Cytokines as therapeutic targets in primary Sjögren syndrome

The role of epithelial cells in the immunopathogenesis of Sjögren's syndrome

Sjögren's syndrome is a systemic autoimmune disease characterized by dysfunction of the affected exocrine glands. Lymphocytic infiltration within the inflamed glands and aberrant B-cell hyperactivation are the two salient pathologic features in Sjögren's syndrome. Increasing evidence indicates that salivary gland epithelial cells act as a key regulator in the pathogenesis of Sjögren's syndrome, as revealed by the dysregulated innate immune signaling pathways in salivary gland epithelium and increased expression of various proinflammatory molecules as well as their interaction with immune cells. In addition, salivary gland epithelial cells can regulate adaptive immune responses as nonprofessional antigen-presenting cells and promote the activation and differentiation of infiltrated immune cells. Moreover, the local inflammatory milieu can modulate the survival of salivary gland epithelial cells, leading to enhanced apoptosis and pyroptosis with the release of intracellular autoantigens, which further contributes to SG autoimmune inflammation and tissue destruction in Sjögren's syndrome. Herein, we reviewed recent advances in elucidating the role of salivary gland epithelial cells in the pathogenesis of Sjögren's syndrome, which may provide rationales for potential therapeutic targeting of salivary gland epithelial cells to alleviate salivary gland dysfunction alongside treatments with immunosuppressive reagents in Sjögren's syndrome.

What exactly is the relationship between plasma cytokines and the clinical phenotype of primary sjögren's syndrome? a single-centre retrospective study

BACKGROUND

The pathogenesis of primary Sjögren's syndrome (pSS) remains unclear. Accumulating evidence suggests that an imbalance of multiple cytokines contributes to the occurrence and development of pSS. To our knowledge, there are few studies on the relationship between plasma cytokines and pSS clinical phenotype (including disease activity), and the available results are controversial. Cytokine-targeted therapy failed to achieve satisfactory effects.

METHODS

We collected the demographic and clinical characteristics (laboratory indicators and clinical presentation) of pSS patients and calculated the European League Against Rheumatism SS disease activity index (ESSDAI) scores and ClinESSDAI. Associations between plasma cytokines and pSS continuous and categorical variables, and between various cytokines were analysed separately.

RESULTS

348 patients were finally included in the analysis, with a female to male ratio of 13.5:1. The disease activity was mild to moderate in 86.78% of patients, with the most and least involved organs being the exocrine glands and neurological system respectively. Among the various cytokines analysed, plasma interleukin(IL)-6 levels were elevated and correlated with a variety of inflammatory indicators and clinical manifestations. A weak positive correlation was found between IL - 10 and ESSDAI. Various degrees of correlation were observed between cytokines and clinical manifestations of pSS and between multiple cytokines.

CONCLUSION

Our study shows that different cytokines are closely associated with the clinical phenotype of pSS. Plasma IL-10 can be used to monitor pSS disease activity. Multiple cytokines form a systemic network and participate in the pathological process of pSS. This study provides a solid foundation for further exploring the pathogenesis of pSS and establishing more effective cytokine-targeted therapeutic regimens.

The Role of Regulatory T Cells in the Onset and Progression of Primary Sjögren's Syndrome

Regulatory T cells (Tregs) play a key role in maintaining immune balance and regulating the loss of self-tolerance mechanisms in various autoimmune diseases, including primary Sjögren's syndrome (pSS). With the development of pSS primarily in the exocrine glands, lymphocytic infiltration occurs in the early stages, mainly due to activated CD4⁺ T cells. Subsequently, in the absence of rational therapy, patients develop ectopic lymphoid structures and lymphomas. While the suppression of autoactivated CD4⁺ T cells is involved in the pathological process, the main role belongs to Tregs, making them a target for research and possible regenerative therapy. However, the available information about their role in the onset and progression of this disease seems unsystematized and, in certain aspects, controversial. In our review, we aimed to organize the data on the role of Tregs in the pathogenesis of pSS, as well as to discuss possible strategies of cell therapy for this disease. This review provides information on the differentiation, activation, and suppressive functions of Tregs and the role of the FoxP3 protein in these processes. It also highlights data on various subpopulations of Tregs in pSS, their proportion in the peripheral blood and minor salivary glands of patients as well as their role in the development of ectopic lymphoid structures. Our data emphasize the need for further research on Tregs and highlight their potential use as a cell-based therapy.

