B cells in the pathogenesis of primary Sjögren syndrome

Pulmonary hypertension in patients with Sjögren's syndrome: Gender differences in cardiovascular risk factors and instrumental data

BACKGROUND

Pulmonary hypertension (pH) is a well-documented complication in patients with connective tissue diseases, including Sjögren's syndrome (SS). However, the prevalence of PH in SS varies considerably across studies, likely due to differences in diagnostic methods.

AIM OF THE STUDY

This study aims to assess the prevalence of PH in a cohort of SS patients and to examine potential differences in age, cardiovascular risk factors, autoimmunity, pulmonary function tests, and echocardiographic parameters between male and female SS patients.

PATIENTS AND METHODS

Sixty-three patients diagnosed with primary SS were included in this study. Male patients were compared to females regarding age, cardiovascular risk factors, autoimmunity, pulmonary function tests, and echocardiographic parameters. All patients underwent comprehensive cardiac echo-color-Doppler evaluations during their most recent follow-up.

RESULTS

The prevalence of PH in the study cohort was 1.6 %. Respiratory function tests revealed significantly lower values in male patients compared to females. Echocardiographic assessments also indicated more pronounced alterations in males in pulmonary artery diameter and TVI-RVOT. In left-sided heart parameters, males showed greater dilatation and signs of diastolic dysfunction. Mass 2D and ejection fraction FE2D were also altered in males.

DISCUSSION AND CONCLUSION

The low prevalence of PH (1.6 %) in SS patients when diagnosed with RHC emphasizes the importance of using accurate diagnostic methods. As male patients demonstrated a greater predisposition to developing PH, as evidenced by altered respiratory function, and early diastolic dysfunction, regular echocardiographic monitoring is recommended for male SS patients, particularly those exhibiting early structural or functional cardiac changes.

Safety and Efficacy of Ianalumab in Patients With Sjögren's Disease: 52-Week Results From a Randomized, Placebo-Controlled, Phase 2b Dose-Ranging Study

OBJECTIVE

The objective of this study was to report 52-week safety and efficacy of ianalumab from phase 2b dose-finding study in patients with Sjögren's disease (SjD).

METHODS

Patients randomly received (1:1:1:1) ianalumab (5, 50, or 300 mg) or placebo subcutaneously every 4 weeks until week 24 (treatment period [TP]1). At week 24, patients on 300 mg were rerandomized to continue 300 mg or receive placebo until week 52 (TP2), patients on placebo were switched to ianalumab 150 mg, and patients on 5 and 50 mg directly entered posttreatment safety follow-up. Patients who discontinued treatment early or completed treatment entered safety follow-up (≥20 weeks).

RESULTS

During TP1, 190 patients were randomized (placebo = 49, 5 mg = 47, 50 mg = 47, 300 mg = 47). Of these 190 patients, 90 (47.4 %; 43 continued 300 mg and 47 received placebo) entered TP2, and 81 of 90 (90.0%) completed the study treatment. By week 52, efficacy was sustained in patients who continued 300 mg in TP2 (EULAR Sjögren's Syndrome Disease Activity Index, EULAR Sjögren's Syndrome Patient Reported Index, patient global assessment, and physician global assessment change from week 24: -1.45, -0.46, -4.69, and -6.86, respectively). Stimulated salivary flow rates and autoantibody levels numerically improved in the 300 mg group. Treatment-emergent adverse events were not dose-dependent, except for injection-site reactions. Cases of decreased neutrophil counts (Common Terminology Criteria for Adverse Events v4.03 grade 3 according to laboratory listings) were observed in three patients during the posttreatment follow-up, occurring at 3.5, 5.5, and 3 months, after the last ianalumab administration. None were associated with infection except one incidental finding of asymptomatic cytomegalovirus infection (IgM-positive).

CONCLUSION

In patients with SjD, ianalumab 300 mg demonstrated sustained efficacy through week 52 and a favorable safety profile up to two years of follow-up.

The role of fatty acid metabolism on B cells and B cell-related autoimmune diseases

Fatty acid metabolism plays a critical role in regulating immune cell function, including B cells, which are central to humoral immunity and the pathogenesis of autoimmune diseases. Emerging evidence suggests that fatty acid metabolism influences B cell development, activation, differentiation, and antibody production, thereby impacting B cell-related autoimmune diseases such as systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), and multiple sclerosis (MS). In this review, we discuss the mechanisms by which fatty acid metabolism modulates B cell biology, including energy provision, membrane composition, and signaling pathways. We highlight how alterations in fatty acid synthesis, oxidation, and uptake affect B cell function and contribute to autoimmune pathogenesis. Additionally, we explore the therapeutic potential of targeting fatty acid metabolism in B cells to treat autoimmune diseases. Understanding the interplay between fatty acid metabolism and B cell immunity may provide novel insights into the development of precision therapies for B cell-mediated autoimmune disorders.

Plasma extracellular vesicles promote follicular T helper cell expansion in primary Sjögren's syndrome

Primary Sjögren's syndrome (pSS) is a prevalent autoimmune disease characterized by exocrine gland dysfunction, with hallmarks of B cell and T cell overactivation, whose underlying mechanism remains largely unknown. Herein, we show that pSS plasma contained more extracellular vesicles (EVs) than HC plasma, which promoted CD4+ T cell activation, Th1, and follicular T helper cell (Tfh) differentiation, aggravating pSS immunopathology. Notably, pSS plasma EVs were enriched with miR-501-3p, mediating CD4+ T cell activation and Tfh cell differentiation. Furthermore, miR-501-3p downregulated special AT-rich sequence-binding protein-1 (SATB1) to promote Tfh differentiation. These findings suggested pSS plasma EVs as an important contributor to pSS pathogenesis, which was of potential clinical interest in managing pSS.

Anti-SSA/SSB antibody double-negative Sjögren's disease patients: a comprehensive clinical study and immune profile

INTRODUCTION/OBJECTIVES

Anti-Sjögren's syndrome A (SSA/Ro60) and anti-Sjögren's syndrome B (SSB/La) antibodies are not present in up to 25% of patients with primary Sjögren's disease (SjD). Our observational study aims to provide a clinical perspective on the presentation, extra-glandular manifestations, as well as the immune profile of anti-SSA/SSB antibody double-negative SjD patients.

METHOD

A total of 615 SjD patients of age 53.21 (± 0.59) were enrolled without acute infection or ongoing treatment that could affect the immune system. Of our participants, 254 (41.3%) were seronegative for both SSA (Ro60) and SSB (La) autoantibodies (SSA/SSB double-negative). A 1:1 propensity score matching was performed to balance age at diagnosis, disease duration, and gender for extra-glandular involvement analyses and immune profiling. Peripheral blood mononuclear cells (PBMCs) were derived from all patients. Flow cytometry was performed to further define the immune cell subsets.

RESULTS

Our study revealed that anti-SSA/SSB seronegative patients had a delayed onset by an average of 7.43 years and exhibited a lower prevalence of parotid gland enlargement compared to the seropositive group (50.8% vs. 59%, p < 0.05). In terms of extra-glandular involvement, seronegative patients exhibited a lower prevalence of white blood cell (WBC), hemoglobin (HGB), and platelet (PLT) reduction (OR 0.406, 95% CI 0.314-0.523; OR 0.751, 95% CI 0.587-0.959; OR 0.56, 95% CI 0.383-0.818, respectively) compared to anti-SSA/SSB antibody-positive group. Additionally, the double-negative group tended to hold higher CD4 + T helper cells and lower CD8 + T cell proportions compared with the anti-SSA/SSB-positive group (40.52% vs. 37.38%, p < 0.001; 28.25% vs. 32.55%, p < 0.001 respectively). Higher proportions of NK cells (13.05% vs. 10.32%, p < 0.001) and CD161 + Treg cells (13.69% vs. 12.03%, p < 0.001) were found in the double-negative group.

CONCLUSION

The observed higher frequency of CD161 + Tregs and NK cells, as well as the lower frequency of CD8 + T cells and B cells, in anti-SSA/SSB antibody double-negative patients suggests a potential role of innate immunity in this subgroup of Sjögren's syndrome. Our findings hint at the importance of serological and immune profiles in tailoring personalized management strategies for these patients. Key Points • Our analyses suggested a potential role of innate immunity in anti-SSA/SSB antibody double-negative SjD patients in comparison to seropositive counterparts. • Higher frequencies of CD4 + T cells, CD161 + Tregs, and NK cells were observed in the peripheral blood of double-negative patients, alongside lower proportions of CD8 + T cells and B cell subsets. • Double-negative patients exhibited a lower prevalence of reductions in white blood cell counts, hemoglobin level, and platelet level.

