Microbiota and arthritis: cause or consequence?

The relationship between intestinal microbiota and arthritis has garnered significant attention, with emerging evidence suggesting a potential association between dysbiosis and various forms of inflammatory arthropathies. While observational studies have provided valuable insights into microbiota alterations in patients with arthritis, establishing causality remains challenging. Observational data, influenced by multiple confounders such as environmental factors, medication effects, and dietary habits, are insufficient to conclusively determine whether microbiota changes are somehow causally linked to arthritis. The heterogeneity of results across independent studies further complicates interpretation. To further support this hypothesis, interventional randomised trials are deemed necessary, yet their implementation in this area presents significant technical limitations. Experimental animal models offer insights into potential pathogenic mechanisms linking dysbiosis to arthritis, including compromised intestinal barrier function, the role of microbiota-derived metabolites and molecular mimicry. However, conflicting findings underscore the complexity of hostmicrobiota interactions and the challenges in establishing causality.Efforts to modulate the microbiota for arthritis treatment or prevention have shown promise, yet efficacy and applicability remains uncertain. Antibacterial drugs, dietary interventions, probiotics, and faecal microbiota transplantation have been explored, but their clinical utility awaits further validation. In conclusion, while the association between intestinal microbiota and arthritis is increasingly recognised, establishing causality remains elusive.

Impact of gender and age at onset on Sjögren's syndrome presentation and outcome: state of the art.

Sjögren's syndrome (SS) is a complex and heterogeneous disease that typically affects middle-aged women. However, while it is rare, the disease may occur in male patients and in females during their childhood/adolescence or in the elderly. Contrasting data have been reported on these three subgroups clinical features and long-term outcomes. Notably, recent studies have pinpointed the severity of the disease in male patients and in both the early and the late-onset subgroups.The aim of this review is, therefore, to summarise the available evidence from the recent literature on these phenotypes. The focus will be on the clinical and laboratory features, and on the lymphoma risk observed in the three subgroups distinct phenotypes: of male patients as well as young-onset SS and elderly-onset SS. Ultimately, an accurate phenotypic stratification may represent the first step towards individualised medical approaches.

Ultrasound scoring systems affect the distribution of sialadenitis scores in Sjögren's syndrome: an inter-system reproducibility study.

OBJECTIVES: Salivary gland ultrasonography (SGUS) is commonly employed in the diagnosis and follow-up of patients with Sjögren's syndrome (SS) and multiple scoring systems have been developed to quantify the grade of sialadenitis of major salivary glands (SG). Their diagnostic performance seems overall comparable, however, the parameters evaluated by the various systems are different. The objective of this study was to compare how four different scoring systems affect the distribution of sialadenitis grades. METHODS: One hundred and three SGUS images from 26 SS patients were blindly scored by two investigators according to the De Vita, Salaffi, Milic and OMERACT scoring systems in independent sessions. RESULTS: The distribution of SGUS images according to De Vita, Salaffi, Milic and OMERACT systems was significantly different. At post-hoc analysis, Milic system performed differently compared to the De Vita (p<0.0001), OMERACT (p<0.0001) and Salaffi (p<0.0001) systems, showing a relative overestimation of sialadenitis grade. CONCLUSIONS: Milic scoring system showed to relatively overestimate the grade of sialadenitis compared to De Vita, Salaffi and OMERACT systems. Although all scoring systems seem to be comparable in terms of diagnostic accuracy, in the prospect of selecting one system to be potentially included in future versions of SS classification criteria, it is important to compare their ability to classify SGUS images among the various degrees of sialadenitis.

Sjögren's syndrome: one year in review 2022.

Primary Sjögren's syndrome (pSS) is a complex disabling systemic autoimmune disorder. The hallmark of pSS is the T-cell-mediated hyperactivation of B-cells, evolving from asymptomatic conditions to systemic complications and lymphoma development. On tissue level, the typical feature is the lymphocytic infiltration of the salivary gland by B-, T- and antigen presenting cells, as mirrored by the diagnostic cornerstone role of minor salivary gland (MSG) biopsy. B-cells show multiple possible roles in disease pathogenesis, from autoantibody production, to antigen presentation, and cytokine production. B-cells hyperactivation is supported by genetic risk factors, T-cell dependent and independent mechanisms, and the presence of different pathogenic B-cell subsets must be reminded.Many aspects have been investigated in the last year regarding genetic and epigenetics, B- and T-cell role in pSS pathogenesis, their interaction with salivary gland epithelial cells (SGECs) and in their direct or indirect use as biomarkers and predictors of disease development, activity, and lymphomagenesis.In this review, following the others of this series, we will summarise the most recent literature on pSS pathogenesis and clinical features focusing in particular on new insights into pSS molecular stratification and therapeutic advances in the era of precision medicine.

