Cutaneous and Mucosal Manifestations of Sjögren's Syndrome

Regional specialization within the mammalian respiratory immune system

The respiratory tract is exposed to infection from inhaled pathogens, including viruses, bacteria, and fungi. So far, a comprehensive assessment that integrates common and distinct aspects of the immune response along different areas of the respiratory tract has been lacking. Here, we discuss key recent findings regarding anatomical, functional, and microbial factors driving regional immune adaptation in the mammalian respiratory system, how they differ between mice and humans, and the similarities and differences with the gastrointestinal tract. We demonstrate that, under evolutionary pressure, mammals evolved spatially organized immune defenses that vary between the upper and lower respiratory tract. Overall, we propose that the functional specialization of the immune response along the respiratory tract has fundamental implications for the management of infectious or inflammatory diseases.

The Impact of Tobacco Smoking on Systemic Sclerosis, Idiopathic Inflammatory Myositis, and Systemic Lupus Erythematosus

This narrative review aims specifically to explore the relationship between tobacco exposure and systemic sclerosis (SSc), idiopathic inflammatory myositis (IIM), and systemic lupus erythematosus (SLE). Relevant articles were obtained by searching key terms such as "tobacco," "smoking," "scleroderma," "myositis," "lupus," and "Sjögren's" in PubMed and Google Scholar databases. The selected articles ranged from the years 2010 to 2023. Inclusion criteria were based on the relevance and contribution to the field of study. Systemic sclerosis is a complex condition involving multiple immune cell lines that can be influenced by tobacco. However, the existing literature does not provide sufficient evidence to support an increased risk of SSc in smokers or the impact on treatment options. Cigarette smoking does increase the risk of skin ulcerations in SSc patients. In addition, cigarette smoking has been associated with IIM through genetic and molecular mechanisms. Smokers with dermatomyositis or polymyositis are at an elevated risk of atherosclerosis and interstitial lung disease. Similarly, smoking in patients with SLE increases the risk of organ damage, thrombosis, and disease severity compared with non-smokers. Smokers with SLE also have more difficulty in controlling disease flares compared with non-smokers. Tobacco exposure can lead to secondary complications in patients with IIM and SLE, although the course of treatment may not differ significantly. No definitive conclusions can be drawn to the clear relationship between tobacco smoking and Sjögren's's syndrome.

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

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

Advances in cellular and molecular pathways of salivary gland damage in Sjögren's syndrome

Sjögren's Syndrome (SS) is an autoimmune disorder characterized by dysfunction of exocrine glands. Primarily affected are the salivary glands, which exhibit the most frequent pathological changes. The pathogenesis involves susceptibility genes, non-genetic factors such as infections, immune cells-including T and B cells, macrophage, dendritic cells, and salivary gland epithelial cells. Inflammatory mediators such as autoantibodies, cytokines, and chemokines also play a critical role. Key signaling pathways activated include IFN, TLR, BAFF/BAFF-R, PI3K/Akt/mTOR, among others. Comprehensive understanding of these mechanisms is crucial for developing targeted therapeutic interventions. Thus, this study explores the cellular and molecular mechanisms underlying SS-related salivary gland damage, aiming to propose novel targeted therapeutic approaches.

Recommendations on cutaneous and hematological manifestations of Sjögren's disease by the Brazilian Society of Rheumatology

Sjogren's disease (SjD) is an autoimmune disease that is characterized not only by the sicca symptoms it causes but also by its systemic nature, which is capable of several and not yet fully understood extraglandular manifestations. To gain a clearer understanding of these manifestations as well as a better practical approach, a panel of experts from the Brazilian Society of Rheumatology conducted a systematic review and meta-analysis on the identification of epidemiologic and clinical features of the extraglandular manifestations present in ESSDAI (EULAR Sjogren´s syndrome disease activity index), followed by a voting panel with recommendations for clinical practice. This publication is complementary to others already published and covers cutaneous and hematological manifestations, with prevalence data generated by a meta-analysis of 13 clinical or laboratory manifestations and 6 clinical management recommendations.

