New developments in Sjogren's syndrome

A novel enzyme-linked immunosorbent assay tool to evaluate plasma soluble CD226 in primary Sjögren's syndrome

CD226 is an important receptor constitutively expressed on most immune cells, performing vital functions in immune responses. However, the levels of soluble CD226 (sCD226) and its roles in primary Sjögren syndrome (pSS) remain unclear. In this study, we developed two novel mouse anti-human CD226 monoclonal antibodies (mAbs) and established a novel sandwich enzyme-linked immunosorbent assay (ELISA) system, which proved to be highly effective in detecting human sCD226. We then analyzed the expression of sCD226 in the plasma of pSS patients. Our results showed that the levels of sCD226 were significantly lower in patients with pSS compared to healthy controls. The significant decline was also observed in active group and the patients with high levels of IgG or positive anti-SSB. Additionally, reduced sCD226 was found to be negatively correlated with the disease activity of pSS and several clinical manifestations, including arthralgia, fatigue, decayed tooth and interstitial lung disease (ILD). Furthermore, receiver operator characteristics (ROC) curve analysis showed that sCD226 displayed outstanding capacity in discriminating pSS and predicting the disease activity. Altogether, plasma sCD226 emerges as a promising candidate for diagnostic markers in the context of pSS.

MiR-23b-3p alleviates Sjögren's syndrome by targeting SOX6 and inhibiting the NF-κB signaling

OBJECTIVE

MicroRNA-23b-3p has been demonstrated to act as a safeguard against several autoimmune diseases. However, its role in Sjögren's syndrome (SS) remains unclear.

METHODS

In order to investigate its role in SS, we administered agomiR-23b-3p or agomiR-NC to non-obese diabetic (NOD) mice via tail vein weekly for 6 weeks. The study examined the saliva flow rate, histological changes in submandibular glands, and levels of autoantibodies. Additionally, the levels of several cytokines, cell apoptosis, and NF-κB signaling were evaluated. The protective effect of miR-23b-3p was confirmed in a cell model.

RESULTS

The results demonstrated that miR-23b-3p overexpression improved salivary flow rates, inhibited lymphocyte infiltration, reduced cytokine levels, and suppressed cell apoptosis in NOD mice. Moreover, NF-κB signaling was inactivated following miR-23b-3p overexpression. In a cellular model of SS, overexpression of miR-23b-3p protected submandibular gland epithelial cells exposed to IFN-γ against apoptosis and inflammation by targeting SOX6.

CONCLUSIONS

The study concludes that miR-23b-3p alleviates SS by targeting SOX6 and inhibiting the NF-κB signaling pathway. The miR-23b-3p/SOX6 axis represents a promising avenue for the development of novel therapeutic strategies for SS.

Safety and efficacy of subcutaneous iscalimab (CFZ533) in two distinct populations of patients with Sjögren's disease (TWINSS): week 24 results of a randomised, double-blind, placebo-controlled, phase 2b dose-ranging study

BACKGROUND

Sjögren's disease is a chronic autoimmune disease with an unmet need for targeted therapies. The aim of the TWINSS study is to evaluate the safety and efficacy of iscalimab, a monoclonal antibody against CD40, in patients with active Sjögren's disease.

METHODS

This randomised, double-blind, placebo-controlled, phase 2b study, conducted at 71 sites in 23 countries, enrolled patients aged 18 years or older fulfilling the American College of Rheumatology/European Alliance of Associations for Rheumatology (EULAR) 2016 criteria. In the dose-ranging cohort 1, patients with a EULAR Sjögren's Syndrome Disease Activity Index (ESSDAI) score of 5 or higher and a EULAR Sjögren's Syndrome Patient Reported Index (ESSPRI) score of 5 or higher were randomly assigned (1:1:1:1) to subcutaneous iscalimab 150 mg, 300 mg, 600 mg, or placebo. In the proof-of-concept cohort 2, patients with an ESSDAI score of less than 5, ESSPRI (dryness or fatigue) score of 5 or higher, and Impact of Dry Eye on Everyday Life score of 30 or higher were randomly assigned (1:1) to iscalimab 600 mg or placebo. The sponsor, investigator, site personnel, and patients were masked to the treatment assignment. The primary objectives were to demonstrate a dose-response relationship of iscalimab based on the change in ESSDAI from baseline to week 24 in cohort 1 by Multiple Comparison Procedure-Modelling (MCP-Mod), and to assess the effect of iscalimab 600 mg on ESSPRI at week 24 in cohort 2. All the efficacy analyses included all patients who were randomly assigned, and safety analysis included all patients who received at least one dose of study drug. This trial is registered with ClinicalTrials.gov (NCT03905525), and is complete.