Novel self-amplificatory loop between T cells and tenocytes as a driver of chronicity in tendon disease.

OBJECTIVES: Increasing evidence suggests that inflammatory mechanisms play a key role in chronic tendon disease. After observing T cell signatures in human tendinopathy, we explored the interaction between T cells and tendon stromal cells or tenocytes to define their functional contribution to tissue remodelling and inflammation amplification and hence disease perpetuation. METHODS: T cells were quantified and characterised in healthy and tendinopathic tissues by flow cytometry (FACS), imaging mass cytometry (IMC) and single cell RNA-seq. Tenocyte activation induced by conditioned media from primary damaged tendon or interleukin-1ß was evaluated by qPCR. The role of tenocytes in regulating T cell migration was interrogated in a standard transwell membrane system. T cell activation (cell surface markers by FACS and cytokine release by ELISA) and changes in gene expression in tenocytes (qPCR) were assessed in cocultures of T cells and explanted tenocytes. RESULTS: Significant quantitative differences were observed in healthy compared with tendinopathic tissues. IMC showed T cells in close proximity to tenocytes, suggesting tenocyte-T cell interactions. On activation, tenocytes upregulated inflammatory cytokines, chemokines and adhesion molecules implicated in T cell recruitment and activation. Conditioned media from activated tenocytes induced T cell migration and coculture of tenocytes with T cells resulted in reciprocal activation of T cells. In turn, these activated T cells upregulated production of inflammatory mediators in tenocytes, while increasing the pathogenic collagen 3/collagen 1 ratio. CONCLUSIONS: Interaction between T cells and tenocytes induces the expression of inflammatory cytokines/chemokines in tenocytes, alters collagen composition favouring collagen 3 and self-amplifies T cell activation via an auto-regulatory feedback loop. Selectively targeting this adaptive/stromal interface may provide novel translational strategies in the management of human tendon disorders.

One year in review 2021: Sjögren's syndrome.

Sjögren's syndrome (SS) is a multifactorial systemic autoimmune disease of unknown aetiology characterised by a wide spectrum of different clinical manifestations and scattered complications. Recently, great efforts have been made to elucidate mechanisms involved in the pathogenesis of the disease in order to identify exploitable therapeutic targets in SS. Similarly, novel insights have enabled to better define disease phenotypes and different outcomes. Ultimately, the discovery of new potential therapeutic targets and a better stratification of patients are paving new avenues for novel treatment options and treat-to-target therapeutic approach. In this review, we will provide a critical digest of the recent literature published in 2020 on SS pathogenesis, clinical manifestations and novel treatment options.

Traditional and disease-related non-computed variables affect algorithms for cardiovascular risk estimation in Sjögren's syndrome and rheumatoid arthritis.

OBJECTIVES: Several cardiovascular (CV) risk algorithms are available to predict CV events in the general population. Their performance and validity in rheumatic disease patients is suboptimal as some disease-specific variables which strongly contribute to the pathogenesis of CV disease are not included in these CV algorithms. We aimed to evaluate the performance of two CV algorithms and investigate which variables not included in the score contribute to CV risk score in a cohort of rheumatoid arthritis (RA) and Sjögren's syndrome (SS) patients. METHODS: A consecutive cohort of 77 RA and 68 SS patients without prior CV events was included. Clinical and serological features and traditional CV risk factors were collected. The 10-year CV risk was assessed by Reynold Risk Score (RSS) and "Progetto Cuore" algorithms. RESULTS: Prevalence of traditional CV risk factors and 10-year risk of fatal and non-fatal CV events assessed by RSS and "Progetto Cuore" were similar between the two cohorts. Multiple linear regression model showed that, among variables not included in both algorithms, body mass index (BMI) and disease activity were predictors of "Progetto Cuore" while BMI and bone erosions of RSS in RA. In SS, C-reactive protein was predictor of "Progetto Cuore" while hypertension, ESSDAI and LDL-cholesterol of RSS. CONCLUSIONS: The 10-year risk of fatal and non-fatal CV events is similar in RA and SS. Traditional CV risk factors, as hypertension, strongly contribute to CV risk in these patients. Inflammatory parameters and disease activity are two disease-specific variables which should be included in CV algorithm assessment in rheumatic disease patients.