Emerging biologic frontiers for Sjogren's syndrome: Unveiling novel approaches with emphasis on extra glandular pathology

Primary Sjögren's Syndrome (pSS) is a complex autoimmune disorder characterized by exocrine gland dysfunction, leading to dry eyes and mouth. Despite growing interest in biologic therapies for pSS, FDA approval has proven challenging due to trial complications. This review addresses the absence of a molecular-target-based approach to biologic therapy development and highlights novel research on drug targets and clinical trials. A literature search identified potential pSS treatment targets and recent advances in molecular understanding. Overlooking extraglandular symptoms like fatigue and depression is a notable gap in trials. Emerging biologic agents targeting cytokines, signal pathways, and immune responses have proven efficacy. These novel therapies could complement existing methods for symptom alleviation. Improved grading systems accounting for extraglandular symptoms are needed. The future of pSS treatment may involve gene, stem-cell, and tissue-engineering therapies. This narrative review offers insights into advancing pSS management through innovative biologic interventions.

Ocular and eyelid involvement in collagen vascular diseases. Part I. Sjögren syndrome and systemic lupus erythematosus

Collagen vascular disease is a heterogeneous group of autoimmune diseases that affect multiple organ systems. Sjögren syndrome, dermatomyositis, scleroderma, systemic lupus erythematosus, and sarcoidosis are collagen vascular diseases that often present with characteristic cutaneous manifestations. Although less known, various ocular manifestations that affect both external and internal structures of the eye can be seen in these conditions. Multidisciplinary management between dermatologists and ophthalmologists is essential in the early diagnosis and management of collagen vascular diseases affecting both the skin and eye. Part I of our series will discuss the ocular manifestations, their diagnosis, and therapeutic options in Sjögren syndrome and systemic lupus erythematosus.

Eyelid cleaning: Methods, tools, and clinical applications

Nowadays, people give more importance and pay closer attention to the condition of their eyelids and lid margins. This increased recognition of eyelid hygiene is due to the growing awareness that improper eyelid cleaning might lead to various ocular surface diseases such as blepharitis and meibomian gland dysfunction. These ocular surface diseases can greatly affect people's quality of life. This article reviews the latest procedures for proper eyelid cleaning, including indications, methods, tools, detergents, and clinical applications, to maintain a healthy ocular surface and assist in the treatment of dry eye and blepharitis.

Confocal Microscopy Abnormalities Preceding Antibody Positivity and Manifestations of Sjogren's Syndrome

An asymptomatic 26-year-old woman underwent confocal microscopy as part of a control population for a research study. Images revealed reduced sub-basal corneal nerve density and multiple activated dendritic cells. Three years later, she presented with a self-limited cutaneous vasculitis in her lower extremities which prompted an evaluation for autoimmune diseases. Laboratory testing revealed positive antinuclear antibodies (1:320, thick granular pattern), and anti-SSA/SSB (SSA, 53.6 U/mL, moderately positive; SSB, 142.7 U/mL, strongly positive). Two weeks later, she presented with ocular pain and an ophthalmologic examination revealed ocular surface staining. An ocular ultrasound was consistent with posterior scleritis. Based on this picture, a diagnosis of Sjögren syndrome (SS) was made. SS is a chronic autoimmune disease that can present with symptoms that diminish the patient's quality of life. Confocal microscopy might be a valuable tool for the early diagnosis of disease.

A Female Patient Recently Diagnosed with Sjogren Syndrome Presents to the Dental Office Seeking Upper and Lower Complete Dentures

Sjogren syndrome (SS) is a common autoimmune disease associated with the immune-mediated destruction of exocrine glands, primarily the salivary and lacrimal glands. As a result, patients have xerophthalmia and xerostomia (Sicca syndrome). The diagnosis of SS can be difficult due to its multifactorial nature and often insidious symptoms, and there is no one test for its diagnosis. The many oral manifestations in SS stemming from the xerostomia present challenges to the treating dentist. Dentists should be knowledgeable about SS and its palliative care to help improve their patients' quality of life.