Involvement of Substance P (SP) and Its Related NK1 Receptor in Primary Sjögren's Syndrome (pSS) Pathogenesis

Primary Sjögren's Syndrome (pSS) is a systemic autoimmune disease that primarily attacks the lacrimal and salivary glands, resulting in impaired secretory function characterized by xerostomia and xerophthalmia. Patients with pSS have been shown to have impaired salivary gland innervation and altered circulating levels of neuropeptides thought to be a cause of decreased salivation, including substance P (SP). Using Western blot analysis and immunofluorescence studies, we examined the expression levels of SP and its preferred G protein-coupled TK Receptor 1 (NK1R) and apoptosis markers in biopsies of the minor salivary gland (MSG) from pSS patients compared with patients with idiopathic sicca syndrome. We confirmed a quantitative decrease in the amount of SP in the MSG of pSS patients and demonstrated a significant increase in NK1R levels compared with sicca subjects, indicating the involvement of SP fibers and NK1R in the impaired salivary secretion observed in pSS patients. Moreover, the increase in apoptosis (PARP-1 cleavage) in pSS patients was shown to be related to JNK phosphorylation. Since there is no satisfactory therapy for the treatment of secretory hypofunction in pSS patients, the SP pathway may be a new potential diagnostic tool or therapeutic target.

Systematic review with meta-analysis: Efficacy and safety of biological treatment on salivary gland function in primary Sjögren's syndrome

Objective: The study aimed to assess the efficacy and safety of clinical trials of biologics in improving the salivary gland (SG) function in primary Sjögren's syndrome (pSS), which has not been analyzed critically and systematically. Methods: PubMed, Web of Science, ClinicalTrials.gov, the EU Clinical Trials Register, and the Cochrane Library were searched for clinical trials that reported effects of biological treatment on the SG function and safety in pSS patients. Inclusion criteria were defined following participants, interventions, comparisons, outcome, and study design (PICOS) recommendations. The objective index (the change of unstimulated whole saliva (UWS) flow) and the serious adverse event (SAE) were assessed as main outcome measures. A meta-analysis of the efficacy and safety of the treatment was conducted. Quality assessment, sensitivity analysis, and publication bias were assessed. The effect size together with a 95% confidence interval was used to estimate the efficacy and safety of biological treatment and was plotted as a forest plot. Results: The literature search yielded 6,678 studies, nine of which fulfilled the inclusion criteria, with seven randomized controlled trials (RCTs) and two non-RCT clinical studies. Generally, biologics do not significantly increase UWS from the baseline of pSS patients compared to the control group at a matched time point (p = 0.55; standard mean difference, SMD = 0.05; 95% confidence interval, CI: -0.11 and 0.21). However, pSS patients with shorter disease duration (≤3 years; SMD = 0.46; 95% CI: 0.06 and 0.85) were prone to have a better response to biological treatment by showing higher increased UWS than patients with longer disease duration (> 3 years; SMD = -0.03; 95% CI: -0.21 and 0.15) (p = 0.03). For the meta-analysis of the safety of biological treatment, the SAEs in the biologics group were significantly higher than those of the control group (p = 0.0021; log odds ratio, OR = 1.03; 95% CI: 0.37 and 1.69). Conclusion: Biological intervention during the early course of the disease may benefit pSS patients better than that during the late course. Significantly, more SAEs in the biologics group indicate that the safety of biologics needs to be addressed for future biological clinical trials and treatment.

