Natural History and Predictors of Progression to Sjögren's Syndrome Among Participants of the Sjögren's International Collaborative Clinical Alliance Registry

Machine learning approach to single cell transcriptomic analysis of Sjogren's disease reveals altered activation states of B and T lymphocytes

Sjogren's Disease (SjD) is an autoimmune disorder characterized by salivary and lacrimal gland dysfunction and immune cell infiltration leading to gland inflammation and destruction. Although SjD is a common disease, its pathogenesis is not fully understood. In this study, we conducted a single-cell transcriptome analysis of peripheral blood mononuclear cells (PBMC) from patients with SjD and symptomatic non-SjD controls to identify cell types and functional changes involved in SjD pathogenesis. All PBMCs populations showed marked differences in gene expression between SjD patients and controls, particularly an increase in interferon (IFN) signaling gene signatures. T and B cells of SjD patients displayed a depletion of ribosomal gene expression and pathways linked to protein translation. SjD patients had increased frequencies of naive B cells, which featured a unique gene expression profile (GEP) distinct from controls and had hallmarks of B cell hyperactivation. Non-negative matrix factorization (NMF) also identified several non-overlapping GEPs in CD4+ and CD8+ T cells with differential usage in SjD patients and controls. Of these, only the Th1 activation GEP was enriched in T cells of SjD patients whereas the other two GEPs were depleted in T cells, emphasizing the important role of Th1 cells in SjD. Our study provides evidence for aberrant and unique gene expression patterns in both B and T lymphocytes of SjD patients that point to their altered activation states and may provide new insights into the pathogenesis of SjD.

British Society for Rheumatology guideline on management of adult and juvenile onset Sjögren disease

Sjögren disease (SD) is a chronic, autoimmune disease of unknown aetiology with significant impact on quality of life. Although dryness (sicca) of the eyes and mouth are the classically described features, dryness of other mucosal surfaces and systemic manifestations are common. The key management aim should be to empower the individual to manage their condition-conserving, replacing and stimulating secretions; and preventing damage and suppressing systemic disease activity. This guideline builds on and widens the recommendations developed for the first guideline published in 2017. We have included advice on the management of children and adolescents where appropriate to provide a comprehensive guideline for UK-based rheumatology teams.

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

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

Can unstimulated whole salivary flow objectively classify salivary gland secretory function in Sjögren's syndrome?

INTRODUCTION

The aim of this study is to investigate whether the testing time for unstimulated whole salivary flow (UWSF) can be shortened to 5 min in patients with suspected Sjögren's syndrome (SjS); and which SjS patients can use UWSF to evaluate salivary gland (SG) secretory function.

METHOD

A diagnostic cohort comprising suspected SjS patients was conducted to investigate the correlation between UWSF measurements taken at 10 min (UWSF_10 min) and those taken at 5 min (UWSF_5 min). A group of SjS patients was enrolled for a comparison between UWSF and stimulated whole salivary flow (SWSF).

RESULTS

In 734 suspected SjS patients, there was a remarkably high concordance between UWSF_10 min and UWSF_5 min (ICC 0.970, P < 0.001; r 0.973, P < 0.001). Reducing the testing time for UWSF to 5 min resulted in a high PPV of 83.8% and an exceptionally high NPV of 98.7%. In 408 SjS patients, the cut-off values of UWSF_10 min were investigated to classify SG secretory function. Using a threshold of > 0.2 mL/min (36.8%, 150/408) instead of SWSF > 0.7 mL/min (indicating mild secretory hypofunction), the specificity and PPV were found to be 94.2% and 94.0%, respectively; and using a threshold of < 0.05 mL/min (16.9%, 69/408) instead of SWSF ≤ 0.7 mL/min (indicating moderate to severe secretory hypofunction), the specificity was remarkably high at 97.6%, accompanied by a high PPV of 91.3%.

CONCLUSIONS

This study supports the possibility of reducing UWSF testing time to 5 min; and the SWSF test may be skipped for SjS patients with USWF > 0.2 mL/min, indicating mild secretory hypofunction, or < 0.05 mL/min, indicating moderate to severe secretory hypofunction. Key Points •A diagnostic cohort of 734 patients with clinical suspicion of SjS provides compelling evidence for the potential to reduce the testing time for UWSF from 10 to 5 min. •Our finding challenges the 2019 treatment recommendation for SjS, which does not require SWSF measurement in SjS patients with UWSF ≥ 0.1 mL/min. •We propose that it may be feasible to consider utilizing UWSF instead of SWSF test for objective classification of SG secretory function in over half of SjS patients.

Evidence that autoantibody production may be driven by acute Epstein-Barr virus infection in Sjögren's disease

OBJECTIVES

Sjögren's disease (SD) is an autoimmune disease affecting the exocrine glands that is associated with autoantibodies against Ro60/SS-A, anti-Ro52/TRIM21, La/SS-B and others. We examined the role of acute Epstein-Barr virus (EBV) infection in the pathogenesis of these autoantibodies in a previously healthy patient (patient 1) with primary EBV infection who developed SD with anti-Ro/La and anti-Smith/U1 ribonucleoprotein (Sm/U1RNP) autoantibodies and had lymphoplasmacytic foci on labial salivary gland biopsy.

METHODS

Immune responses to Epstein-Barr nuclear antigen-1 (EBNA1) and the Ro52/Ro60/La and Sm/U1RNP autoantigens and peptides were examined by immunoassay in patient 1, healthy and disease controls.

RESULTS

Anti-Ro52 and anti-Ro60 autoantibodies were present 7 days after primary infection and underwent IgM to IgG switching, suggesting that EBV infection promoted their production. More than 7 months after primary infection, new and increasing levels of antibodies against EBNA1 and the U1RNP autoantigen appeared concomitantly. These antibodies bound homologous peptide sequences shared by EBNA1, SmB' and the U1-C (U1RNP) protein, consistent with induction by molecular mimicry. Although Ro60 and EBNA1 crossreact immunologically, we found that anti-Ro60/anti-Ro52 antibody production was stimulated by acute EBV infection long before the onset of anti-EBNA1. Unexpectedly, a subset of healthy control sera had anti-SmB' peptide antibodies that were not correlated with anti-EBNA1 peptide antibodies. In contrast, anti-SmB' and EBNA1 peptide antibody levels correlated in anti-Sm/U1RNP+ lupus sera.

CONCLUSIONS

Primary EBV infection can promote anti-Ro60/anti-Ro52 and anti-U1RNP responses, though by different mechanisms. Some healthy individuals produce anti-SmB' peptide autoantibodies independently of a response to EBNA1.