FINDINGS

Between Oct 1, 2019, and Feb 28, 2022, 460 patients were screened; 173 patients were assigned to cohort 1 (44 to iscalimab 150 mg, 43 to 300 mg, 43 to 600 mg, and 43 to placebo) and 100 to cohort 2 (50 to each group). In cohort 1, the MCP step showed a significant dose-response relationship for placebo-adjusted ESSDAI change from baseline in one of four models (Linlog model, one-sided p=0·0041). ESSDAI decreased from baseline to week 24 with all three doses of iscalimab; 150 mg and 600 mg doses showed statistically significant improvement (placebo-adjusted least squares [LS] mean difference -3·0 [95% CI -4·9 to -1·1]; p=0·0025 for 150 mg and -2·9 [-4·9 to -1·0]; p=0·0037 for 600 mg). In cohort 2, ESSPRI showed a trend towards improvement with iscalimab 600 mg (placebo-adjusted LS mean change from baseline -0·57 points [95% CI -1·30 to 0·15]; p=0·12). Serious adverse events were reported in nine patients in cohort 1 (one [2%] of 43 in the placebo group, one [2%] of 44 in the iscalimab 150 mg group, three [7%] of 42 in the 300 mg group, four [9%] of 44 in the 600 mg group) and four patients in cohort 2 (two [4%] of 50 in each group). No deaths occurred over the 24-week period.

INTERPRETATION

The study met the primary objective of demonstrating a significant dose-response relationship with iscalimab in terms of disease activity at week 24. Iscalimab was well tolerated and showed initial clinical benefit over placebo in two distinct populations of patients with Sjögren's disease, to be confirmed in larger trials.

FUNDING

Novartis Pharma.

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.

Weighted Gene Co-expression Network Analysis and Machine Learning Validation for Identifying Major Genes Related to Sjogren's Syndrome

Sjogren's syndrome (SS) is an autoimmune disorder characterized by dry mouth and dry eyes. Its pathogenic mechanism is currently unclear. This study aims to integrate weighted gene co-expression network analysis (WGCNA) and machine learning to identify key genes associated with SS. We downloaded 3 publicly available datasets from the GEO database comprising the gene expression data of 231 SS and 78 control cases, including GSE84844, GSE48378 and GSE51092, and carried out WGCNA to elucidate differences in the abundant genes. Candidate biomarkers for SS were then identified using a LASSO regression model. Totally 6 machine-learning models were subsequently utilized for validating the biological significance of major genes according to their expression. Finally, immune cell infiltration of the SS tissue was assessed using the CIBERSORT algorithm. A weighted gene co-expression network was built to divide genes into 10 modules. Among them, blue and red modules were most closely associated with SS, and showed significant enrichment in type I interferon signaling, cellular response to type I interferon and response to virus, etc. Combined machine learning identified 5 hub genes, including OAS1, EIF2AK2, IFITM3, TOP2A and STAT1. Immune cell infiltration analysis showed that SS was associated with CD8+ T cell, CD4+ T cell, gamma delta T cell, NK cell and dendritic cell activation. WGCNA was combined with machine learning to uncover genes that may be involved in SS pathogenesis, which can be utilized for developing SS biomarkers and appropriate therapeutic targets.

A relatively rare traditional Chinese medicine pattern of primary Sjögren syndrome: A case report

RATIONALE

This report presents a unique case of a patient diagnosed with Primary Sjögren's syndrome and a relatively rare traditional Chinese medicine pattern, known as the combined cold and heat pattern and cold-dampness syndrome. The patient's condition was successfully managed using Chinese herbal medicine, specifically the modified Da-Chai-Hu decoction and Linggui Zhugan decoction.