Altered white matter structural connectivity in primary Sjögren's syndrome: a link-based analysis

PURPOSE

Cognitive impairment has been revealed in primary Sjögren's syndrome (pSS). However, the underlying white matter structural connectivity (SC) changes have not been studied. This study aimed to investigate the altered white matter brain network in patients with pSS using diffusion tensor imaging (DTI).

METHODS

Forty-one pSS patients and sixty matched healthy controls (HCs) underwent neuropsychological tests and the subsequent MRI examinations. The clinical data were gathered from the medical record. The structural brain network was established using DTI, and a link-based comparison was performed between patients with pSS and HCs (false discovery rate correction, P < 0.05). Furthermore, the mean fractional anisotropy (FA) of the altered SCs was correlated with the neuropsychological tests and clinical data in patients with pSS (Bonferroni correction, P < 0.05).

RESULTS

Compared with HCs, patients with pSS mainly exhibited decreased SC in the frontal and parietal lobes and some parts of the temporal and occipital lobes. In addition, increased SC was found between the right caudate nucleus and right median cingulate/paracingulate gyri. Specifically, the reduced SC between the left middle temporal gyrus and left middle occipital gyrus was negatively correlated with white matter high signal intensity (WMH).

CONCLUSIONS

Patients with pSS showed diffusely decreased SC mainly in the frontoparietal network and exhibited a negative correlation between the reduced SC and WMH. SC represents a potential biomarker for preclinical brain impairment in patients with pSS.

Sirolimus therapy restores the PD-1+ICOS+Tfh:CD45RA-Foxp3high activated Tfr cell balance in primary Sjögren's syndrome

BACKGROUND

Primary Sjögren's syndrome (pSS) is a common chronic autoimmune disease characterized by lymphocytic infiltration of salivary and lacrimal glands. The current study was performed to investigate the roles of follicular helper T (Tfh) and follicular regulatory T (Tfr) subsets in patients with pSS, and to evaluate the effects of sirolimus on these cells.

METHODS

Levels of circulating Tfh and Tfr subsets in 58 pSS patients and 26 healthy controls (HC) were determined by flow cytometry. These T cell subsets were also analyzed in 12 patients before and after treatment with sirolimus. Clinical features and correlations with follicular T cells were analyzed systematically. The discriminative ability of the cells and ratios was evaluated based on the area under the receiver operating characteristic curves.

RESULTS

Patients with pSS had higher percentage and absolute number of PD-1+ICOS+Tfh cells, while lower percentage and absolute number of Tfr, activated regulatory T (aTreg) cells, and CD45RA-Foxp3^high activated Tfr cells. Furthermore, increased number of PD-1+ICOS+Tfh cells was associated with B cells, while decreased numbers of Tfr and their subsets was strongly associated with aTreg cells in pSS patients. Also, the higher proportion of PD-1+ICOS+Tfh cells was positively correlated with higher level of autoantibodies, ESR, IgG, cytokines (IL-2, IL-4, IL-10, IL-17, IFN-γ, TNF-α, IL-21 and sIL-2αR), and disease activity. Unexpectedly, the elevated PD-1+ICOS+Tfh:CD45RA-Foxp3^high activated Tfr ratio had the greatest ability to discriminate between pSS and HC, and sirolimus therapy restored the PD-1+ICOS+Tfh cells:CD45RA-Foxp3^high activated Tfr ratio, and controlled disease activity.

CONCLUSION

The novel ratio of PD-1+ICOS+Tfh to CD45RA-Foxp3^high activated Tfr cells can effectively discriminate the pSS patients from controls, and Tfr cell subsets may resemble Treg cell lineages. Furthermore, the PD-1+ICOS+Tfh cells can be used as a biomarker of disease activity and to verify the therapeutic effects of sirolimus in pSS.

