Ectopic Germinal Center-Like Structures in Minor Salivary Gland Biopsy Tissue Predict Lymphoma Occurrence in Patients With Primary Sjögren's Syndrome

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

INTRODUCTION

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

AREAS COVERED

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

EXPERT OPINION

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

Molecular B-cell clonality assay in minor salivary glands as a useful tool for the lymphoma risk assessment in Sjögren's syndrome

OBJECTIVES

Non-Hodgkin's lymphoma (NHL) risk assessment is crucial in Sjögren's syndrome (SS). We studied the prevalence of clonal immunoglobulin gene rearrangements in minor salivary glands (MSG) and their correlations with lymphoma occurrence and with previously established NHL predictors.

METHODS

Molecular B-cell expansion was studied in fresh-frozen MSG of 207 patients with either suspected SS or with suspected lymphoma during SS, using a standardised multiplex PCR assay combined with heteroduplex analysis by microcapillary electrophoresis. The assignation of clonal cases was based on EuroClonality consortium guidelines.

RESULTS

Among 207 studied patients, 31 (15%) had MSG monoclonal B-cell infiltration. Monoclonality was significantly more frequent in patients with SS (28/123, 22.8%) compared with patients without SS (3/84, 3.6%, P<0.001). Monoclonal B-cell infiltration in MSG of SS patients correlated significantly with ongoing salivary gland NHL, salivary gland swelling, CD4+ T-cell lymphopenia, rheumatoid factor (RF) activity, low complement levels and type 2 mixed cryoglobulinemia. The accumulation of biological risk factors was associated with a higher rate of MSG B-cell monoclonality given that patients with only positive RF had no probability of MSG B-cell monoclonality, RF-positive patients with 1 or 2 other risk factors had a 25.0% and 85.7% probability of MSG B-cell monoclonality, respectively.

CONCLUSION

The detection of MSG monoclonal B-cell expansion by this easy-to-perform molecular assay is useful, both at the time of diagnosis and during the course of SS. Monoclonal B-cell expansion is associated with a subset of SS patients presenting either ongoing lymphoma or other established lymphoma predictive factors.

Chemokines and lymphocyte homing in Sjögren's syndrome

Sjögren's syndrome (SS) is a chronic systemic autoimmune disease that typically presents with lymphocyte, dendritic cell, and macrophage infiltration of exocrine gland ducts and the formation of ectopic germinal centers. The interactions of lymphocyte homing receptors and addressins and chemokines and their receptors, such as α4β7/MAdCAM-1, LFA-1/ICAM-1, CXCL13/CXCR5, CCL25/CCR9, CX3CL1/CX3CR1, play important roles in the migration of inflammatory cells to the focal glands and the promotion of ectopic germinal center formation in SS. A variety of molecules have been shown to be involved in lymphocyte homing, including tumor necrosis factor-α, interferon (IFN)-α, IFN-β, and B cell activating factor. This process mainly involves the Janus kinase-signal transducer and activator of transcription signaling pathway, lymphotoxin-β receptor pathway, and nuclear factor-κB signaling pathway. These findings have led to the development of antibodies to cell adhesion molecules, antagonists of chemokines and their receptors, compounds interfering with chemokine receptor signaling, and gene therapies targeting chemokines and their receptors, providing new targets for the treatment of SS in humans. The aim of this study was to explore the relationship between lymphocyte homing and the pathogenesis of SS, and to provide a review of recent studies addressing lymphocyte homing in targeted therapy for SS.

B-Cell Receptor Repertoire: Recent Advances in Autoimmune Diseases

In the field of contemporary medicine, autoimmune diseases (AIDs) are a prevalent and debilitating group of illnesses. However, they present extensive and profound challenges in terms of etiology, pathogenesis, and treatment. A major reason for this is the elusive pathophysiological mechanisms driving disease onset. Increasing evidence suggests the indispensable role of B cells in the pathogenesis of autoimmune diseases. Interestingly, B-cell receptor (BCR) repertoires in autoimmune diseases display a distinct skewing that can provide insights into disease pathogenesis. Over the past few years, advances in high-throughput sequencing have provided powerful tools for analyzing B-cell repertoire to understand the mechanisms during the period of B-cell immune response. In this paper, we have provided an overview of the mechanisms and analytical methods for generating BCR repertoire diversity and summarize the latest research progress on BCR repertoire in autoimmune diseases, including systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), primary Sjögren's syndrome (pSS), multiple sclerosis (MS), and type 1 diabetes (T1D). Overall, B-cell repertoire analysis is a potent tool to understand the involvement of B cells in autoimmune diseases, facilitating the creation of innovative therapeutic strategies targeting specific B-cell clones or subsets.

Is minor salivary gland biopsy still mandatory in Sjogren's syndrome? Does seronegative Sjogren's syndrome exist?

Sjӧgren's disease (SjD) is a systemic autoimmune disorder characterized by the chronic inflammation and dysfunction of exocrine glands, mainly salivary glands, causing dryness of the eyes and of the mouth. The disease may affect different organs and tissues with complex and heterogeneous clinical presentation, usually with sicca symptoms, profound fatigue, chronic pain, major organ involvement, and lymphomas. SjD diagnosis is based on the combination of clinical, serological, and functional tests with histological biomarkers. Minor salivary gland biopsy (mSGB) represents the cornerstone for the diagnosis of SjD, allowing the study of the characteristic focal infiltration of B- and T lymphocytes. Besides, mSGB might also have a prognostic role, being the infiltrates more complex in patients with severe SjD. But biopsy, so far, is not mandatory for SjD and mSG ultrasound and peripheral biomarkers might replace its role in the future. Another important aspect of SjD is the presence of autoantibodies, although 20 to 30% of patients are "seronegative" for specific autoantibodies (ANA, antiRo/SSA, antiLa/SSB). The characteristics of this subset of patients are currently under evaluation and "new" autoantibodies and biomarkers might be necessary for better patient's stratification and follow-up.

A bibliometric analysis of primary Sjögren's syndrome-associated lymphoma from 1991 to 2022

Background

Patients with primary Sjögren's syndrome (pSS) take a higher risk of developing lymphoma, which is the most frequent cause of death in pSS. Based on this situation, the number of publications focusing on pSS-associated lymphoma has been growing. Nevertheless, the extent, range, and nature of available research in this field have not been systematically summarized. This study aimed to map the literature available on pSS-associated lymphoma and identify global hotspots and trends.

Methods

Papers on pSS and lymphoma published from 1991 to 2022 were searched from the Web of Science Core Collection. Microsoft Excel, SPSS Statistics, VOSviewer, and CiteSpace software were used to analyze and visualize the quantity and citations of publications, and the global research hotspots and trends of pSS-associated lymphoma.