Vacuolar Interface Dermatitis as a Histologic Reaction Pattern of Sjögren's Syndrome: A Case Report

Sjögren's syndrome (SS) has been widely known for its dry mouth and dry eyes presentation. Extraglandular disease manifestations may be protean and pose a challenge for clinicians, especially when the typical known manifestations are absent. Skin involvement of SS is variable, and cutaneous signs and symptoms may be the initial presentation of this syndrome. Vacuolar interface dermatitis has been linked to dermatomyositis and systemic lupus erythematosus, but rarely to SS. Herein, we present the case of an 87-year-old man who presented for widespread itchy erythematous scaly plaques that were refractory to topical corticosteroids as well as discontinuation of possible offending medications. A biopsy demonstrated vacuolar interface dermatitis in the setting of strongly positive anti-SSA. Hydroxychloroquine treatment was effective in resolving the plaques.

Localized Cutaneous Nodular Amyloidosis in a Patient with Sjögren's Syndrome

Primary localized cutaneous nodular amyloidosis (PLCNA) is included in the primary forms of cutaneous amyloidosis along with macular and lichenoid amyloidosis. It is a rare disease attributed to plasma cell proliferation and deposition of immunoglobulin light chains in the skin. We present the case of a 75-year-old woman with a personal history of Sjogren's syndrome (SjS), who consulted for asymptomatic yellowish, waxy nodules on the left leg. Dermoscopy of the lesions showed a smooth, structureless, yellowish surface with hemorrhagic areas and few telangiectatic vessels. Histopathology revealed an atrophic epidermis and deposits of amorphous eosinophilic material in the dermis with a positive Congo red stain. The diagnosis of nodular amyloidosis was made. Periodic reevaluation was indicated after the exclusion of systemic amyloidosis. PLCNA is often associated with autoimmune connective tissue diseases, and up to 25% of all PLCNA cases occur in patients with SjS. Therefore, in addition to ruling out systemic amyloidosis, screening for possible underlying SjS should be performed when the diagnosis of PLCNA is confirmed.

Primary-Sjögren's-Syndrome-Related Interstitial Lung Disease: A Clinical Review Discussing Current Controversies

Lung involvement, especially interstitial lung disease, is a potentially severe extra-glandular manifestation of Primary Sjogren's Syndrome (pSS-ILD). ILD can manifest either as a late complication of pSS or anticipate sicca symptoms, likely reflecting two different patho-physiological entities. Presence of lung involvement in pSS subjects can remain subclinical for a long time; therefore, patients should be actively screened, and lung ultrasound is currently being investigated as a potential low cost, radiation-free, easily repeatable screening tool for detection of ILD. In contrast, rheumatologic evaluation, serology testing, and minor salivary gland biopsy are crucial for the recognition of pSS in apparently idiopathic ILD patients. Whether the HRCT pattern influences prognosis and treatment response in pSS-ILD is not clear; a UIP pattern associated with a worse prognosis in some studies, but not in others. Many aspects of pSS-ILD, including its actual prevalence, association with specific clinical-serological characteristics, and prognosis, are still debated by the current literature, likely due to poor phenotypic stratification of patients in clinical studies. In the present review, we critically discuss these and other clinically relevant "hot topics" in pSS-ILD. More specifically, after a focused discussion, we compiled a list of questions regarding pSS-ILD that, in our opinion, are not easily answered by the available literature. We subsequently tried to formulate adequate answers on the basis of an extensive literature search and our clinical experience. At the same, we highlighted different issues that require further investigation.

Localized Cutaneous Nodular Amyloidosis: A Specific Cutaneous Manifestation of Sjögren's Syndrome

Primary localized cutaneous nodular amyloidosis (PLCNA) is a rare condition attributed to plasma cell proliferation and the deposition of immunoglobulin light chains in the skin without association with systemic amyloidosis or hematological dyscrasias. It is not uncommon for patients diagnosed with PLCNA to also suffer from other auto-immune connective tissue diseases, with Sjögren's syndrome (SjS) showing the strongest association. This article provides a literature review and descriptive analysis to better understand the unique relationship between these two entities. To date, 34 patients with PLCNA and SjS have been reported in a total of 26 articles. The co-existence of PLCNA and SjS has been reported, especially in female patients in their seventh decade of life with nodular lesions on the trunk and/or lower extremities. Acral and facial localization, which is a typical localization of PLCNA in the absence of SjS, seems to be much more unusual in patients with associated SjS.