The Clinical and Immunological Activity Depending on the Presence of Interferon γ in Primary Sjögren’s Syndrome—A Pilot Study

The upregulation of IFN pathways and their stimulated genes is associated with primary Sjögren’s syndrome (pSS). The recent studies also indicate the involvement of interferon γ (IFNγ) in the pathogenesis of pSS. The study aimed to assess the clinical and immunological activity depending on the concentration of IFNγ in the peripheral blood in pSS patients. Methods: The study group consisted of patients over 18 years of age with a confirmed diagnosis of pSS. Based on the collected data, disease activity was assessed using the EULAR Sjögren’s syndrome disease activity index (ESSDAI) and the EULAR Sjögren’s syndrome patient reported index (ESSPRI). Results: Among 40 pSS patients, 33 (82%) showed increased levels of IFNγ. The group with positive IFNγ was younger (43 years) than the group with negative IFNγ (57 years) (p < 0.05). In the positive IFNγ group, the time to diagnosis was shorter (p < 0.05). There was a difference in ESSDAI among patients with and without IFNγ (p < 0.05). There were no differences between the groups in ESSPRI and the presence of cryoglobulins, specific anti-SSA, and anti-SSB antibodies and in C3 and C4 hypocomplementemia. RF occurred in both groups with a similar frequency (p = 0.6), but in patients with IFNγ presence, significantly higher RF titers were observed (34.9 vs. 10.5; p < 0.05). Conclusion: In the group of patients with positive IFNγ, the mean value of RF and ESSDAI was higher. This group was also younger than patients with pSS without IFNγ.

An update of targeted therapeutic options for primary Sjögren syndrome: current status and future development

Introduction: Primary Sjögren syndrome (pSS) is a systemic autoimmune disease that may affect 3 in 1,000 people within the general population. The therapeutic scenario is complex, and no therapy has proved to be able to modify the natural course of the disease, nor to prevent the most severe systemic complications.Areas covered: Recently, the EULAR 2020 Recommendations for pSS have underlined the low level of evidence supporting efficacious therapeutic approaches, lacking a definition of specific treatment targets and being far from the 'disease modification' concept that is frequently used in other diseases. Herein, the authors review the status of current targeted therapies and provide the reader with their expert opinion.Expert opinion: The progress in discovering novel treatments for pSS seem to be focused on searching new biological therapies as highly-selective drugs that can be effective without the adverse effects related to the wide, nonspecific immunosuppression induced by the drugs currently used. Most likely, the more disruptive therapeutic approach in pSS that could be seen in a few years is the use of combination strategies targeting different etiopathogenic pathways.

Biological Therapy in Primary Sjögren's Syndrome: Effect on Salivary Gland Function and Inflammation

Primary Sjögren's syndrome (pSS) is a chronic, systemic autoimmune disease. It is the second most common rheumatic autoimmune disorder, affecting 0.7% of European Americans and up to 1% of people globally. pSS is characterized by the impaired secretory function of exocrine glands, including salivary and lachrymal glands. A lymphocytic infiltration of these organs leads to the common and debilitating symptoms of oral and ocular dryness, majorly affecting the quality of life of these patients. Currently, no disease-modifying drug has been approved for the treatment of pSS, with therapies largely aimed at relieving symptoms of dry mouth and dry eyes. In particular, management of oral dryness still represents a major unmet clinical need in pSS and a significant burden for patients with this condition. Recently, several randomized clinical trials in pSS with biological therapies targeting specific mechanistic pathways implicated in the disease pathogenesis, including B-cell hyperactivity, T-cell co-stimulation and the aberrant role of cytokines, have been completed with mixed results. In this review, we summarize evidence from recent clinical trials investigating biological therapy in pSS, specifically highlighting efficacy, or lack thereof, in modulating local inflammation and improving salivary gland function.

Lycium barbarum Polysaccharide Ameliorates Sjögren's Syndrome in a Murine Model

SCOPE

This study aims to evaluate the therapeutic efficacy and mechanisms of Lycium barbarum polysaccharide (LBP) in primary Sjögren's syndrome (pSS).