PATIENT CONCERNS

A 56-year-old woman had chronic dry eye and mouth for over 10 years. She was initially managed with traditional Chinese herbal medicine (TCHM) prescriptions, including the Zengye decoction, but the therapeutic effects were unsatisfactory. As the disease progressed, she was diagnosed with an anxiety disorder due to symptoms of vexation and insomnia. Treatment with alprazolam and venlafaxine failed to alleviate these symptoms. Recently, her general condition gradually worsened, with symptoms including a bitter taste in her mouth, dizziness, hot flashes, chills, poor appetite, chest discomfort, and constipation.

DIAGNOSES

After a series of examinations, including a Schirmer test and labial gland biopsy, she was diagnosed with Sjögren's syndrome.

INTERVENTIONS

Despite regular treatment with pilocarpine, sodium hyaluronate eye drops, venlafaxine, and alprazolam, the dry mouth symptoms intensified. Consequently, she sought further intervention through the TCHM.

OUTCOMES

After 8 weeks of treatment with the modified Da-Chai-Hu decoction and Linggui Zhugan decoction, she reported a significant improvement in her dryness-related symptoms and sleep quality.

LESSONS

This case report demonstrates that TCHM can effectively treat Primary Sjögren's syndrome, and should be considered for broader applications. Furthermore, this underscores the importance of tailoring treatment formulas to patients by identifying their specific syndrome differentiation in a clinical setting.

Sjögren's syndrome and Parkinson's Disease: A bidirectional two-sample Mendelian randomization study

BACKGROUND

Previous observational studies have reported an association between Sjögren's syndrome (SS) and an increased risk of Parkinson's Disease (PD). However, the causal relationship between these conditions remains unclear. The objective of this study was to investigate the causal impact of SS on the risk of developing PD, utilizing the Mendelian randomization (MR) approach.

METHODS

We conducted a bidirectional MR analysis using publicly available genome-wide association studies (GWAS) data. The primary analysis utilized the inverse-variance weighted (IVW) method. Complementary methods, such as MR-Egger regression, weighted mode, weighted median, and MR-pleiotropy residual sum and outlier (MR-PRESSO), were utilized to identify and correct for the presence of horizontal pleiotropy.

RESULTS

The IVW MR analysis revealed no significant association between SS and PD (IVW: OR = 1.00, 95% CI = 0.94-1.07, P = 0.95). Likewise, the reverse MR analysis did not identify any significant causal relationship between PD and SS (IVW: OR = 0.98, 95% CI = 0.85-1.12, P = 0.73). The results from MR-Egger regression, weighted median, and weighted mode approaches were consistent with the IVW method. Sensitivity analyses suggested that horizontal pleiotropy is unlikely to introduce bias to the causal estimates.

CONCLUSION

This study does not provide evidence to support the assertion that SS has a conclusive impact on the risk of PD, which contradicts numerous existing observational reports. Further investigation is necessary to determine the possible mechanisms behind the associations observed in these observational studies.

What can patients tell us in Sjögren's syndrome?

In Sjögren's Syndrome (SS), clinical heterogeneity and discordance between disease activity measures and patient experience are key obstacles to effective therapeutic development. Patient reported outcome measures (PROMs) are useful tools for understanding the unmet needs from the patients' perspective and therefore they are key for the development of patient centric healthcare systems. Initial concern about the subjectivity of PROMs has given way to methodological rigour and clear guidance for the development of PROMs. To date, several studies of patient stratification using PROMs have identified similar symptom-based subgroups. There is evidence to suggest that these subgroups may represent different disease endotypes with differing responses to therapeutic interventions. Stratified medicine approaches, alongside sensitive outcome measures, have the potential to improve our understanding of SS pathobiology and therapeutic development. The inclusion of PROMs is important for the success of such approaches. In this review we discuss the opportunities of using PROMs in understanding the pathogenesis of and therapeutic development for SS.

Increased prevalence of hearing loss, tinnitus and sudden deafness among patients with Sjögren's syndrome

BACKGROUND

This study aimed to provide an updated prevalence of hearing loss, tinnitus, vertigo and sudden deafness on patients with Sjögren's syndrome and matched comparison patients.

METHODS

Data for this study were retrieved from the Taiwan Longitudinal Health Insurance Database and Taiwan's registered catastrophic illness dataset. This study included 20 266 patients with Sjögren's syndrome as the study group and 60 798 propensity score-matched comparison patients as the comparison group. We used multivariable logistic regressions to estimate the ORs and 95% CI for tinnitus, hearing loss, vertigo and sudden deafness among Sjögren's syndrome patients versus comparison patients.

