Serum, but Not Saliva, CXCL13 Levels Associate With Infiltrating CXCL13+ Cells in the Minor Salivary Gland Lesions and Other Histologic Parameters in Patients With Sjögren's Syndrome

Autoimmune disease and risk of lymphoma: analysis from real-world data and Mendelian randomization study

BACKGROUND

Autoimmune diseases (AIDs) appear to be the primary predisposing factors for lymphoma. This study aims to investigate the causal effects between AIDs and lymphomagenesis.

METHODS

A two-sample Mendelian randomization (MR) framework was employed to estimate the causal effect through UK Biobank (UKB) and FinnGen cohorts. Patients with histories of AIDs and diagnosed with lymphoma were enrolled in real-world studies.

RESULTS

MR analysis investigated the potential causal effect of AIDs on the risks of lymphoma [odd ratio (OR) = 1.001, 95% confidence interval (CI) = 1.000-1.002, p = 0.040]. In our real-world data, there are no significantly increased risks for lymphoma when analyzing ORs for the history of rheumatoid arthritis (RA) and psoriasis (PsO) (OR 1.027, 95% CI = 0.516-2.04 for RA, and OR 1.022, 95% CI = 0.442-2.365 for PsO). The serum albumin (ALB) and sialic acid (SA) levels were independent prognostic factors for both progression-free survival (PFS) and overall survival (OS) in AIDs-associated lymphoma (AAL) patients.

CONCLUSIONS

Our results confirmed the causal relationships between AIDs and risks of lymphoma. Serum ALB and SA levels have demonstrated a vital influence on outcomes of AAL patients, in which the IL-17 pathway might play an active role.

Single-cell transcriptomic analysis uncovers heterogeneity in the labial gland microenvironment of primary Sjögren's syndrome

Objective

Primary Sjögren's syndrome (pSS) is a systemic autoimmune disorder with an unclear pathogenetic mechanism in the labial gland. This study aims to investigate the cellular and molecular mechanisms contributing to the development of this disease.

Methods

Single-cell RNA sequencing (scRNA-seq) was performed on 32,337 cells of labial glands from three pSS patients and three healthy individuals. We analyzed all cell subsets implicated in pSS pathogenesis.

Results

Our research revealed diminished differentiation among epithelial cells, concomitant with an enhancement of interferons (IFNs)-mediated signaling pathways. This indicates a cellular functional shift in reaction to inflammatory triggers. Moreover, we observed an augmentation in the population of myofibroblasts and endothelial cells, likely due to the intensified IFNs signaling, suggesting a possible reconfiguration of tissue structure and vascular networks in the impacted regions. Within the immune landscape, there was an apparent increase in immunosuppressive macrophages and dendritic cells (DCs), pointing to an adaptive immune mechanism aimed at modulating inflammation and averting excessive tissue harm. Elevated activation levels of CD4+T cells, along with a rise in regulatory T (Treg) cells, were noted, indicating a nuanced immune interplay designed to manage the inflammatory response. In the CD8+T cell subsests, we detected a notable increase in cells expressing granzyme K (GZMK), signaling an intensified cytotoxic activity. Additionally, the escalated presence of T cells with high levels of heat shock proteins (HSPs) suggests a cellular stress condition, possibly associated with persistent low-grade inflammation, mirroring the chronic aspect of the condition.

Conclusions

Our research identified distinct stromal and immune cell populations linked to pSS, revealing new potential targets for its management. The activation of myeloid, B, and T cells could contribute to pSS pathogenesis, providing important guidance for therapeutic approaches.

Loss of CCL28 and CXCL17 Expression and Increase in CCR1 Expression May Be Related to Malignant Transformation of LGBLEL into Lymphoma

To investigate the differential expression of the chemokine signaling pathway in lacrimal gland benign lymphoepithelial lesion (LGBLEL) and lacrimal lymphoma, providing insights into the mechanisms underlying malignant transformation and aiding clinical differentiation. Transcriptome analysis was conducted on patients with LGBLEL, lymphoma, and orbital cavernous hemangioma (CH). Three cases of LGBLEL and three cases of lymphoma were randomly selected as control and experimental groups, respectively. A real-time quantitative polymerase chain reaction (RT-qPCR) was used to validate genes associated with the chemokine signaling pathway. Immunohistochemical (IHC) staining and quantitative Western blotting (WB) were performed for precise protein quantification. Transcriptome analysis revealed differential expression of the chemokine signaling pathway between the LGBLEL and lymphoma groups, identifying ten differentially expressed genes: CCL17, VAV2, CXCR5, NRAS, HCK, RASGRP2, PREX1, GNB5, ADRBK2, and CCL22. RT-qPCR showed that, compared to the lymphoma group, the LGBLEL group had significantly higher expression of CCL28, CXCL17, HCK, GNB5, NRAS, and VAV2 (p = 0.001, <0.001, <0.001, <0.001, =0.020, <0.001, respectively) and lower expression of CCR1 (p = 0.002). IHC staining and quantitative analysis confirmed significant differences in protein expression between the groups for CCL28, CCR1, CXCL17, HCK, GNB5, NRAS, and VAV2 (p = 0.003, 0.011, 0.001, 0.024, 0.005, 0.019, and 0.031, respectively). While IHC provided localization, WB offered greater precision. WB revealed that, compared to the lymphoma group, the LGBLEL group exhibited significantly higher expression of CCL28, CXCL17, HCK, GNB5, NRAS, and VAV2 (p = 0.012, 0.005, 0.009, 0.011, 0.008, and 0.003, respectively) and lower expression of CCR1 (p = 0.014). The chemokine signaling pathway plays a role in the malignant transformation of LGBLEL. The decreased expression of CCL28 and CXCL17, coupled with the increased expression of CCR1, may be linked to the progression of LGBLEL into lymphoma.