METHODS AND RESULTS

Non-obese diabetic mice (the pSS model) are randomly divided into four groups: Low dose LBP (LBP.L, 5 mg kg-1  d-1 ), high dose LBP (10 mg kg-1  d-1 ), low dose interleukin (IL)-2 (25 000 IU/d), and control (saline water). Drugs were treated for 12 weeks. LBP.L significantly reduces the salivary gland inflammation compared with the control group (histological score p LBP.L vs Control  = 0.019; foci number: p LBP.L vs Control  = 0.038). LBP.L also remarkably reduces the effector follicular helper T (Tfh) cells and the CD4+ IL-17A+ helper T (Th17) cells in both spleen and cervical lymph node (cLN) cells. Additionally, the ratios of regulatory T cell (Treg)/Tfh cells and Treg/Th17 cells are substantially increased in mice treated with LBP.L in both spleen and cLNs. LBP also inhibits Th17 and Tfh cells and markedly increases the Treg/Tfh ratio in human peripheral blood mononuclear cells.

CONCLUSION

LBP.L inhibits the progression of pSS in mice, associated with modulation of T cell differentiation.

Primary Sjögren's Syndrome: A Retrospective Cohort Study of Burden of Illness in Sweden

INTRODUCTION

Primary Sjögren's syndrome (pSS) is an autoimmune disease that affects salivary and lachrymal glands and is associated with complex extraglandular manifestations. This study investigates the clinical and economic burden and disease course of pSS in Sweden.

METHODS

This retrospective cohort study utilizes data from Swedish national registries and consists of patients at least 18 years of age diagnosed in secondary care with pSS, and matched members of the Swedish general population. Healthcare resource utilization (HRU) and costs were compared. The clinical burden of pSS during follow-up was explored via year-on-year prevalence of and time-to-first extraglandular manifestation. Employment status and retirement rates were used to investigate the impact of pSS on productivity.

RESULTS

A total of 8884 patients with pSS and 88,233 general population comparators were included. Patients with pSS had significantly higher rates of HRU and higher healthcare costs than matched comparators, including twice as many outpatient visits. Costs were highest in year 1 post index before reducing in years 2 and 3 and stabilizing thereafter. Almost two-thirds of patients received their index diagnosis during an outpatient visit, and < 30% of diagnoses were from rheumatology departments. Overall, 41% of patients experienced a healthcare encounter that included a relevant extraglandular manifestation code during follow-up. Patients with pSS had significantly higher odds of early retirement than the general population at 5 years post index.

CONCLUSIONS

Patients with pSS experience a high clinical and economic disease burden in Sweden.

Cytokine profiles and clinical characteristics in primary Sjögren´s syndrome patient groups

BACKGROUND

Primary Sjögren's syndrome (pSS) is an autoimmune disease characterized by a lymphocytic infiltrate in salivary glands driving to epithelial damage. The pSS patients present heterogenic clinical and serological characteristics. This heterogenicity could be due to the cytokine microenvironment. Cytokine levels have been analyzed and reported individually, showing controversial results; for that reason, we considered essential to evaluate a cluster of cytokines and relate them with antibody levels and clinical characteristics to find pSS subgroups.

METHODS

Ninety-nine pSS patients, diagnosed by the 2016 ACR/EULAR classification criteria, and 76 control subjects (CS) were included. Cytokine quantification was performed by Multiplex assay. Principal component analysis (PCA) was realized, and the K-mean test was used to identify clusters/groups. Groups were analyzed by the Kruskal-Wallis test and the Bonferroni test.

RESULTS

Higher IFN-γ, IL-17F, IL-21, IL-23, IL-4, and IL-31 levels were observed in pSS patients in comparison with control subjects. PCA analysis showed three groups. The severe group was characterized by higher cytokine concentrations as well as an increase in clinical parameters such as antibody levels, damage index score, and others. The moderate group presented intermediate severity; meanwhile, the mild group presented the lowest severity.