RESULTS

χ2 tests showed there were statistically significant differences between the study group and comparison group in the prevalence of tinnitus (10.1% vs 6.3%, p<0.001), hearing loss (5.6% vs 3.3%, p<0.001), vertigo (4.6% vs 3.2%, p<0.001) and sudden deafness (0.8% vs 0.6%, p<0.001). Multiple logistic regression revealed that patients with Sjögren's syndrome had a greater tendency to have tinnitus (OR=1.690, 95% CI 1.596-1.788), sudden deafness (OR=1.368, 95% CI 1.137-1.647), hearing loss (OR=1.724, 95% CI 1.598-1.859) and vertigo (OR=1.473, 95% CI 1.360-1.597) relative to comparison patients after adjusting for age, income, geographic location, residential urbanisation level, diabetes, hypertension, hyperlipidaemia and rheumatoid arthritis.

CONCLUSIONS

We found higher prevalence of hearing loss, vertigo, tinnitus and sudden deafness among patients with Sjögren's syndrome relative to comparison patients. Findings may provide guidance to physicians in counselling patients with Sjögren's syndrome regarding a higher risk of hearing loss, tinnitus, sudden deafness and vertigo.

Genome-wide DNA methylation sequencing reveals epigenetic features and potential biomarkers of Sjögren syndrome

AIM

Sjögren syndrome (SS) is a slowly progressive, inflammatory, autoimmune disease. The aim of this study was to construct the DNA methylation profiles of whole blood of SS patients and healthy controls (HC), and to explore the role of differentially methylated genes in the pathogenesis of the disease.

METHODS

Whole-genome bisulfite sequencing was performed on three SS patients and four HC. The biological function of genes associated with differentially methylated regions (DMRs) was investigated using Gene Ontology functional analysis and Kyoto Encyclopedia of Genes and Genomes pathway analysis, using network-based key driver analysis (KDA) to find KDA genes. In clinical samples of SS patients and controls, the expression levels of KDA genes were validated by quantitative real-time polymerase chain reaction and immunohistochemical analysis. Moreover, the diagnostic value of KDA genes for SS was confirmed using receiver operating characteristic curves.

RESULTS

We identified 322 DMRs, annotated as 162 associated genes. Six genes were selected via the number of networks of KDA genes. Differential expression of genes such as human leukocyte antigen (HLA) class I, ADAR, and OAS2 was observed in patients' peripheral blood mononuclear cells and the minor salivary glands, which can be used as potential diagnostic biomarkers for SS.

CONCLUSION

Clinical sample validation suggested that HLA class I, ADAR, and OAS2 might play a role in the development of SS. Our study shows epigenetic regulatory mechanisms and potential disease markers associated with SS, which in turn will enable us to identify new therapeutic targets.

Increased prevalences of head and neck cancers in patients with Sjögren's syndrome

OBJECTIVE

This study aimed to investigate prevalences of head and neck cancers in patients with and those without Sjögren's syndrome using a population-based dataset.

METHODS

We retrieved sampled patients from Taiwan's Longitudinal Health Insurance Database. This study included 38 930 patients with Sjögren's syndrome and 155 720 propensity-score matched comparison patients without Sjögren's syndrome.

RESULTS

Chi-squared tests revealed that there was a statistically significant difference in the prevalences of head and neck cancers between patients with Sjögren's syndrome and comparison patients (1.77% vs. 1.22%, p < 0.001). The odds ratio for head and neck cancers for patients with Sjögren's syndrome relative to the comparison group was 1.452 (95% CI = 1.325-1.592).

CONCLUSIONS

Our study demonstrated that patients with Sjögren's syndrome face increased odds of head and neck cancers, encompassing several sites including the oral cavity, oropharynx, nasopharynx, and thyroid.

