Clinical and immunological parameters of Sjögren's syndrome

Association of increased serum I-309 with phenotypes, disease activity, and cytokine pattern in primary Sjögren's syndrome

The aim of this study was to determine serum I-309 levels in primary Sjögren's syndrome (pSS) patients, as well as the association with disease phenotype, systemic activity, and T helper cell-related cytokines. A total of 58 pSS patients and 30 healthy controls (HC) were enrolled in this study. The concentrations of serum I-309, interleukin-4 (IL-4), IL-6, IL-9, IL-13, IL-17, IL-22, IL-23, tumor-necrosis factor-α (TNF-α), interferon-γ (IFN-γ), IFN-α, and IFN-β were measured with multiplex immunoassay. The relationships between I-309 and various clinical and laboratory variables were analyzed. The serum concentrations of I-309 were significantly increased (median, IQR, 14.24, 10.99--20.35, pg/ml) in pSS patients compared with HC (median, IQR, 8.27, 6.74--9.62, pg/ml) (P < 0.001). Serum I-309 is increased in pSS, and may be associated with systemic inflammation, Th1-, Th17,- and Th9 cells, type Key Points • Serum I-309 levels are increased in pSS patients. • Increased I-309 may be associated with systemic rather than local manifestations in pSS. • Increased I-309 may be associated with Th1, Th17 and Th9 other than Th2 in pSS. • There may be close relationships between I-309 and type land type II IFNs in pSS.

Gut microbiota on anxiety and depression in primary Sjogren's syndrome: A novel insight

Primary Sjogren's syndrome (pSS) is a prevalent disease in rheumatology and immunology. Anxiety, depression, and other mood disorders are pervasive across diverse sectors of society. Recent theories on the gut-brain axis have elucidated that the gut microbiota considered the second brain of humans, can modulate the central nervous system and behavior by mediating bidirectional response systems, including immunity, vagus nerve, and neuroendocrine pathways. This article reviews recent advancements that explore the mechanism between gut microbiota and emotional disorders in pSS. It aims to provide novel therapies for these emotional disorders in pSS.

How to focus on autoantigen-specific lymphocytes: a review on diagnosis and treatment of Sjogren's syndrome

Sjogren's syndrome (SS) is an autoimmune epithelitis characterized by focal lymphocytic infiltration against self-antigens leading to progressive glandular dysfunction, which can develop to multisystem manifestation. The classification criteria for SS emphasizes glandular lymphocyte infiltrates and anti-SSA/SSB seropositivity, which is usually manifested in advanced patients. Therapeutically, apart from symptomatic treatment, treatment of SS is based on glucocorticoids and conventional synthetic disease-modifying antirheumatic drugs with global immunosuppression, but the efficacy of biologic or targeted synthetic therapies is still sparse. Currently, emerging studies focus on autoantigen-specific immunotherapies to treat autoimmune disorders by directly eliminating autoreactive cell subsets and inducing tolerance by increasing the autoreactive regulatory lymphocytes. Herein, we summarize the current state of research on the autoantigen-specific approaches for detecting autoreactive lymphocytes and outline the current autoantigen-specific immunotherapies in other autoimmune disorders and their attempts in treatment of SS. Last, we discuss the potential value of focusing on autoantigen-specific lymphocytes in the early diagnosis, monitoring, and targeted treatment of SS. Potential strategies for targeting autoreactive lymphocytes need to be confirmed in SS.

Regenerative fibroblasts derived from autologous skin tissue for the treatment of Sjögren's syndrome: a case report

Background

Sjögren's syndrome (SS) is a systemic autoimmune disease, with major symptoms including dry mouth and dry eyes, for which there is no effective treatment. Recent studies have demonstrated that mesenchymal stem cells (MSCs) are effective in the treatment of SS, but the efficacy of allogeneic MSCs is affected by variability among different cell donors, and they are easily cleared by the immune system of the recipient. Autologous MSCs are one of the ideal options for the treatment of SS; however, their function decreases with age. Regenerative fibroblast (rFib) is a type of new MSC obtained through chemical reprogramming technology from skin fibroblasts. In this study, we report the safety and efficacy of intravenous infusion of autologous rFib in a volunteer with SS.

Case report

In March 2021, the volunteer was diagnosed with SS due to positive anti-SSB antibodies, lymphocyte infiltration in the lip gland, dry eyes, and a large area of purpura in both lower limbs. From May 2021 to November 2022, she received allogeneic Umbilical cord mesenchymal stem cells (UCMSC) therapy (5.0 × 107 UCMSCs per time, totaling 10 infusions), but her condition did not improve. In May 2023, the rFib for the volunteer was prepared, meeting the quality standard of T/CSCB0003-2021 Human Mesenchymal Stem Cells. Between October 2023 and June 2024, the volunteer received a total of 12 intravenous transfusions of autologous rFib. After the treatments, the volunteer experienced no recurrence of purpura in both lower limbs. Symptoms of dry mouth, dry eyes, and fatigue were relieved. ESR, B lymphocytes, rheumatoid factor IgM, and IgA declined, while the proportion of NK cells increased, and most of the cytokines returned to normal levels. In vitro experiments showed that rFib could significantly inhibit the proliferation of T lymphocytes after PHA stimulation. No adverse effects were associated with the use of rFib in the volunteer during the clinical trial.

Summary

The results of this clinical trial indicate that intravenous injections of autologous rFib are both safe and effective for treating SS. Autologous rFib may be more suitable for treating autoimmune diseases than allogeneic MSCs.

Sonography of Salivary Gland Tumors and Disorders

Diseases of the salivary glands are as common as they are diverse and can have different causes. Clinicians can differentiate salivary gland changes based on chronic systemic diseases, congenital and vascular malformations, and benign and malignant tumors. Acute infectious pathologies can also arise as a result of obstructive pathologies. A large number of diseases with similar clinical presentations have to be differentiated. Due to the improved resolution of ultrasound technology over the last 20 years, it is now used as the first imaging modality to examine salivary gland pathologies. It allows a quick, dynamic, and non-invasive examination of the salivary glands and the soft tissue of the neck. In order to accurately diagnose and treat patients, a very good knowledge of these diseases and their appearance on sonography is required.

The Role of Oral Biomarkers in the Assessment of Noncommunicable Diseases

Background/Objectives: Oral biomarkers have gained attention as non-invasive tools for assessing systemic diseases due to their potential to reflect physiological and pathological conditions. This review aims to explore the role of oral biomarkers in diagnosing and monitoring systemic diseases, emphasizing their diagnostic relevance and predictive capabilities in clinical practice. Methods: This narrative review synthesizes the current literature on biochemical, immunological, genetic, and microbiological oral biomarkers, with a focus on their sources, types, and clinical applications. Key studies were analyzed to identify associations between oral biomarkers and systemic diseases such as cardiovascular diseases, type 2 diabetes mellitus, autoimmune disorders, and cancers. Results: Oral fluids, including saliva and gingival crevicular fluid, contain diverse biomarkers such as matrix metalloproteinases, cytokines, and genetic indicators. These markers have demonstrated potential in diagnosing and monitoring systemic conditions. Among others, elevated levels of salivary glucose and inflammatory cytokines correlate with diabetes progression, while vascular endothelial growth factor (VEGF) and salivary C-reactive protein might be applicable as indicators for periodontal disease and cardiovascular risk. Additionally, salivary biomarkers like amyloid-beta and tau are promising in detecting neurodegenerative disorders. Conclusions: Oral biomarkers might represent a transformative and point-of-care approach to the early management of systemic diseases; however, challenges in measurement variability, standardization, and validation remain.

Salivary Flow Rate in Patients with Sjögren's Syndrome: Correlations with Salivary Gland Ultrasound Findings and Biomarkers of Disease Activity

Sjögren's syndrome (SS) is a slowly progressive, chronic autoimmune inflammatory condition characterized by the affliction of the exocrine glands, with issues that derive from it markedly decreasing the quality of life of these patients. Salivary gland involvement can be identified through imaging methods. Among them, salivary gland ultrasonography (SGUS) is used as a diagnostic and prognostic tool in pSS. The aim of the present study was to assess the salivary flow rate and correlations between it and SGUS findings and markers of pSS activity. A total of 112 patients with pSS and 56 healthy subjects were included in this study. All patients underwent investigations including the measurement of serum autoantibodies, salivary flow rate determination, and ultrasonographic evaluation. SGUS modifications had a strong inverse correlation with salivary flow (r = -68.002, p < 0.0001) and a positive, strong correlation with IL-6 and Beta-2-microglobulin (r = -0.78 and r = -0.84, respectively, p < 0.001 in both cases). The SGUS findings were also strongly and positively correlated with the ESSDAI (r = -0.88, p < 0.0001) and Focus scores (r = -0.82, p < 0.0001). SGUS represents a non-invasive means of assessing the state of the salivary glands and, implicitly, the salivary flow of patients, offering valuable insights into disease progression and steps that can be taken in order to improve patients' quality of life.