The anti-viral facet of anti-rheumatic drugs: Lessons from COVID-19.

The outbreak of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has posed the world at a pandemic risk. Coronavirus-19 disease (COVID-19) is an infectious disease caused by SARS-CoV-2, which causes pneumonia, requires intensive care unit hospitalization in about 10% of cases and can lead to a fatal outcome. Several efforts are currently made to find a treatment for COVID-19 patients. So far, several anti-viral and immunosuppressive or immunomodulating drugs have demonstrated some efficacy on COVID-19 both in vitro and in animal models as well as in cases series. In COVID-19 patients a pro-inflammatory status with high levels of interleukin (IL)-1B, IL-1 receptor (R)A and tumor necrosis factor (TNF)-α has been demonstrated. Moreover, high levels of IL-6 and TNF-α have been observed in patients requiring intensive-care-unit hospitalization. This provided rationale for the use of anti-rheumatic drugs as potential treatments for this severe viral infection. Other agents, such as hydroxychloroquine and chloroquine might have a direct anti-viral effect. The anti-viral aspect of immunosuppressants towards a variety of viruses has been known since long time and it is herein discussed in the view of searching for a potential treatment for SARS-CoV-2 infection.

One year in review 2020: comorbidities, diagnosis and treatment of primary Sjögren's syndrome.

Primary Sjögren's syndrome (pSS) is a complex and heterogeneous disorder characterised by a wide spectrum of glandular and extra-glandular features. The discovery of novel biomarkers allowed to characterise the disease not only phenotypically on the basis of clinical presentation, but also on the basis of the endotype. Moreover, a better stratification of patients has important value in the evaluation of mechanisms underlying the risk of lymphoproliferative disorders in these patients. Finally, novel targeted therapies may open new possibilities for the application of personalised medicine in pSS.

Significance of anti-La/SSB antibodies in primary Sjögren's syndrome patients with combined positivity for anti-Ro/SSA and salivary gland biopsy.

OBJECTIVES: Immunological parameters exert a relevant diagnostic and prognostic role in primary Sjögren's syndrome (pSS) and may identify specific disease phenotypes. Among disease-associated immunological features, anti-La/SSB are rarely found without concomitant anti-Ro/SSA and their clinical significance in patients with pSS has been poorly investigated. Thus, we aimed to characterise the value of anti-La/SSB analysing clinical and serologic features of a wide cohort of pSS patients with both circulating anti-Ro/SSA and positive salivary gland biopsy (SGB). METHODS: Clinical and serological data of 600 pSS patients with both anti-Ro/SSA and SGB positivity and categorised according to anti-La/SSB status were retrospectively analysed. Comparisons between patients with and without circulating anti-La/SSB were performed. RESULTS: Among the whole cohort, 319 (53%) of patients were anti-La/SSB negative and 281 (47%) were anti-La/SSB positive. Anti-La/SSB positive patients were younger at disease diagnosis and had a longer disease duration. Moreover, anti-La/SSB positive patients had a higher prevalence of hypergammaglobulinaemia and circulating rheumatoid factor and of lymphoproliferative disorders in comparison to seronegative group. At multivariate analysis, hypergammaglobulinaemia (OR=1,7; 95% CI 1.17, 2.43), rheumatoid factor (OR=2.3; 95% CI 1.6, 3.3) and lymphoma (OR=2.6; 95% CI 1.12, 5.96) were identified as independent variables significantly associated with anti-La/SSB positivity. CONCLUSIONS: In patients with pSS and concomitant anti-Ro/SSA and SGB positivity, the presence of anti-La/SSB may help in identifying a disease subset with distinct prognostic features, especially in terms of higher risk of lymphoproliferative complications.