Research progress on the clinical application and mechanism of iguratimod in the treatment of autoimmune diseases and rheumatic diseases

Autoimmune diseases are affected by complex pathophysiology involving multiple cell types, cytokines, antibodies and mimicking factors. Different drugs are used to improve these autoimmune responses, including nonsteroidal anti-inflammatory drugs (NSAIDs), corticosteroids, antibodies, and small molecule drugs (DMARDs), which are prevalent clinically in the treatment of rheumatoid arthritis (RA), etc. However, low cost-effectiveness, reduced efficacy, adverse effects, and patient non-response are unattractive factors driving the development of new drugs such as iguratimod. As a new disease-modifying antirheumatic drug, iguratimod has pharmacological activities such as regulating autoimmune disorders, inflammatory cytokines, regulating immune cell activation, differentiation and proliferation, improving bone metabolism, and inhibiting fibrosis. In recent years, clinical studies have found that iguratimod is effective in the treatment of RA, SLE, IGG4-RD, Sjogren 's syndrome, ankylosing spondylitis, interstitial lung disease, and other autoimmune diseases and rheumatic diseases. The amount of basic and clinical research on other autoimmune diseases is also increasing. Therefore, this review systematically reviews the latest relevant literature in recent years, reviews the research results in recent years, and summarizes the research progress of iguratimod in the treatment of related diseases. This review highlights the role of iguratimod in the protection of autoimmune and rheumatic bone and related immune diseases. It is believed that iguratimod's unique mode of action and its favorable patient response compared to other DMARDs make it a suitable antirheumatic and bone protective agent in the future.

Association of Chronic Otitis Media with Sjogren's Syndrome: A Case-Control Study

There is a paucity of large-scale population-based study whether patients with Sjögren's syndrome are at higher risk of chronic otitis media. This study aimed to investigate the association of chronic otitis media with Sjögren's syndrome by utilizing the representative dataset of the Taiwanese population. We identified 9473 patients with chronic otitis media as cases. We used propensity score matching to select 28,419 controls. We used multiple logistic regression analysis to examine the association of chronic otitis media with prior Sjögren's syndrome after adjusting for age, sex, monthly income category, geographic location and urbanization level of the patient's residence, allergic rhinitis, chronic rhinosinusitis and tonsillitis and adenoiditis. Chi-square tests showed a statistically significant difference in Sjögren's syndrome between patients with chronic otitis media and controls (4.89% vs. 2.93%, p < 0.001). In addition, we found patients with chronic otitis media were more likely to have Sjögren's syndrome (OR = 1.698, 95% CI = 1.509~1.910) relative to controls after adjusting for age, income, geographic location, residential urbanization level, allergic rhinitis, chronic rhinosinusitis and tonsillitis and adenoiditis. We also found that of the male patients, patients with chronic otitis media had a greater tendency to Sjögren's syndrome than controls (adjusted OR = 1.982, 95% CI = 1.584~2.481). Similarly, a statistically significant association between Sjögren's syndrome and chronic otitis media remains in female sampled patients (adjusted OR = 1.604, 95% CI = 1.396~1.842). We found that patients with Sjögren's syndrome were associated with the occurrence of chronic otitis media. It may guide physicians as they counsel patients with Sjögren's syndrome on the possibility of chronic otitis media occurrence.

TLR7 agonism accelerates disease in a mouse model of primary Sjögren's syndrome and drives expansion of T-bet+ B cells

Primary Sjögren's syndrome (pSS) is a systemic autoimmune disease characterized by chronic inflammation of exocrine tissue, resulting in loss of tears and saliva. Patients also experience many extra-glandular disease manifestations. Treatment for pSS is palliative, and there are currently no treatments available that target disease etiology. Previous studies in our lab demonstrated that MyD88 is crucial for pSS pathogenesis in the NOD.B10Sn-H2^b (NOD.B10) pSS mouse model, although the way in which MyD88-dependent pathways become activated in disease remains unknown. Based on its importance in other autoimmune diseases, we hypothesized that TLR7 activation accelerates pSS pathogenesis. We administered the TLR7 agonist Imiquimod (Imq) or sham treatment to pre-disease NOD.B10 females for 6 weeks. Parallel experiments were performed in age and sex-matched C57BL/10 controls. Imq-treated pSS animals exhibited cervical lymphadenopathy, splenomegaly, and expansion of TLR7-expressing B cells. Robust lymphocytic infiltration of exocrine tissues, kidney and lung was observed in pSS mice following treatment with Imq. TLR7 agonism also induced salivary hypofunction in pSS mice, which is a hallmark of disease. Anti-nuclear autoantibodies, including Ro (SSA) and La (SSB) were increased in pSS mice following Imq administration. Cervical lymph nodes from Imq-treated NOD.B10 animals demonstrated an increase in the percentage of activated/memory CD4+ T cells. Finally, T-bet⁺ B cells were expanded in the spleens of Imq-treated pSS mice. Thus, activation of TLR7 accelerates local and systemic disease and promotes expansion of T-bet-expressing B cells in pSS.