Apigenin alleviates Sjögren's syndrome-induced salivary gland epithelial cell ferroptosis via ERα signaling-mediated regulation of the ATF3/SLC7A1l axis

BACKGROUND

In Sjögren's syndrome (SS)-an autoimmune disease characterized by dry mouth and eyes-salivary gland epithelial cells (SGECs) undergo ferroptosis, which disrupts their integrity and impairs saliva secretion. Apigenin, a phytoestrogen, is known to activate estrogen signalling and alleviate xerostomia in ovariectomized mice; however, its effect on SGEC survival and function in SS remains unclear. We hypothesized that apigenin alleviates SS symptoms and progression by inhibiting ferroptosis in SGECs and aimed to elucidate the underlying mechanism.

METHODS

Apigenin (50 mg/kg) was orally gavaged to non-obese diabetic (NOD)/LtJ female mice (SS model); changes in SS functional indicators were analyzed using mRNA sequencing and bioinformatic analyses of submandibular glands. Interferon-gamma (IFN-γ)-stimulated SGECs were used to model SS in vitro; SGEC activity and aquaporin 5 (AQP5) expression were analyzed. Immunohistochemical staining, transmission electron microscopy, RT-qPCR, western blotting and other methods were used to verify the mechanisms.

RESULTS

Apigenin significantly increased salivary secretion and AQP5 expression while inhibiting ferroptosis and immune infiltration in NOD mouse submandibular glands. The oxidative stress gene ATF3 was upregulated and GPX4 was downregulated in NOD mice compared to that in control group (ICR mice); however, apigenin reversed this effect. IFN-γ treatment downregulated AQP5, SLC7A11, and GPX4 expression while promoting ATF3 expression and ferroptosis, which was mitigated by apigenin. ATF3 knockdown increased SLC7A11 and GPX4 expression, inhibiting SS and ferroptosis. Furthermore, apigenin inhibited ferroptosis in SGECs through ESR1 binding to ATF3.

CONCLUSION

Apigenin alleviates SS by regulating SGEC ferroptosis via the ERα-regulated ATF3/SLC7A11 axis, highlighting its therapeutic potential in SS.

Tear cytokine levels in Sjogren's syndrome-related dry eye disease compared with non-Sjogren's syndrome-related dry eye disease patients: A meta-analysis

BACKGROUND

As a common complication of Sjogren syndrome (SS), SS-related dry eye disease (SS-DED) significantly affects the patients' quality of life. Pro-inflammatory cytokines in tears are widely believed to play a crucial role in the pathogenesis of SS-DED. A systematic literature review with meta-analyses was conducted to provide a quantitative summary of tear cytokine levels in SS-DED compared with non-SS-DED and healthy controls.

METHODS

The PubMed, Embase, Web of Science, Ovid, and Scopus databases were searched until June 2022. Original case-control studies investigating tear cytokines in SS-DED patients compared with non-SS-DED or healthy individuals were included. Differences of cytokines levels were compared with random-effects standardized mean differences ± 95% confidence intervals calculated as the effect size.

RESULTS

A total of 15 articles, 809 subjects (302 for SS-DED, 220 for non-SS-DED, and 287 for healthy controls) were included in the study. SS-DED patients had higher tear levels of interferon-gamma, interleukin (IL)-17, IL-1β, IL-2, IL-4, IL-6, and IL-8 as compared to healthy controls. As for comparison between SS-DED and non-SS-DED group, the levels of IL-12p70, IL-17, IL-4, IL-6, IL-8, and tumor necrosis factor-alpha were significantly higher in SS-DED patients compared with the non-SS-DED group. The level of epidermal growth factor was significantly lower in SS-DED patients compared with both non-SS-DED patients and healthy controls.

CONCLUSION

The findings from this study provide evidence for levels of tear cytokines in SS-DED to become potential diagnostic biomarkers or therapeutic targets. Further studies with a higher number of subjects and improved quality are necessary.

Immune and non-immune mediators in the fibrosis pathogenesis of salivary gland in Sjögren's syndrome

Sjögren's syndrome (SS) or Sjögren's disease (SjD) is a systemic autoimmune disease clinically manifested as sicca symptoms. This disease primarily impacts the functionality of exocrine glands, specifically the lacrimal and salivary glands (SG). SG fibrosis, an irreversible morphological change, is a severe consequence that occurs in the later stages of the disease due to sustained inflammation. However, the mechanism underlying SG fibrosis in SS remains under-investigated. Glandular fibrosis may arise from chronic sialadenitis, in which the interactions between infiltrating lymphocytes and epithelial cells potentially contributes to fibrotic pathogenesis. Thus, both immune and non-immune cells are closely involved in this process, while their interplays are not fully understood. The molecular mechanism of tissue fibrosis is partly associated with an imbalance of immune responses, in which the transforming growth factor-beta (TGF-β)-dependent epithelial-mesenchymal transition (EMT) and extracellular matrix remodeling are recently investigated. In addition, viral infection has been implicated in the pathogenesis of SS. Viral-specific innate immune response could exacerbate the autoimmune progression, resulting in overt inflammation in SG. Notably, post-COVID patients exhibit typical SS symptoms and severe inflammatory sialadenitis, which are positively correlated with SG damage. In this review, we discuss the immune and non-immune risk factors in SG fibrosis and summarize the evidence to understand the mechanisms upon autoimmune progression in SS.

A 3D-printed acinar-mimetic silk fibroin-collagen-astragalus polysaccharide scaffold for tissue reconstruction and functional repair of damaged parotid glands

Salivary glands are the principal organs responsible for secreting saliva in the oral cavity. Tumors, trauma, inflammation, and other factors can cause functional or structural damage to the glands, leading to reduced saliva secretion. In this study, we innovatively prepared a acinar-mimetic silk fibroin-collagen-astragalus polysaccharide (SCA) scaffold using low-temperature three-dimensional (3D) printing and freeze-drying techniques. We evaluated the material properties and cell compatibility of the scaffold in vitro and implanted it into the damaged parotid glands (PG) of rats to assess its efficacy in tissue reconstruction and functional repair. The results demonstrated that the SCA scaffold featured a porous structure resembling natural acini, providing an environment conducive to cell growth and orderly aggregation. It exhibited excellent porosity, water absorption, mechanical properties, and biocompatibility, fulfilling the requirements for tissue engineering scaffolds. In vitro, the scaffold facilitated adhesion, proliferation, orderly polarization, and spherical aggregation of PG cells. In vivo, the SCA scaffold effectively recruited GECs locally, forming gland-like acinar structures that matured gradually, promoting the regeneration of damaged PGs. The SCA scaffold developed in this study supports tissue reconstruction and functional repair of damaged PGs, making it a promising implant material for salivary gland regeneration.

Iguratimod Alleviates Experimental Sjögren's Syndrome by Inhibiting NLRP3 Inflammasome Activation

Iguratimod (T-614) is a compound widely used as anti-rheumatic drug. This study investigated the effect and underlying mechanism of T-614 on experimental Sjögren's syndrome (ESS). ESS mice model was established by injection of submandibular gland protein. Mice were randomly divided into control, experimental Sjögren's syndrome (ESS), ESS + T-614 (10 mg/kg), ESS + T-614 (20 mg/kg), and ESS + T-614 (30 mg/kg) groups. Human submandibular gland (HSG) were cultured with 0, 0.5, 5, or 50 μg/ml T-614 in the absence or presence of interferon-α (IFN-α). Haematoxylin and eosin (H&E) and cytokine levels were used to detect immune cells activation in submandibular glands. Apoptosis in submandibular glands tissues and cells was determined by TUNEL and flow cytometry. Apoptosis and NLRP3 inflammasome-related proteins were detected by western blotting. T-614 treatment attenuated submandibular gland damage in ESS mice. T-614 administration inhibited submandibular gland cell apoptosis in ESS mice. Furthermore, T-614 blocked inflammatory factor levels and NLRP3 inflammasome activation in the submandibular glands. In vitro, results corroborated that T-614 could protect HSG cells from IFN-α-induced cell apoptosis and inflammation by inhibiting NLRP3 inflammasome activation. Our results expounded that T-614 alleviated ESS by inhibiting NLRP3 inflammasome activation.

Epidemiologic and genetic associations between primary biliary cholangitis and extrahepatic rheumatic diseases

Patients with primary biliary cholangitis (PBC) commonly experience extrahepatic rheumatic diseases. However, the epidemiologic and genetic associations as well as causal relationship between PBC and these extrahepatic conditions remain undetermined. In this study, we first conducted systematic review and meta-analyses by analyzing 73 studies comprising 334,963 participants across 17 countries and found strong phenotypic associations between PBC and rheumatic diseases. Next, we utilized large-scale genome-wide association study summary data to define the shared genetic architecture between PBC and rheumatic diseases, including rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), systemic sclerosis (SSc) and Sjögren's syndrome (SS). We observed significant genetic correlations between PBC and each of the four rheumatic diseases. Pleiotropy and heritability enrichment analysis suggested the involvement of humoral immunity and interferon-associated processes for the comorbidity. Of note, we identified four variants shared between PBC and RA (rs80200208), SLE (rs9843053), and SSc (rs27524, rs3873182) using cross-trait meta-analysis. Additionally, several pleotropic loci for PBC and rheumatic diseases were found to share causal variants with gut microbes possessing immunoregulatory functions. Finally, Mendelian randomization revealed consistent evidence for a causal effect of PBC on RA, SLE, SSc, and SS, but no or inconsistent evidence for a causal effect of extrahepatic rheumatic diseases on PBC. Our study reveals a profound genetic overlap and causal relationships between PBC and extrahepatic rheumatic diseases, thus providing insights into shared biological mechanisms and novel therapeutic interventions.