Frequency and clinical correlates of antiphospholipid antibodies arising in patients with SARS-CoV-2 infection: findings from a multicentre study on 122 cases.

OBJECTIVES: COVID-19 features include disseminated intravascular coagulation and thrombotic microangiopathy indicating a hypercoagulable state. We aimed to investigate antiphospholipid antibodies (aPL) prevalence and clinical relationships in a large cohort of COVID-19 patients. METHODS: We analysed the prevalence and titres of serum aPL in 122 patients with COVID-19 and 157 with primary antiphospholipid syndrome (PAPS) and 91 with other autoimmune rheumatic diseases (oARD) for comparison. IgG/IgM anticardiolipin (aCL) and IgG/IgM anti-beta2glycoprotein I (ß2GPI) were assayed using homemade ELISA, IgA aCL and anti-ß2GPI by commercial ELISA kits and lupus anticoagulant (LAC) by multiple coagulation tests following updated international guidelines. RESULTS: Prevalence of IgG and IgM aCL and of IgG and IgM anti-ß2GPI across COVID-19 patients were 13.4%, 2.7%, 6.3% and 7.1%, being significantly lower than in PAPS (p<0.0001 for all). Frequency of IgG aCL and IgM anti-ß2GPI was comparable to oARD (13.4% vs. 13.2% and 7.1% vs. 11%, respectively), while IgG anti-ß2GPI and IgM aCL were lower (p<0.01). IgA aCL and IgA anti-ß2GPI were retrieved in 1.7% and 3.3% of COVID-19 patients, respectively. Positive LAC was observed in 22.2% COVID-19 vs. 54.1% of PAPS (p<0.0001) and 14.6% of oARD (p=0.21). Venous or arterial thromboses occurred in 18/46 (39.1%) COVID-19 patients and were not associated with positive aPL (p=0.09). CONCLUSIONS: Thrombosis is a frequent manifestation during COVID-19 infection. However, prevalence and titres of aPL antibodies or LAC were neither consistently increased nor associated with thrombosis when measured at a single timepoint, therefore not representing a suitable screening tool in the acute stage of disease.

Application of artificial neural network analysis in the evaluation of cardiovascular risk in primary Sjögren's syndrome: a novel pathogenetic scenario?

OBJECTIVES: The aim of the present study was to verify whether artificial neural networks (ANNs) might help to elucidate the mechanisms underlying the increased prevalence of cardiovascular events (CV) in primary Sjögren's syndrome (pSS). METHODS: 408 pSS patients (395 F: 13 M), with a mean age of 61 (±14) years and mean disease duration of 8.8 (±7.8) years were retrospectively included. CV risk factors and events were analysed and correlated with the other pSS clinical and serological manifestations by using both a traditional statistical approach (i.e. Agglomerative Hierarchical Clustering (AHC)) and Auto-CM, a data mining tool based on ANNs. RESULTS: Five percent of pSS patients experienced one or more CV events, including heart failure (8/408), transient ischaemic attack (6/408), stroke (4/408), angina (4/408), myocardial infarction (3/408) and peripheral obliterative arteriopathy (2/408). The AHC provided a dendrogram with at least three clusters that did not allow us to infer specific differential associations among variables (i.e. CV comorbidity and pSS manifestations). On the other hand, Auto-CM identified two different patterns of distributions in CV risk factors, pSS-related features, and CV events. The first pattern, centered on "non-ischaemic CV events/generic condition of HF", was characterised by the presence of traditional CV risk factors and by a closer link with pSS glandular features rather than to pSS extra-glandular manifestations. The second pattern included "ischaemic neurological, cardiac events and peripheral obliterative arteriopathy" and appeared to be strictly associated with extra-glandular disease activity and longer disease duration. CONCLUSIONS: This study represents the first application of ANNs to the analysis of factors contributing to CV events in pSS. When compared to AHC, ANNs had the advantage of better stratifying CV risk in pSS, opening new avenues for planning specific interventions to prevent long-term CV complications in pSS patients.

One year in review 2019: Sjögren's syndrome.