The Critical Biomarkers Identification of Insulin Signaling Involved in Initiating cAMP Signaling Mediated Salivary Secretion in Sjogren Syndrome: Transcriptome Sequencing in NOD Mice Model

BACKGROUND

Sjogren's syndrome (SS) is an autoimmune disorder characterized by the destruction of exocrine glands, resulting in dry mouth and eyes. Currently, there is no effective treatment for SS, and the mechanisms associated with inadequate salivary secretion are poorly understood.

METHODS

In this study, we used NOD mice model to monitor changes in mice's salivary secretion and water consumption. Tissue morphology of the submandibular glands was examined by H&E staining, and Immunohistochemical detected the expression of AQP5 (an essential protein in salivary secretion). Global gene expression profiling was performed on submandibular gland tissue of extracted NOD mice model using RNA-seq. Subsequently, a series of bioinformatics analyses of transcriptome sequencing was performed, including differentially expressed genes (DEGs) identification, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis, PPI network construction, hub gene identification, and the validity of diagnostic indicators using the dataset GSE40611. Finally, IFN-γ was used to treat the cells, the submandibular gland tissue of NOD mice model was extracted, and RT-qPCR was applied to verify the expression of hub genes.

RESULTS

We found that NOD mice model had reduced salivary secretion and increased water consumption. H&E staining suggests acinar destruction and basement membrane changes in glandular tissue. Immunohistochemistry detects a decrease in AQP5 immunostaining within acinar. In transcriptome sequencing, 42 overlapping DEGs were identified, and hub genes (REN, A2M, SNCA, KLK3, TTR, and AZGP1) were identified as initiating targets for insulin signaling. In addition, insulin signaling and cAMP signaling are potential pathways for regulating salivary secretion and constructing a regulatory relationship between target-cAMP signaling-salivary secretion.

CONCLUSION

The new potential targets and signal axes for regulating salivary secretion provide a strategy for SS therapy in a clinical setting.

Severe extra-glandular involvement and pleural effusions complicating primary Sjogren's syndrome: a case report

Background

Sjogren’s syndrome, an autoimmune disease of the exocrine glands, results in keratoconjunctivitis sicca, xerostomia, and dental caries. It is often overlooked, considered by clinicians to be a benign disease. However, it can cause life-threatening extra-glandular complications that affect multiple organ systems.

Case presentation

Here we present a 78-year-old Caucasian woman with a history of primary Sjogren’s syndrome (pSS) whose symptoms of keratoconjunctivitis sicca were managed managed conservatively. She was evaluated for sub-acute shortness of breath. Imaging showed severe bronchiectasis with features of lymphocytic interstitial pneumonia. She also had exudative bilateral pleural effusions and skin ulcers, likely vasculitic in origin. The workup was significant for anti-Ro antibody, pancytopenia, hypocomplementia, cryoglobulinemia and monoclonal gammopathy, all of which reflect disease severity. Although there was no evidence of malignancy, she developed B-cell non-Hodgkin lymphoma during follow-up.

Conclusions

Primary Sjogren’s syndrome can result in severe multi-organ disease. Pleural effusions are a rare complication of pSS, with only ten cases reported in the literature over the last 30 years, and tend to respond well to steroids. Prognostic biomarkers for disease severity include hypocomplementia, cryoglobulinemia, monoclonal gammopathy, and hypergammaglobulinemia. In this report we review the literature and the management of the disease.

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.