Diagnostic and therapeutic potentials of extracellular vesicles for primary Sjögren's Syndrome: A review

Primary Sjögren syndrome (pSS) is a chronic autoimmune disease mainly affecting salivary and lacrimal glands. The current pSS biomarkers, serum autoantibodies, are negative in many pSS patients diagnosed with histopathology changes, indicating the need of novel biomarkers. The current therapies of pSS are merely short-term symptomatic relief and can't provide effective long-term remedy. Extracellular vehicles (EVs) are nano-sized lipid bilayer-delimited particles spontaneously released by almost all types of cells and carrying various bioactive molecules to mediate inter-cellular communications. Recent studies found that EVs from salivary gland epithelial cells and immune cells play essential roles in pSS pathogenesis. Correspondingly, EVs and their cargos in plasma and saliva are promising candidate biomarkers for pSS diagnosis. Moreover, EVs from mesenchymal stem cells have shown promises to improve pSS treatment by modulating immune responses. This review summarizes recent findings in roles of EVs in pSS pathogenesis, diagnosis, and treatment of pSS, as well as related challenges and future research directions.

A graph-learning based model for automatic diagnosis of Sjögren's syndrome on digital pathological images: a multicentre cohort study

BACKGROUND

Sjögren's Syndrome (SS) is a rare chronic autoimmune disorder primarily affecting adult females, characterized by chronic inflammation and salivary and lacrimal gland dysfunction. It is often associated with systemic lupus erythematosus, rheumatoid arthritis and kidney disease, which can lead to increased mortality. Early diagnosis is critical, but traditional methods for diagnosing SS, mainly through histopathological evaluation of salivary gland tissue, have limitations.

METHODS

The study used 100 labial gland biopsy, creating whole-slide images (WSIs) for analysis. The proposed model, named Cell-tissue-graph-based pathological image analysis model (CTG-PAM) and based on graph theory, characterizes single-cell feature, cell-cell feature, and cell-tissue feature. Building upon these features, CTG-PAM achieves cellular-level classification, enabling lymphocyte recognition. Furthermore, it leverages connected component analysis techniques in the cell graph structure to perform SS diagnosis based on lymphocyte counts.

FINDINGS

CTG-PAM outperforms traditional deep learning methods in diagnosing SS. Its area under the receiver operating characteristic curve (AUC) is 1.0 for the internal validation dataset and 0.8035 for the external test dataset. This indicates high accuracy. The sensitivity of CTG-PAM for the external dataset is 98.21%, while the accuracy is 93.75%. In comparison, the sensitivity and accuracy for traditional deep learning methods (ResNet-50) are lower. The study also shows that CTG-PAM's diagnostic accuracy is closer to skilled pathologists compared to beginners.

INTERPRETATION

Our findings indicate that CTG-PAM is a reliable method for diagnosing SS. Additionally, CTG-PAM shows promise in enhancing the prognosis of SS patients and holds significant potential for the differential diagnosis of both non-neoplastic and neoplastic diseases. The AI model potentially extends its application to diagnosing immune cells in tumor microenvironments.

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.

Relationship between Sjogren's syndrome and gastroesophageal reflux: A bidirectional Mendelian randomization study

The clinical incidence of sjogren's syndrome combined with gastroesophageal reflux disease is high. Existing observational studies have shown inconsistent results in the association between gastroesophageal reflux disease (GERD) and Sjogren's syndrome (SS).We observed that the symptoms of SS patients also improved after receiving GERD-related treatment. Therefore, we aimed to investigate the relationship between GERD and SS through a bidirectional two-sample Mendelian randomization (MR) study. Independent SNPs associated with GERD and SS were selected from a genome-wide association study (GWAS) as instrumental variables to conduct a bidirectional two-sample Mendelian analysis of GERD and SS. Genetic data were obtained from two databases for the following two outcomes: Gastroesophageal reflux (IEU Open GWAS) [sample size = 602,604 (patients = 129,080; nonpatients = 473,524)] and SS (FinnGen) [sample size = 392,423 (patients = 2,495; nonpatients = 389,928)]. Statistical methods for the MR analysis included the inverse-variance weighting method, weighted median, simple mode and weighted mode, as well as heterogeneity and sensitivity analyses using the Cochran Q statistic, MR‒Egger regression, outlier detection methods (MR-PRESSO). In addition, Steiger Test was conducted to test the direction of causality. MR analysis showed a positive correlation between GERD and SS risk [odds ratio (OR) = 1.3279 (95% confidence interval 1.0312-1.7099, P = 0.0280)]. However, in contrast, no significant causal effect of SS on GERD was observed [OR = 1.0024 (95% CI 0.9651-1.0412; P = 0.8995)]. This bidirectional two-sample Mendelian randomization study confirmed a causal relationship between SS and GERD, and suggested that GERD is a risk factor for SS, while SS does not affect GERD.

Crucial Roles of RSAD2/viperin in Immunomodulation, Mitochondrial Metabolism and Autoimmune Diseases

Autoimmune diseases are typically characterized by aberrant activation of immune system that leads to excessive inflammatory reactions and tissue damage. Nevertheless, precise targeted and efficient therapies are limited. Thus, studies into novel therapeutic targets for the management of autoimmune diseases are urgently needed. Radical S-adenosyl methionine domain-containing 2 (RSAD2) is an interferon-stimulated gene (ISG) renowned for the antiviral properties of the protein it encodes, named viperin. An increasing number of studies have underscored the new roles of RSAD2/viperin in immunomodulation and mitochondrial metabolism. Previous studies have shown that there is a complex interplay between RSAD2/vipeirn and mitochondria and that binding of the iron-sulfur (Fe-S) cluster is necessary for the involvement of viperin in mitochondrial metabolism. Viperin influences the proliferation and development of immune cells as well as inflammation via different signaling pathways. However, the function of RSAD2/viperin varies in different studies and a comprehensive overview of this emerging theme is lacking. This review will describe the characteristics of RSAD2/viperin, decipher its function in immunometabolic processes, and clarify the crosstalk between RSAD2/viperin and mitochondria. Furthermore, we emphasize the crucial roles of RSAD2 in autoimmune diseases and its potential application value.

Disease Duration Affects the Clinical Phenotype of Primary Sjögren Syndrome: A Medical Records Review Study of 952 Cases

OBJECTIVES

To investigate the impact of disease duration on clinical phenotypes in Chinese patients with primary Sjögren syndrome (pSS) and examine the correlation between clinical phenotypes and onset age, age at diagnosis, and disease duration.

METHODS

Data from 952 patients diagnosed with pSS in China between January 2013 and March 2022 were analyzed based on medical records. Patients were categorized into 3 groups based on disease duration: short (<5 years), moderate (≥5 and <10 years), and long (≥10 years) group. Clinical characteristics were compared among the 3 groups, and pSS patients with a long disease duration were compared with the other patients after matching age at diagnosis and age at onset.

RESULTS

Among the patients, 20.4% had a disease duration over 10 years. After matching for age at onset and age at diagnosis, pSS patients with a long disease duration exhibited a significantly higher prevalence of dry mouth ( p <0.001), dry eyes ( p <0.001), fatigue ( p <0.001), arthralgia ( p <0.001), and dental caries ( p <0.001) and higher rates of anti-Sjögren syndrome A ( p < 0.05), anti-Ro52 ( p < 0.05), and anti-SSB ( p < 0.05) positivity than their control groups, with prevalence increasing with disease duration ( ptrend < 0.001). However, no differences were noted in the prevalence of interstitial lung disease and leukopenia between different disease duration groups after matching for age at onset, although differences were shown when matching for age at diagnosis.

CONCLUSION

Longer disease duration in pSS patients correlates with increased prevalence of sicca symptoms, fatigue, and arthralgia and higher positivity of autoantibodies associated with pSS. However, the prevalence of interstitial lung disease and leukopenia did not correlate with disease duration after matching for age at onset.

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.

Identification and verification of inflammatory biomarkers for primary Sjögren's syndrome

INTRODUCTION

Primary Sjögren's syndrome (pSS) is an autoimmune disease characterized by inflammatory infiltration, and dysfunction of the salivary and lacrimal glands. This research aimed to explore the disease pathogenesis and improve the diagnosis and treatment of pSS by mining inflammation-associated biomarkers.

METHODS

Five pSS-related datasets were retrieved from the Gene Expression Omnibus (GEO) database. Inflammation-associated biomarkers were determined by the least absolute shrinkage and selection operator (LASSO) and support vector machines recursive feature elimination (SVM-RFE). Single sample gene set enrichment analysis (ssGSEA) was implemented to profile the infiltration levels of immune cells. Real-time quantitative PCR (RT-qPCR) verified the expression of biomarkers in clinical samples.