Results

629 publications from 50 countries/regions and 538 institutions were included in this study. From 1991 to 2022, the cumulative publications steadily increased. The USA ranked first in the number of publications (n = 118, 18.76 %), followed by Italy (n = 94, 14.94 %) and France (n = 73, 11.61 %). Udine University (n = 29) and Salvatore De Vita (n = 39) were the most prolific affiliation and author, respectively. Claudio Vitali was the most frequently cited author (n = 335). In total, the most frequently occurring keywords were clustered into four well-defined groups. The first group of keywords pointed to the clinical assessment and treatment of pSS-associated lymphoma. The second group highlighted the pathogenesis. The third group identified the predictors and prognosis of pSS-associated Lymphoma, while the fourth group focused on interstitial lung disease and pulmonary lymphoma in patients with pSS. Currently, the hot keywords include consensus, disease activity, and pathogenesis. Ultrasonography, mucosa-associated lymphoid tissue (MALT) lymphoma, and epidemiology are the emerging research trends in pSS-associated lymphoma.

Conclusion

Research on pSS-associated lymphoma is burgeoning. Despite clinical assessment, treatment and pathogenesis, researchers also showed great interest in the predictors, prognosis, and pulmonary manifestations of pSS-associated lymphoma. Current research of pSS-associated lymphoma mainly focuses on consensus, disease activity, and pathogenesis, while the emerging research trends in pSS are pointing to ultrasonography, MALT lymphoma and epidemiology.

Unraveling the transcriptome-based network of tfh cells in primary sjogren syndrome: insights from a systems biology approach

Background

Primary Sjogren Syndrome (pSS) is an autoimmune disease characterized by immune cell infiltration. While the presence of follicular T helper (Tfh) cells in the glandular microenvironment has been observed, their biological functions and clinical significance remain poorly understood.

Methods

We enrolled a total of 106 patients with pSS and 46 patients without pSS for this study. Clinical data and labial salivary gland (LSG) biopsies were collected from all participants. Histological staining was performed to assess the distribution of Tfh cells and B cells. Transcriptome analysis using RNA-sequencing (RNA-seq) was conducted on 56 patients with pSS and 26 patients without pSS to uncover the underlying molecular mechanisms of Tfh cells. To categorize patients, we employed the single-sample gene set enrichment analysis (ssGSEA) algorithm, dividing them into low- and high-Tfh groups. We then utilized gene set enrichment analysis (GSEA), weighted gene co-expression network analysis (WGCNA), and deconvolution tools to explore functional and immune infiltration differences between the low- and high-Tfh groups.

Results

Patients with pSS had a higher positive rate of the antinuclear antibody (ANA), anti-Ro52, anti-SSA, anti-SSB and hypergammaglobulinaemia and higher levels of serum IgG compared to the non-pSS. Histopathologic analyses revealed the presence of Tfh cells (CD4+CXCR5+ICOS+) in germinal centers (GC) within the labial glands of pSS patients. GSEA, WGCNA, and correlation analysis indicated that the high-Tfh group was associated with an immune response related to virus-mediated IFN response and metabolic processes, primarily characterized by hypoxia, elevated glycolysis, and oxidative phosphorylation levels. In pSS, most immune cell types exhibited significantly higher infiltration levels in the high-Tfh group compared to the low-Tfh group. Additionally, patients in the Tfh-high group demonstrated a higher positive rate of the ANA, rheumatoid factor (RF), and hypergammaglobulinaemia, as well as higher serum IgG levels.

Conclusion

Our study suggests that Tfh cells may play a crucial role in the pathogenesis of pSS and could serve as potential therapeutic targets in pSS patients.

An immuno-lipidomic signature revealed by metabolomic and machine-learning approaches in labial salivary gland to diagnose primary Sjögren's syndrome

Introduction

Assessing labial salivary gland exocrinopathy is a cornerstone in primary Sjögren's syndrome. Currently this relies on the histopathologic diagnosis of focal lymphocytic sialadenitis and computing a focus score by counting lym=phocyte foci. However, those lesions represent advanced stages of primary Sjögren's syndrome, although earlier recognition of primary Sjögren's syndrome and its effective treatment could prevent irreversible damage to labial salivary gland. This study aimed at finding early biomarkers of primary Sjögren's syndrome in labial salivary gland combining metabolomics and machine-learning approaches.

Methods

We used a standardized targeted metabolomic approach involving high performance liquid chromatography coupled with mass spectrometry among newly diagnosed primary Sjögren's syndrome (n=40) and non- primary Sjögren's syndrome sicca (n=40) participants in a prospective cohort. A metabolic signature predictive of primary Sjögren's syndrome status was explored using linear (logistic regression with elastic-net regularization) and non-linear (random forests) machine learning architectures, after splitting the data set into training, validation, and test sets.

Results

Among 126 metabolites accurately measured, we identified a discriminant signature composed of six metabolites with robust performances (ROC-AUC = 0.86) for predicting primary Sjögren's syndrome status. This signature included the well-known immune-metabolite kynurenine and five phospholipids (LysoPC C28:0; PCaa C26:0; PCaaC30:2; PCae C30:1, and PCaeC30:2). It was split into two main components: the first including the phospholipids was related to the intensity of lymphocytic infiltrates in salivary glands, while the second represented by kynurenine was independently associated with the presence of anti-SSA antibodies in participant serum.

Conclusion

Our results reveal an immuno-lipidomic signature in labial salivary gland that accurately distinguishes early primary Sjögren's syndrome from other causes of sicca symptoms.

Comparative Analysis of Hematological and Immunological Parameters in Patients with Primary Sjögren's Syndrome and Peripheral Neuropathy

BACKGROUND

Primary Sjögren syndrome (pSS) is a multisystem disorder of autoimmune etiology, frequently involving peripheral nerves. Early detection of peripheral neuropathy (PN) manifestations might improve prognosis and disease control. The purpose of the study was to evaluate the predictive potential of hematological and immunological parameters associated with PN development in pSS patients.

METHODS

This single-center retrospective study included patients with pSS who were divided into two groups, according to the occurrence of neurological manifestations throughout the follow-up period.

RESULTS

From the total of 121 pSS patients included in the study, 31 (25.61%) developed neurological manifestations (PN+ group) during the follow-up period. At the moment of pSS diagnosis, 80.64% of PN+ patients exhibited increased disease activity, with ESSDAI scores above 14 (p = 0.001), and significantly higher values for VASp score (p = 0.001), with a mean value of 4.90 ± 2.45, compared to 1.27 ± 1.32 in the PN- group. The hematological assessment at the moment of pSS diagnosis revealed that neutrophils and neutrophil-to-lymphocyte ratio (NLR) were significantly higher in the PN+ group (p = 0.001), while lymphocytes, monocytes and monocyte-to-lymphocyte ratio (MLR) were significantly lower (p = 0.025, p = 0.13 and p = 0.003, respectively). Immuno-inflammatory parameters-gammaglobulins, complement fractions C3, C4, total proteins and vitamin D were significantly lower in the PN+ patients' group. In multivariate analysis, the independent predictive character for PN development in pSS patients was confirmed for NLR (95% CI 0.033 to 0.263, p = 0.012), MLR (95% CI -1.289 to -0.194, p = 0.008), gammaglobulins (95% CI -0.426 to -0.088, p < 0.003), complement fraction C4 (95% CI -0.018 to -0.001, p < 0.030) and vitamin D (95% CI -0.017 to -0.003, p < 0.009).