Sicca syndrome/Sjögren's disease associated with cancer immunotherapy: a narrative review on clinical presentation, biomarkers, and management

INTRODUCTION

Almost one-quarter of immune checkpoint inhibitor (ICI) recipients experience sicca syndrome, while Sjögren's disease (SjD) is estimated at 0.3-2.5%, possibly underreported.

AREAS COVERED

This narrative review (Medline/Embase until January/31/2024) addresses the pathophysiology, incidence, demographic/clinical features, biomarkers, labial salivary gland biopsy (LSGB), fulfillment of the idiopathic SjD (iSjD) classificatory criteria, differential diagnosis, and management of sicca syndrome/SjD associated with ICIs.

EXPERT OPINION

SjD associated with ICIs is underdiagnosed, since studies that performed the mandatory SjD investigation identified that 40-60% of patients with sicca syndrome associated with ICIs meet the iSjD classificatory criteria. LSGB played a fundamental role in recognizing these cases, as most of them had negative anti-Ro/SS-A antibody. Despite the finding of focal lymphocytic sialoadenitis in LSGB samples mimicking iSjD, immunohistochemical analysis provided novel evidence of a distinct pattern for sicca syndrome/SjD associated with ICIs compared to iSjD. The former has scarcity of B lymphocytes, which are a hallmark of iSjD. Additionally, patients with sicca syndrome/SjD associated with ICIs have demographical/clinical/serological and treatment response dissimilarities compared to iSjD. Dryness symptoms are more acute in the former than in iSjD, with predominance of xerostomia over xerophthalmia, and partial/complete response to glucocorticoids. Dryness symptoms in ICI-treated patients warrant prompt SjD investigation.

Exploring Salivary Epithelial Dysfunction in Sjögren's Disease

Sjögren's Disease (SjD) is an autoimmune disease of the exocrine tissues. Etiological events result in the loss of epithelial homeostasis alongside extracellular matrix (ECM) destruction within the salivary and lacrimal glands, followed by immune cell infiltration. In this review, we have assessed the current understanding of epithelial-mesenchymal transition (EMT)-associated changes within the salivary epithelium potentially involved in salivary dysfunction and SjD pathogenesis. We performed a PubMed literature review pertaining to the determination of pathogenic events that lead to EMT-related epithelial dysfunction and signaling in SjD. Molecular patterns of epithelial dysfunction in SjD salivary glands share commonalities with EMT mediating wound healing. Pathological changes altering salivary gland integrity and function may precede direct immune involvement while perpetuating MMP9-mediated ECM destruction, inflammatory mediator expression, and eventual immune cell infiltration. Dysregulation of EMT-associated factors is present in the salivary epithelium of SjD and may be significant in initiating and perpetuating the disease. In this review, we further highlight the gap regarding mechanisms that drive epithelial dysfunction in salivary glands in the early or subclinical pre-lymphocytic infiltration stages of SjD.

TLR7 activation of age-associated B cells mediates disease in a mouse model of primary Sjögren's disease

Primary Sjögren's disease (pSD) (also referred to as Sjögren's syndrome) is an autoimmune disease that primarily occurs in women. In addition to exocrine gland dysfunction, pSD patients exhibit B cell hyperactivity. B cell-intrinsic TLR7 activation is integral to the pathogenesis of systemic lupus erythematosus, a disease that shares similarities with pSD. The role of TLR7-mediated B cell activation in pSD, however, remains poorly understood. We hypothesized that age-associated B cells (ABCs) were expanded in pSD and that TLR7-stimulated ABCs exhibited pathogenic features characteristic of disease. Our data revealed that ABC expansion and TLR7 expression were enhanced in a pSD mouse model in a Myd88-dependent manner. Splenocytes from pSD mice showed enhanced sensitivity to TLR7 agonism as compared with those derived from control animals. Sort-purified marginal zone B cells and ABCs from pSD mice showed enhanced inflammatory cytokine secretion and were enriched for antinuclear autoantibodies following TLR7 agonism. Finally, IgG from pSD patient sera showed elevated antinuclear autoantibodies, many of which were secreted preferentially by TLR7-stimulated murine marginal zone B cells and ABCs. These data indicate that pSD B cells are hyperresponsive to TLR7 agonism and that TLR7-activated B cells contribute to pSD through cytokine and autoantibody production. Thus, therapeutics that target TLR7 signaling cascades in B cells may have utility in pSD patients.

Evaluation and management of dry mouth and its complications in rheumatology practice

INTRODUCTION

The symptom of dry mouth has multiple potential etiologies and can be a diagnostic clue to the presence of common systemic diseases encountered in rheumatology practice. The presence of decreased saliva flow (i.e. salivary hypofunction) defines a subset of dry mouth patients in whom there may be reversible drug effects, an iatrogenic insult such as head and neck irradiation, or a disease that directly involves the salivary glands (e.g. Sjögren's disease). The assessment of salivary hypofunction includes sialometry, salivary gland imaging, salivary gland biopsy, and an assessment for relevant systemic diseases. Optimal management of dry mouth requires accurate definition of its cause, followed by general measures that serve to alleviate its symptoms and prevent its complications.

AREAS COVERED

Through a literature search on xerostomia and salivary hypofunction, we provide an overview of the causes of dry mouth, highlight the potential impact of salivary hypofunction on oral and systemic health, detail routine evaluation methods and treatment strategies, and emphasize the importance of collaboration with oral health care providers.

EXPERT OPINION

Our Expert Opinion is provided on unmet needs in the management of dry mouth and relevant research progress in the field.

Central Corneal Subbasal Nerve Plexus Abnormalities in Sjögren Disease: A Pilot Study

PURPOSE

Small-fiber neuropathy (SFN) is known to be associated with Sjögren disease (SjD), and in vivo corneal confocal microscopy can identify features compatible with SFN. Here, we performed a descriptive study to identify features of SFN of the corneal subbasal nerve plexus using in vivo confocal microscopy.

METHODS

We recruited 10 participants from the Sjögren's International Collaborative Clinical Alliance (SICCA), 1 new participant (in an effort to expand the SICCA cohort), and 22 healthy controls. All participants underwent slit-lamp examination and in vivo confocal microscopy of the central corneal subbasal nerve plexus centered about the central whorl to create a 30-image montage. Each image was analyzed with automated software (ACCmetrics, Manchester, United Kingdom) to produce 7 nerve metrics. We performed t-tests and age-adjusted regressions to make comparisons of nerve metrics between participants with SjD and healthy controls.