RESULTS

Four genes (LY6E, EIF2AK2, IL15, and CXCL10) were screened as inflammation-associated biomarkers in pSS, the predictive performance of which were determined among three pSS-related datasets (AUC > 0.7). Functional enrichment results suggested that the biomarkers were involved in immune and inflammation-related pathways. Immune infiltration analysis revealed that biomarkers were notably connected with type 2 T helper cells, regulatory T cells which were significantly expressed between pSS and control. TESTOSTERONE and CYCLOSPORINE were predicted to take effect by targeting CXCL10 and IL15 in pSS, respectively.

CONCLUSION

Four inflammation-associated biomarkers (LY6E, EIF2AK2, IL15, and CXCL10) were explored, and the underlying regulatory mechanisms and targeted drugs associated with these biomarkers were preliminarily investigated according to a series of bioinformatics methods based on the online datasets of pSS, which provided a reference for understanding the pathogenesis of pSS. Key Points • Inflammation-associated biomarkers (LY6E, EIF2AK2, IL15, and CXCL10) were firstly identified in Sjögren's syndrome based on LASSO and SVM-RFE analyses. • CXCL10, EIF2AK2 and LY6E were prominently positively correlated with immature B cells, while IL15 were significantly negatively correlated with memory B cells in Sjögren's syndrome. • LY6E, EIF2AK2, IL15, and CXCL10 were significantly more highly expressed in clinical Sjögren's syndrome samples compared to healthy control samples, which was consistent with the analysis results of the GEO database. •LY6E, EIF2AK2, IL15, and CXCL10 might be used as the biomarkers for the treatment and diagnosis of Sjögren's syndrome.

Impact of sex differences on the clinical presentation, pathogenesis, treatment and prognosis of Sjögren's syndrome

Sjögren's syndrome is a common chronic autoimmune disease that manifests as dry mouth, dry eyes and systemic complications. There are sex differences in the clinical manifestations between men and women, with the average age of onset being around 55 years and the majority of female patients developing the disease during the menopausal years. Understanding the impact of sex differences on SS may help in the treatment and prognosis of patients. Studies have confirmed that a number of factors are associated with the onset of SS, but the exact mechanisms are not fully understood. Sex hormones (especially oestrogens and androgens) play a very important role, and the balance of sex hormone levels in the body is crucial for maintaining homeostasis in the acinar cells of the lacrimal and salivary glands. In addition, chromosomes play a very important role in the sex differences in SS. The gut microbiota also has some influence on sex differences in SS. In this review, we focus on oestrogens and androgens, which are important in the pathogenesis of SS, and summarize the progress of non-clinical studies. Sex differences may influence differences in individualized treatment regimens and further studies are needed.

CFL1 restores the migratory capacity of bone marrow mesenchymal stem cells in primary Sjögren's syndrome by regulating CCR1 expression

BACKGROUND

Primary Sjögren's syndrome (pSS) is a chronic systemic autoimmune disease. There is no relevant research on whether the migratory ability of bone marrow mesenchymal stem cells (BM-MSC) is impaired in patients with pSS (pSS-BMMSC).

METHODS

Trajectories and velocities of BM-MSC were analyzed. Transwell migration assay and wound healing assay were used to investigate the migratory capacity of BM-MSC. The proliferative capacity of BM-MSC was evaluated by EDU and CCK8 assay. RNA-seq analysis was then performed to identify the underlying mechanism of lentivirus-mediated cofilin-1 overexpression BM-MSC (BMMSCCFL1). The therapeutic efficacy of BMMSCCFL1 was evaluated in NOD mice.

RESULTS

The migratory capacity of pSS-BMMSC was significantly reduced compared to normal volunteers (HC-BMMSC). The expression of the motility-related gene CFL1 was decreased in pSS-BMMSC. Lentivirus-mediated CFL1 overexpression of pSS-BMMSC promoted the migration capacity of pSS-BMMSC. Furthermore, RNA-seq revealed that CCR1 was the downstream target gene of CFL1. To further elucidate the mechanism of CFL1 in regulating BM-MSC migration and proliferation via the CCL5/CCR1 axis, we performed a rescue experiment using BX431 (a CCR1-specific inhibitor) to inhibit CCR1. The results showed that CCR1 inhibitors suppressed the migration and proliferation capacity of MSC induced by CFL1.

CONCLUSION

The pSS-BMMSC leads to impaired migration and proliferation, and overexpression of CFL1 can rescue the functional deficiency and alleviate disease symptoms in NOD mice. Mechanically, CFL1 can regulate the expression level of the downstream CCL5/CCR1 axis to enhance the migration and proliferation of BM-MSC.

Prediction of Sjögren's disease diagnosis using matched electronic dental-health record data

BACKGROUND

Sjögren's disease (SD) is an autoimmune disease that is difficult to diagnose early due to its wide spectrum of clinical symptoms and overlap with other autoimmune diseases. SD potentially presents through early oral manifestations prior to showing symptoms of clinically significant dry eyes or dry mouth. We examined the feasibility of utilizing a linked electronic dental record (EDR) and electronic health record (EHR) dataset to identify factors that could be used to improve early diagnosis prediction of SD in a matched case-control study population.

METHODS

EHR data, including demographics, medical diagnoses, medication history, serological test history, and clinical notes, were retrieved from the Indiana Network for Patient Care database and dental procedure data were retrieved from the Indiana University School of Dentistry EDR. We examined EHR and EDR history in the three years prior to SD diagnosis for SD cases and the corresponding period in matched non-SD controls. Two conditional logistic regression (CLR) models were built using Least Absolute Shrinkage and Selection Operator regression. One used only EHR data and the other used both EHR and EDR data. The ability of these models to predict SD diagnosis was assessed using a concordance index designed for CLR.

RESULTS

We identified a sample population of 129 cases and 371 controls with linked EDR-EHR data. EHR factors associated with an increased risk of SD diagnosis were the usage of lubricating throat drugs with an odds ratio (OR) of 14.97 (2.70-83.06), dry mouth (OR = 6.19, 2.14-17.89), pain in joints (OR = 2.54, 1.34-4.76), tear film insufficiency (OR = 27.04, 5.37-136.), and rheumatoid factor testing (OR = 6.97, 1.94-25.12). The addition of EDR data slightly improved model concordance compared to the EHR only model (0.834 versus 0.811). Surgical dental procedures (OR = 2.33, 1.14-4.78) were found to be associated with an increased risk of SD diagnosis while dental diagnostic procedures (OR = 0.45, 0.20-1.01) were associated with decreased risk.

CONCLUSION

Utilizing EDR data alongside EHR data has the potential to improve prediction models for SD. This could improve the early diagnosis of SD, which is beneficial to slowing or preventing complications of SD.

New investigational drugs to treat Sjogren's syndrome: lessons learnt from immunology

INTRODUCTION

Sjögren's syndrome is a heterogeneous autoimmune condition that impairs quality of life because of dryness, fatigue, pain, and systemic involvements. Current treatment largely depends on empirical evidence, with no effective therapy approved. Clinical trials on targeted drugs often fail to report efficacy due to common factors.

AREAS COVERED

This review summarizes the pathogenesis and what caused the failure of new investigational drugs in clinical trials, highlighting solutions for more effective investigations, with greater consistency between research outcomes, clinical use, and patient needs.

EXPERT OPINION

Unlinked pathobiology with symptoms resulted in misidentified targets and disappointing trials. Useful stratification tools are necessary for the heterogeneous SS patients. Composite endpoints or improvements in ESSDAI scores are needed, considering the high placebo response, and the unbalance between symptom burden and disease activity. Compared to classic biologics, targeted cell therapy will be a more promising field of investigation in the coming years.

Mitochondrial protein C15ORF48 is a stress-independent inducer of autophagy that regulates oxidative stress and autoimmunity

Autophagy is primarily activated by cellular stress, such as starvation or mitochondrial damage. However, stress-independent autophagy is activated by unclear mechanisms in several cell types, such as thymic epithelial cells (TECs). Here we report that the mitochondrial protein, C15ORF48, is a critical inducer of stress-independent autophagy. Mechanistically, C15ORF48 reduces the mitochondrial membrane potential and lowers intracellular ATP levels, thereby activating AMP-activated protein kinase and its downstream Unc-51-like kinase 1. Interestingly, C15ORF48-dependent induction of autophagy upregulates intracellular glutathione levels, promoting cell survival by reducing oxidative stress. Mice deficient in C15orf48 show a reduction in stress-independent autophagy in TECs, but not in typical starvation-induced autophagy in skeletal muscles. Moreover, C15orf48-/- mice develop autoimmunity, which is consistent with the fact that the stress-independent autophagy in TECs is crucial for the thymic self-tolerance. These results suggest that C15ORF48 induces stress-independent autophagy, thereby regulating oxidative stress and self-tolerance.