Risk Allele rs117026326-Mediated Alternative Splicing of GTF2I Promotes B Cell Proliferation in Primary Sjögren's Syndrome

Objectives: Primary Sjögren's syndrome (pSS) is associated with a risk allele T of rs117026326 located at a potential splicing enhancer within the intronic region of general transcription factor II-I (GTF2I). This study aimed to explore the rs117026326-regulated alternative splicing of GTF2I and its role in B cell overactivation in pSS. Methods: GTF2I isoform expressions and rs117026326 genotypes of pSS peripheral blood mononuclear cells (PBMCs) were examined using quantitative PCR and Sanger sequencing, respectively. GTF2IΔ was overexpressed in B cells, T cells, and macrophages using plasmid transfection. Proliferation of B cells and T cells was determined using Cell Counting Kit-8 (CCK8) assay. CD4+ T cell differentiation was inspected using flow cytometry. Proinflammatory cytokine production of macrophages was investigated using quantitative PCR. c-FOS expression in GTF2IΔ-transfected B cells was tested by quantitative PCR, and proliferation of GTF2IΔ-transfected B cells treated with c-FOS siRNA or c-FOS inhibitor was interrogated using CCK8 assay. Results: pSS patients with risk allele of rs117026326 expressed higher levels of GTF2IΔ and GTF2Iζ isoforms. GTF2IΔ expression was correlated with serum immunoglobulin G (IgG). GTF2IΔ promoted B cell proliferation and upregulated c-FOS expression. Knocking down or inhibition of c-FOS reversed B cell proliferation driven by GTF2IΔ. Conclusion: pSS risk allele of rs117026326 modulates alternative splicing of GTF2I and upregulates GTF2IΔ isoform, which promotes B cell proliferation through enhancing binding and transcription of c-FOS.

Loss of STIM1 and STIM2 in Salivary Glands Disrupts ANO1 Function but Does Not Induce Sjogren's Disease

Ca2+ signaling via the store-operated Ca2+ entry (SOCE) mediated by STIM1 and STIM2 proteins and the ORAI1 Ca2+ channel is important in saliva fluid secretion and has been associated with Sjogren's disease (SjD). However, there are no studies addressing STIM1/2 dysfunction in salivary glands or SjD in animal models. We report that mice lacking Stim1 and Stim2 [Stim1/2K14Cre(+)] in salivary glands exhibited reduced Ca2+ levels and hyposalivate. SOCE was functionally required for the activation of the Ca2+ activated Cl- channel ANO1. Ageing Stim1/2K14Cre(+) mice showed no evidence of lymphocytic infiltration or increased levels of autoantibodies characteristic of SjD, possibly associated with a downregulation of toll-like receptor 8 (Tlr8) expression. Salivary gland biopsies of SjD patients showed increased expression of STIM1 and TLR7/8. Our study shows that SOCE activates ANO1 function and fluid secretion in salivary glands and highlights a potential link between SOCE and TLR signaling in SjD.

The spectrum and prognosis of Sjögren's syndrome with membranous nephropathy

Background

This study aims to investigate the spectrum and prognosis of membranous nephropathy (MN) in patients with Sjögren's syndrome (SS).

Methods

SS patients with biopsy-proven kidney involvement who were diagnosed at our center between April 2007 and February 2024 were retrospectively reviewed and analyzed.

Results

A total of 290 SS patients with kidney involvement were enrolled. The frequency of MN increased from 16.28% during the 2007-2010 period to 44.05% during the 2021-2024 period. After 2016, MN became the most common renal pathologic type, surpassing tubulointerstitial nephritis. PLA2R antibody or antigen was detected in 74 SS-MN patients, in whom 37 (50%) showed a negative result. Within the PLA2R-negative group, five out of 15 showed positivity for EXT1/EXT2 antigen and one out of eight for THSD7A antigen. Sixty-one SS patients with MN were followed up for >6 months, and 44 (72.13%) of them achieved renal complete remission (CR). Compared with PLA2R-negative patients, PLA2R-positive patients spent a longer time to achieve CR (1.46 ± 1.16 vs. 0.74 ± 0.47 years, P = .015) and had a higher rate of progression to the renal endpoint (8/32 vs. 1/29, P = .028). After adjusting for age, proteinuria, and eGFR, Cox regression analysis showed that PLA2R positivity remained a risk factor for CR [HR = 0.511, 95% CI (0.262 to 0.998), P = .049].

Conclusions

MN has become the predominant renal pathologic type in SS. PLA2R-positivity testing followed by EXT1/EXT2 and THSD7A testing is recommended for SS-MN patients. Although most patients can achieve renal CR, the prognosis is usually poor in PLA2R-positive SS-MN patients.

Psoriasis increases the risk of Sjögren's syndrome: evidence from a propensity score-matched cohort study and transcriptomic analysis

BACKGROUND

Despite the well-documented immune dysregulation in both psoriasis and Sjögren's syndrome (SS), the specific link between these two autoimmune diseases has not been extensively explored. The present study aims to investigate the impact of psoriasis on the risk of SS.

METHODS

A retrospective cohort study using TriNetX data compared SS development in patients with psoriasis and controls using propensity score matching, Kaplan-Meier curves, and Cox models. Transcriptome data were analyzed to identify shared differentially expressed genes and pathways between the two diseases.

RESULTS

A total of 293,905 patients with psoriasis and an equal number of individuals without psoriasis were included. After propensity score matching, the baseline characteristics of both groups were balanced. During the follow-up period, 3339 patients with psoriasis and 1937 individuals without psoriasis developed SS. The Kaplan-Meier curves indicated a significantly higher risk of developing SS in the psoriasis group compared to the non-psoriasis group. Upon adjustment for multiple confounding factors, the risk of developing SS in the psoriasis group was 50% higher in the psoriasis group than the non-psoriasis group (hazard ratio [HR] 1.50, 95% confidence interval [CI] 1.42-1.58). Subgroup analyses confirmed the elevated risk of SS associated with psoriasis. Patients with psoriatic arthritis (PsA) and those treated with biological agents had an even higher risk of developing SS. Transcriptomic analysis revealed potential shared pathogenesis of psoriasis and SS involving cellular proliferation, immune cell recruitment, cytokine secretion, and the interferon response to viral infections.

CONCLUSIONS

Psoriasis might increase the risk of developing SS, which is augmented by PsA. The overlapping immunological mechanisms may underlie the co-occurrence of psoriasis and SS.

Genetic insight into dissecting the immunophenotypes and inflammatory profiles in the pathogenesis of Sjogren syndrome

BACKGROUND

Sjogren syndrome (SS) is a chronic systemic autoimmune disease and its pathogenesis often involves the participation of numerous immune cells and inflammatory factors. Despite increased researches and studies recently focusing on this area, it remains to be fully elucidated. We decide to incorporate genetic insight into investigation of the causal link between various immune cells, inflammatory factors and pathogenesis of Sjogren syndrome (SS).

METHODS

Our study leveraged the genetic variants of multi-omics statistics extracted from genome-wide association study (GWAS), the University of Bristol and the FinnGen study. We performed a bidirectional Mendelian randomization and mediation study based on randomly allocated instrumental variables to infer causality, followed by external validation with UK Biobank data and Bayesian colocalization.

RESULTS

We demonstrated that an elevated level of CD27 on IgD + CD24 + B cell, a subset of B cells expressing both IgD and CD24, was associated with a higher risk of SS (OR = 1.119, 95% CI: 1.061-1.179, P < 0.001), while CD3 on CD45RA + CD4 + Treg was a protective factor (OR = 0.917, 95%CI: 0.877-0.959, P < 0.001). Results of meta-analysis and colocalization further supported the significant results identified in the primary analysis. A total of 4 inflammatory cytokines and 7 circulating proteins exhibited potential causal relationships with SS despite no significant result achieved after FDR correction. Finally, results of mediation analysis indicated that CD40L receptor levels had significant mediating effects (β = 0.0314, 95% CI: 0.0004-0.0624, P = 0.0471) at a mediation proportion of 28% (95% CI: 0.364%-55.6%) in causal relationship between CD27 on IgD + CD24 + B cell and SS.

CONCLUSIONS

By providing a novel genetic insight into unveiling the roles of autoimmunity and inflammation in Sjogren syndrome, our findings may potentially lead to identifying new clinical biomarkers for disease monitoring and therapeutic targets that offer more effective alternatives for treating this condition. Therefore, our study may provide valuable evidence for future clinical intervention and targeted immunotherapy.

CXCR5-targeted chimeric antigen receptor T regulatory cells for the selective inhibition of follicular helper T cell and B cell interaction

BACKGROUND

The dysregulation of follicular helper T (Tfh) cell function, followed by the proliferation of self-reactive B cells, can lead to the development of autoimmune diseases. Recently, adaptive T regulatory cell (Treg) transfer therapy has attracted considerable attention for inducing effective immune tolerance owing to Tregs' diverse immune-inhibitory activities. However, preclinical studies and recent clinical trials of polyclonal Treg therapy have suggested further improving the efficacy of Treg therapy through targeted tissue specificity and local persistence by gene engineering. In this study, we reported a novel approach to specifically inhibit Tfh cells by CXC motif chemokine receptor 5-targeted chimeric antigen receptor (CXCR5-CAR) Tregs.

METHODS

Tregs expressing CAR against CXCR5 were generated from human peripheral blood mononuclear cells-derived Tregs. The phenotype and suppressive capacity of the engineered Tregs were evaluated using coculture assays with naïve T cells, circulating Tfh (cTfh) cells, or a combination of cTfh cells and naïve B cells through flow cytometry analysis.