Loss of ATG5 in KRT14+ cells leads to accumulated functional impairments of salivary glands via pyroptosis

Macroautophagy/autophagy is critically involved in the process of salivary gland (SG) diseases such as xerostomia, which has a serious impact on quality of life. KRT14⁺ progenitor cells are found to be the main progenitors for maintaining the ductal homeostasis of the submandibular SGs. In this study, we investigated the role of ATG5 in SG KRT14⁺ cells in mice and humans. Human labial salivary glands (LSG) from primary Sjogren's syndrome (pSS) and non-pSS patients (normal), and submandibular glands (SMG) from Atg5^flox/flox ; Krt14-Cre (cKO) mice were used. ATG5⁺ KRT14⁺ and p62⁺ KRT14⁺ cells were detected by immunofluorescence staining in LSG. TUNEL, immunofluorescence, immunohistochemistry, and western blot were performed to detect cell death in SMG. Saliva was collected in 12-week-old (12 W) and 32-week-old (32 W) mice, then the concentration of calcium and buffering capacity were detected to analyze the function of SG. We found that LSG from pSS patients showed increased p62 and decreased ATG5 in KRT14⁺ cells. We further revealed that in 32 W, (1) the function of salivary glands was significantly impaired in cKO mice, (2) cell death increased in cKO mice, but cl-Caspase 3 was not significantly changed, and (3) cleaved gasdermin D increased and was highly expressed in KRT14⁺ cells of cKO mice. After applying a pyroptosis inhibitor to 32 W mice, the reduced saliva flow rate was rescued. In addition, pyroptosis was also found in KRT14⁺ cells of pSS patients. Collectively, our results indicate that Atg5 deficiency would induce pyroptosis in mice SG, which could lead to functional impairments of SG.

Elevated CXCL13 in primary Sjögren's syndrome and its correlation with disease activity: a systematic review and meta-analysis

OBJECTIVES

CXCL13 levels have been reported to be elevated in primary Sjögren's syndrome (pSS) patients. This study investigated alterations involving the CXCL13/CXCR5 axis in pSS patients and explored the correlation between CXCL13 expression and disease severity.

METHODS

Six databases, including PubMed, Web of Science, Embase, Ovid Medline, China National Knowledge Infrastructure, and Wanfang, were searched. The quality of the included studies was assessed using the Newcastle-Ottawa Scale criteria. We analyzed CXCL13 concentrations in the serum and saliva of pSS patients and healthy controls (HCs). Next, we analyzed the percentage of CXCR5⁺CD4⁺ T cells among CD4⁺ T cells in pSS patients and HCs. Correlations between CXCL13 levels and serological, clinical, and histological parameters of patients were also assessed. Publication bias was determined using funnel plots and Egger's test.

RESULTS

Twenty-three articles were included; of these, 14 studies reported CXCL13 levels, and 5 reported CXCR5⁺CD4⁺ T cell count of pSS patients and HCs. Nine articles covering 32 studies reported correlations between serum CXCL13 levels and serological, clinical, and histological parameters in pSS patients. Expressions of CXCL13 and CXCR5⁺CD4⁺ T cell count were significantly increased in pSS patients compared with those in HCs. There was a positive correlation between CXCL13 levels and serum IgG levels, disease activity indices, and focus score in minor salivary gland biopsy of patients.

CONCLUSIONS

CXCL13 abundance was evidently elevated in pSS patients and correlated with disease activity and can therefore probably be employed as a robust biomarker to monitor and diagnose pSS. Key Points • Serum CXCL13 is significantly elevated in primary Sjögren's syndrome patients. • CXCL13 level correlates with disease severity and activity of primary Sjögren's syndrome. • CXCL13 can probably be used as a robust biomarker to monitor and diagnose primary Sjögren's syndrome.