Exploring Immune Cell Diversity in the Lacrimal Glands of Healthy Mice: A Single-Cell RNA-Sequencing Atlas

The lacrimal gland is responsible for maintaining the health of the ocular surface through the production of tears. However, our understanding of the immune system within the lacrimal gland is currently limited. Therefore, in this study, we utilized single-cell RNA sequencing and bioinformatic analysis to identify and analyze immune cells and molecules present in the lacrimal glands of normal mice. A total of 34,891 cells were obtained from the lacrimal glands of mice and classified into 18 distinct cell clusters using Seurat clustering. Within these cell populations, 26 different immune cell subpopulations were identified, including T cells, innate lymphocytes, macrophages, mast cells, dendritic cells, and B cells. Network analysis revealed complex cell-cell interactions between these immune cells, with particularly significant interactions observed among T cells, macrophages, plasma cells, and dendritic cells. Interestingly, T cells were found to be the main source of ligands for the Thy1 signaling pathway, while M2 macrophages were identified as the primary target of this pathway. Moreover, some of these immune cells were validated using immunohistological techniques. Collectively, these findings highlight the abundance and interactions of immune cells and provide valuable insights into the complexity of the lacrimal gland immune system and its relevance to associated diseases.

Elevated plasma levels of specific antiplatelet glycoprotein autoantibodies in patients with primary Sjögren syndrome with thrombocytopenia

INTRODUCTION

Thrombocytopenia is one of the primary Sjögren's syndrome (pSS) hematological manifestations. The objective of this study was to evaluate the possible roles of antiplatelet glycoprotein autoantibodies in the pathogenesis of thrombocytopenia in primary Sjögren's syndrome (pSS).

METHODS

The level of plasma anti-glycoprotein Ib, IIIa and IIb/IIIa autoantibodies in 36 pSS patients without thrombocytopenia and 35 pSS patients with thrombocytopenia, 36 Idiopathic thrombocytopenic purpura (ITP) patients and 39 normal control were measured with enzyme-linked immunosorbent assay (ELISA).

RESULTS

The level of anti-GPIb, GPIIIa, GPIIb/IIIa autoantibodies (A490) in the pSS with thrombocytopenia was significantly higher than that of pSS without thrombocytopenia (0.813 ± 0.161 vs 0.688 ± 0.133; 0.917 ± 0.094 vs 0.802 ± 0.070; 0.911 ± 0.125 vs 0.782 ± 0.109). Incidences of the anti-GPIb, GPIIIa, GPIIb/IIIa autoantibodies in the pSS with thrombocytopenia was significantly higher than that of pSS without thrombocytopenia (25.7% vs 0%; 65.7% vs 11.1%; 31.4% vs 0%). In patients with pSS, there was a lower platelet count in anti-GPIb, GPIIIa, GPIIb/IIIa autoantibodies positive patients ((25.67 ± 5.5) × 10^9/L vs (116.8 ± 84.52) × 10^9/L; 29.04 ± 11.33 × 10^9/L vs (152.0 ± 75.47) × 10^9/L; (31.55 ± 14.0) × 10^9/L vs (118.8 ± 85.24) × 10^9/L).

CONCLUSION

Elevated plasma levels of anti-platelet glycoprotein autoantibodies may play a role in the pathogenesis of thrombocytopenia in pSS. Key Points • The level of anti-GPIb, GPIIIa, GPIIb/IIIa autoantibodies (A490) in the pSS with thrombocytopenia was increased. • Incidences of the anti-GPIb, GPIIIa, GPIIb/IIIa autoantibodies in the pSS with thrombocytopenia was increased. • In patients with pSS, there was a lower platelet count in anti-GPIb, GPIIIa, GPIIb/IIIa autoantibodies positive patients.

Modes and Mechanisms of Salivary Gland Epithelial Cell Death in Sjogren's Syndrome

Sjogren's syndrome is an autoimmune disease in middle and old-aged women with a dry mucosal surface, which is caused by the dysfunction of secretory glands, such as the oral cavity, eyeballs, and pharynx. Pathologically, Sjogren's syndrome are characterized by lymphocyte infiltration into the exocrine glands and epithelial cell destruction caused by autoantibodies Ro/SSA and La/SSB. At present, the exact pathogenesis of Sjogren's syndrome is unclear. Evidence suggests epithelial cell death and the subsequent dysfunction of salivary glands as the main causes of xerostomia. This review summarizes the modes of salivary gland epithelial cell death and their role in Sjogren's syndrome progression. The molecular mechanisms involved in salivary gland epithelial cell death during Sjogren's syndrome as potential leads to treating the disease are also discussed.

Exploring the mechanisms of action of Zengye decoction (ZYD) against Sjogren's syndrome (SS) using network pharmacology and animal experiment

CONTEXT

Zengye decoction (ZYD) has been considered to have a curative effect on Sjogren's syndrome (SS). However, its therapeutic mechanisms remain obscure.

OBJECTIVES

This research explores the mechanisms of ZYD against SS.

MATERIALS AND METHODS

The active compounds and targets of ZYD were searched in the TCMSP and BATMAN-TCM databases. SS-related targets were obtained from the GeneCards database. The GO and KEGG enrichment analyses elucidated the molecular mechanisms. Animal experiments were performed using 8 C57BL/6 mice that served as the control group (physiological saline treatment) and 16 NOD mice randomly divided into the model group (physiological saline treatment) and the ZYD group (ZYD treatment) for 8 weeks to verify the therapeutic effects of ZYD on SS.

RESULTS

Twenty-nine active compounds with 313 targets of ZYD and 1038 SS-related targets were screened. Thirty-two common targets were identified. β-Sitosterol and stigmasterol might be important components. GO analysis suggested that the action of ZYD against SS mainly involved oxidative stress, apoptotic processes, and tumor necrosis factor receptor superfamily binding, etc. KEGG analysis indicated the most significant signaling pathway was apoptosis-multiple species. Animal experiments showed that ZYD improved lymphocytic infiltration of the submandibular glands (SMGs), reduced the serum levels of TNF-α, IL-1β, IL-6, and IL-17, upregulated the expression of Bcl-2, and downregulated the expression of Bax and Caspase-3 in the model mice.

DISCUSSION AND CONCLUSION

ZYD has anti-inflammatory and anti-apoptotic effects on SS, which provides a theoretical basis for the treatment of SS with ZYD.

Treatment with a Lactococcus lactis that chromosomally express E. coli cfaI mitigates salivary flow loss in a Sjögren's syndrome-like disease

Sjögren's Syndrome (SjS) results in loss of salivary and lacrimal gland excretion due to an autoimmune attack on these secretory glands. Conventional SjS treatments address the symptoms, but not the cause of disease. Recognizing this deficit of treatments to reverse SjS disease, studies were pursued using the fimbriae from enterotoxigenic E. coli, colonization factor antigen I (CFA/I), which has anti-inflammatory properties. To determine if CFA/I fimbriae could attenuate SjS-like disease in C57BL/6.NOD-Aec1Aec2 (SjS) females, the Lactococcus lactis (LL) 301 strain was developed to chromosomally express the cfaI operon. Western blot analysis confirmed CFA/I protein expression, and this was tested in SjS females at different stages of disease. Repeated dosing with LL 301 proved effective in mitigating salivary flow loss and in reducing anti-nuclear antibodies (ANA) and inflammation in the submandibular glands (SMGs) in SjS females and in restoring salivary flow in diseased mice. LL 301 treatment reduced proinflammatory cytokine production with concomitant increases in TGF-β+ CD25+ CD4+ T cells. Moreover, LL 301 treatment reduced draining lymph and SMG follicular T helper (Tfh) cell levels and proinflammatory cytokines, IFN-γ, IL-6, IL-17, and IL-21. Such evidence points to the therapeutic capacity of CFA/I protein to suppress SjS disease and to have restorative properties in combating autoimmune disease.

Predictors for future development of systemic lupus erythematosus in Korean Sjögren's syndrome patients

OBJECTIVE

This study determined the impact of demographic factors, clinical manifestations, disease activity, and serological tests at baseline on future SLE development in Sjögren's syndrome (SS) patients.

METHODS

This retrospective study assessed 1,082 SS patients without other autoimmune diseases at baseline who visited our hospital between January 2012 and March 2021. We analyzed demographic features, extra-glandular manifestations (EGMs), clinical indices, and laboratory values at baseline between the two groups divided per future SLE development (SS/SLE group vs SS group). The probability and predictors of SLE development in SS patients were estimated using the Kaplan-Meier method and Cox proportional hazards models.

RESULTS

The median follow-up duration was 1083.5 days. Forty-nine patients (4.5%) developed SLE that met the 2012 Systemic Lupus International Collaborating Clinics or 2019 EULAR/ACR classification criteria. The baseline EULAR SS disease activity index (ESSDAI) score was significantly higher in the SS/SLE group (p < .001). The SS/SLE group had more lymphadenopathy and renal involvement (p = .015 and p = .017, respectively). Shorter SS disease duration (<3 years) (hazard ratio [HR] = 2.12, p = .0328), high ESSDAI (HR = 8.24, p < .0001), leukopenia (HR = 4.17, p = .0005), thrombocytopenia (HR = 3.38, p = .0059), hypocomplementemia (HR = 29.06, p<.0001), and positive for anti-dsDNA (HR = 13.70, p < .0001), anti-ribonucleoprotein (RNP) (HR = 3.82, p = .0027), and anti-ribosomal P (HR = 6.70, p = .0002) at baseline were SLE development predictors in SS patients.