RESULTS

Most nerve metrics were significantly lower in participants with SjD compared with healthy controls. The mean corneal nerve fiber density was found to be 3.5 mm/mm 2 in participants with SjD compared with 10.6 mm/mm 2 in healthy controls (95% confidence interval, -8.4 to -0.93; P = 0.02). Within the 11 participants with SjD, 22 eyes were analyzed on confocal microscopy, and 16 of those eyes (from 9 individuals) did not have an identifiable central whorl. Within the 22 healthy controls, 22 eyes (right eye alone) were analyzed on confocal microscopy, and 21 of those eyes had an identifiable central whorl.

CONCLUSIONS

SjD exhibits lower corneal nerve metrics compared with healthy controls. These findings suggest that features compatible with SFN can distinguish SjD from healthy controls and may serve as a potential novel biomarker in identifying SjD.

Marginal Zone B (MZB) Cells: Comparison of the Initial Identification of Immune Activity Leading to Dacryoadenitis and Sialadenitis in Experimental Sjögren's Syndrome

Although multiple mouse strains have been advanced as models for Sjögren's syndrome (SS), which is a human systemic autoimmune disease characterized primarily as the loss of lacrimal and salivary gland functions, the C57BL/6.NOD-Aec1Aec2 recombinant inbred (RI) mouse derived from the NOD/ShiLtJ line is considered one of the more appropriate models exhibiting virtually all the characteristics of the human disease. This mouse model, as well as other mouse models of SS, have shown that B lymphocytes are essential for the onset and development of observed clinical manifestations. Recently, studies carried out in the C57BL/6.IL14α transgenic mouse have provided clear evidence that the marginal zone B (MZB) cell population is directly involved in the early pathological events initiating the development of the clinical SS disease, as well as late-stage lymphomagenesis resulting in B-cell lymphomas. Since MZB cells are difficult to study in vivo and in vitro, we carried out a series of ex vivo investigations that utilize temporal global RNA transcriptomic analyses to profile differentially expressed genes exhibiting temporal upregulation during the initial onset and subsequent development of pathophysiological events within the lacrimal and salivary gland tissues per se or associated with the leukocyte cell migrations into these glands. The initial transcriptomic analyses revealed that while the upregulated gene expression profiles obtained from lacrimal and salivary glands overlap, multiple genetic differences exist between the defined activated pathways. In the current study, we present a concept suggesting that the initial pathological events differ between the two glands, yet the subsequent upregulated TLR4/TLR3 signal transduction pathway that activates the type-1 interferon signature appears to be identical in the two glands and indicates an autoimmune response against dsRNA, possibly a virus. Here, we attempt to put these findings into perspective and determine how they can impact the design of future therapeutic protocols.

Phases and Natural History of Sjögren's Disease: A New Model for an Old Disease?

Sjögren's disease (SjD) is an archetypal and heterogenous autoimmune disorder that is characterized by exocrine glandular dysfunction. A proportion of patients develop severe extraglandular manifestations, such as cryoglobulinemia, and have an increased risk of lymphoma, both of which can adversely affect quality of life and occasionally mortality. As with most autoimmune disorders, the pathogenesis is poorly understood and difficult to predict, and, frustratingly, there is a lack of targeted therapies to cure this disease. We review the disease manifestations of SjD and propose a staged model for understanding the evolution of pathology. In longitudinal studies, most patients remain relatively stable in terms of their laboratory and clinical parameters. However, in the setting of various risk factors, a proportion of patients develop severe symptoms and/or lymphoma. We discuss potential underlying mechanisms for disease progression and the strengths and limitations of using a staged model to correlate the pathogenesis and spectrum of manifestations in SjD. Ultimately, understanding how and why some patients remain relatively stable, whereas others progress and develop florid systemic disease and a fraction develop lymphoma, is key to developing preventative and therapeutic treatments.

VDR Gene Single Nucleotide Polymorphisms and Autoimmunity: A Narrative Review

The vitamin D/Vitamin D receptor (VDR) axis is crucial for human health as it regulates the expression of genes involved in different functions, including calcium homeostasis, energy metabolism, cell growth and differentiation, and immune responses. In particular, the vitamin D/VDR complex regulates genes of both innate and adaptive immunity. Autoimmune diseases are believed to arise from a genetic predisposition and the presence of triggers such as hormones and environmental factors. Among these, a role for Vitamin D and molecules correlated to its functions has been repeatedly suggested. Four single nucleotide polymorphisms (SNPs) of the VDR gene, ApaI, BsmI, TaqI, and FokI, in particular, have been associated with autoimmune disorders. The presence of particular VDR SNP alleles and genotypes, thus, was observed to modulate the likelihood of developing diverse autoimmune conditions, either increasing or reducing it. In this work, we will review the scientific literature suggesting a role for these different factors in the pathogenesis of autoimmune conditions and summarize evidence indicating a possible VDR SNP involvement in the onset of these diseases. A better understanding of the role of the molecular mechanisms linking Vitamin D/VDR and autoimmunity might be extremely useful in designing novel therapeutic avenues for these disorders.

Sex-specific differences in primary Sjögren's disease

Many autoimmune diseases show a striking female sex predilection, including primary Sjögren's disease (pSD). Patients with pSD display exocrine gland pathology, such as salivary hypofunction and salivary and lacrimal gland inflammation. Moreover, many serious systemic disease manifestations are well-documented, including interstitial nephritis, hypergammaglobulinemia and neuropathies. Of note, women and men with pSD display distinct clinical phenotypes. While the underlying reasons for these clinical observations were poorly understood for many years, recent studies provide mechanistic insights into the specific regulatory landscapes that mediate female susceptibility to autoimmunity. We will review factors that contribute to the female sex bias, with an emphasis on those that are most relevant to pSD pathogenesis. Specifically, we will focus on sex hormones in disease, genetic alterations that likely contribute to the significant disease prevalence in females, and studies that provide evidence for the role of the gut microbiota in disease. Lastly, we will discuss therapeutics that are in clinical trials for pSD that may be particularly efficacious in targeting signaling networks that mediate inflammation in a sex-specific manner.

How Are Sicca Signs and Symptoms Associated With Depression Among Men Classified With and Without Sjögren Disease?

PURPOSE

Sjögren disease (SjD) cohorts represent rich resources to study associations between dry eye/mouth (sicca) signs/symptoms and depression. Because SjD affects mainly women, little is known about men with sicca signs/symptoms and associations with depression. The Sjögren's International Collaborative Clinical Alliance contained many men allowing for studying associations between sicca signs/symptoms and depression. We hypothesized that sicca symptoms would be positively associated with depression in males.