CONCLUSIONS

Readily available and frequently used hematological and immunological markers, such as NLR, MLR, gammaglobulins, C4 and vitamin D could be helpful in predicting the neurological involvement in pSS patients. These biological parameters might become useful tools for clinicians to monitor disease progression and identify potentially severe extraglandular manifestations in pSS patients.

Complications after minor salivary gland biopsy: a retrospective study of 630 patients from two Swedish centres

OBJECTIVES

The aims of the study were to investigate the prevalence of impaired sensation after minor salivary gland biopsy (MSGB) in two Swedish centres [Karolinska University Hospital (KUH) and Skåne University Hospital (SUH)] and to assess its impact on quality of life (QoL) and associated risk factors.

METHOD

A questionnaire including questions regarding the presence of impaired sensation, impact on QoL, and impact on everyday life was sent to patients who had undergone MSGB between 2007 and 2016, and their medical notes were scrutinized.

RESULTS

The study included 630 patients (505 from KUH and 125 from SUH). In KUH the biopsies were performed by rheumatologists and in SUH by dentists or oral and maxillofacial surgeons (OMSs). Long-standing, probably permanent, impaired sensation after MSGB was reported by 21% of patients, and was associated with lower age and absence of anti-SSA antibodies. Patients with long-standing impaired sensation reported the inconvenience (1-10) of impaired sensation as 4.0 (2.0-7.0) [median (interquartile range)], and 32% reported an influence on their QoL, the reported influence (1-10) on everyday life being 3.0 (1.0-5.0). When comparing the outcomes from KUH and SUH, patients from SUH reported a significantly lower frequency of long-standing impaired sensation (14% vs 23%; p = 0.02).

CONCLUSION

A high frequency of long-standing impaired sensation after MSGB was found among patients who had undergone MSGB, although it had a low impact on everyday life. The complication frequency was less pronounced when a dentist or an OMS had performed the biopsy.

Autoimmune epithelitis in primary Sjögren's syndrome

Primary Sjögren's syndrome (pSS) is characterized by an autoimmune epithelitis associated with chronic inflammation of the exocrine glands. Alterations of extra-glandular functions in pSS is associated with lymphocytic infiltrates that invade the epithelial structures of affected organs. Within epithelial tissue, the expression of class II major histocompatibility complexes and costimulatory molecules by epithelial cells acting as non-professional antigen presenting cells, leads to the activation of T and B lymphocytes through multiple cellular crosstalk pathways. Although the pathogenetic mechanisms underlying pSS have not yet been elucidated, it is accepted that glandular epithelial cells are central regulators of the local autoimmune response.

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.

The Predictive Role of Neutrophil-to-Lymphocyte Ratio (NLR), Platelet-to-Lymphocyte Ratio (PLR), Monocytes-to-Lymphocyte Ratio (MLR) and Gammaglobulins for the Development of Cutaneous Vasculitis Lesions in Primary Sjögren's Syndrome

Background: In primary Sjögren’s Syndrome (pSS), cutaneous vasculitis lesions (CVL) are extraglandular manifestations with an important clinical and prognostic impact and their early detection might contribute to the improvement of disease control and even patients’ survival. The aim of this study was to evaluate the predictive potential of hematological elements in the development of CVL in pSS patients. Methods: In this single center, retrospective study, a total of 245 participants were included (124 pSS patients and 121 healthy controls). Complete blood count, inflammatory and immunological parameters were determined at the initial visit. pSS patients underwent a periodical follow-up program, when disease progression and response to therapy was monitored, including the emergence of CVL. Results: In pSS, leucocytes, lymphocyte, neutrophil, monocyte, erythrocyte and platelet counts are significantly decreased compared to healthy subjects (p < 0.001), whereas cellular ratios: NLR, PLR, MLR, and immunological and inflammatory parameters are significantly increased (p < 0.001). A total of 34 patients with pSS (27.41%) developed CVL during the follow-up period. The occurrence of CVL was positively correlated with neutrophil and platelet counts (p < 0.001), while for lymphocytes the correlation was negative (p < 0.001). Cellular ratios: NLR, PLR and MLR, and gammaglobulins also revealed significant positive correlations with the emergence of CVL in pSS (p < 0.001). The multivariate analysis confirmed the independent predictive character for CVL emergence in pSS for NLR (CI95% 0.053−0.2, p < 0.002), PLR (CI95% 0.001−0.003, p < 0.003), MLR (CI95% 0.086−0.935, p < 0.019), and gammaglobulins (CI95% 0.423−0.688, p < 0.001). Conclusions: Standard hematological parameters, widely used in the assessment of pSS patients, such as NLR, PLR, MLR and gammaglobulins could become valid elements that might be used for the early detection of patients at risk for the development of CVL.

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.

The five major autoimmune diseases increase the risk of cancer: epidemiological data from a large-scale cohort study in China

Background

Cancer incidence and mortality have received critical attention during the long‐term management of morbidities in patients with autoimmune diseases (AIDs). This study aimed to investigate and compare the risk of cancer associated with five major AIDs in a large‐scale Chinese cohort.

Methods

A total of 8,120 AID patients consecutively admitted to a national tertiary referral center in China were included and followed‐up for 38,726.55 patient‐years, including those with systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), Sjögren's syndrome (SS), systemic scleroderma (SSc), and idiopathic inflammatory myositis (IIM). Demographic data, cancer incidence, predilecting sites and cancer onset time were recorded and compared among the five AIDs.

Results

Four hundred and thirty (5.3%) patients developed cancer. Their median age was 57.5 years and AID duration was 79.8 months. The estimated total standardized incidence ratio (SIR) of cancer in AIDs patients was 3.37, with the highest SIR observed in IIM (4.31), followed by RA (3.99), SSc (3.77), SS (2.88) and SLE (2.58). The increased SIR of cancers in AID patients showed a female predominance (female vs. male: 3.59 vs. 2.77) and younger patient involvement (age <50 vs. ≥50 years: 4.88 vs. 3.04). Patients with SLE had increased SIRs for developing hematologic malignancies and solid tumors located in the urinary bladder, corpus uteri and cervix uteri. Patients with SS had a significantly high SIR for developing non‐Hodgkin's lymphoma. Within 3 years of IIM diagnosis, 74.6% of the patients developed cancer and they had a high risk of ovarian cancer. RA was associated with a wide distribution of scancers, including non‐Hodgkin's lymphoma, gynecologic, urinary tract, thyroid gland and lung cancers. SSc patients had increased SIRs for developing cervical uterine, lung, and breast cancers.

Conclusion

Patients with five major AIDs in China had an increased risk of developing cancer, with a predominance in women and younger patients, although cancer incidence, predilection sites and cancer onset time may vary greatly in each AID entity.