CONCLUSION

Cluster analysis revealed three groups that were different in cytokine levels and clinical parameters in which the mild group was defined by lower severity, the moderate group with intermediate severity, and the severe group with higher severity. This analysis could help subclassify the primary Sjögren syndrome patients for a better understanding of the clinical phenotype that impacts the treatment approach.

Innate Immunity and Biological Therapies for the Treatment of Sjögren's Syndrome

Sjögren's syndrome (SS) is a systemic autoimmune disorder affecting approximately 3% of the population in the United States. This disease has a female predilection and affects exocrine glands, including lacrimal and salivary glands. Dry eyes and dry mouths are the most common symptoms due to the loss of salivary and lacrimal gland function. Symptoms become more severe in secondary SS, where SS is present along with other autoimmune diseases like systemic lupus erythematosus, systemic sclerosis, or rheumatoid arthritis. It is known that aberrant activation of immune cells plays an important role in disease progression, however, the mechanism for these pathological changes in the immune system remains largely unknown. This review highlights the role of different immune cells in disease development, therapeutic treatments, and future strategies that are available to target various immune cells to cure the disease.

Hydroxychloroquine in rheumatic autoimmune disorders and beyond

Initially used as antimalarial drugs, hydroxychloroquine (HCQ) and, to a lesser extent, chloroquine (CQ) are currently being used to treat several diseases. Due to its cost‐effectiveness, safety and efficacy, HCQ is especially used in rheumatic autoimmune disorders (RADs), such as systemic lupus erythematosus, primary Sjögren's syndrome and rheumatoid arthritis. Despite this widespread use in the clinic, HCQ molecular modes of action are still not completely understood. By influencing several cellular pathways through different mechanisms, CQ and HCQ inhibit multiple endolysosomal functions, including autophagy, as well as endosomal Toll‐like receptor activation and calcium signalling. These effects alter several aspects of the immune system with the synergistic consequence of reducing pro‐inflammatory cytokine production and release, one of the most marked symptoms of RADs. Here, we review the current knowledge on the molecular modes of action of these drugs and the circumstances under which they trigger side effects. This is of particular importance as the therapeutic use of HCQ is expanding beyond the treatment of malaria and RADs.

Primary Sjogren Syndrome: Focus on Innate Immune Cells and Inflammation

Primary Sjogren Syndrome (pSS) is a complex, multifactorial rheumatic disease that mainly targets salivary and lacrimal glands, inducing epithelitis. The cause behind the autoimmunity outbreak in pSS is still elusive; however, it seems related to an aberrant reaction to exogenous triggers such as viruses, combined with individual genetic pre-disposition. For a long time, autoantibodies were considered as the hallmarks of this disease; however, more recently the complex interplay between innate and adaptive immunity as well as the consequent inflammatory process have emerged as the main mechanisms of pSS pathogenesis. The present review will focus on innate cells and on the principal mechanisms of inflammation connected. In the first part, an overview of innate cells involved in pSS pathogenesis is provided, stressing in particular the role of Innate Lymphoid Cells (ILCs). Subsequently we have highlighted the main inflammatory pathways, including intra- and extra-cellular players. A better knowledge of such processes could determine the detection of new therapeutic targets that are a major need for pSS.

Clinical significance of serum bilirubin in primary Sjögren syndrome patients

Objective

The purpose of our research was to demonstrate the clinical significance of serum bilirubin in primary Sjögren syndrome patients (pSS).

Patients and methods

A total of 116 patients with primary Sjögren syndrome and 138 matched individuals were included in our study. The laboratory parameters of patients with pSS and healthy controls were retrospectively analyzed.