DESIGN

Cross-sectional study.

METHODS

At baseline, participants completed questionnaires and underwent ocular and oral examinations. Depression was assessed using the Patient Health Questionnaire-9. Logistic regression models were used to identify associations between depression and SjD diagnostic criteria and sicca symptoms.

RESULTS

Of 309 males, 98 were classified as SjD, whereas 198 were classified as non-SjD. We found that having a labial salivary gland biopsy with focus score ≥1 foci/mm² was associated with a lower odds of being classified as depressed (odds ratio [OR]: 0.36, 95% CI: 0.18-0.73, P = .01). Having positive anti-Sjögren syndrome antigen A antibody was associated with lower odds of being classified as depressed (OR: 0.44, 95% CI: 0.23-0.88, P = .02). Higher odds of depression were found with ocular burning (OR: 3.16, 95% CI: 1.74-5.73, P < .001), light sensitivity (OR: 2.59, 95% CI: 1.48-4.55, P = .001), and complaints of dry mouth (OR: 4.58, 95% CI: 1.54-13.63, P = .006).

CONCLUSION

Ophthalmologists should be specific when inquiring about ocular discomfort (focusing on burning and light sensitivity) and consider querying about depression and/or providing mental health resources to those who endorse such qualities.

Associations of diagnostic findings with disease activity in primary Sjӧgren's syndrome: a cluster analysis

OBJECTIVE

The diagnosis of primary Sjӧgren's syndrome still relies upon a constellation of clinical, laboratory, imaging, and pathological findings. We aimed to evaluate the relation of the disease activity with the results of diagnostic tests for primary Sjӧgren's syndrome.

METHODS

A principal component with cluster analysis was performed to classify 69 patients with primary Sjӧgren's syndrome based on the results of diagnostic evaluations.

RESULTS

Anti-SSA autoantibody was the most represented feature on the principal components. The anti-SSA and ultrasound score were positively correlated (p=0.001). We identified two distinct clusters of low or high disease activity (p<0.001). Except for disease duration and serum beta2-microglobulin, the clusters were significantly different in salivary flow (p= 0.004), ultrasound findings (p<0.001), IgG (p= 0.001), and salivary beta2-microglobulin (p= 0.048). Also, positive findings were significantly different between the clusters in rheumatoid factor, antinuclear antibody, anti-SSA, and anti-SSB (all p≤0.013).

CONCLUSION

Patients with higher syndrome activity were best recognized with serological and ultrasound assessments. However, patients with lower syndrome activity had a longer disease duration, higher stimulated salivary flow rate, and a positive biopsy of minor salivary glands (56%).

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.

Clinical and laboratory evaluation of sicca complaints: distinctive aspects of primary, secondary and non-Sjogren syndrome

Background

Sjögren Syndrome (SS) is a systemic autoimmune disease with a wide spectrum of manifestations that can lead to misdiagnosis. This study describes and compares demographic, clinical, serological, and histopathological data from subjects with SS and non-Sjögren Syndrome (NSS). It also details specific features within the primary SS (pSS) and secondary SS (sSS) groups identifying sub-groups.

Methods

The sample included individuals referred to an academic medical center in Brazil for investigation of SS from 2012 to 2020. Patients were retrospectively classified as primary SS (pSS), secondary SS (sSS), or NSS, based on the American-European Consensus Group criteria (AECG-2002), after multi-professional clinical and laboratory evaluation.

Results

A total of 676 individuals were screened and 510 (75.4%) completed the assessments; 198 patients were classified as pSS, 149 as sSS, and 163 as NSS. Symptoms and glandular dysfunction tests were similar in the groups. Concerning pSS, extraglandular manifestations were present in 59% of patients; the elderly had more dry symptoms and peripheral neurological disorders; and 2.5% developed non-Hodgkin lymphoma. In sSS, each overlap promoted distinct clinical and laboratory variants. Several alternative diagnoses were identified as a cause of sicca complex in NSS group.

Conclusions

The diagnosis of SS remains a challenge behind dryness. Up to 31% of the suspected cases had other conditions associated to the symptoms. Histopathological analysis of LSG and SSa determined the diagnostic. Aging in pSS and overlap disease in sSS were responsible for distinct phenotypes and characteristic sub-groups in SS.

Updates in diagnostics, treatments, and correlations between oral and ocular manifestations of Sjogren's syndrome

Sjogren's syndrome (SS) is characterized as an autoimmune disorder targeting secretory glands, including the lacrimal and salivary glands, causing dry eye and dry mouth predominantly in women over the age of 40. In this review, we summarize recent advancements in SS diagnostics, treatments, and our understanding of correlations between oral and ocular manifestations of SS. Google Scholar and PubMed databases were utilized to search peer-reviewed papers since 2016 on SS diagnosis, treatment, and correlations between oral and ocular manifestations. For diagnostics, we discuss the updated SS classification criteria by the American College of Rheumatology/European League Against Rheumatism (ACR/EULAR), new biomarkers, and compare studies of current diagnostic methods with alternative technologies. For treatments, we discuss topical, systemic, and surgical treatment developments in the management of oral and ocular symptoms of SS as there is still no cure for the disorder. Finally, we report studies that directly suggest correlations between the ocular surface disease and oral disease in SS, as well as shared abnormalities in the microbiome and cytokine expression that may be correlated. We conclude by stating limitations to our review as well as paths moving forward. Elucidating correlations between oral and ocular manifestations may be the key to furthering our understanding of SS pathogenesis as well as defining new standards for diagnosis and treatment.

Cardiovascular Disease in Primary Sjögren's Syndrome: Raising Clinicians' Awareness

In the ever evolving landscape of systemic immune mediated diseases, an increased awareness regarding the associated cardiovascular system impairment has been noted in recent years. Even though primary Sjögren's Syndrome (pSS) is one of the most frequent autoimmune diseases affecting middle-aged individuals, the cardiovascular profile of this specific population is far less studied, at least compared to other autoimmune diseases. Traditional cardiovascular risk factors and disease specific risk factors are inextricably intertwined in this particular case. Therefore, the cardiovascular risk profile in pSS is a multifaceted issue, sometimes difficult to assess. Furthermore, in the era of multimodality imaging, the diagnosis of subclinical myocardial and vascular damage is possible, with recent data pointing that the prevalence of such involvement is higher in pSS than in the general population. Nevertheless, when approaching patients with pSS in terms of cardiovascular diseases, clinicians are often faced with the difficult task of translating data from the literature into their everyday practice. The present review aims to synthesize the existing evidence on pSS associated cardiovascular changes in a clinically relevant manner.