Salivary Gland Function, Development and Regeneration

Salivary glands produce and secrete saliva, which is essential for maintaining oral health and overall health. Understanding both the unique structure and physiological function of salivary glands, as well as how they are affected by disease and injury will direct the development of therapy to repair and regenerate them. Significant recent advances, particularly in the OMICS field, increase our understanding of how salivary glands develop at the cellular, molecular and genetic levels; the signaling pathways involved, the dynamics of progenitor cell lineages in development, homeostasis and regeneration and the role of the extracellular matrix microenvironment. These provide a template for cell and gene therapies as well as bioengineering approaches to repair or regenerate salivary function.

Recent Advances of Salivary Gland Biopsy in Sjögren's Syndrome

Sjögren's syndrome (SS) is a chronic, systemic, inflammatory autoimmune disease characterized by lymphocyte proliferation and progressive damage to exocrine glands. The diagnosis of SS is challenging due to its complicated clinical manifestations and non-specific signs. Salivary gland biopsy plays an important role in the diagnosis of SS, especially with anti-Sjögren's syndrome antigen A (SSA) and anti-SSB antibody negativity. Histopathology based on biopsy has clinical significance for disease stratification and prognosis evaluation, such as risk assessment for the development of non-Hodgkin's lymphoma. Furthermore, histopathological changes of salivary gland may be implicated in evaluating the efficacy of biological agents in SS. In this review, we summarize the histopathological features of salivary gland, the mechanism of histopathological changes and their clinical significance, as well as non-invasive imaging techniques of salivary glands as a potential alternative to salivary gland biopsy in SS.

Disease mechanisms in Sjögren's syndrome: what do we know?

Why should we explore and study disease mechanisms? This is particularly important when we are dealing with complex pathogenesis without a direct causal agent e.g. syndromes with multiple organ involvements. Sjögren's syndrome is definitely such an entity. Also, there are a number of reasons for such studies such as disclosing the aetiology, to identify biomarkers for diagnosis and assessment of the disease process and monitor response to treatment, to determine targets for treatment, to define critical items in classification criteria, among others. Samples available for the study of disease mechanisms in Sjögren's syndrome have included serum (autoantibodies, cytokines), DNA (gene profiling, GWAS), cells (phenotypes/flow cytometry, proportion of cells/CyTOF), tissue (focal inflammation, germinal centres, mass cytometry), saliva (proteomics, biochemistry, mucosal immunity). An original explanatory concept for the pathogenesis of Sjögren's syndrome proposed a specific and self-perpetuating immune mediated loss of exocrine tissue as the principal cause of glandular hypofunction. This hypothesis however falls short of accommodating several Sjögren's syndrome-related phenomena and experimental findings. Today, the emergence of advanced bio-analytical platforms has further enabled the identification of central pathogenic processes and potential biomarkers. The purpose of this minor review is to highlight a selection of previous but also recent and novel aspects on the disease mechanisms in 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.

Focal lymphocytic sialadenitis and ectopic germinal centers in oral reactive lesions and primary Sjögren's syndrome: a comparative study

Focal lymphocytic sialadenitis (FLS), an important diagnostic criterion for Sjögren's syndrome (SS) diagnosis, can also be observed when assessing minor salivary gland (mSG) biopsies from healthy asymptomatic individuals (non-SS patients). Fifty cases of primary SS (pSS group) and 31 cases of oral reactive lesions (non-SS non-sicca group) containing also typical FLS features, were assessed by morphological and immunohistochemical (CD10, CD23 and Bcl-6) analysis, aiming at the detection of GCs. All pSS cases showed FLS with focus score (FS) ≥ 1. In the non-SS non-sicca group, 12, 10 and 9 cases showed FLS with FS ≥ 1, FLS with FS < 1 and FLS associated with chronic sclerosing sialadenitis with FS < 1, respectively. The morphological analysis revealed similar frequency of GCs in pSS (20%) and non-SS non-sicca group (19%). The area (p = 0.052) and largest diameter (p = 0.245) of GCs were higher in pSS than non-SS non-sicca group. The FS and number of foci were significantly higher in pSS than non-SS non-sicca group with FS < 1. Immunohistochemistry confirmed all morphological findings (GCs showing CD23 and Bcl-6 positivity, with variable CD10 expression) and additionally in 3 and 1 cases of the pSS and non-SS non-sicca group, respectively. Moreover, another 6 and 2 cases of the pSS and non-SS non-sicca group with FS ≥ 1, respectively, showed positivity only for CD23. FLS can also be observed when assessing oral reactive lesions, which showed similar frequency of GCs with those found in pSS patients. Further studies, including functional analysis of lymphocytic populations and GCs in FLS, are encouraged.

Inflammatory Stratification in Primary Sjögren's Syndrome Reveals Novel Immune Cell Alterations in Patients' Minor Salivary Glands

There is a critical need to deconvolute the heterogeneity displayed by the minor salivary glands of primary Sjögren’s syndrome (pSS) patients. This is challenging primarily because the disease etiology remains unknown. The hypothesis includes that initial events in the disease pathogenesis target the salivary glands, thereby triggering the development of focal infiltrates (≥50 mononuclear cells) and finally germinal center-like structures. However, the proportion of key mononuclear immune cells residing at these sites, in combination with the overall ratio of morphometric tissue atrophy and adipose infiltration within the minor salivary glands (MSG) parenchyma at distinct phases of inflammatory disease establishment and progression have not been quantified in detail. In this cross-sectional study, we intended to address this problem by stratifying 85 patients into mild (S1), moderate (S2), and severe (S3) stages using the Inflammatory severity index. We found that mild (<3%) and marked (≥3%) levels of atrophy were accompanied by the respective levels of adipose infiltration in the non-SS sicca controls (p <0.01), but not in pSS patients. The percentage of adipose infiltration significantly correlated with the age of patients (r = 0.458, p <0.0001) and controls (r = 0.515, p <0.0001). The CD4⁺ T helper cell incidence was reduced in the focal infiltrates of the MSG of S2 patients compared to S1 (p <0.01), and in S2 compared to S1 and S3 combined (p <0.05). CD20⁺ B cells increased from S1 to S3 (p <0.01) and S2 to S3 (p <0.01), meanwhile CD138⁺ plasma cells diminished in S3 patients compared to both S1 and S2 groups combined (p <0.01). The proportion of patients with anti-Ro/SSA⁺, anti-La/SSB⁺, and RF⁺ increased over the course of inflammatory disease progression and they were significantly more common in the S3 group relative to S1 (p <0.05). On the other hand, S2 patients measured a higher mean salivary flow relative to S1 and S3 patients combined (p <0.05). Our results demonstrate how the proposed Inflammatory severity index stratification revealed pathological cell and tissue-associated aberrations in the salivary component over the course of inflammatory progression, and their correlations to clinical outcomes. This could be directly transferred to the optimization of available diagnostic strategies applied for pSS patients.