Results

Serum total bilirubin, direct bilirubin, and indirect bilirubin were significantly reduced (P < .001, P = .001, P < .001) while ESR was significantly increased (P < .001) in patients with pSS when compared with healthy checkup individuals. Statistically, the AUC in patients with pSS is as follows: TBIL = 0.77, P < .001, cutoff value = 7.96; DBIL = 0.617, P = .001 cutoff value = 2.2; and IBIL = 0.786, P < .001 cutoff value = 4.5. Furthermore, our study revealed that TBIL, DBIL, and IBIL were significantly negativity related to ESR (r = −.406, P < .001; r = −.206, P = .026; r = −.429, P < .001). Interestingly, multiple linear regression analysis showed that when adjusted for sex, age, ALT, and AST, the levels of TBIL, DBIL, and IBIL in patients with pSS were independently correlated with ESR.

Conclusions

This study found that the levels of serum bilirubin were reduced and the inflammatory marker was elevated in patients with pSS. Additionally, serum bilirubin was negatively related with ESR and TBIL, DBIL, and IBIL can be used in the clinical diagnosis and follow‐up visits of the patients with pSS.

EULAR recommendations for the management of Sjögren’s syndrome with topical and systemic therapies

The therapeutic management of Sjögren syndrome (SjS) has not changed substantially in recent decades: treatment decisions remain challenging in clinical practice, without a specific therapeutic target beyond the relief of symptoms as the most important goal. In view of this scenario, the European League Against Rheumatism (EULAR) promoted and supported an international collaborative study (EULAR SS Task Force) aimed at developing the first EULAR evidence and consensus-based recommendations for the management of patients with SjS with topical and systemic medications. The aim was to develop a rational therapeutic approach to SjS patients useful for healthcare professionals, physicians undergoing specialist training, medical students, the pharmaceutical industry and drug regulatory organisations following the 2014 EULAR standardised operating procedures. The Task Force (TF) included specialists in rheumatology, internal medicine, oral health, ophthalmology, gynaecology, dermatology and epidemiology, statisticians, general practitioners, nurses and patient representatives from 30 countries of the 5 continents. Evidence was collected from studies including primary SjS patients fulfilling the 2002/2016 criteria; when no evidence was available, evidence from studies including associated SjS or patients fulfilling previous sets of criteria was considered and extrapolated. The TF endorsed the presentation of general principles for the management of patients with SjS as three overarching, general consensus-based recommendations and 12 specific recommendations that form a logical sequence, starting with the management of the central triplet of symptoms (dryness, fatigue and pain) followed by the management of systemic disease. The recommendations address the use of topical oral (saliva substitutes) and ocular (artificial tear drops, topical non-steroidal anti-inflammatory drugs, topical corticosteroids, topical CyA, serum tear drops) therapies, oral muscarinic agonists (pilocarpine, cevimeline), hydroxychloroquine, oral glucocorticoids, synthetic immunosuppressive agents (cyclophosphamide, azathioprine, methotrexate, leflunomide and mycophenolate), and biological therapies (rituximab, abatacept and belimumab). For each recommendation, levels of evidence (mostly modest) and TF agreement (mostly very high) are provided. The 2019 EULAR recommendations are based on the evidence collected in the last 16 years in the management of primary 2002 SjS patients and on discussions between a large and broadly international TF. The recommendations synthesise current thinking on SjS treatment in a set of overarching principles and recommendations. We hope that the current recommendations will be broadly applied in clinical practice and/or serve as a template for national societies to develop local recommendations.

Effectiveness and safety of abatacept for the treatment of patients with primary Sjögren's syndrome