Beyond Systemic Lupus Erythematosus and Anti-Phospholipid Syndrome: The Relevance of Complement From Pathogenesis to Pregnancy Outcome in Other Systemic Rheumatologic Diseases

Evidence about the relevance of the complement system, a highly conserved constituent of the innate immunity response that orchestrates the elimination of pathogens and the inflammatory processes, has been recently accumulated in many different rheumatologic conditions. In rheumatoid arthritis, complement, mainly the classical pathway, contributes to tissue damage especially in seropositive subjects, with complement activation occurring in the joint. Data about complement pathways in psoriatic arthritis are dated and poorly consistent; among patients with Sjögren syndrome, hypocomplementemia exerts a prognostic role, identifying patients at risk of extra-glandular manifestations. Hints about complement involvement in systemic sclerosis have been recently raised, following the evidence of complement deposition in affected skin and in renal samples from patients with scleroderma renal crisis. In vasculitides, complement plays a dual role: on one hand, stimulation of neutrophils with anti-neutrophil cytoplasmic antibodies (ANCA) results in the activation of the alternative pathway, on the other, C5a induces translocation of ANCA antigens, favouring the detrimental role of antibodies. Complement deposition in the kidneys identifies patients with more aggressive renal disease; patients with active disease display low serum levels of C3 and C4. Even though in dermatomyositis sC5b-9 deposits are invariably present in affected muscles, data on C3 and C4 fluctuation during disease course are scarce. C3 and C1q serum levels have been explored as potential markers of disease activity in Takayasu arteritis, whereas data in Behçet disease are limited to in vitro observations. Pregnancies in women with rheumatologic conditions are still burdened by a higher rate of pregnancy complications, thus the early identification of women at risk would be invaluable. A fine-tuning of complement activation is required from a physiological progression of pregnancy, from pre-implantation stages, through placentation to labour. Complement deregulation has been implicated in several pregnancy complications, such as recurrent abortion, eclampsia and premature birth; low complement levels have been shown to reliably identify women at risk of complications. Given its physiologic role in orchestrating pregnancy progression and its involvement as pathogenic effector in several rheumatologic conditions, complement system is an attractive candidate biomarker to stratify the obstetric risk among women with rheumatologic conditions.

An Update on the Lived Experience of Dry Mouth in Sjögren's Syndrome Patients

This paper aims to provide an update on research findings on the lived experience of dry mouth in Sjögren's Syndrome (SS) patients. Dry mouth is a significant condition that impacts on the daily lives of people with SS. There will first be a summary of the definition, etiology, and manifestation of dry mouth in SS patients. There will next be an overview of the measurement of the impact of dry mouth on the quality of life in SS patients. This will include a deliberation of both quantitative and qualitative methods. Lastly, there will be discussion on the consequences of dry mouth, with a focus on qualitative studies that seek to understand patients' physical, emotional, and social domains of life.

Immune-Intrinsic Myd88 Directs the Production of Antibodies With Specificity for Extracellular Matrix Components in Primary Sjögren's Syndrome

Primary Sjögren's syndrome is an autoimmune disease that is predominantly seen in women. The disease is characterized by exocrine gland dysfunction in combination with serious systemic manifestations. At present, the causes of pSS are poorly understood. Pulmonary and renal inflammation are observed in pSS mice, reminiscent of a subset of pSS patients. A growing body of evidence indicates that inflammation mediated by Damage-Associated Molecular Patterns (DAMPs) contributes to autoimmunity, although this is not well-studied in pSS. Degraded extracellular matrix (ECM) constituents can serve as DAMPs by binding pattern-recognition receptors and activating Myd88-dependent signaling cascades, thereby exacerbating and perpetuating inflammatory cascades. The ECM components biglycan (Bgn) and decorin (Dcn) mediate sterile inflammation and both are implicated in autoimmunity. The objective of this study was to determine whether these ECM components and anti-ECM antibodies are altered in a pSS mouse model, and whether this is dependent on Myd88 activation in immune cells. Circulating levels of Bgn and Dcn were similar among pSS mice and controls and tissue expression studies revealed pSS mice had robust expression of both Bgn and Dcn in the salivary tissue, saliva, lung and kidney. Sera from pSS mice displayed increased levels of autoantibodies directed against ECM components when compared to healthy controls. Further studies using sera derived from conditional knockout pSS mice demonstrated that generation of these autoantibodies relies, at least in part, on Myd88 expression in the hematopoietic compartment. Thus, this study demonstrates that ECM degradation may represent a novel source of chronic B cell activation in the context of pSS.

The Transcriptome of Paired Major and Minor Salivary Gland Tissue in Patients With Primary Sjögren's Syndrome

Background

While all salivary glands (SGs) can be involved in primary Sjögren's syndrome (pSS), their respective role in pathogenesis remains unclear. Our objective was to assess immunopathway activation in paired parotid and labial gland tissue from biopsy-positive and biopsy-negative pSS and non-SS sicca patients.

Methods

Paraffin-embedded, paired parotid and labial salivary gland tissue and peripheral blood mononuclear cells were obtained from 39 pSS and 20 non-SS sicca patients. RNA was extracted, complementary DNA libraries were prepared and sequenced. For analysis of differentially expressed genes (DEGs), patients were subdivided based on fulfillment of ACR-EULAR criteria and histopathology.

Results

With principal component analysis, only biopsy-positive pSS could be separated from non-SS sicca patients based on SG gene expression. When comparing the transcriptome of biopsy-positive pSS and biopsy-negative non-SS sicca patients, 1235 and 624 DEGs (FDR<0.05, log2FC<-1 or >1) were identified for parotid and labial glands, respectively. The number of DEGs between biopsy-negative pSS and non-SS sicca patients was scarce. Overall, transcript expression levels correlated strongly between parotid and labial glands (R2 = 0.86, p-value<0.0001). Gene signatures present in both glands of biopsy-positive pSS patients included IFN-α signaling, IL-12/IL-18 signaling, CD3/CD28 T-cell activation, CD40 signaling in B-cells, DN2 B-cells, and FcRL4+ B-cells. Signature scores varied considerably amongst pSS patients.

Conclusion

Transcriptomes of paired major and minor SGs in pSS were overall comparable, although significant inter-individual heterogeneity in immunopathway activation existed. The SG transcriptome of biopsy-negative pSS was indistinguishable from non-SS sicca patients. Different patterns of SG immunopathway activation in pSS argue for personalized treatment approaches.