Management of Sjögren's Syndrome: Present Issues and Future Perspectives

In view of the new possibilities for the treatment of primary Sjögren's syndrome (pSS) given by the availability of new biotechnological agents targeting the various molecular and cellular actors of the pathological process of the disease, classification criteria aimed at selecting patients to be enrolled in therapeutic trials, and validated outcome measures to be used as response criteria to these new therapies, have been developed and validated in the last decades. Unfortunately, the therapeutic trials so far completed with these new treatments have yielded unsatisfactory or only partially positive results. The main issues that have been evoked to justify the poor results of the new therapeutic attempts are: (i) the extreme variability of the disease phenotypes of the patients enrolled in the trials, which are dependent on different underlying patterns of biological mechanisms, (ii) the fact that the disease has a long indolent course, and that most of the enrolled patients might already have irreversible clinical features. The advances in the research of new disease biomarkers that can better distinguish the different clinical phenotypes of patients and diagnose the disease in an earlier phase are also discussed.

Lymphomagenesis predictors and related pathogenesis

Sjögren's syndrome (SS) is a systemic autoimmune disease characterised by a wide range of clinical manifestations and complications, including B-cell lymphoma. This study aims to describe the predictors associated with lymphomagenesis in patients with Sjögren's syndrome, emphasising the pathophysiological bases that support this association. We performed a review of the literature published through a comprehensive search strategy in PubMed/MEDLINE, Scopus, and Web of science. Forty publications describing a total of 45,208 patients with SS were retrieved. The predictors were grouped according to their pathophysiological role in the lymphoproliferation process. Also, some new biomarkers such as MicroRNAs, P2X7 receptor-NLRP3 inflammasome, Thymic stromal lymphopoietin, and Three-prime repair exonuclease 1 (TREX1) were identified. The knowledge of the pathophysiology allows the discrimination of markers that participate in the initial stages. Considering that the lymphoproliferation process includes the progression of lymphoma towards more aggressive subtypes, it is essential to recognise biomarkers associated with a worse prognosis.

New frontiers in precision medicine for Sjogren's syndrome

Introduction: Sjögren's syndrome is a unique systemic autoimmune disease, placed in the center of systemic autoimmunity and at the crossroads of autoimmunity and lymphoproliferation. The diverse clinical picture of the disease, the inefficacy of current biologic treatments, and the co-existence with lymphoma conferring to the patients' morbidity and mortality force the scientific community to review disease pathogenesis and reveal the major implicated cellular and molecular elements.Areas covered: Biomarkers for early diagnosis, prediction, stratification, monitoring, and targeted treatments can serve as a tool to interlink and switch from the clinical phenotyping of the disease into a more sophisticated classification based on the underlying critical molecular pathways and endotypes. Such a transition may define the establishment of the so-called precision medicine era in which patients' management will be based on grouping according to pathogenetically related biomarkers. In the current work, literature on Sjogren's syndrome covering several research fields including clinical, translational, and basic research has been reviewed.Expert opinion: The perspectives of clinical and translational research are anticipated to define phenotypic clustering of high-risk pSS patients and link the clinical picture of the disease with fundamental molecular mechanisms and molecules implicated in pathogenesis.

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

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

Pathogenetic Mechanisms Implicated in Sjögren's Syndrome Lymphomagenesis: A Review of the Literature

Sjögren's Syndrome (SS) is a chronic autoimmune disorder characterized by focal mononuclear cell infiltrates that surround the ducts of the exocrine glands, impairing the function of their secretory units. Compared to other autoimmune disorders, SS is associated with a notably high incidence of non-Hodgkin lymphoma (NHL) and more frequently mucosa associated lymphoid tissue (MALT) lymphoma, leading to increased morbidity and mortality rates. High risk features of lymphoma development include systemic extraepithelial manifestations, low serum levels of complement component C4 and mixed type II cryoglobulinemia. The discrimination between reactive and neoplastic lymphoepithelial lesion (LEL) is challenging, probably reflecting a continuum in the evolution from purely inflammatory lymphoid infiltration to the clonal neoplastic evolution. Early lesions display a predominance of activated T cells, while B cells prevail in severe histologic lesions. This strong B cell infiltration is not only a morphologic phenomenon, but it is also progressively associated with the presence of ectopic germinal centers (GCs). Ectopic formation of GCs in SS represents a complex process regulated by an array of cytokines, adhesion molecules and chemokines. Chronic antigenic stimulation is the major driver of specific B cell proliferation and increases the frequency of their transformation in the ectopic GCs and marginal zone (MZ) equivalents. B cells expressing cell surface rheumatoid factor (RF) are frequently detected in the salivary glands, suggesting that clonal expansion might arise from antigen selection of RF-expressing B cells. Abnormal stimulation and incomplete control mechanisms within ectopic lymphoid structures predispose RF MZ like cells to lymphoma development. Immunoglobulin recombination, somatic mutation and isotype switching during B cell development are events that may increase the translocation of oncogenes to immunoglobulin loci or tumor suppressor gene inactivation, leading to monoclonal B cell proliferation and lymphoma development. Concerning chronic antigenic stimulation, conclusive data is so far lacking. However immune complexes containing DNA or RNA are the most likely candidates. Whether additional molecular oncogenic events contribute to the malignant overgrowth remains to be proved.

Indicators for Malignant Transformation in Patients With Lymphoepithelial Lesion

PURPOSE

Salivary lesion (LEL) represents a unique disease, and some patients have malignant transformations. The study aims were to estimate the frequency of malignant transformation and the subtype of the malignant component and to identify factors associated with malignant transformation and subtype of the malignant component in patients with LEL.

PATIENTS AND METHODS

This study was based on a retrospective cohort study between 2005 and 2017 from patients who were diagnosed as LEL. The predictor variable was composed of a set of variables grouped into demographic, clinical, and pathologic features. The outcome variables were malignant transformation status and subtype of the malignant components. All parameters between the predictor variables and outcome variables were analyzed using the χ² test and a logistic regression model.

RESULTS

The sample was composed of 252 cases of LEL (including with or without malignant transformation) with a mean age of 50.3 years; 58 (58 of 252; 23.0%) were males, 194 (194 of 252; 77.0%) were females. The parotid gland was the most common site of LEL (206 of 252; 81.7%), and 36.5% (92 of 252) of the patients had a history of Sjögren syndrome (SS). Masses greater than 2 cm in diameter had evidence of malignant transformation (P < .001). Factors associated with the subtype of malignant components were a history of SS (P < .001) and Epstein-Barr virus infection. The percentages of nonmalignant transformations, LEL with extranodal marginal zone lymphomas of mucosa-associated lymphoid tissue (MALT lymphoma), and LEL progressing to lymphoepithelial carcinoma were 44.8 (113 of 252), 47.6 (120 of 252), and 7.6% (19 of 252), respectively.

CONCLUSIONS

More than half of cases have a malignant transformation, and MALT lymphoma is the most common malignant subtype. A larger mass (>2 cm) is an independent indicator of malignant transformation in LEL patients. History of SS among LEL patients is considered a risk factor for MALT lymphoma.