A Novel Technique for the Evaluation and Interpretation of Elastography in Salivary Gland Involvement in Primary Sjögren Syndrome

Ultrasound (US) of major salivary glands (MSG) evaluates echogenicity, border features and vascularization, with elastography, it can detect tissue elasticity and glandular fibrosis, related to inflammation in Primary Sjögren’s syndrome (pSS). This study aimed to develop a novel technique by pixel analysis for evaluation and interpretation of elastography in MSG in pSS. A cross-sectional and observational multicenter study was conducted. The US of MSG performed in orthogonal planes in grayscale, Doppler, and shear-wave elastography. For elastography images of each gland were analyzed with the open-source program ImageJ to perform a pixel analysis. Statistical analysis was performed with the IBM-SPSS v25 program. Fifty-nine women with a mean age of 57.69 (23–83) years were recruited; pSS mean duration of 87 (5–275) months, and 12 healthy women without sicca symptoms as a control group with a mean age of 50.67 (42–60) years. Intragroup analysis showed p-values >0.05 between sicca symptoms, ocular/dryness tests, biopsy, US, and pixel analysis; correlation between Hocevar and pixel analysis was not found (rho < 0.1, p >0.5). MSG anatomical size was 41.7 ± 28.2 mm vs. 67.6 ± 8.8 mm (p ≤ 0.0001); unstimulated whole saliva flow rate was 0.80 ± 0.80 ml/5 min vs. 1.85 ± 1.27 ml/5 min (p = 0.016). The elastography values (absolute number of pixels) were 572.38 ± 99.21 vs. 539.69 ± 93.12 (p = 0.290). A cut-off point risk for pSS identified with less than 54% of red pixels in the global MSG mass [OR of 3.8 95% CI (1.01–15.00)]. Pixel analysis is a new tool that could lead to a better understanding of the MSG chronic inflammatory process in pSS.

Therapeutic Potential of Microvesicles in Cell Therapy and Regenerative Medicine of Ocular Diseases With an Especial Focus on Mesenchymal Stem Cells-Derived Microvesicles

These days, mesenchymal stem cells (MSCs), because of immunomodulatory and pro-angiogenic abilities, are known as inevitable factors in regenerative medicine and cell therapy in different diseases such as ocular disorder. Moreover, researchers have indicated that exosome possess an essential potential in the therapeutic application of ocular disease. MSC-derived exosome (MSC-DE) have been identified as efficient as MSCs for treatment of eye injuries due to their small size and rapid diffusion all over the eye. MSC-DEs easily transfer their ingredients such as miRNAs, proteins, and cytokines to the inner layer in the eye and increase the reconstruction of the injured area. Furthermore, MSC-DEs deliver their immunomodulatory cargos in inflamed sites and inhibit immune cell migration, resulting in improvement of autoimmune uveitis. Interestingly, therapeutic effects were shown only in animal models that received MSC-DE. In this review, we summarized the therapeutic potential of MSCs and MSC-DE in cell therapy and regenerative medicine of ocular diseases.

Dry eye in Sjögren's syndrome - characteristics and therapy

BACKGROUND

Sjögren's syndrome is an autoimmune disease, and its important feature is the lymphocyte infiltration of exocrine glands, including lacrimal glands. It contributes to defects of their activity and causes that one of the main manifestation of Sjögren's syndrome is dry eye. Unfortunately, the discrimination between dry eye related and non-related to Sjögren's syndrome is difficult at the initial stages of diseases. In addition, the available agents for the treatment of Sjögren's syndrome-related dry eye have limited efficacy.

AIM

The purpose of this study was to describe and emphasize differences between Sjögren's Syndrome-related dry eye and non-Sjögren's Syndrome-related dry eye together with the determination of novel therapeutic options for Sjögren's Syndrome-related dry eye.

METHOD

A review of the relevant papers describing characteristics of Sjögren's Syndrome-related dry eye and its therapy was conducted. This article is based on both pre-clinical and clinical evidences.

RESULTS

On the basis of our analysis, we indicated differences between Sjögren's Syndrome-related dry eye and non-Sjögren's Syndrome-related dry eye. Moreover, there are some novel markers that could be used in the diagnosis of Sjögren's Syndrome-related dry eye. In addition, expect artificial tear, other agents e.g. hydroxychloroquine can be effective in therapy of disease.