RESULT

CXCR5-CAR Tregs induced more potent inhibition of circulating cTfh cell proliferation while maintaining similar suppressive properties on CXCR5-negative responder cells compared with non-selective polyclonal Tregs. The antigen-dependent activation of CXCR5-CAR Tregs was confirmed by latency-associated peptide (LAP) expression in the coculture with cTfh cells. In the coculture condition with both cTfh and naïve B cells, the activation of naïve B cells induced by cTfh cells was more effectively inhibited by CXCR5-CAR Tregs than by polyclonal Tregs.

CONCLUSION

The results demonstrate the potential of CXCR5-CAR Tregs to effectively inhibit the Tfh-B cell response in autoimmune diseases, paving the way for further research to confirm their functional superiority in vivo. This novel approach offers promise for achieving local, long-term immune tolerance compared with existing approaches such as nonspecific immunosuppression and polyclonal Treg therapy.

IFN-γ-producing TH1 cells and dysfunctional regulatory T cells contribute to the pathogenesis of Sjögren's disease

Sjögren's disease (SjD) is an autoimmune disorder characterized by progressive salivary and lacrimal gland dysfunction, inflammation, and destruction, as well as extraglandular manifestations. SjD is associated with autoreactive B and T cells, but its pathophysiology remains incompletely understood. Abnormalities in regulatory T (Treg) cells occur in several autoimmune diseases, but their role in SjD is ambiguous. We had previously shown that the function and development of Treg cells depend on store-operated Ca2+ entry (SOCE), which is mediated by ORAI1 Ca2+ channels and stromal interaction protein 1 (STIM1) and STIM2. Here, we show that mice with a Foxp3+ Treg cell-specific deletion of Stim1 and Stim2 develop a phenotype that fulfills all classification criteria of human SjD. Mutant mice have salivary and lacrimal gland inflammation characterized by strong lymphocyte infiltration and transcriptional signatures dominated by T helper 1 (TH1) and interferon (IFN) signaling. CD4+ T cells from mutant mice are sufficient to induce SjD-like disease in an IFN-γ-dependent manner. Inhibition of IFN signaling with the JAK1/2 inhibitor baricitinib alleviated CD4+ T cell-induced SjD in mice. These findings are consistent with the transcriptional profiles of CD4+ T cells from patients with SjD, which indicate enhanced TH1 but reduced memory Treg cell function. Together, our study provides evidence for a critical role of dysfunctional Treg cells and IFN-γ-producing TH1 cells in the pathogenesis of SjD.

The advent of chimeric antigen receptor T Cell therapy in recalibrating immune balance for rheumatic autoimmune disease treatment

CAR-T cell therapy, a cutting-edge cellular immunotherapy with demonstrated efficacy in treating hematologic malignancies, also exhibits significant promise for addressing autoimmune diseases. This innovative therapeutic approach holds promise for achieving long-term remission in autoimmune diseases, potentially offering significant benefits to affected patients. Current targets under investigation for the treatment of these conditions include CD19, CD20, and BCMA, among others. However, CAR-T therapy faces difficulties such as time-consuming cell manufacturing, complex and expensive process, and the possibility of severe adverse reactions complicating the treatment, etc. This article examines CAR-T therapy across various rheumatic autoimmune diseases, including systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), Sjögren's syndrome (SS), systemic sclerosis (SSc), antisynthetase syndrome (ASS), and ANCA-associated vasculitis (AAV), highlighting both therapeutic advancements and ongoing challenges.

EZH2 promotes B-cell autoimmunity in primary Sjogren's syndrome via METTL3-mediated m6A modification

OBJECTIVE

Enhancer of zeste homologue 2 (EZH2) plays an important role in promoting B-cell activation and differentiation. This study aimed to elucidate the role of EZH2 in the B-cell autoimmune response in primary Sjögren's syndrome (pSS) and to explore the therapeutic potential of inhibiting EZH2 in pSS.

METHODS

Single-cell RNA sequencing analysis of B cells in peripheral blood from pSS patients was conducted to identify abnormal expression of EZH2 and METTL3 in B-cell subsets. The levels of EZH2 were further validated across multiple B-cell subsets and the salivary glands (SGs) of pSS patients, as well as three different mouse models of Sjögren's syndrome (SS). Correlation analyses were performed to explore the relationship between the expression of EZH2 and clinical features of pSS patients. Following EZH2 inhibition, SS-like signs and antibody production were assessed in an experimental Sjögren syndrome (ESS) mouse model. RNA sequencing (RNA-seq) and chromatin immunoprecipitation sequencing (ChIP-seq) data post-EZH2 inhibition were bioinformatically analyzed to identify the EZH2 targets in pSS. ChIP-qPCR was performed to validate the binding of H3K27me3 to the CDKN1A promoter. Flow cytometric apoptosis analysis and Carboxy Fluorescein Succinimidyl Ester (CFSE) assay were used to assess the impact of an EZH2 inhibitor on B-cell apoptosis and proliferation. Additionally, METTL3 expression and its correlation with disease activity were analyzed in pSS patients. EZH2 expression was examined after METTL3 knockdown. METTL3-RNA immunoprecipitation (RIP) and actinomycin D assays were conducted to confirm the direct binding of METTL3 to EZH2 mRNA and its impact on mRNA stability. M6A-RIP-qPCR was performed to validate the presence of m6A modifications on EZH2 mRNA.

RESULTS

EZH2 was found upregulated in multiple B-cell subsets from the peripheral blood and SGs of pSS patients, as well as in three different animal models of SS. The expression of EZH2 in B cells was positively correlated with the ESSDAI score, which is a measure of disease activity. With treatment of EZH2 inhibitor, SS-like signs alleviated and autoantibody production reduced in ESS mice. Similarly, in pSS patients, METTL3 expression was increased in the SGs and peripheral blood CD19+ B cells, also showing a positively correlated with the ESSDAI score. With knockdown of METTL3, the expression of EZH2 reduced. Mechanistically, EZH2 inhibited B-cell apoptosis and promoted B-cell proliferation by catalyzing H3K27me3 modification at the CDKN1A locus. Furthermore, METTL3 bound to EZH2 mRNA and increased m6A modification on EZH2 mRNA, enhancing its stability and promoting EZH2 expression.

CONCLUSIONS

The upregulation of EZH2 mediated by METTL3 is implicated in the B-cell autoimmune response in pSS. Inhibition of EZH2 presents a promising therapeutic strategy for pSS treatment.

Autoimmune hepatitis: Towards a personalized treatment

Autoimmune hepatitis is an uncommon condition that affects both adults and children and is characterized by chronic and recurrent inflammatory activity in the liver. This inflammation is accompanied by elevated IgG and autoantibody levels. Historically, treatment consists of steroids with the addition of azathioprine, which results in remission in approximately 80% of patients. Despite significant advancements in our understanding of the immune system over the past two decades, few modifications have been made to treatment algorithms, which have remained largely unchanged since they were first proposed more than 40 years ago. This review summarized the various treatment options currently available as well as our experiences using them. Although steroids are the standard treatment for induction therapy, other medications may be considered. Cyclosporin A, a calcineurin inhibitor that decreases T cell activation, has proven effective for induction of remission, but its long-term side effects limit its appeal for maintenance. Tacrolimus, a drug belonging to the same family, has been used in patients with refractory diseases with fewer side effects. Sirolimus and everolimus have interesting effects on regulatory T cell populations and may become viable options in the future. Mycophenolate mofetil is not effective for induction but is a valid alternative for patients who are intolerant to azathioprine. B cell-depleting drugs, such as rituximab and belimumab, have been successfully used in refractory cases and are useful in both the short and long term. Other promising treatments include anti-tumor necrosis factors, Janus kinases inhibitors, and chimeric antigen receptor T cell therapy. This growing armamentarium allows us to imagine a more tailored approach to the treatment of autoimmune hepatitis in the near future.

The critical involvement of monocytes/macrophages in the pathogenesis of primary Sjögren's syndrome: New evidence from Mendelian randomization and single-cell sequencing

Background

Primary Sjögren's syndrome (pSS) stands as a chronic autoimmune disease characterized by an elusive pathogenesis. The synergy of single-cell RNA sequencing and Mendelian randomization (MR) analysis provides an opportunity to comprehensively unravel the contributory role of monocytes/macrophages in the intricate pathogenesis of pSS.

Methods

Differentially expressed genes (DEGs) of various types of immune cells were analyzed after annotating single-cell RNA sequencing (scRNA-seq) data. MR analysis of expression quantitative trait loci (eQTL) and protein quantitative trait loci (pQTL) was conducted to search for key pathogenic genes and proteins. Cellular localization of pathogenic genes was performed based on scRNA-seq data. Variations in signaling pathways between immune cells were further analyzed.

Results

A total of 1434 significant DEGs were identified. Among these, 60 genes exhibited strong relevance to the occurrence of pSS, of which 32 genes differentially expressed in monocytes/macrophages. CTSS was found to be a significant risk protein with a p-value of 0.001 and an odds ratio of 1.384 (1.147-1.669), showing pronounced expression in monocytes/macrophages. Furthermore, monocytes/macrophages displayed heightened expression levels of MXD1, AMPD2, TNFSF10, FTL, UBXN11, CSF3R, and LILRA5. The analysis of intercellular signaling revealed increased signal intensity in both incoming and outgoing signals in monocytes/macrophages. The signaling interactions between monocytes/macrophages, B cells, and T cells exhibited varying degrees of deviation.