Impaired Interleukin-27-Mediated Control of CD4+ T Cell Function Impact on Ectopic Lymphoid Structure Formation in Patients With Sjögren's Syndrome

OBJECTIVE

Ectopic lymphoid structures (ELS) develop at sites of infection, autoimmunity, and cancer. In patients with Sjögren's syndrome (SS), ELS support autoreactive B cell activation and lymphomagenesis. Interleukin-27 (IL-27) is a key regulator of adaptive immunity and limits Th17 cell-driven pathology. We undertook this study to elucidate the role of IL-27 in ELS formation and function in autoimmunity using a murine model of sialadenitis and in patients with SS.

METHODS

ELS formation was induced in wild-type and Il27ra-/- mice via salivary gland (SG) cannulation of a replication-deficient adenovirus in the presence or absence of IL-17A neutralization. In SG biopsy samples, IL-27-producing cells were identified by multicolor immunofluorescence microscopy. Lesional and circulating IL-27 levels were determined by gene expression and enzyme-linked immunosorbent assay. The in vitro effect of IL-27 on T cells was assessed using fluorescence-activated cell sorting and cytokine release.

RESULTS

In experimental sialadenitis, Il27ra-/- mice had larger and more hyperactive ELS (focus score; P < 0.001), increased autoimmunity, and an expanded Th17 response (P < 0.001), compared to wild-type mice. IL-17 blockade in Il27ra-/- mice suppressed the aberrant ELS response (B and T cell reduction against control; P < 0.01). SS patients displayed increased circulating IL-27 levels (P < 0.01), and in SG biopsy samples, IL-27 was expressed by DC-LAMP+ dendritic cells in association with CD3+ T cells. Remarkably, in SS T cells (but not in T cells from patients with rheumatoid arthritis or healthy controls), IL-27-mediated suppression of IL-17 secretion was severely impaired and associated with an aberrant interferon-γ release upon IL-27 stimulation.

CONCLUSION

Our data indicate that the physiologic ability of IL-27 to limit the magnitude and function of ELS through control of Th17 cell expansion is severely impaired in SS patients, highlighting a defective immunoregulatory checkpoint in this condition.

Sjögren's Syndrome: The Clinical Spectrum of Male Patients

Background: To compare the clinical, serological and histologic features between male and female patients with Sjögren’s syndrome (SS) and explore the potential effect of gender on lymphoma development. Methods: From a multicenter population (Universities of Udine, Pisa and Athens, Harokopion and Ioannina (UPAHI)) consisting of consecutive SS patients fulfilling the 2016 ACR/EULAR criteria, male patients were identified, matched and compared with female controls. Data-driven multivariable logistic regression analysis was applied to identify independent lymphoma-associated factors. Results: From 1987 consecutive SS patients, 96 males and 192 matched female controls were identified and compared. Males had a higher frequency of lymphoma compared to females (18% vs. 5.2%, OR = 3.89, 95% CI: 1.66 to 8.67; p = 0.0014) and an increased prevalence of serum anti-La/SSB antibodies (50% vs. 34%, OR = 1.953, 95% CI: 1.19 to 3.25; p = 0.0128). No differences were observed in the frequencies of lymphoma predictors between the two genders. Data-driven multivariable logistic regression analysis revealed negative association of the female gender with lymphoma and positive association with lymphadenopathy. Conclusion: Male SS patients carry an increased risk of lymphoma development. Although statistics showed no difference in classical lymphoma predictors compared to females, data-driven analysis revealed gender and lymphadenopathy as independent lymphoma-associated features.

Relevance on the diagnosis of malignant lymphoma of the salivary gland

Malignant lymphoma originates from the lymphohematopoietic system. It can occur in any lymphoid tissue. Malignant lymphoma of the salivary gland is rare, but its incidence has increased in recent years. Its clinical- presentations are non-specific, and it is often manifested as a painless mass in a salivary gland, which can be accompanied by multiple swollen cervical lymph nodes. Confirmation of the diagnosis before an invasive procedure is difficult. Clinically, malignant lymphoma of the salivary gland tends to be misdiagnosed, leading to an inappropriate treatment plan and the ultimate delay in the optimal treatment of the disease. This article reviews the pathogenesis, clinical features, imaging findings, diagnosis, treatment and prognosis of malignant lymphoma of the salivary gland.

Pulmonary Involvement in a Mouse Model of Sjögren's Syndrome Induced by STING Activation

Sjögren's Syndrome (SS), a chronic autoimmune disorder affecting multiple organ systems, is characterized by an elevated type I interferon (IFN) response. Activation of Stimulator of Interferon Genes (STING) protein induces type I IFN and in mice, several features of SS, including anti-nuclear antibodies, sialadenitis, and salivary gland dysfunction. Since lung involvement occurs in one-fifth of SS patients, we investigated whether systemic activation of STING also leads to lung inflammation. Lungs from female C57BL/6 mice injected with the STING agonist 5, 6-Dimethylxanthenone-4-acetic acid (DMXAA), were evaluated for acute and chronic inflammatory responses. Within 4h of DMXAA injection, the expression of Ifnb1, Il6, Tnf, Ifng, and Mx1 was significantly upregulated. At 1 and 2 months post-treatment, lungs showed lymphocytic infiltration in the peri-bronchial regions. The lungs from DMXAA treated mice showed an increased expression of multiple chemokines and an increase in lymphatic endothelial cells. Despite STING expression in bronchial epithelium and cells lining the alveolar wall, bone marrow chimeras between STING knockout and wild type mice showed that STING expression in hematopoietic cells was critical for lung inflammation. Our results suggest that activation of the STING pathway might be involved in SS patients with concomitant salivary gland and lung disease.

Expression of BAFF and BAFF receptors in primary Sjögren's syndrome patients with ectopic germinal center-like structures

B cell-activating factor (BAFF) is an essential cytokine in primary Sjögren's syndrome (pSS) physiopathology. It has been reported that pSS patients develop germinal center-like (GC-like) structures in their minor salivary glands (MSGs). BAFF, BAFF-R, TACI, and BCMA expression was analyzed in MSGs from 29 subjects (nonspecific chronic sialadenitis and focal lymphocytic sialadenitis with the presence [pSS-GC(+)] or absence [pSS-GC(-)] of GC-like structures). Twenty-four percent of patients showed ectopic GC-like structures and a high focus score [p < 0.001 vs pSS-GC(-)]. BAFF serum levels (sBAFF) were high in pSS patients (p = 0.025 vs healthy subjects). However, the pSS-GC(-) group showed higher sBAFF levels than pSS-GC(+) patients. BAFF and BAFF-R glandular expression levels were higher in pSS-GC(+) patients, without significant differences compared to pSS-GC(-) patients. Soluble levels of BAFF correlated with anti-La/SSB antibodies and disease duration. Our results showed that BAFF could contribute to focal lymphocytic infiltration. The role of BAFF-binding receptors in MSGs is proposed as a mechanism for the possible establishment of ectopic GC-like structures and disease progression in some patients. In conclusion, this study supports previous evidence that considers the active BAFF system role in the pathogenesis of pSS and the need for strong biomarkers in this disease.