CONCLUSIONS

Sjögren's Syndrome-related dry eye is a disorder, whose diagnosis may be difficult and mistaken for non-Sjögren's Syndrome-related dry eye. However, Sjögren's Syndrome-related dry eye has some specific features. In addition, the development of newer and safer therapeutic agents for Sjögren's syndrome-related dry eye is needed, and therefore further clinical, randomized studies are necessary.

A Link Between Mitochondrial Dysfunction and the Immune Microenvironment of Salivary Glands in Primary Sjogren’s Syndrome

Background

Primary Sjogren’s syndrome (pSS) is a slowly progressive, inflammatory autoimmune disease characterized by lymphocytic infiltration into salivary and lacrimal glands. It becomes more recognized that morphology alterations of epithelial mitochondria are involved in altered cellular bioenergetics in pSS patients. The integrated analysis of the mitochondrial role in the pathogenesis and aberrant immune microenvironment in pSS remains unknown.

Methods

The mitochondria-related genes and gene expression data were downloaded from the MitoMiner, MitoCarta, and NCBI GEO databases. We performed novel transcriptomic analysis and constructed a network between the mitochondrial function and immune microenvironment in pSS-salivary glands by computer-aided algorithms. Subsequently, real-time PCR was performed in clinical samples in order to validate the bioinformatics results. Histological staining and transmission electron microscopy (TEM) were further studied on labial salivary gland samples of non-pSS and pSS patients characterized for mitochondria-related phenotypic observation in the different stages of the disease.

Results

The bioinformatic analysis revealed that the expression of several mitochondria-related genes was altered in pSS. Quantitative real-time PCR showed that four hub genes, CD38, CMPK2, TBC1D9, and PYCR1, were differentially expressed in the pSS clinical samples. These hub genes were associated with the degree of immune cell infiltration in salivary glands, the mitochondrial respiratory chain complexes, mitochondrial metabolic pathway in gluconeogenesis, TCA cycle, and pyruvate/ketone/lipid/amino acid metabolism in pSS. Clinical data revealed that the gene expression of fission (Fis1, DRP1, and MFF) and fusion (MFN1, MFN2, and OPA1) was downregulated in pSS samples, consistent with the results from the public validation database. As the disease progressed, cytochrome c and Bcl-2 proteins were regionally distributed in salivary glands from pSS patients. TEM revealed cytoplasmic lipid droplets and progressively swollen mitochondria in salivary epithelial cells.

Conclusion

Our study revealed cross talk between mitochondrial dysfunction and the immune microenvironment in salivary glands of pSS patients, which may provide important insights into SS clinical management based on modulation of mitochondrial function.

Antimitochondrial Antibodies: from Bench to Bedside

Anti-mitochondrial antibodies (AMA) are directed against the E2 subunits of the 2-oxo acid dehydrogenase complexes (PDC-E2) and are the typical biomarkers of primary biliary cholangitis (PBC), being present in 90-95% of patients, with increasing sensitivity at increasing titers. Albeit being highly specific for PBC diagnosis, AMA can be detected in less than 1% of healthy subjects, and thus the management subjects with no sign or symptom of liver disease is still a challenge and data concerning clinical risk of developing PBC in this subgroup of patients are controversial. Moreover, AMA can also be detected in patients affected by overlap syndrome, as well as hepatic diseases (i.e., NASH and viral hepatitis), while the association with autoimmune diseases, in particular Sjögren's syndrome, systemic sclerosis, and systemic lupus erythematosus, is well established. Furthermore, new associations are being identified with inflammatory myositis and heart disease. AMA are directed towards the pyruvate dehydrogenase multi enzyme complex (PDC-E2) subunit, which represents an epithelial specific autoantigen for PBC. This review focuses on the main characteristics of AMA, their association with autoimmune diseases and liver diseases.