Conclusions

This study highlights the significant involvement of monocytes/macrophages in the pathogenesis of pSS, as evidenced by MR analysis and scRNA-seq analysis. This suggests monocytes/macrophages as a focal point for pathogenesis research and potential therapeutic targeting in pSS.

Myeloid-derived growth factor promotes M2 macrophage polarization and attenuates Sjögren's syndrome via suppression of the CX3CL1/CX3CR1 axis

Introduction

Primary Sjögren syndrome (pSS) is a systemic autoimmune disease that is characterized by the infiltration of immune cells into the salivary glands. The re-establishment of salivary glands (SGs) function in pSS remains a clinical challenge. Myeloid-derived growth factor (MYDGF) has anti-inflammatory, immunomodulatory, and tissue-functional restorative abilities. However, its potential to restore SGs function during pSS has not yet been investigated.

Methods

Nonobese diabetic (NOD)/LtJ mice (pSS model) were intravenously administered with adeno-associated viruses carrying MYDGF at 11 weeks of age. Salivary flow rates were determined before and after treatment. Mice were killed 5 weeks after MYDGF treatment, and submandibular glands were collected for analyses of histological disease scores, inflammatory cell infiltration, PCR determination of genes, and Western blotting of functional proteins. Furthermore, mRNA sequencing and bioinformatics were used to predict the mechanism underlying the therapeutic effect of MYDGF.

Results

Treatment of NOD/LtJ mice with MYDGF alleviated pSS, as indicated by increased salivary flow rate, reduced lymphocyte infiltration, attenuated glandular inflammation, and enhanced AQP5 and NKCC1 expression. The gene expression levels of cytokines and chemokines, including Ccl12, Ccl3, Il1r1, Ccr2, Cx3cr1, Il7, Mmp2, Mmp14, Il1b, and Il7, significantly decreased after treatment with MYDGF, as determined by RNA sequencing. Meanwhile, MYDGF inhibits infiltration of macrophages (Mϕ) in SGs, induces polarization of M2ϕ, and suppresses C-X3C motif ligand 1 (CX3CL1)/C-X3C motif receptor 1 (CX3CR1) axis.

Conclusions

Our findings showed that MYDGF could revitalize the SGs function of pSS, inhibit infiltration of Mϕ, and promote M2ϕ polarization via suppression of the CX3CL1/CX3CR1 axis, which has implications for potential therapy for pSS.

Impact of Infections During Pregnancy on Transplacental Antibody Transfer

Vaccination in pregnancy is important to protect the mother and fetus from infectious diseases. The transfer of maternal antibodies across the placenta during pregnancy can continue to protect the neonate for several months after birth while the neonatal adaptive immune system develops. Several pathogens have been shown to impair the transplacental transfer of maternal antibodies, including human immunodeficiency virus, malaria, the severe acute respiratory syndrome coronavirus 2, and cytomegalovirus. This review discusses the mechanisms contributing to decreased transplacental antibody transfer in the setting of maternal infections, such as changes in antibody glycosylation profile, maternal hypergammaglobulinemia, and placental injury. The frequency of epidemics is increasing, and pregnant people are more likely to become exposed to novel pathogens now than they were in the past. Understanding the mechanisms by which infectious diseases impair maternal-fetal antibody transfer is important for pandemic preparedness to maximize the impact of maternal vaccination for child health.

Histopathological comparison of Sjögren-related features between paired labial and parotid salivary gland biopsies of sicca patients

OBJECTIVES

To compare focus score and other histopathological features between paired labial and parotid salivary gland biopsies in a diagnostic cohort of suspected Sjögren's disease (SjD) patients.

METHODS

Labial and parotid salivary gland biopsies were simultaneously obtained from patients with sicca complaints, suspected of having SjD. Biopsies were formalin fixed and paraffin embedded. Sections were stained with haematoxylin & eosin, and for CD3, CD20, CD45, cytokeratin, CD21, Bcl6, activation-induced deaminase (AID) and IgA/IgG. Focus score and other histopathological features characteristic for SjD were analysed.

RESULTS

Based on the expert opinion of three experienced rheumatologists, 36 patients were diagnosed as SjD and 63 as non-SjD sicca patients. When taking all patients together, absolute agreement of various histopathological features between labial and parotid biopsies was high and varied between 80% (focus score) and 93% [(pre-)lymphoepithelial lesions (LELs)]. More labial gland biopsies had a focus score ≥1 compared with their parotid counterpart. Accordingly, the area of infiltrate was larger in labial gland biopsies. When considering only SjD patients, labial glands contained significantly fewer B-lymphocytes and germinal centres/mm2, and less severe LELs compared with parotid glands.

CONCLUSION

Labial and parotid glands from SjD patients contain similar histopathological key features, and thus both glands can be used for diagnosis and classification of SjD. However, parotid salivary glands reveal more evident B-lymphocyte-related features, while labial glands exhibit more inflammation, which may be partially unrelated to SjD.

Salivary gland biopsy as a prognostic tool in Sjögren's syndrome

INTRODUCTION

Primary Sjögren's syndrome (pSS) is an autoimmune disorder primarily affecting salivary and lacrimal glands, although about 40% of patients experience systemic complications. In this setting, the identification of patient phenotypes characterized by increased risk of extra-glandular involvement still represents an unmet need.

AREAS COVERED

The aim of this paper is to review the scientific evidence on the utility of salivary gland biopsies in pSS, emphasizing their role in defining prognosis. In latest years, research focused on disease-specific clinical, serological, or histological features able to categorize patient prognosis. Among histopathological features, focus score and ectopic germinal centers exhibit associations with glandular and extraglandular manifestations, including higher rates of lymphomagenesis.

EXPERT OPINION

Pathological characterization of salivary glands provides information that go beyond a mere diagnostic or classification utility, providing insights for a stratification of disease severity and for predicting systemic manifestations. Thus, a salivary gland biopsy should be offered to all patients and included in routine practice, even when not strictly required for diagnostic purposes. More advanced analysis techniques of the tissue, including immunohistochemistry and 'omics' should be further explored in longitudinal studies to boost the ability to further stratify and predict disease evolution.

Epidemiology of Sjogren's syndrome in a sample of the Egyptian population: a cross-sectional study

OBJECTIVE

To investigate the prevalence of Sjögren's syndrome (SS) and the associated factors in a sample of the Egyptian population.

METHODS

This cross-sectional study obtained data by screening subjects from several hospitals in different governorates across Egypt. Demographic and health data were collected including symptoms and type of Sjögren's syndrome, associated autoimmune diseases, the presence of specific autoantibodies and associated malignancies.

RESULTS

The study analysed 7960 participants and 64 (0.80%) had SS. Of these, 22 (34.38%) had primary SS and 42 patients (65.63%) had secondary SS. For the total study cohort, the prevalence of primary and secondary SS was 0.28% and 0.53%, respectively. There was a higher prevalence of SS in females compared with males and SS was more common in the fifth and sixth decades. All patients with SS complained of oral and ocular dryness. The most common concomitant autoimmune disease was rheumatoid arthritis. Anti-SSA (Ro) and anti-SSB (La) antibodies were the most frequently associated autoantibodies. Only two patients had non-Hodgkin's lymphoma.

CONCLUSION

This was the first study to describe the prevalence of SS in Egypt. SS is not a rare disease in Egypt, so raising awareness of SS in both patients and healthcare professionals is very important.

m6A RNA methylation controls salivary gland epithelial cell function and has a protective role in Sjögren's disease

OBJECTIVES

The RNA epitranscriptomic modification known as N6-methyladenosine (m6A) represents a novel mechanism of gene regulation that is poorly understood in human autoimmune diseases. Our research explores the role of this RNA m6A modification in salivary gland epithelial cells (SGEC) and its impact on the pathogenesis of Sjögren's disease (SjD).

METHODS

SGECs from SjD patients and controls were analysed for m6A writers METTL3 and METTL14 expression using RNA-seq, quantitative PCR and immunohistochemistry. Functional assays assessed the impact of METTL3 knockdown or pharmacological inhibition on proinflammatory gene expression and immune cell interactions (using transwell and coculture systems). Mechanistic studies examined METTL3-mediated m6A modifications in double-stranded RNA (dsRNA) formation through immunofluorescence. Unsupervised clustering identified patterns of interferon activation in salivary glands and their correlation with m6A writers.

RESULTS

METTL3 and METTL14 were elevated in SGEC from SjD patients in comparison to controls. Paradoxically, inhibiting METTL3 increased proinflammatory gene expression, enhancing SGEC's ability to attract immune cells and activate B cells. Conversely, inhibiting the eraser FTO had the opposite effect. METTL3-mediated m6A modifications prevented dsRNA formation and IFN signalling activation. SGEC from SjD showed insufficient METTL3 upregulation compared with controls in response to inflammatory triggers, indicating a limited capacity to regulate the inflammatory response. SjD patients with elevated disease activity and higher interferon signature exhibit reduced METTL3 expression.