Role of Viral Infections in the Pathogenesis of Sjögren's Syndrome: Different Characteristics of Epstein-Barr Virus and HTLV-1

Viruses are possible pathogenic agents in several autoimmune diseases. Sjögren’s syndrome (SS), which involves exocrine dysfunction and the appearance of autoantibodies, shows salivary gland- and lacrimal gland-oriented clinical features. Epstein-Barr virus (EBV) is the most investigated pathogen as a candidate that directly induces the phenotype found in SS. The reactivation of the virus with various stimuli induced a dysregulated form of EBV that has the potential to infect SS-specific B cells and plasma cells that are closely associated with the function of an ectopic lymphoid structure that contains a germinal center (GC) in the salivary glands of individuals with SS. The involvement of human T-cell leukemia virus type 1 (HTLV-1) in SS has been epidemiologically established, but the disease concept of HTLV-1-associated SS remains unexplained due to limited evidence from basic research. Unlike the cell-to-cell contact between lymphocytes, biofilm-like structures are candidates as the mode of HTLV-1 infection of salivary gland epithelial cells (SGECs). HTLV-1 can infect SGECs with enhanced levels of inflammatory cytokines and chemokines that are secreted from SGECs. Regardless of the different targets that viruses have with respect to affinitive lymphocytes, viruses are involved in the formation of pathological alterations with immunological modifications in SS.

CXCL13 as biomarker for histological involvement in Sjögren's syndrome

OBJECTIVES

SS is an autoimmune condition characterized by systemic B-cell activation, autoantibody production and ectopic germinal centres' formation within the salivary gland (SG). The extent of SG infiltrate has been proposed as a biomarker of disease severity. Plasma levels of CXCL13 correlate with germinal centres' activity in animal models and disease severity in SS, suggesting its potential use as a surrogate serum marker to monitor local B-cell activation. The aim of this study was to evaluate the potential role of CXCL13 as a biomarker of SG pathology in two independent SS cohorts.

METHODS

109 patients with SS were recruited at Sapienza University of Rome (Italy) (n = 60), or at Queen Elizabeth Hospital in Birmingham and Barts Health NHS Trust in London (n = 49). Both sera and matched minor SG biopsy were available. Sicca (n = 57) and healthy subjects' (n = 19) sera were used as control.

RESULTS

CXCL13 serum level was higher in SS patients compared with controls. Correlations between its serum levels and a series of histomorphological parameters, including size of the aggregates and the presence germinal centres', were observed.

CONCLUSION

Our data foster the use of CXCL13 to monitor the extent of local pathology in SS and its validation in longitudinal clinical studies.

Population-based study of patients with primary Sjögren's syndrome and lymphoma: lymphoma subtypes, clinical characteristics, and gender differences

Objective: To examine lymphoma subtypes, clinical characteristics, and gender differences in patients with primary Sjögren's syndrome (pSS) and lymphoma in a population-based setting.Method: Patients with Sjögren's syndrome and lymphoma diagnoses were identified by linkage of the Swedish Patient Register 1964-2007 with the Cancer Register 1990-2007. Clinical data were collected from medical records and lymphoma tissues were re-examined. The lymphoma subtype distribution was compared with the Swedish Lymphoma Register.Results: We identified 105 pSS patients with lymphoma. Diffuse large B-cell lymphoma (DLBCL) (32%) and marginal zone lymphoma [MZL including mucosa-associated lymphoid tissue (MALT) lymphoma] (31%) were the most common lymphoma subtypes. The proportion of DLBCL was not increased compared to the general population reference (32%, p = 1), in contrast to MZL (general population 5%, p < 0.0001). Compared to DLBCL, MALT lymphoma was diagnosed at a younger age (55 vs 67 years, p = 0.0001), and earlier after patient-reported sicca onset (7 vs 18 years, p = 0.0001) and pSS diagnosis (2 vs 9 years, p = 0.0005). Sixteen of the pSS-lymphoma cases were men (15%), twice the proportion in general pSS populations. Compared to women, men had a shorter median time from pSS diagnosis to lymphoma diagnosis (1 vs 8 years, p = 0.0003) and more often had lymphoma in the salivary glands (56% vs 29%, p = 0.04).Conclusion: DLBCL and MZL are common in pSS patients, but only MZL/MALT lymphoma occurs at an increased relative frequency in pSS compared to the general population. The study supports increased awareness of signs of lymphoma in men in the first years after pSS diagnosis.

[Primary Sjögren's Syndrome - News on Diagnostics and Therapy]

Primary Sjögren's Syndrome - News on Diagnostics and Therapy Abstract. Primary Sjögren's syndrome is an autoimmune disease that affects primarily the exocrine glands and is mainly characterized by sicca symptoms of the eyes and mouth, but also nose, throat, vagina and skin can be affected. Fatigue and pain are also very characteristic. Systemic manifestations can occur, e.g. in joints, muscles, lungs, kidneys, skin or the nervous system. A feared complication is the development of a lymphoma, the risk being especially high in case of positive anti-SSA-(Ro) antibodies, but also in case of a high ESSDAI score, hypocomplementemia, cytopenia or evidence of ectopic germinal centers in salivary gland biopsies. Diagnosis is principally made by verification of sicca symptoms (e.g. Schirmer's test) and detection of typical antibodies or a typical gland biopsy. Sicca symptoms are primarily treated symptomatically (e.g. artificial tears or saliva). In case of systemic manifestations glucocorticoids, conventional DMARDs or biologics (mostly rituximab) are treatment options. In severe cases, intravenous immunoglobulins or plasma exchange may be required.

Recommendations from the Brazilian society of rheumatology for the diagnosis of Sjögren's syndrome (Part I): glandular manifestations (systematic review)

BACKGROUND

Primary Sjögren's syndrome (pSS) is a systemic immune-mediated disease whose main characteristic is exocrine gland inflammation and, subsequent reduction in tear and saliva production. A delayed diagnosis is common due to the nonspecific clinical manifestations of disease. The aim of the present study was to develop recommendations for the diagnosis of glandular manifestations of pSS based on evidence and expert opinion. We conducted a systematic literature review to retrieve the best evidence available on the accuracy of diagnostic tests for pSS. We also held two in-person meetings with experts (rheumatologists, pathologists, ophthalmologists and dentists) to establish their level of agreement using the Delphi method. Ultimately, we generated 18 recommendations that aim to facilitate the diagnosis of the glandular manifestations of pSS.

CONCLUSION

The diagnosis of glandular manifestations of pSS is complex and multidisciplinary. It requires specific knowledge in the field of ophthalmology, immunology, pathology and imaging, making it compulsory for the rheumatologist to work with professionals from these different areas in order to improve accuracy and early diagnosis. Glandular dysfunction tests, ANA, RF, Anti-Ro, protein electrophoresis, urinalysis, blood count, C-Reactive protein, complement, testing for syphilis and viruses (HCV, HIV) and SGUS should be investigated when dryness or systemic manifestation are present. Minor salivary gland biopsy is recommended for all anti-Ro negative or incomplete criteria cases.