Stimulated whole salivary flow rate: The most appropriate technique for assessing salivary flow in Sjögren syndrome

BACKGROUND

We sought to determine the most appropriate method for measuring salivary flow to aid the diagnosis of Sjögren's syndrome (SS). Specifically, we compared the unstimulated whole salivary flow rate (UWSFR) with the stimulated whole salivary flow rate (SWSFR).

MATERIAL AND METHODS

This case-control study comprised one group of 103 patients with SS and a control group of 50 healthy people. We measured the UWSFR and SWSFR in both groups according to the guidelines established by Navacet [1993].

RESULTS

The UWSFR and SWSFR were significantly lower in the patient group compared with the controls (p < 0.01). Among the participants in the patient group, we found a decreased UWSFR in 84 individuals (81.5%) and a decreased SWSFR in 90 individuals (87.4%). We encountered difficulties obtaining saliva in 37 (35.9%) patients during the UWSFR test, and in 12 (11.7%) patients during the SWSFR test. There was no significant statistical difference in the UWSFR or SWSFR between patients with primary and secondary SS.

CONCLUSIONS

Compared with the UWSFR, the SWSFR is a more suitable and effective method for measuring salivary flow in patients with SS, as well as for qualitative analysis of the obtained saliva.

Ocular Pathophysiology of Sjögren's Syndrome

The purpose of this review is to delve into the clinical and research understanding of the pathophysiology and presentation of Sjögren's-related keratoconjunctivitis sicca in order address the diagnostic and management challenge that it represents, as well as to provide a basis for appreciating the pharmacotherapies designed to treat the ophthalmic symptoms of Sjögren's disease.

Clinical and laboratory features of patients with focal lymphocytic sialadenitis on minor salivary gland biopsy for sicca symptoms: A single-center experience

Minor salivary gland biopsy (MSGB) is often used in patients lacking specific autoantibodies (seronegative patients) to confirm the presence of focal lymphocytic sialadenitis (FLS), which would suggest a diagnosis of Sjogren syndrome. There are no current guidelines indicating when to refer patients for MSGB. The objective of our study was to ascertain distinguishing clinical and laboratory features among individuals with sicca symptoms based on their serologic and histopathologic status, and to identify factors associated with FLS.Using a cross-sectional study design, patients ages 18 years or older with sicca symptoms who had MSGB performed at the University of Iowa from January 2000 to December 2016 were selected for chart reviews. The clinical and laboratory features of patients with and without FLS were analyzed using exact univariate and multivariable logistic regression, with Bonferroni correction for multiple comparisons.We identified 177 patients who had MSGB performed and available clinical data. A total of 133 patients had FLS, 37 (27.8%) were seropositive (positive-anti-Sjogren syndrome type A [SSA] and/or anti-Sjogren syndrome type B) and 96 (72.2%) were seronegative. Dry eyes (unadjusted odds ratio [OR]: 5.17, 95% confidence interval [CI]: 1.16-26.30; adjusted odds ratio [aOR]: 12.58, 95% CI: 1.70-167.77) and the presence of anti-SSA (OR: 7.16, 95% CI: 1.70-64.24; aOR: 8.82, 95% CI: 1.73-93.93) were associated with FLS. Smoking (aOR 0.27, 95% CI: 0.11-0.63) and antihistamine use (aOR 0.23, 95% CI: 0.08-0.63) were associated with lower odds of FLS.Our study suggests that dry eyes and anti-SSA positivity are associated with FLS. Smoking and antihistamine use were associated with lower odds of FLS. In the appropriate clinical context, seronegative patients with sicca symptoms and no smoking history could be considered for MSGB. A thorough medication and smoking history should be performed in all patients before referral for MSGB.

Tissue-specific activation of Myd88-dependent pathways governs disease severity in primary Sjögren's syndrome

Myd88 activation is an important driver of autoimmunity. Primary Sjögren's syndrome (pSS) is an autoimmune disease characterized by exocrine gland dysfunction in combination with serious systemic disease manifestations. Myd88-dependent signaling networks remain incompletely understood in the context of pSS. The objective of this study was to establish the contribution of tissue-specific Myd88 activation to local (exocrine) and systemic pSS manifestations. To this end, we generated two novel conditional knockout pSS mouse models; one lacking Myd88 in hematopoietic cells and a second strain in which Myd88 was deleted in the stromal compartment. Spontaneous production of inflammatory mediators was altered in salivary tissue, and nephritis was diminished in both conditional knockout strains. In contrast, pulmonary inflammation was increased in mice lacking Myd88 in hematopoietic cells and was reduced when Myd88 was ablated in stromal cells. Finally, anti-nuclear autoantibodies (ANAs) were attenuated in pSS mice lacking Myd88 in immune cells. Additionally, the ANA-specific B cell repertoire was skewed in the Myd88-deficient strains. Collectively, these data demonstrate that Myd88 activation in specific cell types is essential for distinct aspects of pSS pathology.

A New Screening Questionnaire to Identify Patients With Dry Eye With a High Likelihood of Having Sjögren Syndrome

PURPOSE

To develop a screening questionnaire to identify patients with dry eye with a high likelihood of having underlying Sjögren syndrome (SS).

METHODS

This was a cross-sectional study of participants with dry eye complaints who were self-referred or referred by an ophthalmologist to the Sjögren's International Collaborative Clinical Alliance study. Symptoms and ocular surface examination findings were candidate predictors. Univariable and multivariable logistic regression analyses were performed to estimate odds ratios (ORs) and 95% confidence intervals (95% CI) for the association of a symptom and/or ocular sign with SS. Area under the receiver operating characteristic curve (AUC) was used to summarize the predictive ability of different regression models and the derived likelihood score.

RESULTS

Four questions were statistically significant in the final multivariable model: 1) Is your mouth dry when eating a meal? [Yes = OR 1.63 (1.18-2.26)]; 2) Can you eat a cracker without drinking a fluid or liquid? [No = OR 1.46 (1.06-2.01)]; 3) How often do you have excessive tearing? [None of the time = OR 4.06 (1.81-9.10)]; and 4) Are you able to produce tears? [No = OR 2.24 (1.62-3.09)]. The SS likelihood score had an AUC of 0.70 (95% CI, 0.66-0.73), and when including tear break-up time and conjunctival staining, it yielded an AUC of 0.79 (95% CI, 0.77-0.82).

CONCLUSIONS

This questionnaire can be used to identify patients with dry eye with a high likelihood of having SS. With future refinement and validation, this screening tool could be used alone or in combination with examination findings to identify patients with SS earlier, thereby facilitating better clinical outcomes.