CONCLUSIONS

Impairment of m6A modifications in SGEC in response to inflammatory triggers favour the formation of dsRNA, potentially amplifying the interferon loop and contributing to SjD pathogenesis.

Histological differences related to autophagy in the minor salivary gland between primary and secondary types of Sjögren's syndrome

Some forms of Sjögren's syndrome (SS) follow a clinical course accompanied by systemic symptoms caused by lymphocyte infiltration and proliferation in the liver, kidneys, and other organs. To better understand the clinical outcomes of SS, here we used minor salivary gland tissues from patients and examine their molecular, biological, and pathological characteristics. A retrospective study was performed, combining clinical data and formalin-fixed paraffin-embedded (FFPE) samples from female patients over 60 years of age who underwent biopsies at Okayama University Hospital. We employed direct digital RNA counting with nCounter® and multiplex immunofluorescence analysis with a PhenoCycler™ on the labial gland biopsies. We compared FFPE samples from SS patients who presented with other connective tissue diseases (secondary SS) with those from stable SS patients with symptoms restricted to the exocrine glands (primary SS). Secondary SS tissues showed enhanced epithelial damage and lymphocytic infiltration accompanied by elevated expression of autophagy marker genes in the immune cells of the labial glands. The close intercellular distance between helper T cells and B cells positive for autophagy-associated molecules suggests accelerated autophagy in these lymphocytes and potential B cell activation by helper T cells. These findings indicate that examination of FFPE samples from labial gland biopsies can be an effective tool for evaluating molecular histological differences between secondary and primary SS through multiplexed analysis of gene expression and tissue imaging.

A comprehensive review of Sjögren's syndrome: Classification criteria, risk factors, and signaling pathways

Sjögren's syndrome (SS) is a chronic autoimmune disease that affects the exocrine glands and may lead to a range of systemic symptoms that impact various organs. Both innate and adaptive immune pathways might trigger the disease. Studying the signaling pathways underlying SS is crucial for enhancing diagnostic and therapeutic effectiveness. SS poses an ongoing challenge for medical professionals owing to the limited therapeutic options available. This review offers a comprehensive understanding of the intricate nature of SS, encompassing disease classification criteria, risk factors, and signaling pathways in immunity and inflammation. The advancements summarized herein have the potential to spark new avenues of research into SS.

The role of cytokines from salivary gland epithelial cells in the immunopathology of Sjögren's syndrome

In the pathogenesis and progression of Sjögren's syndrome (SS), hematopoietic cells in the peripheral circulation, tissue-resident immune cells, and parenchymal cells of salivary gland tissues (such as epithelial cells, endothelial cells, fibroblasts, etc.) all play crucial roles. These diverse cells form intricate networks and interact with each other, leading to tissue destruction and persistent chronic inflammation, ultimately causing irreversible damage in glandular function. Among these, salivary gland epithelial cells (SGECs) consistently hold a key position, characterized by their functions in expressing co-stimulatory and antigen-presenting molecules and secreting pro-inflammatory cytokines and chemokines. Moreover, SGECs actively engage in and facilitate the development of specific pathological structures within the salivary gland, such as lymphoepithelial lesions (LELs) and tertiary lymphoid structures (TLSs), thereby substantially elevating the risk of mucosa-associated lymphoid tissue (MALT) lymphoma. Overall, SGECs are recognized for their essential and irreplaceable contributions to the pathogenesis of SS. This review article initially delves into the anatomical composition of salivary gland epithelial cells, subsequently focusing on elucidating the different cytokines derived from SGECs, encompassing chemokines, pro-inflammatory cytokines, anti-inflammatory cytokines, pro-survival cytokines, and damage-associated molecular patterns (DAMPs), to explore their key roles in the pathogenesis of SS.

Subpopulation dynamics of T and B lymphocytes in Sjögren's syndrome: implications for disease activity and treatment

Sjögren's syndrome (SS) is an autoimmune disorder primarily affecting the body's exocrine glands, particularly the salivary and lacrimal glands, which lead to severe symptoms of dry eyes and mouth. The pathogenesis of SS involves the production of autoantibodies by activated immune cells, and secretion of multiple cytokines, which collectively lead to tissue damage and functional impairment. In SS, the Immune interaction among T and B cells is particularly significant. Lymphocytic infiltration in the salivary glands is predominantly composed of CD4+ T cells, whose activation cause the death of glandular epithelial cells and subsequent tissue destruction. The excessive activity of T cells contributes significantly to the disease mechanism, with helper T cells (CD4+) differentiating into various subgroups including Th1/Th2, Th17, as well as Treg, each contributing to the pathological process through distinct cytokine secretion. In patients with SS, B cells are excessively activated, leading to substantial production of autoantibodies. These antibodies can attack self-tissues, especially the lacrimal and salivary glands, causing inflammation and tissue damage. Changes in B cell subpopulations in SS patients, such as increases in plasmablasts and plasma cells, correlate positively with serum autoantibody levels and disease progression. Therapies targeting T cells and B cells are extensively researched with the aim of alleviating symptoms and improving the quality of life for patients. Understanding how these cells promote disease development through various mechanisms, and further identifying novel T and B cell subgroups with functional characterization, will facilitate the development of more effective strategies to treat SS.

Auto-immuno-deficiency syndromes

Autoimmune diseases constitute a broad, heterogenous group with many diverse and often overlapping symptoms. Even so, they are traditionally classified as either systemic, rheumatic diseases or organ-directed diseases. Several theories exist about autoimmune diseases, including defective self-recognition, altered self, molecular mimicry, bystander activation and epitope spreading. While there is no consensus about these theories, it is generally accepted that genetic, pre-disposing factors in combination with environmental factors can result in autoimmune disease. The relative contribution of genetic and environmental factors varies between diseases, as does the significance of individual contributing factors within related diseases. Among the genetic factors, molecules involved in antigen (Ag) recognition, processing, and presentation stand out (e.g., MHC I and II) together with molecules involved in immune signaling and regulation of cellular interactions (i.e., immuno-phenotypes). Also, various immuno-deficiencies have been linked to development of autoimmune diseases. Among the environmental factors, infections (e.g., viruses) have attracted most attention, but factors modulating the immune system have also been the subject of much research (e.g., sunlight and vitamin D). Multiple sclerosis currently stands out due to a very strong and proven association with Epstein-Barr virus infection, notably in cases of late infection and in cases of EBV-associated mononucleosis. Thus, a common picture is emerging that both systemic and organ-directed autoimmune diseases may appropriately be described as auto-immuno-deficiency syndromes (AIdeSs), a concept that emphasizes and integrates existing knowledge on the role of immuno-deficiencies and chronic infections with development of overlapping disease syndromes with variable frequencies of autoantibodies and/or autoreactive T cells. This review integrates and exemplifies current knowledge on the interplay of genetically determined immuno-phenotypes and chronic infections in the development of AIdeSs.

Identification and Validation of IFI44 as a Novel Biomarker for Primary Sjögren's Syndrome

Background

Primary Sjögren's syndrome (pSS) is an autoimmune condition marked by lymphocyte infiltration in the exocrine glands. Our study aimed to identify a novel biomarker for pSS to improve its diagnosis and treatment.

Methods

The gene expression profiles of pSS were obtained from the Gene Expression Omnibus (GEO) database. The specific differentially expressed genes (DEGs) were screened by the Least Absolute Shrinkage and Selection Operator (LASSO), Random Forest (RF), and Recursive Feature Elimination with Support Vector Machines (SVM-RFE). A biomarker was picked out based on correlation and diagnostic performance, the connection between the biomarker and clinical traits and immune infiltrating cells was explored, and the biomarker's protein expression level in the serum of pSS patients was detected by enzyme-linked immunosorbent assay (ELISA). The competitive endogenous RNA (ceRNA) network regulated by the biomarker was predicted to verify the reliability of the biomarker in diagnosing pSS.

Results

IFI44, XAF1, GBP1, EIF2AK2, IFI27, and IFI6 showed prominent diagnostic ability, with the high accuracy (AUC = 0.859) and significance (R ≥ 0.8) of IFI44 within the training dataset. IFI44 strongly exhibited a negative correlation with resting NK cells, macrophages M0, and eosinophils, and a positive correlation with activated dendritic cells, naive B cells, and activated CD4 memory T cells. Furthermore, IFI44 was significantly positively correlated with clinical traits such as IgG, SSA, SSB, ANA, and ESSDAI, with its protein expression level in the serum of pSS patients being notably elevated compared to controls (p < 0.001). Finally, the ceRNA regulatory network showed that hsa-miR-944, hsa-miR-9-5p, hsa-miR-126-5p, and hsa-miR-335-3p were significantly targeted IFI44, suggesting that IFI44 may serve as a dependable biomarker for pSS.

Conclusion

In this study, we dug out IFI44 as a biomarker for pSS, systematically studied the potential regulatory mechanism of IFI44, and verified its reliability as a biomarker for pSS.