CONCLUSION

Shorter disease duration and higher disease activity of SS at baseline may be risk factors for future SLE development. Serologic predictors of SLE development are hypocomplementemia, leukopenia, thrombocytopenia, and positivity for anti-dsDNA, anti-RNP, and anti-ribosomal P antibodies. If the above factors are observed, close monitoring will be necessary during the follow-up period, considering the possibility of future SLE development.

Role of artesunate in autoimmune diseases and signaling pathways

Artesunate (ART) is a derivative of artemisinin. Compared with artemisinin, ART has excellent water solubility, high stability and oral bioavailability. In this review, the application of ART in classic autoimmune diseases such as rheumatoid arthritis, systemic lupus erythematosus and ulcerative colitis is summarized. ART exhibited similar or even better efficacy than other highly effective immunosuppressive agents, such as methotrexate and cyclophosphamide. In addition, ART exerts its pharmacological effects mainly by inhibiting the production of inflammatory factors, reactive oxygen species, autoantibodies and the migration of cells to reduce damage to tissues or organs. Moreover, ART widely affected the NF-κB, PI3K/Akt, JAK/STAT and MAPK pathways to exert pharmacological effects.

Development and initial validation of the Comprehensive Geriatric Oral Health Assessment Tool

OBJECTIVES

Improving the oral health of the elderly is crucial to improving their general health and quality of life. To reach this goal, it is necessary to start with a comprehensive oral health assessment and a detailed treatment plan. The aim of this study was, therefore, to develop a comprehensive Oral Health Assessment Tool for the geriatric population.

MATERIAL AND METHODS

Following a panel of experts' consultation, a clinical form and a self-assessment questionnaire were developed, encompassing eight domains: dental caries, periodontal diseases, partial and complete edentulism, oral soft tissue lesions, occlusion, xerostomia, temporomandibular joints, and oral or oral prostheses hygiene. Subsequently, a pilot study was conducted to appraise the clinical form and questionnaire involving 84 residents of an Iranian nursing home. After securing ethics approval, both the qualitative and quantitative aspects of the self-assessment questions' validity and reliability were assessed, and specificity and sensitivity were calculated.

RESULTS

The mean age of the participants was 69.8 (±4.1) years, and 86% had less than 12 years of education. The questions regarding the number of remaining teeth and the number of decayed teeth had the highest sensitivity (97% and 88%), respectively. Questions regarding the presence of periodontitis and gingivitis had the highest specificity (both 100%).

CONCLUSIONS

A Comprehensive Geriatric Oral Health Assessment Tool has been developed and its validity and reliability evaluated in a pilot study. It should now be further evaluated in larger studies.

Association of Inflammatory Cytokine Levels with Extra Glandular Manifestations, Fatigue, and Disease Activity in Primary Sjögren's Syndrome in Saudi Patients: A Cross-Sectional Study

BACKGROUND

Primary Sjögren's syndrome (pSS) is an autoimmune disease that can cause fatigue and extraglandular manifestations (EGMs). pSS is associated with cytokine network dysregulation, which may be related to the immune-mediated destruction of exocrine glands.

OBJECTIVE

We determined cytokine levels and their relationship to EGMs, the European League Against Rheumatism (EULAR) Sjögren's syndrome disease activity index (ESSDAI), and fatigue in Saudi patients with pSS.

METHODS

This study was a cross-sectional, single-center study. We included forty-one patients and 71 controls. Serum samples were collected from random healthy people and pSS patients who were followed in the rheumatology and pulmonary clinics of King Saud University Medical City in Riyadh, Saudi Arabia. Levels of the frequently studied cytokines were measured using Luminex xMAP technology. Each ESSDAI score and EGM were recorded, and the Arabic version of the fatigue severity scale (FSS) was applied to assess fatigue. The main outcome measures were cytokine levels in pSS Saudi patients using/not using immune-suppressive medications (ISMs).

RESULTS

Thirty-six (87.8%) patients had one or more EGMs, and the mean ESSDAI score was 9.95 ± 7.73. There was a significant decrease in TNFα and IL-21 levels in the pSS group compared to those in the control group (p = 0.034 and p < 0.001, respectively), whereas IL-12 levels were significantly elevated in the pSS group (p = 0.002). Cytokine levels in patients who used ISMs were the same as those in patients who did not use medications. Decreased IL-1β (p = 0.014), IL-2 (p = 0.035), IL-6 (p = 0.014), and IL-35 (p = 0.010) levels were observed in patients who had EGMs. Patients who had low disease activity exhibited low IL-10 (p = 0.018) and high IFN-α (p = 0.049), IFN-β (p = 0.049), IL-1β (p = 0.006), and IL-35 (p = 0.032) levels compared to patients with high disease activity. A negative association between a positive fatigue score and IL-1β (p = 0.010), IL-2 (p = 0.037), IFN-α (p = 0.025), TNFα (p = 0.030), IL-17 (p = 0.029), IL-12 (p = 0.046), and IL-21 (p = 0.005) levels was found.

CONCLUSIONS

Cytokine profiles correlate with EGMs, ESSDAI, and fatigue. Patients with controlled disease activity have a normal cytokine profile that is similar to that of controls.

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.

Iguratimod suppresses Tfh cell differentiation in primary Sjögren's syndrome patients through inhibiting Akt/mTOR/STAT3 signaling

BACKGROUND

Iguratimod (IGU) reduces hypergammaglobulinemia and disease activity in pSS (primary Sjögren's syndrome) patients. However, the therapeutical mechanism of IGU for pSS remains largely unknown. This study aimed to investigate the regulation of Tfh cell differentiation by IGU in pSS patients.

METHODS

We prospectively enrolled 13 pSS patients treated with IGU for 3 months and examined circulating T cell and B cell subsets by flow cytometry. We measured Tfh cell differentiation treated by IGU in pSS patients and healthy controls. Transcriptome analysis combined with molecular docking were employed to identify potential therapeutical targets of IGU, which were verified by Western blot and Tfh cell differentiation.

RESULTS

Tfh, plasmablast, and plasma cells were suppressed by IGU treatment at 1 and 3 months. Tfh cell differentiation and function were significant inhibited by IGU in pSS patients and healthy controls in vitro. Pyruvate dehydrogenase kinase 1 (PDK1) was identified as a target of IGU during Tfh cell differentiation, and the downstream Akt phosphorylation was attenuated by IGU. Moreover, the activity of mTORC1 and phosphorylation of STAT3 were suppressed by IGU, with downregulation of BCL6 and upregulation of PRDM1. Finally, Akt activator restored IGU-suppressed Tfh cell differentiation.

CONCLUSIONS

IGU suppresses Tfh cell differentiation in pSS patients through interacting with PDK1 and suppressing Akt-mTOR-STAT3 signaling.

Interferon-γ induces salivary gland epithelial cell ferroptosis in Sjogren's syndrome via JAK/STAT1-mediated inhibition of system Xc. Free Radic Biol Med 2023;205:116-128. [PMID: 37286044 DOI: 10.1016/j.freeradbiomed.2023.05.027]

The elevated level of interferon-γ (IFN-γ) in Sjogren's syndrome (SS) triggers salivary gland epithelial cells (SGEC) death. However, the underlying mechanisms of IFN-γ-induced SGEC death modes are still not fully elucidated. We found that IFN-γ triggers SGEC ferroptosis via Janus kinase/signal transducer and activator of transcription 1 (JAK/STAT1)-mediated inhibition of cystine-glutamate exchanger (System Xc-). Transcriptome analysis revealed that ferroptosis-related markers are differentially expressed in SS human and mouse salivary glands with distinct upregulation of IFN-γ and downregulation of glutathione peroxidase 4 (GPX4) and aquaporin 5 (AQP5). Inducing ferroptosis or IFN-γ treatment in the Institute of cancer research (ICR) mice aggravated and inhibition of ferroptosis or IFN-γ signaling in SS model non-obese diabetic (NOD) mice alleviated ferroptosis in the salivary gland and SS symptoms. IFN-γ activated STAT1 phosphorylation and downregulated system Xc- components solute carrier family 3 member 2 (SLC3A2), glutathione, and GPX4 thereby triggering ferroptosis in SGEC. JAK or STAT1 inhibition in SGEC rescued IFN-γ-downregulated SLC3A2 and GPX4 as well as IFN-γ-induced cell death. Our results indicate the role of ferroptosis in SS-related death of SGEC and SS pathogenicity.