Precision medicine in Sjögren's disease

Sjögren's disease is a clinically and pathophysiologically heterogeneous disease to which precision medicine, on the basis of clinical and biological heterogeneity, has been not always applicable. In patients with Sjögren's disease, the relationship between dysregulated biological pathways and symptoms such as fatigue and pain or clinical manifestations is often difficult to establish. This clinical and biological dissociation also poses challenges when defining appropriate clinical endpoints for clinical trials. In the last few years, however, research efforts have been focused on gaining a better understanding of the considerable heterogeneity of Sjögren's disease by developing stratification models aimed at clustering patients with this condition into homogenous subgroups characterised by distinctive molecular signatures, biomarkers, clinical features, and outcomes. In this Review, we discuss current evidence regarding clinical, laboratory, histological, and biomolecular stratification in Sjögren's disease and examine how available stratification data can guide precision medicine and inform the design of future clinical trials.

Integrated Analysis Identifies Upregulated SAMD9L as a Potential Biomarker Correlating with the Severity of Primary Sjögren's Syndrome

Background

Primary Sjögren's syndrome (pSS) is an autoimmune disease with lymphocytic infiltration of the salivary and lachrymal glands, whose present disease-specific objective indicators are few and have shortcomings that should be addressed. An integrated analysis of sequencing data from different cohorts has the potential to unveil novel biomarkers in pSS.

Methods

We identified 3 GEO datasets, including gene expression data from minor salivary gland (MSG) biopsy samples of 49 patients with pSS and 31 non-pSS and whole blood cells of 30 pSS patients and 30 healthy controls (HCs). Differentially expressed genes (DEGs) involved in pSS were identified from these datasets. Function Enrichment Analyses of common upregulated DEGs and PPI (protein-protein interaction) networks were performed. Furthermore, we have carried out further analysis of these DEGs to explore their potential clinical significance and diagnostic efficacy as a biomarker for pSS. Sterile Alpha Motif Domain Containing 9 Like (SAMD9L), one of the DEGs, has been identified as a promising candidate biomarker that correlates with the severity of pSS. This has been validated by analyzing local clinical samples from 30 pSS and non-pSS patients' MSG biopsies, as well as serum samples of 18 pSS and HC individuals. Finally, we performed correlation analysis to understand the relationship between SAMD9L and infiltrated immune cells.

Results

We identified 10 common highly expressed DEGs in pSS of different tissues. These genes were mainly involved in virus infection-related pathways and inferno-related pathways. GEO data and our clinical data showed that SAMD9L increases with disease severity. Public and local cohorts showed that SAMD9L has high diagnostic performance (AUC=0.845-0.867) as a biomarker, and its AUC was comparable to the Focus score when combined with RF or SSA.

Conclusion

Up-regulated SAMD9L may serve as a promising novel pSS diagnostic biomarker and have potential value for evaluating the severity of pSS.

Diagnostic role of CXCL13 biomarker in primary Sjogren's syndrome patients with parotid non-Hodgkin's lymphoma complication

INTRODUCTION

Serum biomarkers are important predictive factors for development of parotid non-Hodgkin's lymphoma (NHL) complication in primary Sjogren's syndrome (pSS) patients. The aim was to evaluate the diagnostic accuracy of serum CXCL13 chemokine in pSS patients with parotid NHL complication.

MATERIAL AND METHODS

Serum CXCL13 chemokine was assessed in 33 patients with pSS [7 with parotid NHL complication (pSS+NHL subgroup) and 26 without NHL (pSS-NHL subgroup)] and 30 healthy subjects.

RESULTS

The serum CXCL13 levels in pSS+NHL subgroup [175.2 (107.9-220.4) pg/ml] were significantly higher comparing to the healthy subjects group (p=0.018) and the pSS-NHL subgroup (p=0.048). A cut-off value of 123.45pg/ml (Se=71.4%, Sp=80.8%, AUROC=0.747) was established for parotid lymphoma diagnosis.