Update on the pathophysiology and treatment of primary Sjögren syndrome

Sjögren syndrome or Sjögren disease is a chronic form of autoimmune epithelitis characterized by lymphocytic infiltration of the exocrine glands, particularly the salivary and lacrimal glands, leading to progressive glandular dysfunction and subsequent xerostomia and xerophthalmia. Other common manifestations include pain and fatigue, various systemic manifestations and non-Hodgkin's lymphoma. Sjögren syndrome is therefore a complex and disabling disease associated with a reduced quality of life and with considerable long-term damage. Most of the available treatments are merely symptomatic with limited efficacy in both preventing glandular damage and suppressing systemic disease activity. In the past 10 years, great progress has been made in understanding the pathophysiology of Sjögren syndrome, opening new avenues towards a more targeted and individualized therapeutic approach to the disease. Indeed, several randomized controlled trials have just been completed or are poised to commence evaluating the effectiveness of novel drugs targeting both innate and adaptive immune pathways, including pro-inflammatory cytokines, the type I interferon system, B cell activation, B cell and T cell co-stimulation pathway, and ectopic germinal centre formation. Novel clinical trials are also ongoing exploring various targeted approaches (that is, IgG recycling inhibition, nuclease therapy and CAR-T cell therapy) for Sjögren syndrome.

Transcriptomics explores potential mechanisms for the development of Primary Sjogren's syndrome to diffuse large B-cell lymphoma in B cells

PURPOSE

Primary Sjogren's syndrome (pSS) is a prevalent autoimmune disease. The immune dysregulation it causes often leads to the development of diffuse large B-cell lymphoma (DLBCL) in clinical practice. However, how it contributes to these two disorders at the molecular level is not yet known. This study explored the potential molecular mechanisms associated with the differences between DLBCL and pSS.

PATIENTS AND METHODS

Gene expression matrices from discovery cohort 1, discovery cohort 2, and the validation cohort were downloaded from the GEO and TCGA databases. Weighted gene coexpression network analysis (WGCNA) was performed to identify the coexpression modules of DLBCL and pSS in discovery cohort 1 and obtain shared genes. GO and KEGG enrichment analyses and PPI network analysis were performed on the shared genes. Immune-related genes (IRGs) were intersected with shared genes to obtain common genes. Afterward, common genes were identified via machine learning methods. The immune infiltration analysis, miRNA-TF-hub gene regulatory chart, gene interactions of the hub genes, and gene‒drug target analysis were performed. Finally, STAT1 was identified as a possible essential gene by the above analysis, and immune infiltration and GSEA pathway analyses were performed in the high- and low-expression groups in discovery cohort 2. The diagnostic efficacy of the hub genes was assessed in the validation cohort, and clinical samples were collected for validation.

RESULTS

By WGCNA, one modular gene in each group was considered highly associated with the disease, and we obtained 28 shared genes. Enrichment analysis revealed shared genes involved in the viral response and regulation. We obtained four hub genes (ISG20, STAT1, TLR7, and RSAD2) via the algorithm. Hub genes and similar genes are primarily involved in regulating type I IFNs. The construction of a miRNA-TF-hub gene regulatory chart revealed that hsa-mir-155-5p, hsa-mir-146b-5p, hsa-mir-21-3p, and hsa-mir-126-3p play essential roles in both diseases. Hub genes were differentially expressed in B-cell memory according to immune infiltration analysis. Hub genes had a strong diagnostic effect on both diseases. STAT1 plays an essential role in immune cells in both diseases.

CONCLUSION

We identified hub susceptibility genes for DLBCL and pSS and identified hub genes and potential therapeutic targets that may act as biomarkers.

[Sjögren's disease: From pathophysiology to treatment]

Sjögren's disease (SjD) is a systemic autoimmune disorder characterized by a triad of key symptoms affecting almost all patients (salivary and lacrimal dryness, pain and fatigue) and extra-glandular systemic involvement affecting one to two-thirds of patients. Over the past decade, knowledge of the epidemiology, classification criteria, assessment of systemic activity and symptoms presented by patients has grown. In addition, advances in understanding the pathophysiology of SjD have enabled a more targeted therapeutic approach. Current management of SjD is based on EULAR treatment guidelines. But since these recommendations, new drugs targeting specific pathophysiological pathways of the disease, and essentially B lymphocyte activation, have shown efficacy in phase 2 trials. In this review, we will summarize the available evidence on systemic therapies, including: 1. advances in outcome assessment, 2. current evidence on targeted disease-modifying therapies and biologic drugs targeting primarily B lymphocytes, 3. an overview of promising drugs being tested in ongoing trials.

Polyarthritis in Sjögren's Syndrome: Difficulties in Distinguishing Extraglandular Manifestation and Associated Rheumatoid Arthritis

Aim of the study was to investigate the demographic data and disease course characteristics of patients with Sjögren's syndrome (SS) and inflammatory joint pain of various origins and to search for factors that might help with the distinction of polyarthritis as an extraglandular manifestation and rheumatoid arthritis as an associated systemic autoimmune disorder. A total of 355 patients were retrospectively analyzed, 128 of whom served as controls (SS-C), while 159 had polyarthritis as an extraglandular symptom of Sjögren's syndrome (SS-pa) and 68 were diagnosed as having associated rheumatoid arthritis (SS-RA). The patients without any inflammatory joint manifestations were significantly older than the SS-pa patients, while, for the SS-RA group, the difference was not significant. The onset of joint pain appeared significantly earlier in the SS-RA patients. Regarding either extraglandular manifestations or associated autoimmune disorders, there were significant differences between the controls and both SS-pa and SS-RA groups, while no significant difference was found between the SS-pa and SS-RA groups. Thus, laboratory and imaging methods should be used to differentiate between the two conditions, but laboratory biomarkers are even more important for early diagnosis. A ROC curve analysis showed an acceptable diagnostic accuracy in differentiating between SS-pa and SS-RA patients using a binary logistic regression model, where highly positive rheumatoid factor (RF) and anti-cyclic citrullinated peptide (CCP) values, kidney involvement, and anti-Ro/SS-A positivity were shown to significantly raise the odds of having RA, whereas anti-La/SS-B positivity seemed to have a protective role, since it significantly decreased the odds of having it. Further biomarkers are needed to better classify SS patient cohorts with inflammatory joint pain of different origins and, consequently, different management requirements.

Advances in cellular and molecular pathways of salivary gland damage in Sjögren's syndrome

Sjögren's Syndrome (SS) is an autoimmune disorder characterized by dysfunction of exocrine glands. Primarily affected are the salivary glands, which exhibit the most frequent pathological changes. The pathogenesis involves susceptibility genes, non-genetic factors such as infections, immune cells-including T and B cells, macrophage, dendritic cells, and salivary gland epithelial cells. Inflammatory mediators such as autoantibodies, cytokines, and chemokines also play a critical role. Key signaling pathways activated include IFN, TLR, BAFF/BAFF-R, PI3K/Akt/mTOR, among others. Comprehensive understanding of these mechanisms is crucial for developing targeted therapeutic interventions. Thus, this study explores the cellular and molecular mechanisms underlying SS-related salivary gland damage, aiming to propose novel targeted therapeutic approaches.

Increased Interferon Signaling in Vaginal Tissue of Patients With Primary Sjögren Syndrome

OBJECTIVE

Vaginal dryness is an important factor influencing sexual function in women with primary Sjögren syndrome (pSS). Previous studies showed a higher degree of inflammation in vaginal biopsies from patients with pSS compared to non-pSS controls. However, the molecular pathways that drive this inflammation remain unclear. Therefore, the aim of this study was to investigate inflammatory pathway activity in the vaginal tissue of patients with pSS.

METHODS

Vaginal biopsies of 8 premenopausal patients with pSS experiencing vaginal dryness and 7 age-matched non-pSS controls were included. Expression of genes involved in inflammation and tissue homeostasis was measured using NanoString technology and validated using TaqMan Real-Time PCR. Vaginal tissue sections were stained by immunohistochemistry for myxovirus resistance protein 1 (MxA) and CD123 (plasmacytoid dendritic cells [pDCs]).

RESULTS

The most enriched pathway in vaginal biopsies from patients with pSS compared to non-pSS controls was the interferon (IFN) signaling pathway (P < 0.01). Pathway scores for Janus kinase and signal transducer and activator of transcription (JAK-STAT) and Notch signaling were also higher (P < 0.01 for both pathways). Conversely, transforming growth factor-β signaling and angiogenesis pathway scores were lower in pSS (P = 0.02 and P = 0.04, respectively). Differences in IFN signaling between patients with pSS and non-pSS controls were confirmed by PCR and MxA tissue staining. No CD123+ pDCs were detected in vaginal biopsies. IFN-stimulated gene expression levels correlated positively with CD45+ cell numbers in vaginal biopsies and serum anti-SSA/Ro positivity.

CONCLUSION

Upregulation of IFN signaling in vaginal tissue of women with pSS, along with its association with tissue pathology, suggests that IFNs contribute to inflammation of the vaginal wall and potentially also to clinical symptomatology (ie, vaginal dryness).