Sjögren's syndrome is an autoimmune disease characterized by inflammation of the exocrine glands. The disease can be primary or secondary (if it is associated with another autoimmune disease). In Barring symptom management, there is no established treatment. To evaluate the effectiveness and safety of abatacept as a treatment of primary Sjögren's syndrome over the course of 24 months. Eleven patients with primary Sjögren's syndrome from the Rheumatology Department of Universidade Santo Amaro, Sao Paulo, Brazil were enrolled for a prospective observational study. Eligible participants were diagnosed according to the 2002 American-European consensus criteria and had a score greater than 3 on the EULAR Sjögren's Syndrome Disease Activity Index (ESSDAI). Participants received intravenous abatacept for 24 months at a weight-adjusted dose of 500 mg for patients weighing < 60 kg and 750 mg for those weighing > 60 kg. The outcomes were ESSDAI activity index, non-stimulated salivary flow rate, ocular dryness (Schirmer test, tear film break-up time, and ocular staining score), SF-36 questionnaire, and Fatigue domain of the FACIT (Functional Assessment of Chronic Illness Therapy) index. There was a statistically significant reduction in ESSDAI index and improvement of salivary flow. One subscale of the SF-36 index-emotional role functioning-showed improvement. There was no change in ocular parameters or in the FACIT index. In this sample of 11 patients with primary Sjögren's syndrome, abatacept therapy improved xerostomia and systemic disease activity.Key Points• Abatacept is safe and effective for the treatment of primary Sjögren's syndrome.• Abatacept can improve salivary flow and ESSDAI index in this patient population.

MicroRNA-130a Contributes to Type-2 Classical DC-activation in Sjögren's Syndrome by Targeting Mitogen- and Stress-Activated Protein Kinase-1

Objectives: Considering the critical role of microRNAs (miRNAs) in regulation of cell activation, we investigated their role in circulating type-2 conventional dendritic cells (cDC2s) of patients with primary Sjögren's syndrome (pSS) compared to healthy controls (HC). Methods: CD1c-expressing cDC2s were isolated from peripheral blood. A discovery cohort (15 pSS, 6 HC) was used to screen the expression of 758 miRNAs and a replication cohort (15 pSS, 11 HC) was used to confirm differential expression of 18 identified targets. Novel targets for two replicated miRNAs were identified by SILAC in HEK-293T cells and validated in primary cDC2s. Differences in cytokine production between pSS and HC cDC2s were evaluated by intracellular flow-cytometry. cDC2s were cultured in the presence of MSK1-inhibitors to investigate their effect on cytokine production. Results: Expression of miR-130a and miR-708 was significantly decreased in cDC2s from pSS patients compared to HC in both cohorts, and both miRNAs were downregulated upon stimulation via endosomal TLRs. Upstream mediator of cytokine production MSK1 was identified as a novel target of miR-130a and overexpression of miR-130a reduced MSK1 expression in cDC2s. pSS cDC2s showed higher MSK1 expression and an increased fraction of IL-12 and TNF-α-producing cells. MSK1-inhibition reduced cDC2 activation and production of IL-12, TNF-α, and IL-6. Conclusions: The decreased expression of miR-130a and miR-708 in pSS cDC2s seems to reflect cell activation. miR-130a targets MSK1, which regulates pro-inflammatory cytokine production, and we provide proof-of-concept for MSK1-inhibition as a therapeutic avenue to impede cDC2 activity in pSS.

Innate and Adaptive Cell Populations Driving Inflammation in Dry Eye Disease

Dry eye disease (DED) is the most common ocular disease and affects millions of individuals worldwide. DED encompasses a heterogeneous group of diseases that can be generally divided into two forms including aqueous-deficient and evaporative DED. Evidence suggests that these conditions arise from either failure of lacrimal gland secretion or low tear film quality. In its secondary form, DED is often associated with autoimmune diseases such as Sjögren's syndrome and rheumatoid arthritis. Current treatment strategies for DED are limited to anti-inflammatory medications that target the immune system as the source of deleterious inflammation and tissue injury. However, there is a lack of understanding of the underlying pathogenesis of DED, and subsequently, there are very few effective treatment strategies. The gap in our knowledge of the etiology of primary DED is in part because the majority of research in DED focused on secondary autoimmune causes. This review focuses on what is currently understood about the contribution of innate and adaptive immune cell populations in the pathogenesis of DED and highlights the need to continue investigating the central role of immunity driving DED.