Primary Sjögren's syndrome (pSS) is a complex and heterogeneous disorder characterised by a wide spectrum of glandular and extra-glandular features. Novel insights into disease pathogenesis and the discovery of novel biomarkers are allowing us to characterise the disease not only phenotypically on the basis of clinical presentation, but also on the basis of the endotype. Ultimately, a better stratification of patients may pave new avenues for novel targeted therapies, opening new possibilities for the application of personalised medicine in pSS.

A Platelet's Guide to Synovitis.

BACKGROUND: Platelets have the ability to influence the immune system and the inflammatory process and may be strongly involved in the whole pathogenic process of chronic inflammatory joint diseases, such as rheumatoid arthritis. They may play a significant role even before the clinical onset of the disease, contributing to the loss of tolerance of the immune system and the induction of autoimmunity. Subsequently, they can interact with the most important cellular players involved in autoimmunity and inflammation, namely innate immunity cells and T cells and eventually contribute to the building of inflammation in the synovium, thus inducing the activation, migration, and proliferation of fibroblasts that eventually lead to joint damage. Due to their peculiar features, studying the behavior of platelets is a challenging task; however, platelets may prove to be valuable therapeutic targets in the future.

One year in review 2018: Sjögren's syndrome.

Sjögren's syndrome is a complex and potentially disabling slow progressive, systemic disorder. During the last twelve months several original and important contributions have been published on the pathogenesis, diagnosis and therapy of the disease. This review, following the others of this series is aimed at summarising some of the most significant studies that have been recently published. Regarding the pathogenesis, we will specifically focus on novel insights on miRNA, gut microbiota, adaptive and innate autoimmunity and animal models. Concerning novelties in pSS diagnosis, we will focus on salivary gland ultrasonography and histology. Finally, we will conclude with an update of the clinical manifestations of the disease and with an overview of the future therapies.

Prevalence and significance of anti-saccharomyces cerevisiae antibodies in primary Sjögren's syndrome.

OBJECTIVES: Saccharomyces cerevisiae is a common yeast used in the food industry. IgG and IgA antibodies against the phosphopeptidomannan of the S. cerevisiae cell wall (ASCA) are a well known marker of disease severity in Crohn's disease. Moreover, a number of studies assessed ASCA in several systemic and organ-specific autoimmune diseases postulating molecular mimicry as a possible link between ASCA and autoimmunity. However, since they have never been tested in primary Sjögren's syndrome (pSS), the purpose of this study was to investigate these antibodies in a large cohort of pSS patients, compared to healthy donors (HD), and their significance as potentially helpful biomarker in a clinical setting. METHODS: ASCA IgG+IgA were assessed with ASCA screen dot for Blue Diver instrument (Alphadia sa/nv, Belgium). The comparison between the aminoacid sequence of mannan of S. cerevisiae and well characterised auto-antigens peculiar to pSS (52kD and 60kD Ro/SSA, La/SSB) was performed with the Basic Local Alignment Search Tool (BLAST). RESULTS: The prevalence of ASCA in our pSS cohort was 4.8%. We also reported that the ASCA target protein has a high similarity with Ro60/SSA protein further supporting the molecular mimicry hypothesis. Finally, we observed that ASCA positivity is associated with pSS specific clinical and serological features. ASCA+ pSS patients displayed a triple combination of circulating anti-Ro52/SSA, anti-Ro60/SSA and anti-La/SSB antibodies, associated with low complement and cutaneous involvement. CONCLUSIONS: Our data suggest a possible pathogenic/prognostic significance of ASCA in pSS.

Discrepancy between subjective symptoms, objective measures and disease activity indexes: the lesson of primary Sjögren's syndrome.

Mucosal dryness is a key clinical feature in primary Sjögren's syndrome (pSS) and its assessment relies on both objective measurement of residual secretion and subjective symptoms reported by patients. However, while the objective assessment and grading of glandular dysfunction can be easily performed, the spectrum of clinical symptoms encompassed by the terms 'dry eye' and 'dry mouth' is wide and heterogeneous. Therefore, patient reported outcomes (PROs) for dryness in pSS poorly correlate with the amount of glandular secretion. In addition, subjective dryness is not correlated with the severity of systemic disease and severely affects the patient quality of life even in presence of active extraglandular manifestations. The purpose of this review article is to provide an overview of glandular dysfunction in pSS as well as the impact of discrepancy between objective assessment, subjective symptom and extraglandular disease activity on disease management.