Profiles of peripheral B cell subsets in a cohort of primary Sjögren's syndrome patients and their potential clinical significance

Background/purpose

Primary Sjögren's syndrome is a prototypical autoimmune disease, with B cell dysfunction as a dominant feature. Further insights into distribution of B cell subsets in primary Sjögren's syndrome are urgently required to identify the most appropriate target subpopulation. We aimed to evaluate the profiles of B lymphocyte subpopulations in primary Sjögren's syndrome patients and to investigate their clinical significance.

Materials and methods

Thirty primary Sjögren's syndrome patients and 15 age-and sex-matched healthy controls were recruited. Peripheral B cell subsets were analyzed by flow cytometry.

Results

Compared to healthy controls, circulating CD19+ B cells, CD19+CD20- B cells, CD19+CD27-IgD+ naïve B cells, CD19+IgD+CD38high plasmablasts, CD19+CD24highCD38high transitional B cells and CD19+CD20-CD27+CD38+ plasma cells were elevated in patients with primary Sjögren's syndrome, whereas CD19+CD27+ memory B cells, CD19+CD27-IgD- double negative B cells and CD19+CD24hiCD27+ Bregs were decreased. Furthermore, the percentage of circulating CD19+CD20-CD27+CD38+ plasma cells was positively correlated with serum IgG levels and the proportional area of lymphocytic infiltration of labial gland.

Conclusion

We identified a comprehensive B lymphocyte subset distribution profile in primary Sjögren's syndrome. Moreover, we detected a clinical significance of CD19+CD20-CD27+CD38+ plasma cells, suggesting that these cells might play a key role in disease pathology and represent potential therapeutic targets.

Primary Sjogren syndrome - A bibliometric analysis via CiteSpace

This study employs CiteSpace software to analyze the research status, hotspots, and trends of primary Sjogren syndrome (pSS). Relevant publications from 1999 to 2023 were searched in the Web of Science Core Collection (WoSCC) set, followed by generating a network map using CiteSpace software to identify top authors, institutions, countries, keywords, journals, references, and research trends. A total of 3564 valid articles were included in this study. The People Republic of China had the highest number of articles (n = 524), while the University of Bergen emerged as the institution with the highest publication count (n = 94). Mariette X was identified as the author with the most publications (n = 67), whereas Vitali C received recognition as the most cited author (n = 1706). Annals of Rheumatic Diseases stood out as the journal with the highest citation count (n = 2530). Notably, an article published in the Annals of Rheumatic Diseases in 2017 garnered significant attention by being cited a remarkable 304 times. The bibliometric analysis reveals that key areas of research in pSS encompass investigating pathogenesis; advancing and applying targeted biological agents; and establishing treatment and diagnostic standards.

Emerging biologic frontiers for Sjogren's syndrome: Unveiling novel approaches with emphasis on extra glandular pathology

Primary Sjögren's Syndrome (pSS) is a complex autoimmune disorder characterized by exocrine gland dysfunction, leading to dry eyes and mouth. Despite growing interest in biologic therapies for pSS, FDA approval has proven challenging due to trial complications. This review addresses the absence of a molecular-target-based approach to biologic therapy development and highlights novel research on drug targets and clinical trials. A literature search identified potential pSS treatment targets and recent advances in molecular understanding. Overlooking extraglandular symptoms like fatigue and depression is a notable gap in trials. Emerging biologic agents targeting cytokines, signal pathways, and immune responses have proven efficacy. These novel therapies could complement existing methods for symptom alleviation. Improved grading systems accounting for extraglandular symptoms are needed. The future of pSS treatment may involve gene, stem-cell, and tissue-engineering therapies. This narrative review offers insights into advancing pSS management through innovative biologic interventions.

Long Non-Coding RNAs in Sjögren's Disease

Sjögren's disease (SjD) is a heterogeneous autoimmune disease characterized by severe dryness of mucosal surfaces, particularly the mouth and eyes; fatigue; and chronic pain. Chronic inflammation of the salivary and lacrimal glands, auto-antibody formation, and extra-glandular manifestations occur in subsets of patients with SjD. An aberrant expression of long, non-coding RNAs (lncRNAs) has been described in many autoimmune diseases, including SjD. Here, we review the current literature on lncRNAs in SjD and their role in regulating X chromosome inactivation, immune modulatory functions, and their potential as biomarkers.

Emerging role of gut microbiota in autoimmune diseases

Accumulating studies have indicated that the gut microbiota plays a pivotal role in the onset of autoimmune diseases by engaging in complex interactions with the host. This review aims to provide a comprehensive overview of the existing literatures concerning the relationship between the gut microbiota and autoimmune diseases, shedding light on the complex interplay between the gut microbiota, the host and the immune system. Furthermore, we aim to summarize the impacts and potential mechanisms that underlie the interactions between the gut microbiota and the host in autoimmune diseases, primarily focusing on systemic lupus erythematosus, rheumatoid arthritis, Sjögren's syndrome, type 1 diabetes mellitus, ulcerative colitis and psoriasis. The present review will emphasize the clinical significance and potential applications of interventions based on the gut microbiota as innovative adjunctive therapies for autoimmune diseases.

The diagnosis and misdiagnosis of Sjögren disease

Although one of the most common systemic autoimmune disorders, Sjögren disease (SjD) may be overlooked in patients presenting with non-specific symptoms or no complaints of sicca symptoms. SjD is not a condition to be missed as patients could present with serious extra-glandular manifestations, including lymphomas. In this article, we discuss the diagnostic pitfalls of this disorder and encourage physicians to consider carefully the 'non-textbook' presentations.

PET/CT in Inflammatory and Auto-immune Disorders: Focus on Several Key Molecular Concepts, FDG, and Radiolabeled Probe Perspectives

Chronic immune diseases mainly include autoimmune and inflammatory diseases. Managing chronic inflammatory and autoimmune diseases has become a significant public health concern, and therapeutic advancements over the past 50 years have been substantial. As therapeutic tools continue to multiply, the challenge now lies in providing each patient with personalized care tailored to the specifics of their condition, ushering in the era of personalized medicine. Precise and holistic imaging is essential in this context to comprehensively map the inflammatory processes in each patient, identify prognostic factors, and monitor treatment responses and complications. Imaging of patients with inflammatory and autoimmune diseases must provide a comprehensive view of the body, enabling the whole-body mapping of systemic involvement. It should identify key cellular players in the pathology, involving both innate immunity (dendritic cells, macrophages), adaptive immunity (lymphocytes), and microenvironmental cells (stromal cells, tissue cells). As a highly sensitive imaging tool with vectorized molecular probe capabilities, PET/CT can be of high relevance in the management of numerous inflammatory and autoimmune diseases. Relying on key molecular concepts of immunity, the clinical usefulness of FDG-PET/CT in several relevant inflammatory and immune-inflammatory conditions, validated or emerging, will be discussed in this review, together with radiolabeled probe perspectives.

Hyperactivation and altered selection of B cells in patients with paediatric Sjogren's syndrome

OBJECTIVES

Paediatric Sjögren's syndrome (pSS) is a rare chronic autoimmune disorder, characterised by inflammation of exocrine glands. B cell hyperactivation plays a central role in adult-onset Sjogren. This study was designed to analyse B cell and T cell phenotype, levels of BAFF, and selection of autoreactive B cells in patients with pSS.

METHODS

A total of 17 patients diagnosed with pSS and 13 healthy donors (controls) comparable for age were enrolled in the study. B cell and T cell subsets and frequency of autoreactive B cells in peripheral blood were analysed by flow cytometry. Levels of BAFF were analysed by ELISA.

RESULTS

The relative frequency of total B cells, transitional, naïve and switched memory B cells was similar between pSS patients and controls. In patients with pSS, we observed a reduction in the frequency of unswitched memory B cells, an increased frequency of atypical memory B cells and an expansion of PD1hi CXCR5- T peripheral helper cells. Levels of BAFF were higher in patients with pSS compared with controls and correlated with serum levels of total IgG and titres of anti-Ro antibodies. The frequency of autoreactive B cells in the transitional, unswitched memory and plasmablast compartment was significantly higher in pSS patients than in controls.

CONCLUSIONS

Our results point to a hyperactivation of B cells in pSS. Current therapies do not seem to affect B cell abnormalities, suggesting that novel therapies targeting specifically B cell hyperactivation need to be implemented for paediatric patients.

Functional significance of DNA methylation: epigenetic insights into Sjögren's syndrome

Sjögren's syndrome (SjS) is a systemic, highly diverse, and chronic autoimmune disease with a significant global prevalence. It is a complex condition that requires careful management and monitoring. Recent research indicates that epigenetic mechanisms contribute to the pathophysiology of SjS by modulating gene expression and genome stability. DNA methylation, a form of epigenetic modification, is the fundamental mechanism that modifies the expression of various genes by modifying the transcriptional availability of regulatory regions within the genome. In general, adding a methyl group to DNA is linked with the inhibition of genes because it changes the chromatin structure. DNA methylation changes the fate of multiple immune cells, such as it leads to the transition of naïve lymphocytes to effector lymphocytes. A lack of central epigenetic enzymes frequently results in abnormal immune activation. Alterations in epigenetic modifications within immune cells or salivary gland epithelial cells are frequently detected during the pathogenesis of SjS, representing a robust association with autoimmune responses. The analysis of genome methylation is a beneficial tool for establishing connections between epigenetic changes within different cell types and their association with SjS. In various studies related to SjS, most differentially methylated regions are in the human leukocyte antigen (HLA) locus. Notably, the demethylation of various sites in the genome is often observed in SjS patients. The most strongly linked differentially methylated regions in SjS patients are found within genes regulated by type I interferon. This demethylation process is partly related to B-cell infiltration and disease progression. In addition, DNA demethylation of the runt-related transcription factor (RUNX1) gene, lymphotoxin-α (LTA), and myxovirus resistance protein A (MxA) is associated with SjS. It may assist the early diagnosis of SjS by serving as a potential biomarker. Therefore, this review offers a detailed insight into the function of DNA methylation in SjS and helps researchers to identify potential biomarkers in diagnosis, prognosis, and therapeutic targets.