Effect of adipose tissue-derived stem cells therapy on clinical response in patients with primary Sjogren's syndrome

The purpose of this trial was to clinically assess the effect and safety of Adipose Tissue-derived Stem Cells (ADSCs) treatment on primary Sjogren's Syndrome (pSS). In this 6-month randomized, triple-blind, placebo-controlled clinical trial, pSS patients were randomly assigned to two groups. After demographic characteristics and clinical examination were achieved, local injection of ADSCs into bilateral glands was performed with patients in ADSCs group (n = 35) and placebo solution was used for another group (n = 39) at three time points. Patients were followed up at 1-, 3- and 6-month. At each visit, studies of clinical and laboratory outcomes, as well as subjective symptoms, were conducted. A total of 74 subjects who met the including criteria were allocated in two groups and eventually 64 subjects (86.5%) completed the treatments and the follow-up assessments. Secretion of salivary and lachrymal glands were significantly improved in 3-month (P < 0.05). A great improvement of European League Against Rheumatism Sjögren's Syndrome Disease Activity Index (ESSDAI) was found after ADSCs treatment with intergroup comparison from baseline to follow-up (P < 0.05). There is also a significant difference of European Alliance of Associations for Rheumatology SS Patient Reported Index (ESSPRI) between the two groups in the follow-up (P < 0.05). A significant abatement of IgG, IgM, C3, C4 and ESR between two groups was observed in part of follow-up time points (P < 0.05). The ADSCs therapy can provide relief of oral and eye's dryness in our trial in a short time and has potential improvement of subjective and systemic syndromes of pSS.

Thymosin β4 Alleviates Autoimmune Dacryoadenitis via Suppressing Th17 Cell Response

Purpose

We investigated the therapeutic effect of recombinant thymosin β4 (rTβ4) on rabbit autoimmune dacryoadenitis, an animal model of SS dry eye, and explore its mechanisms.

Methods

Rabbits were treated topically with rTβ4 or PBS solution after disease onset for 28 days, and clinical scores were determined by assessing tear secretion, break-up time, fluorescein, hematoxylin and eosin staining, and periodic acid-Schiff. The expression of inflammatory mediators in the lacrimal glands were measured by real-time PCR. The expression of T helper 17 (Th17) cell-related transcription factors and cytokines were detected by real-time PCR and Western blotting. The molecular mechanism underlying the effects of rTβ4 on Th17 cell responses was investigated by Western blotting.

Results

Topical administration of rTβ4 after disease onset efficiently ameliorated the ocular surface inflammation and relieved the clinical symptoms. Further analysis revealed that rTβ4 treatment significantly inhibited the expression of Th17-related genes (RORC, IL-17A, IL-17F, IL-1R1, IL-23R, and granulocyte-macrophage colony-stimulating factor) and IL-17 protein in lacrimal glands, and meanwhile decreased the inflammatory mediators expression. Mechanistically, we demonstrated that rTβ4 repressed the phosphorylation of signal transducer and activator of transcription 3 (STAT3) both in vivo and in vitro. Activation of the STAT3 signal pathway by Colivelin partly reversed the suppressive effects of rTβ4 on IL-17 expression in vitro.

Conclusions

rTβ4 could alleviate ongoing autoimmune dacryoadenitis in rabbits, probably by suppressing Th17 response via partly affecting the STAT3 pathway. These data may provide a new insight into the therapeutic effect and mechanism of rTβ4 in dry eye associated with Sjögren's syndrome.

The Spectrum of Extraglandular Manifestations in Primary Sjögren's Syndrome

Extraglandular manifestations (EGMs) in primary Sjogren's syndrome (pSS) represent the clinical expression of the systemic involvement in this disease. EGMs are characterized by a wide heterogeneity; virtually any organ or system can be affected, with various degrees of dysfunction. The existing gaps of knowledge in this complex domain of extraglandular extension in pSS need to be overcome in order to increase the diagnostic accuracy of EGMs in pSS. The timely identification of EGMs, as early as from subclinical stages, can be facilitated using highly specific biomarkers, thus preventing decompensated disease and severe complications. To date, there is no general consensus on the diagnostic criteria for the wide range of extraglandular involvement in pSS, which associates important underdiagnosing of EGMs, subsequent undertreatment and progression to severe organ dysfunction in these patients. This review article presents the most recent basic and clinical science research conducted to investigate pathogenic mechanisms leading to EGMs in pSS patients. In addition, it presents the current diagnostic and treatment recommendations and the trends for future therapeutic strategies based on personalized treatment, as well as the latest research in the field of diagnostic and prognostic biomarkers for extraglandular involvement in pSS.

Increased METTL3 expression and m6A RNA methylation may contribute to the development of dry eye in primary Sjögren's syndrome

BACKGROUND

Primary Sjögren's syndrome (pSS) is a chronic autoimmune disorder defined by xerostomia and keratoconjunctivitis sicca, and its etiology remains unknown. N6-methyladenosine (m⁶A) is the predominant posttranscriptional modification in eukaryotic mRNAs and is dynamically regulated by m⁶A regulators. Dysregulation of m⁶A modification is closely associated with several autoimmune disorders, but the role of m⁶A modification in pSS remains unknown. This study investigated the potential role of m⁶A and m⁶A-related regulators in pSS patients with dry eye.

METHODS

This cross-sectional study included forty-eight pSS patients with dry eye and forty healthy controls (HCs). Peripheral blood mononuclear cells (PBMCs) were isolated, and the level of m⁶A in total RNA was measured. The expression of m⁶A regulators was determined utilizing real-time PCR and western blotting. The serological indicators detected included autoantibodies, immunoglobulins (Igs), complement factors (Cs), and inflammatory indicators. Dry eye symptoms and signs were measured, including the ocular surface disease index, Schirmer's test (ST), corneal fluorescein staining score (CFS), and tear break-up time. Spearman's correlation coefficient was employed to assess the associations of m⁶A and m⁶A-related regulator expression with clinical characteristics.

RESULTS

The expression level of m⁶A was markedly increased in the PBMCs of pSS patients with dry eye compared to HCs (P _value<0.001). The relative mRNA and protein expression levels of the m⁶A regulators methyltransferase-like 3 (METTL3) and YT521-B homology domains 1 were markedly elevated in pSS patients with dry eye (both P _value<0.01). The m⁶A RNA level was found to be positively related to METTL3 expression in pSS patients (r = 0.793, P _value<0.001). Both the m⁶A RNA level and METTL3 mRNA expression correlated with the anti-SSB antibody, IgG, ST, and CFS (all P _values < 0.05). The m⁶A RNA level was associated with C4 (r = -0.432, P _value = 0.002), while METTL3 mRNA expression was associated with C3 (r = -0.313, P _value = 0.030).

CONCLUSIONS

Our work revealed that the upregulation of m⁶A and METTL3 was associated with the performance of serological indicators and dry eye signs in pSS patients with dry eye. METTL3 may contribute to the pathogenesis of dry eye related to pSS.

Development and verification of a combined diagnostic model for primary Sjögren's syndrome by integrated bioinformatics analysis and machine learning

Primary Sjögren's syndrome (pSS) is a chronic, systemic autoimmune disease mostly affecting the exocrine glands. This debilitating condition is complex and specific treatments remain unavailable. There is a need for the development of novel diagnostic models for early screening. Four gene profiling datasets were downloaded from the Gene Expression Omnibus database. The 'limma' software package was used to identify differentially expressed genes (DEGs). A random forest-supervised classification algorithm was used to screen disease-specific genes, and three machine learning algorithms, including artificial neural networks (ANN), random forest (RF), and support vector machines (SVM), were used to build a pSS diagnostic model. The performance of the model was measured using its area under the receiver operating characteristic curve. Immune cell infiltration was investigated using the CIBERSORT algorithm. A total of 96 DEGs were identified. By utilizing a RF classifier, a set of 14 signature genes that are pivotal in transcription regulation and disease progression in pSS were identified. Through the utilization of training and testing datasets, diagnostic models for pSS were successfully designed using ANN, RF, and SVM, resulting in AUCs of 0.972, 1.00, and 0.9742, respectively. The validation set yielded AUCs of 0.766, 0.8321, and 0.8223. It was the RF model that produced the best prediction performance out of the three models tested. As a result, an early predictive model for pSS was successfully developed with high diagnostic performance, providing a valuable resource for the screening and early diagnosis of pSS.

The aryl hydrocarbon receptor in immune regulation and autoimmune pathogenesis

As a ligand-activated transcription factor, the aryl hydrocarbon receptor (AhR) is activated by structurally diverse ligands derived from the environment, diet, microorganisms, and metabolic activity. Recent studies have demonstrated that AhR plays a key role in modulating both innate and adaptive immune responses. Moreover, AhR regulates innate immune and lymphoid cell differentiation and function, which is involved in autoimmune pathogenesis. In this review, we discuss recent advances in understanding the mechanism of activation of AhR and its mediated functional regulation in various innate immune and lymphoid cell populations, as well as the immune-regulatory effect of AhR in the development of autoimmune diseases. In addition, we highlight the identification of AhR agonists and antagonists that may serve as potential therapeutic targets for the treatment of autoimmune disorders.