Early diagnosis and treatment for Sjögren's syndrome: current challenges, redefined disease stages and future prospects

There are some challenges and unmet needs in the early diagnosis and management of Sjögren's syndrome (SjS) such as prominent glandular dysfunction at diagnosis and long diagnostic delay. Those challenges are partly attributed to the lack of a good knowledge of the early stages of SjS, which is a major obstacle to delivering appropriate care to SjS patients. Findings from both clinical and experimental studies suggest the plausibility of a redefined SjS course consisting of 4 stages, which includes initiation stage, preclinical stage, asymptomatic SjS stage and overt SjS stage. More studies focusing on the pathological processes and changes during the early stages of SjS are needed. To enable early diagnosis and treatment for SjS, more useful biomarkers of the early stages of SjS need to be identified, and individuals at high risk of SjS development need to be identified. Appropriate screening can be performed to facilitate the early diagnosis of SjS among those high-risk individuals.

Novel insights on lymphoma and lymphomagenesis in primary Sjögren's Syndrome

Primary Sjögren's Syndrome (pSS) is a systemic autoimmune disease characterized by a chronic inflammatory process mainly affecting the exocrine glands but also burdened by a wide range of extraglandular manifestations. Non-Hodgkin lymphoma (NHL) is the most severe pSS complication worsening disease prognosis. We summarized original articles published between April 2018 and May 2020 on this topic aiming to highlight novelties on lymphoma and lymphomagenesis. Results have been grouped by epidemiology, etiopathogenesis and predictors of lymphoma. NHL is the most severe complication of pSS and occurs in around 5-10% of patients. Over the last two years, several clinical, serological, and histopathological features have been proposed as predictive for lymphoma in pSS patients, allowing early diagnosis and consequently, better management and prognosis. Individual monitoring for disease activity and possible lymphoma development is a central clue in the evaluation of pSS patients.

Prevalence of Novel Candidate Sjögren Syndrome Autoantibodies in the Penn Sjögren's International Collaborative Clinical Alliance Cohort

PURPOSE

To evaluate the prevalence of novel candidate autoantibodies associated with Sjögren syndrome (SS) and their ability to identify those with SS among participants with dry eye enrolled in the Sjögren's International Collaborative Clinical Alliance (SICCA) study at the University of Pennsylvania (Penn).

METHODS

All participants previously underwent a full ocular and systemic evaluation for possible SS as part of the SICCA study. An enzyme-linked immunosorbent assay was used to detect IgG, IgA, and IgM autoantibodies to salivary protein 1 (SP-1), parotid secretory protein (PSP), and carbonic anhydrase 6 from previously banked baseline serum samples from SICCA study participants enrolled at Penn. The prevalence rate of each autoantibody, calculated by considering the presence of any isotype as antibody positive, was compared between participants with dry eye with SS (n = 81) or without SS (n = 129) using the Fisher exact test.

RESULTS

The prevalence of SP-1 IgM autoantibodies was higher in those with SS compared with those without SS (14% vs. 5%; P = 0.03). Similarly, the prevalence of PSP IgA autoantibodies was higher in those with SS compared with non-SS dry eye participants (21% vs. 11%; P = 0.048). There was no statistically significant difference in the prevalence of carbonic anhydrase 6 autoantibodies between those with or without SS (15% vs. 20%; P = 0.36).

CONCLUSIONS

In the Penn SICCA cohort, SP-1 IgM and PSP IgA autoantibodies were more prevalent in the serum of SS-related dry eye participants compared with those without SS. Further longitudinal studies are needed to determine the clinical significance of these findings.

Serum immunoglobulin G4 in Sjögren’s syndrome: a pilot study

Immunoglobulin IgG4 plays a role in the pathogenesis of the Mikulicz disease previously considered a form of primary Sjögren's syndrome (pSS). We investigated serum levels of IgG4, total IgG, C3, and C4 serum complementary components in patients suspected of Sjögren’s syndrome. Basic laboratory and immunological tests, including IgG4 and IgG concentration, were performed on 20 healthy and 68 suspected of pSS individuals. We distinguished: group I: 48 pSS patients; group II (sicca): 20 patients with dryness without pSS. We revealed: statistical differences between groups I and II concerning hypergammaglobulinemia, ESR, RF, ANA, Ro, and La antibodies; lower IgG4 levels and IgG4/IgG ratio in group I compared to healthy individuals (p < 0.0435; 0.0035, respectively); no significant differences in the concentrations of IgG4 and IgG4/IgG ratio between sicca and control groups. significantly lower (p < 0.0002) C4 levels in group I compared to other groups; significant differences in C4 concentration and IgG4/IgG ratio between three groups (p = 0.0002 and p = 0.0090, respectively); a weak negative correlation between C4 and IgG (r =− 0.274) in the whole database; weak positive correlation between C4 and IgG4/IgG ratio (r = 0.237); a negative correlation of IgG4, IgG4/Ig ratio and C4 with focus score (r = − 0.281; r = − 0.327; r = − 0.406, respectively). IgG4 serum levels were significantly decreased compared to healthy subjects. IgG4 and C4 levels correlated with infiltrations in minor salivary glands. Hypergammaglobulinemia and decreased serum C4 component levels are typical for pSS.

Toward better outcomes in Sjögren's syndrome: The promise of a stratified medicine approach

Sjögren's syndrome is a systemic autoimmune disease defined by its targeted inflammation of the salivary and lacrimal glands, resulting in dry mouth and eyes in the majority and persistent or recurrent salivary gland enlargement in a minority of those affected. Involvement of major organs, an increased risk of lymphoma, and autoantibodies against ubiquitous cellular ribonucleoproteins define some of its systemic features. Those affected have a high symptom burden and the development of disease-modifying therapies is thus an urgent need. A stratified medicine approach offers promise as a means of targeting specific therapies to patients for whom the mechanism of action is most relevant. Implementation of this approach will require an understanding of the pathophysiological processes underlying different patient subsets, and then identifying or developing a drug that targets this pathway. Such therapies would be most effective if implemented early in the disease course before the advent of adverse outcomes or glandular damage. This review will provide a disease overview followed by an analysis of the feasibility of a stratified medicine approach, focusing on the disease heterogeneity, predictors of disease progression and adverse outcomes, and recent advances in the development of relevant outcome measures and new therapies.