B cell dysregulation in primary Sjögren's syndrome: A review

Primary Sjögren’s syndrome is a chronic autoimmune disorder of unknown etiology and is characterized by progressive focal lymphocytic infiltration of the lacrimal and salivary glands. Comparison of B cell subsets from the peripheral blood and salivary glands of patients with primary Sjögren’s syndrome and those from healthy individuals shows dysregulation and derangement of B cell subsets in both peripheral circulation and in inflamed glandular tissues. This dysregulation is expressed as a decrease in the percentage of CD27+ memory B cells in peripheral blood and an increase in the CD27+ memory B cells in the affected glands. Further, the overall percentage of long-lived autoantibodies-producing plasma cells within the affected glands is increased. In the last two decades, several studies have shown growing evidences that B cells play multiple roles in primary Sjögren’s syndrome pathophysiology, and that dysregulation of these cells may actually play a central role in the disease development.

Predictive markers of lymphomagenesis in Sjögren's syndrome: From clinical data to molecular stratification

Sjögren's syndrome (SS) is a chronic systemic autoimmune disease, affecting predominantly the exocrine glands, a large array of systemic manifestations and high risk of lymphoma development. The latter constitutes the major adverse outcome of SS contributing in the increased morbidity and mortality of the disease. The vast majority of lymphomas in SS are B-cell non-Hodgkin's lymphomas (NHL), primarily indolent mucosa-associated lymphoid tissue (MALT) lymphomas, followed by nodal marginal zone lymphomas (NMZL) and diffuse large B cell lymphomas (DLBCL). In the last 3 decades and due to the adverse impact of NHL in disease outcome, an effort has been undertaken to identify markers and models predicting patients with SS at high risk for lymphoma development. Several epidemiological, clinical, laboratory and histological parameters, some of which are evident at the time of SS diagnosis, were proved to independently predict the development of NHL. These include salivary gland enlargement, skin vasculitis/purpura, glomerulonephritis, peripheral neuropathy, Raynaud's phenomenon, lymphadenopathy, splenomegaly, cytopenias, hypocomplementemia, cryoglobulinemia, rheumatoid factor, anti-Ro/La autoantibodies, hypergammaglobulinemia, serum monoclonal gammopathy, biopsy focus score and organization of lymphocytic infiltrates in the salivary glands into ectopic germinal centers. Prediction models combining some of the afore-mentioned predictors have also been described. However, the identification of specific and sensitive molecular biomarkers, related to the process of lymphomagenesis is still pending. Recently, we described a novel biomarker the miR200b-5p micro-RNA. Low levels of this miRNA in the minor salivary glands, appears to discriminate with high specificity and sensitivity the SS patients who have from those who do not have NHL. miR200b-5p, being expressed years before the clinical onset of NHL, independently predicts NHL development with a predictive value higher than the previously published multifactorial models and has a possible role in the monitoring of therapeutic response. Thus, it is a strong candidate for the identification and follow-up of patients at risk.

Prognostic markers of lymphoma development in primary Sjögren syndrome

Sjögren syndrome is a systemic autoimmune disease that principally affects women between the fourth and sixth decades of life who present with sicca symptomatology caused by dryness of the main mucosal surfaces. The clinical spectrum of Sjögren syndrome extends from dryness to systemic involvement. Since 1978, Sjögren syndrome has been closely associated with an enhanced risk of lymphoma, one of the most severe complications a patient may develop. Primary Sjögren syndrome patients have a 10-44-fold greater risk of lymphoma than healthy individuals, higher than that reported for systemic lupus erythematosus and rheumatoid arthritis. The close link between lymphoma and Sjögren syndrome is clearly exemplified by the very specific type of lymphoma arising in Sjögren syndrome patients, mainly low-grade B-cell lymphomas (predominantly a marginal zone histological type) with primary extranodal involvement of the major salivary glands (overwhelmingly parotid), with a primordial role of cryoglobulinemic-related markers (both clinical and immunological). The most recent studies support a higher number of risk factors detected in an individual leads to a higher lymphoma risk. A close follow-up of high-risk groups with longitudinal assessments of all known risk factors, including cryoglobulin-related markers and EULAR Sjögren's syndrome disease activity index measurement in particular, is mandatory.

[Sjögren's syndrome update: Clinical and therapeutic aspects]

Sjögren's syndrome (SS) is a systemic orphan disease. It is characterized by the involvement of epithelial tissues leading to the term of autoimmune epithelitis. New classification criteria have been developed in 2016. New scores have also been developed: a patient-reported outcome called ESSPRI and a score assessing systemic activity of the disease called ESSDAI. These new tools are very helpful to better stratify patients and to customize the management of this very heterogeneous disease. Among the autoimmune diseases, SS is associated with the highest risk of lymphoma. Five to ten percent of the patients will have a B cell lymphoma mostly a low-grade lymphoma developing from mucosa-associated lymphoid tissue (MALT). Major advances have been made in this field: pathogeny is better understood, new predictors are available and progresses have been made in the management of this severe complication. Research in the field of SS is very dynamic as illustrated by the high number of therapeutic trials. There is hope that these innovations, reviewed in the present article, will have potential significant repercussions for the patients in the next few years.

Lymphomas complicating primary Sjögren's syndrome: from autoimmunity to lymphoma

Lymphoma development is the most serious complication of SS and the main factor impacting on mortality rate in patients with this condition. Lymphomas in SS are most commonly extranodal non-Hodgkin B-cell lymphomas of the mucosa-associated lymphoid tissue and frequently arise in salivary glands that are the target of a chronic inflammatory autoimmune process. Extensive work on lymphomagenesis in SS has established that the progression towards B-cell lymphoma is a multistep process related to local chronic antigenic stimulation of B cells. These neoplastic B cells in SS frequently derived from autoreactive clones, most commonly RF-producing B cells, which undergo uncontrolled proliferation and malignant escape. In this review, we highlight the most important recent findings that have enhanced our understanding of lymphoma development in SS, with particular reference to the close link between autoimmunity and lymphomagenesis. We also discuss how the identification of key factors involved in B-cell malignancies may impact on our ability to identify at early stages patients at increased risk of lymphoma with potential significant repercussions for the clinical management of SS patients. Finally, we identified the most promising areas of current and further research with the potential to provide novel basic and translational discoveries in the field. The questions of finding new biomarkers, developing a validated score for predicting lymphoma occurrence and assessing if a better control of disease activity will decrease the risk of lymphoma in primary SS will be the enthralling questions of the next few years.

Update on Sjögren's Syndrome 2018

Primary Sjögren’s syndrome (pSS) is a chronic systemic autoimmune disease with a diverse clinical picture, extending from exocrine involvement to extraglandular manifestations. Although pSS remains a disease of unknown etiology, an interaction between genetic susceptibility and environmental triggers is thought to play a key role in disease initiation and progress. Despite the extensive research during the past years, the pathogenetic mechanisms are still elusive and effective therapeutic intervention is still missing. This review aims to provide an overview of the recent literature on the pathogenesis, clinical features and new therapeutic aspects of pSS.