Efficacy and safety of telitacicept in primary Sjögren's syndrome: a randomized, double-blind, placebo-controlled, phase 2 trial

OBJECTIVE

To evaluate the efficacy and safety of telitacicept in adult patients with primary SS (pSS) in a phase II randomized double-blind placebo-controlled trial.

METHODS

Patients with pSS with positive anti-SSA antibody and ESSDAI ≥ 5 were randomly assigned, in a 1:1:1 ratio, to receive weekly subcutaneous telitacicept 240 mg, 160 mg, or placebo for 24 weeks. The primary end point was the change from baseline in the ESSDAI at week 24. Safety was monitored.

RESULTS

A total of 42 patients were enrolled and randomized (n = 14 per group). Administration of telitacicept 160 mg resulted in a significant reduction in ESSDAI score from baseline to week 24 compared with placebo (P < 0.05). The placebo-adjusted least-squares mean change from baseline was -4.3 (95% CI -7.0, -1.6; P = 0.002). While, mean change of ESSDAI in telitacicept 240 mg was -2.7(-5.6-0.1) with no statistical difference when compared that in placebo group (P = 0.056). In addition, MFI-20 and serum immunoglobulins decreased significantly (P < 0.05) at week 24 in both telitacicept groups compared with placebo. No serious adverse events were observed in the telitacicept treating group.

CONCLUSION

Telitacicept showed clinical benefits and good tolerance and safety in the treatment of pSS.

TRIAL REGISTRATION

ClinicalTrials.gov, https://clinicaltrials.gov, NCT04078386.

Manifestations and management of Sjögren's disease

Sjögren's disease is a heterogeneous autoimmune disorder that may be associated with systemic manifestations such as pulmonary or articular involvement. Systemic complications have prognostic implications and need to be identified and managed in a timely manner. Treatment should be tailored to the type and severity of organ involvement, ideally based on multidisciplinary evaluation.

B Cells Dynamic in Aging and the Implications of Nutritional Regulation

Aging negatively affects B cell production, resulting in a decrease in B-1 and B-2 cells and impaired antibody responses. Age-related B cell subsets contribute to inflammation. Investigating age-related alterations in the B-cell pool and developing targeted therapies are crucial for combating autoimmune diseases in the elderly. Additionally, optimal nutrition, including carbohydrates, amino acids, vitamins, and especially lipids, play a vital role in supporting immune function and mitigating the age-related decline in B cell activity. Research on the influence of lipids on B cells shows promise for improving autoimmune diseases. Understanding the aging B-cell pool and considering nutritional interventions can inform strategies for promoting healthy aging and reducing the age-related disease burden.

Multimodal Single-Cell Sequencing of B Cells in Primary Sjögren's Syndrome

OBJECTIVE

B cells are important in the pathogenesis of primary Sjögren's syndrome (pSS). Patients positive for Sjögren's syndrome antigen A/Sjögren syndrome antigen B (SSA/SSB) autoantibodies are more prone to systemic disease manifestations and adverse outcomes. We aimed to determine the role of B cell composition, gene expression, and B cell receptor usage in pSS subgroups stratified for SSA/SSB antibodies.

METHODS

Over 230,000 B cells were isolated from peripheral blood of patients with pSS (n = 6 SSA-, n = 8 SSA+ single positive and n = 10 SSA/SSB+ double positive) and four healthy controls and processed for single-cell RNA sequencing (scRNA-seq) and single-cell variable, diversity, and joining (VDJ) gene sequencing (scVDJ-seq).

RESULTS

We show that SSA/SSB+ patients present the highest and lowest proportion of naïve and memory B cells, respectively, and the highest up-regulation of interferon-induced genes across all B cell subtypes. Differential usage of IGHV showed that IGHV1-69 and IGHV4-30-4 were more often used in all pSS subgroups compared with controls. Memory B cells from SSA/SSB+ patients displayed a higher proportion of cells with unmutated VDJ transcripts compared with other pSS patient groups and controls, indicating altered somatic hypermutation processes. Comparison with previous studies revealed heterogeneous clonotype pools, with little overlap in CDR3 sequences. Joint analysis using scRNA-seq and scVDJ-seq data allowed unsupervised stratification of patients with pSS and identified novel parameters that correlated to disease manifestations and antibody status.

CONCLUSION

We describe heterogeneity and molecular characteristics in B cells from patients with pSS, providing clues to intrinsic differences in B cells that affect the phenotype and outcome and allowing stratification of patients with pSS at improved resolution.

Regulatory T cells and IFN-γ-producing Th1 cells play a critical role in the pathogenesis of Sjögren's Syndrome

Objectives

Sjögren's Disease (SjD) is an autoimmune disorder characterized by progressive dysfunction, inflammation and destruction of salivary and lacrimal glands, and by extraglandular manifestations. Its etiology and pathophysiology remain incompletely understood, though a role for autoreactive B cells has been considered key. Here, we investigated the role of effector and regulatory T cells in the pathogenesis of SjD.

Methods

Histological analysis, RNA-sequencing and flow cytometry were conducted on glands, lungs, eyes and lymphoid tissues of mice with regulatory T cell-specific deletion of stromal interaction proteins (STIM) 1 and 2 ( Stim1/2 Foxp3 ), which play key roles in calcium signaling and T cell function. The pathogenicity of T cells from Stim1/2 Foxp3 mice was investigated through adoptively transfer into lymphopenic host mice. Additionally, single-cell transcriptomic analysis was performed on peripheral blood mononuclear cells (PBMCs) of patients with SjD and control subjects.

Results

Stim1/2 Foxp3 mice develop a severe SjD-like disorder including salivary gland (SG) and lacrimal gland (LG) inflammation and dysfunction, autoantibodies and extraglandular symptoms. SG inflammation in Stim1/2 Foxp3 mice is characterized by T and B cell infiltration, and transcriptionally by a Th1 immune response that correlates strongly with the dysregulation observed in patients with SjD. Adoptive transfer of effector T cells from Stim1/2 Foxp3 mice demonstrates that the SjD-like disease is driven by interferon (IFN)-γ producing autoreactive CD4 + T cells independently of B cells and autoantiboodies. scRNA-seq analysis identifies increased Th1 responses and attenuated memory Treg function in PBMCs of patients with SjD.

Conclusions

We report a more accurate mouse model of SjD while providing evidence for a critical role of Treg cells and IFN-γ producing Th1 cells in the pathogenesis of SjD, which may be effective targets for therapy.

Research hotspots and emerging trends in the treatment of Sjogren's syndrome: A bibliometric analysis from 1900 to 2022

OBJECTIVE

Sjogren's syndrome (SS) is an autoimmune disease that mainly affects the salivary and lacrimal glands and further leads to dry mouth and eyes. In recent years, knowledge about the treatment of SS is developing rapidly. This study aims to assess research progress on SS treatment using a bibliometric approach and to identify research hotspots and emerging trends in this area.

METHODS

The publications related to the treatment of SS were retrieved from the Science Citation Index Expanded (SCI-E) database. The following search terms were used to extract document data: TS=(Sjogren* OR Sicca*) AND TS= (Treat* OR Therap* OR Disease Management). Articles and review articles published in English from 1900 to 2022 were selected. After the manual screening, the publication data were exported to a plain text file and applied for cooperative network analysis, keyword analysis, and reference co-citation analysis by using CiteSpace.

RESULTS

A total of 2038 publications were included in the analysis from 571 journals by 9063 authors. The annual number of published studies and times cited showed an overall upward trend since 1992. There was a degree of national/regional collaboration in this area, but direct collaboration between institutions and authors was still lacking. The country with the highest number of publications was in the United States, followed by China and Japan. Five SS-related treatments as the research hotspots were summarized by analyzing keywords and references, including immunosuppressive and anti-inflammatory therapy, regenerative therapy, gene therapy, surgical treatment, and symptomatic treatment. Among them, B cells, T cells, mucosal-associated invariant T (MAIT) cells, mesenchymal stem cells (MSCs), rituximab, belimumab, cell-target therapy, and immunosuppressive and anti-inflammatory therapy were emerging trends in this field.

CONCLUSIONS

This study conducted a data-based and objective introduction to the treatment of SS from a fresh perspective. An analysis of the intellectual bases, research hotspots, and emerging trends in the field will contribute to future research and treatment decisions, which will ultimately benefit SS patients.