Persistent serological activity in primary Sjögren's syndrome

To assess the presence of persistent serological activity and its association with clinical outcomes in primary Sjögren's syndrome. Clinical charts of 275 patients were reviewed retrospectively. Persistent serological activity was defined as an increase IgG ≥ 1.6 mg/dL or globulins > 3.7 g/dL or diminished C3 < 52 mg/dL or C4 < 12 mg/dL at least during two consecutive visits during a year (index period). The ClinESSDAI at the index period and the cumulative ClinESSDAI and the SSDDI at the last medical appointment were scored. A total of 159 patients with complete serological data were included mostly women and median disease duration of 10.2 years. Persistent serological activity was identified in 85 patients (53.1%). Only 13 patients changed their status to serological inactivity though the follow-up. Comparison of patients with (n = 85) versus without persistent serological activity (n = 74) showed that the first group had a higher frequency of impaired non-stimulated salivary flow, anti-La/SSB antibody, and RF, as well as higher ClinESSDAI scores. The most affected domains were the constitutional, glandular, cutaneous, renal, and hematological domains. On logistic regression analysis, the RF (OR 6.4, 95% CI 1.8-22, p = 0.003), the renal (OR 12.8, 95% CI 1.7-92, p = 0.01), and the hematological involvement (OR 4.7, 95% CI 1.6-13.4, p = 0.004) remained associated. Half of the patients studied had persistent serological activity, being this status constant through the follow-up. Persistent serological activity was associated with positive RF and higher ESSDAI scores due to hematological and renal activity. Scoring serological activity is an important issue in SS patients.

Salivary Gland Stem Cells Age Prematurely in Primary Sjögren's Syndrome

OBJECTIVE

A major characteristic of the autoimmune disease primary Sjögren's syndrome (SS) is salivary gland (SG) hypofunction. The inability of resident SG stem cells (SGSCs) to maintain homeostasis and saliva production has never been explained and limits our comprehension of mechanisms underlying primary SS. The present study was undertaken to investigate the role of salivary gland stem cells in hyposalivation in primary SS.

METHODS

SGSCs were isolated from parotid biopsy samples from controls and patients classified as having primary SS or incomplete primary SS, according to the American College of Rheumatology/European League Against Rheumatism criteria. Self-renewal and differentiation assays were used to determine SGSC regenerative potential, RNA was extracted for sequencing analysis, single telomere length analysis was conducted to determine telomere length, and frozen tissue samples were used for immunohistochemical analysis.

RESULTS

SGSCs isolated from primary SS parotid gland biopsy samples were regeneratively inferior to healthy control specimens. We demonstrated that SGSCs from samples from patients with primary SS are not only lower in number and less able to differentiate, but are likely to be senescent, as revealed by telomere length analysis, RNA sequencing, and immunostaining. We further found that SGSCs exposed to primary SS-associated proinflammatory cytokines we induced to proliferate, express senescence-associated genes, and subsequently differentiate into intercalated duct cells. We also localized p16+ senescent cells to the intercalated ducts in primary SS SG tissue, suggesting a block in SGSC differentiation into acinar cells.

CONCLUSION

This study represents the first characterization of SGSCs in primary SS, and also the first demonstration of a linkage between an autoimmune disease and a parenchymal premature-aging phenotype. The knowledge garnered in this study indicates that disease-modifying antirheumatic drugs used to treat primary SS are not likely to restore saliva production, and should be supplemented with fresh SGSCs to recover saliva production.

Expression of ETS1 and LEF1 in salivary glands of Sjögren syndrome patients

OBJECTIVE

Primary Sjögren's syndrome (pSS) is a systemic autoimmune disease affecting exocrine glands, thereby causing dry mouth and eyes (sicca). Our objective was to determine the expression of pSS pathogenic biomarker MMP9 and its putative transcription factors ETS1 and LEF1, in labial salivary glands of pSS patients.

METHODS

Sicca patients were assigned to three groups based on focus score (FS): non-pSS sicca (i.e., GR1 [FS = 0] and GR2 [0 < FS < 1]) and pSS (i.e., GR3 [FS ≥ 1]). We determined the mRNA and protein expression of MMP9, ETS1, and LEF1 in salivary gland biopsies. Also, ETS1-CD4 and LEF1-CD4 co-expression analyses were performed.

RESULTS

The mRNA expression of MMP9, ETS1, and LEF1 was upregulated in GR3 compared to GR1 (p < 0.01). Most GR3 salivary gland areas had moderate to high MMP9, ETS1, and LEF1 protein expression compared to GR1 and GR2. Further, ETS1-CD4 and LEF1-CD4 dual staining demonstrated that both salivary gland epithelial cells and lymphocytic infiltrates had increased levels of ETS1 and LEF1. Moreover, there was a strong correlation between ETS1(+)-CD4(-) and LEF1(+)-CD4(-) cells.

CONCLUSION

These results suggest, for the first time, a concerted increase in ETS1 and LEF1 expression in salivary gland epithelial cells of pSS patients that is reflective of the etiopathogenesis of pSS.

Performance of the 2016 ACR-EULAR classification criteria for primary Sjogren's syndrome in a Korean cohort

This study compared the performance of the newly proposed 2016 American College of Rheumatology (ACR)/European League Against Rheumatism (EULAR) criteria to the 2002 American-European Consensus Group (AECG) and 2012 ACR classification criteria for primary Sjogren's syndrome (pSS) in well-characterized Korean patients. Patients with pSS from 12 university-affiliated hospitals in Korea were enrolled from October 2013 to January 2017. Clinical and laboratory data were reviewed. For the validation set, patients who underwent evaluation tests to rule out pSS at Seoul St. Mary's hospital from November 2016 to December 2017 were analyzed. Baseline registry data were available in 458 patients, and 328 patients had sufficient data to determine the fulfillment of each criteria set. All three sets of criteria were met by 307 patients (93.6%). The newly proposed 2016 ACR/EULAR criteria were met by 325 patients (99.1%). The 2002 AECG and 2012 ACR criteria were met by 325 (99.1%) and 310 patients (94.5%), respectively. In a validation cohort consisting of 161 patients with pSS-related symptoms/signs, the sensitivity and specificity of the 2016 ACR/EULAR criteria were 100% [95% confidence interval (CI), 96.11-100.00] and 81.8% [95% CI, 76.15-94.26], respectively. Agreement between the 2016 criteria and 2012 or 2002 criteria was high (Cohen's kappa 0.736 and 0.769, respectively). The newly proposed 2016 ACR/EULAR criteria were met by most patients diagnosed with pSS according to previous criteria and showed higher sensitivity and lower specificity compared with both previous criteria sets.