CONCLUSION

The serum CXCL13 biomarker could be considered a valuable tool for the diagnosis of parotid NHL complication in pSS patients.

Predisposing Factors, Clinical Picture, and Outcome of B-Cell Non-Hodgkin’s Lymphoma in Sjögren’s Syndrome

Among other systemic autoimmune diseases, primary Sjögren syndrome (pSS) bears the highest risk for lymphoma development. In pSS, chronic antigenic stimulation gradually drives the evolution from polyclonal B-cell expansion to oligoclonal/monoclonal B-cell predominance to malignant B-cell transformation. Thus, most pSS-related lymphomas are B-cell non-Hodgkin lymphomas (NHLs), with mucosa-associated lymphoid tissue (MALT) lymphomas predominating, followed by diffuse large B-cell lymphomas (DLBCLs) and nodal marginal zone lymphomas (NMZLs). Since lymphomagenesis is one of the most serious complications of pSS, affecting patients’ survival, a plethora of possible predisposing factors has been studied over the years, ranging from classical clinical, serological, hematological, and histological, to the more recently proposed genetic and molecular, allowing clinicians to timely detect and to closely follow-up the subgroup of pSS patients with increased risk for lymphoma development. Overall predisposing factors for pSS-related lymphomagenesis reflect the status of B-cell hyperactivity. Different clinical features have been described for each of the distinct pSS-related B-cell NHL subtypes. While generally pSS patients developing B-cell NHLs display a fairly good prognosis, outcomes in terms of treatment response and survival rates seem to differ depending on the lymphoma subtype, with MALT lymphomas being characterized by a rather indolent course and DLBCLs gravely affecting patients’ survival.

Biomarkers of lymphoma in Sjögren's syndrome: what's the latest?

INTRODUCTION

Primary Sjögren's syndrome (pSS) is a chronic autoimmune disease standing in the crossroads of autoimmunity and lymphomagenesis, characterized by chronic B-cell hyperactivity and ectopic lymphoid tissue neoformation, potentially driving lymphoid malignant transformation. Lymphoma development is considered the most serious complication of pSS.

AREAS COVERED: “

Old-classical" biomarkers (clinical, serological, hematological, and histological) validated in the past are analyzed under the perspective of recently published research. Biomarkers that have emerged during the last decade are subdivided to "old-new" and "newly proposed-novel" ones, including biomarkers pathophysiologically related to B-cell differentiation, lymphoid organization, and immune responses, identified in serum and tissue, both at genetic and protein level. Upcoming new imaging biomarkers, promising for further patient stratification, are also analyzed.

EXPERT OPINION

Salivary gland enlargement and cryoglobulinemia still remain the best validated "classical-old" biomarkers for lymphoma development. Though new biomarkers still need to be validated, some can be used for the identification of high-risk patients long before lymphoma diagnosis, some might be more relevant in distinct age subgroups, while others have an added value in the assessment of lymphoma remission or relapse. Future development of composite indices integrating old and recently proposed biomarkers could contribute to a more precise lymphoma prediction model.

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.

Cellular and molecular diversity in Sjogren's syndrome salivary glands: Towards a better definition of disease subsets

Primary Sjögren's syndrome (pSS) is a highly heterogeneous disease in terms of clinical presentation ranging from a mild disease localised to the salivary and lacrimal glands, to multiorgan complications of various degrees of severity, finishing with the evolution, in around 5% of pSS patients, to B cell lymphomas most commonly arising in the inflamed salivary glands. Currently, there are poor positive or negative predictors of disease evolution able to guide patient management and treatment at early stages of the diseases. Recent understanding of the pathogenic mechanisms driving immunopathology in pSS, particularly through histological and transcriptomic analysis of minor and parotid salivary gland (SG) biopsies, has highlighted a high degree of cellular and molecular heterogeneity of the inflammatory lesions but also allowed the identification of clusters of patients with similar underlying SG immunopathology. In particular, patients presenting with high degrees of B/T cell infiltration and the formation of ectopic lymphoid structures (ELS) in the SG have been associated, albeit with conflicting results, with higher degree of disease severity and enhanced risk of lymphoma evolution, suggesting that a dysregulated adaptive immune response plays a key role in driving disease manifestations in pSS. Recent data from randomised clinical trials with novel biological therapies in pSS have also highlighted the potential role of SG immunopathology and molecular pathology in stratifying patients for trial inclusion as well as assessing proof of mechanisms in longitudinal SG biopsies before and after treatment. Although significant progress has been made in the understanding of disease pathogenesis and heterogeneity through cellular and molecular SG pathology, further work is needed to validate their clinical utility in routine clinical settings and in randomised clinical trials.