PCSK3 Overexpression in Sjögren's Syndrome Patients May Be Regulated by rs4932178 SNP in Its Promoter Region and Correlates with IFN-γ Gene Expression

BACKGROUND

The PCSK3 gene encodes for the protease enzyme Furin, which promotes proteolytic maturation of important regulators of the immune response, and also enhances the secretion of interferon-γ (IFN). Several studies have suggested its possible involvement in the pathogenesis of chronic inflammatory diseases.

METHODS

We investigated the PCSK3 gene expression level in peripheral blood mononuclear cells isolated from Sjögren's Syndrome (SS) patients and healthy controls and we evaluated a possible correlation with IFN-γ gene expression. Moreover, we also explored the variability of two PCSK3 genetic polymorphisms (rs4932178 and rs4702) to evaluate a possible association between these polymorphisms and the expression levels of this gene.

RESULTS

We observed, by RT-qPCR, that the PCSK3 expression level was significantly higher in SS patients compared to the controls (p = 0.028), and we confirmed a positive correlation between PCSK3 and IFN-γ expression levels (p < 0.001). Moreover, we reported that the variant homozygous genotype of rs4932178 SNP is associated with a higher expression of the PCSK3 gene (p = 0.038) and with the SS susceptibility (p = 0.016).

CONCLUSIONS

Our data suggest that Furin could play a role in SS development, also promoting IFN-γ secretion.

TFOS lifestyle: Impact of societal challenges on the ocular surface

Societal factors associated with ocular surface diseases were mapped using a framework to characterize the relationship between the individual, their health and environment. The impact of the COVID-19 pandemic and mitigating factors on ocular surface diseases were considered in a systematic review. Age and sex effects were generally well-characterized for inflammatory, infectious, autoimmune and trauma-related conditions. Sex and gender, through biological, socio-economic, and cultural factors impact the prevalence and severity of disease, access to, and use of, care. Genetic factors, race, smoking and co-morbidities are generally well characterized, with interdependencies with geographical, employment and socioeconomic factors. Living and working conditions include employment, education, water and sanitation, poverty and socioeconomic class. Employment type and hobbies are associated with eye trauma and burns. Regional, global socio-economic, cultural and environmental conditions, include remoteness, geography, seasonality, availability of and access to services. Violence associated with war, acid attacks and domestic violence are associated with traumatic injuries. The impacts of conflict, pandemic and climate are exacerbated by decreased food security, access to health services and workers. Digital technology can impact diseases through physical and mental health effects and access to health information and services. The COVID-19 pandemic and related mitigating strategies are mostly associated with an increased risk of developing new or worsening existing ocular surface diseases. Societal factors impact the type and severity of ocular surface diseases, although there is considerable interdependence between factors. The overlay of the digital environment, natural disasters, conflict and the pandemic have modified access to services in some regions.

FcγRIIIA activation-mediated up-regulation of glycolysis alters MDSCs modulation in CD4+ T cell subsets of Sjögren syndrome

Our and other researchers' previous studies found that myeloid-derived suppressor cells (MDSCs) were increased, and these MDSCs, supposed to play immunosuppressive roles, showed significant pro-inflammatory effects in Sjögren's syndrome (SS). However, the key factors and potential mechanisms leading MDSCs to be inflammatory remain unclear. In this study, we found that MDSCs from SS patients were positively correlated with the percentages of Th17 cells, disease activity and serum autoantibodies, and showed higher levels of Fc gamma receptor (FcγR) IIIA and glycolysis. Most importantly, SS MDSCs or heat-aggregated IgG (HAIG)-treated MDSCs down-regulated Th1/Th2 ratio and up-regulated Th17/Treg ratio, which could be obviously rescued by IgG monomer or glycolysis inhibitor 2-DG. As well, the levels of FcγRIV and glycolysis in MDSCs and the ratio of Th17/Treg were increased, and the ratio of Th1/Th2 was decreased in SS-like NOD mice. Our study indicated that MDSCs showed pro-inflammatory phenotypes by disturbing CD4⁺ T-cell balances in SS. The pro-inflammatory effects of MDSCs might be directly linked to the enhanced glycolysis mediated by FcγRIIIA activation.

TOX promotes follicular helper T cell differentiation in patients with primary Sjögren's syndrome

OBJECTIVES

Whether naive CD4+ T cells are dysregulated and associated with the overactivation of CD4+ T cells in primary SS (pSS) remains unclear. We aimed to explore the role and underlying mechanism of naive CD4+ T cells in pSS.

METHODS

We examined the activation, proliferation and differentiation of naive CD4+ T cells from pSS patients and healthy controls. Differentially expressed genes were identified using RNA sequencing, and were overexpressed or silenced to determine the gene regulating follicular helper T (Tfh) cells. Assay for transposase-accessible chromatin with high-throughput sequencing (ATAC-seq) with chromatin immunoprecipitation with high-throughput sequencing (ChIP-seq) was performed to explore the epigenetic mechanism. Naive CD4+ T cells were treated with pSS-related cytokines to explore the upstream signalling pathway.

RESULTS

pSS naive CD4+ T cells had higher potentials of activation, proliferation and differentiation towards Tfh cells. Thymocyte selection-associated high mobility group box protein (TOX) was upregulated in pSS naive CD4+ T cells and promoted T cell activation and Tfh cell polarization. TOX silencing in pSS naive CD4+ T cells downregulated B cell lymphoma 6 (BCL6) expression and altered levels of multiple Tfh-associated genes. ChIP-seq analysis implied that TOX bound to the BCL6 locus, where there were accessible regions found by ATAC-seq. IFN-α induced TOX overexpression, which was attenuated by Janus kinase (JAK) and signal transducer and activator of transcription 1 (STAT1) inhibitors.

CONCLUSION

Our data suggest that TOX in pSS naive CD4+ T cells is upregulated, which facilitates Tfh cell differentiation. Mechanistically, IFN-α induces TOX overexpression in naive CD4+ T cells through JAK-STAT1 signalling and TOX regulates BCL6 expression. Therefore, IFN-α-JAK-STAT1 signalling and TOX might be potential therapeutic targets in pSS.

Development of Clinical Decision Models for the Prediction of Systemic Lupus Erythematosus and Sjogren's Syndrome Overlap

OBJECTIVE

To explore the clinical features of patients with systemic lupus erythematosus and Sjögren's syndrome overlap (SLE-SS) compared to concurrent SLE or primary SS (pSS) patients, we utilized a predictive machine learning-based tool to study SLE-SS.

METHODS

This study included SLE, pSS, and SLE-SS patients hospitalized at Nanjing Drum Hospital from December 2018 to December 2020. To compare SLE versus SLE-SS patients, the patients were randomly assigned to discovery cohorts or validation cohorts by a computer program at a ratio of 7:3. To compare SS versus SLE-SS patients, computer programs were used to randomly assign patients to the discovery cohort or the validation cohort at a ratio of 7:3. In the discovery cohort, the best predictive features were determined using a least absolute shrinkage and selection operator (LASSO) logistic regression model among the candidate clinical and laboratory parameters. Based on these factors, the SLE-SS prediction tools were constructed and visualized as a nomogram. The results were validated in a validation cohort, and AUC, calibration plots, and decision curve analysis were used to assess the discrimination, calibration, and clinical utility of the predictive models.

RESULTS

This study of SLE versus SLE-SS included 290 patients, divided into a discovery cohort (n = 203) and a validation cohort (n = 87). The five best characteristics were selected by LASSO logistic regression in the discovery cohort of SLE versus SLE-SS and were used to construct the predictive tool, including dry mouth, dry eye, anti-Ro52 positive, anti-SSB positive, and RF positive. This study of SS versus SLE-SS included 266 patients, divided into a discovery cohort (n = 187) and a validation cohort (n = 79). In the discovery cohort of SS versus SLE-SS, by using LASSO logistic regression, the eleven best features were selected to build the predictive tool, which included age at diagnosis (years), fever, dry mouth, photosensitivity, skin lesions, arthritis, proteinuria, hematuria, hypoalbuminemia, anti-dsDNA positive, and anti-Sm positive. The prediction model showed good discrimination, good calibration, and fair clinical usefulness in the discovery cohort. The results were validated in a validation cohort of patients.

CONCLUSION

The models are simple and accessible predictors, with good discrimination and calibration, and can be used as a routine tool to screen for SLE-SS.

Differential diagnosis of systemic lupus erythematosus and Sjögren's syndrome using machine learning and multi-omics data

Systemic lupus erythematosus and primary Sjogren's syndrome are complex systemic autoimmune diseases that are often misdiagnosed. In this article, we demonstrate the potential of machine learning to perform differential diagnosis of these similar pathologies using gene expression and methylation data from 651 individuals. Furthermore, we analyzed the impact of the heterogeneity of these diseases on the performance of the predictive models, discovering that patients assigned to a specific molecular cluster are misclassified more often and affect to the overall performance of the predictive models. In addition, we found that the samples characterized by a high interferon activity are the ones predicted with more accuracy, followed by the samples with high inflammatory activity. Finally, we identified a group of biomarkers that improve the predictions compared to using the whole data and we validated them with external studies from other tissues and technological platforms.