansion, which strongly correlates with HAQ. In SF, ZETA-downregulation in CD8+ CD28null and consequent CD8+ CD28nullZETAlow/null cell expansion correlate with CRP elevation and neutrophilic influx into SF, whereas ZAP-downregulation in CD8+ CD28+ and consequent CD8+ CD28lowZAPlow cell expansion strongly correlate with HAQ and DAS. ZETA-downregulation is preponderant in SF of seronegative arthritides, with seronegative rheumatoid arthritis showing significant down-regulation in CD8+ CD28null, and non-rheumatoid arthritides showing significant down-regulation in CD4+ CD28+ . Altogether, we identified new molecular and cellular biomarkers of arthritis-related T-cell inflammation, useful for assessing arthritis activity, predicting polyarticular progression and functional impairment, characterizing seronegative arthritides, and possibly tailoring immunotherapies.

Basic immunology may lead to translational therapeutic rationale: SARS-CoV-2 and rheumatic diseases.

COVID-19 pandemia is a major concern for patients and healthcare systems. The fear of infection by patients with concomitant rheumatic diseases (either adult or children) and connective tissue diseases is arising worldwide, because of their immunological background and immunological therapies. Analysing the basic biology of single diseases, the data suggest that there is an "immunological umbrella" that seems to protect against the infection, through IFN type 1 and NK cell function. To date, reports from China, United States and Europe did not reveal an higher risk of infection, either for rheumatoid arthritis, juvenile idiopathic arthritis nor for lupus erythematosus. Antimalarials, anti-IL6-Anti-IL6 receptor, anti-IL1, anti-GM-CSF receptor and JAK1/2/3 inhibitors, are under investigation in COVID-dedicated clinical trials to control the inflammation raised by SARS-CoV-2 infection. Initial reports on the occurrence of autoimmune phenomena in the convalescence phase of SARS-CoV-2 infection suggests that the immunological consequences of the infection need to be strictly understood. Reporting of the study conforms to broad EQUATOR guidelines (Simera et al January 2010 issue of EJCI).

The B side of rheumatoid arthritis pathogenesis.

In the last years, a dramatic amount of research has been performedincreasing the knowledge about the biological mechanism underpinning Rheumatoid Arthritis (RA) inflammation, putting B lymphocytes in the center of RA pathogenesis. Nowadays, B cell phenotypes and autoantibodies positivity arose as important biomarkers in early and long-standing disease. Moreover, comparative analysis of peripheral blood and synovial tissue compartments enables the identification of novel physiopathological mechanisms promoting inflammation. In this narrative review we will discuss the biological relevance of B cell derived autoimmunity and in RA course, from disease onset to remission achievement.

Synovial features of patients with rheumatoid arthritis and psoriatic arthritis in clinical and ultrasound remission differ under anti-TNF therapy: a clue to interpret different chances of relapse after clinical remission?

OBJECTIVE: To define the synovial characteristics of patients with rheumatoid arthritis (RA) and psoriatic arthritis (PsA) in clinical and ultrasound remission achieved by combination therapy with methotrexate (MTX) and tumour necrosis factor (TNF) blockers. METHODS: Patients with RA in remission (n=25) (disease activity score (DAS)<1.6 for at least 6 months), patients with RA in low disease activity (LDA) (n=10) (1.6

The Role of High-Mobility Group Box-1 and Its Crosstalk with Microbiome in Rheumatoid Arthritis.

Rheumatoid arthritis (RA) is a chronic, definitely disabling, and potentially severe autoimmune disease. Although an increasing number of patients are affected, a key treatment for all patients has not been discovered. High-mobility group box-1 (HMGB1) is a nuclear protein passively and actively released by almost all cell types after several stimuli. HMGB1 is involved in RA pathogenesis, but a convincing explanation about its role and possible modulation in RA is still lacking. Microbiome and its homeostasis are altered in patients with RA, and the microbiota restoration has been proposed to patients with RA. The purpose of the present review is to analyze the available evidences regarding HMGB1 and microbiome roles in RA and the possible implications of the crosstalk between the nuclear protein and microbiome in understanding and possibly treating patients affected by this harmful condition.

CTLA-4 Ig as an effective treatment in a patient with type I diabetes mellitus and seropositive rheumatoid arthritis.

We describe a patient suffering from seropositive rheumatoid arthritis (RA) and type I diabetes mellitus (T1DM), who achieved a good EULAR response together with an improvement of the glycemic profile under treatment with CTLA-4 Ig. A close association is known to exist between T1DM and RA, and CTLA-4 exon 1 polymorphism has been associated to RA with coexisting autoimmune endocrinopathies. The possible common genetic background and the potential role of CTLA-4 Ig in the early phases of T1DM, could be considered in the therapeutic interventions in RA patients with type 1 diabetes.