Preferences of Sjögren's syndrome patients regarding potential new saliva substitutes

OBJECTIVES

Sjögren's syndrome (SS) patients should be involved in the development of new saliva substitutes at an early stage. The purpose of the current study was to explore the preferences of these patients regarding various product characteristics of potential new saliva substitutes.

MATERIAL AND METHOD

A questionnaire was distributed among SS patients. They could anonymously indicate their preferences for saliva substitute characteristics using 5-point Likert scales.

RESULTS

Fifty-nine SS patients filled in the questionnaire. According to their opinion, the most ideal saliva substitute has a thin-watery consistency with a neutral flavour that should be applied as a spray. Patients demand a prolonged alleviation of dry mouth complaints and neutralization of harmful bacteria. The patients mainly object against the presence of artificial sweeteners and alcohol in saliva substitutes, but have limited objections against the presence of vegetable-based ingredients and natural enzymes. Major objections were against the potential side effects "bitter taste" and "discoloration of teeth". Age and severity of xerostomia affected desire of flavours. Younger patients preferred menthol flavour, while respondents with severe xerostomia preferred the use of "neutral flavours" significantly more.

CONCLUSION

The most ideal saliva substitute has thin-watery consistency in spray form with a neutral flavour and providing long alleviation of dry mouth complaints. Besides, it should not contain artificial sweeteners or alcohol, and should not have a bitter taste or cause discoloration of the teeth.

CLINICAL RELEVANCE

Investigating the opinion of SS patients provides tailoured insights into their preference, which may contribute to the development of more effective saliva substitutes.

Sicca syndrome associated with immune checkpoint inhibitor therapy

Cancer immunotherapy, which seeks to stimulate a patient's own immune system to combat cancer, is quickly becoming a central pillar of cancer therapeutics and has resulted in the development of many novel anticancer therapies. One subtype of cancer immunotherapy, immune checkpoint inhibitors (ICIs), has revolutionized cancer treatment and changed the standard of care for multiple indications. However, the advent of ICIs has produced a wide variety of inflammatory side effects termed immune-related adverse events (IRAEs), including ICI-induced Sicca syndrome. This article outlines the clinical features of ICI-induced Sicca syndrome and assesses its reported incidence in clinical trials, case series, and case reports across numerous cancers and treatment modalities. Presentations of ICI-induced Sicca syndrome in patients with pre-existing Sjӧgren's disease and with extra-glandular manifestations will also be explored. The pathophysiological mechanisms underlying IRAEs, including ICI-induced Sicca syndrome, will be evaluated through an examination of existing literature. Finally, the various treatment and management strategies as well as aims for future work will be discussed and reviewed.

Studying Sjögren's syndrome in mice: What is the best available model?

Sjögren's syndrome (SS) is a common autoimmune disease characterized by lymphocytic infiltration and destruction of exocrine glands. The disease manifests primarily in the salivary and lacrimal glands, but other organs are also involved, leading to dry mouth, dry eyes, and other extra-glandular manifestations. Studying the disease in humans is entailed with many limitations and restrictions; therefore, the need for a proper mouse model is mandatory. SS mouse models are categorized, depending on the disease emergence into spontaneous or experimentally manipulated models. The usefulness of each mouse model varies depending on the SS features exhibited by that model; each SS model has advanced our understanding of the disease pathogenesis. In this review article, we list all the available murine models which have been used to study SS and we comment on the characteristics exhibited by each mouse model to assist scientists to select the appropriate model for their specific studies. We also recommend a murine strain that is the most relevant to the ideal SS model, based on our experience acquired during previous and current investigations.

Epidemiology of cutaneous involvement in Sjögren syndrome: Data from three French pSS populations (TEARS, ASSESS, diapSS)

OBJECTIVE

To determine the prevalence and significance of dermatological disorders in primary Sjögren syndrome (pSS).

METHODS

We used 2 pSS French cohorts (ASSESS, in which prevalence of skin disorders in 395 patients was evaluated; and diapSS, in which 76 on 139 pSS patients had an examination by a dermatologist) and baseline data of the TEARS randomized trial (110 patients with recent or active pSS treated with rituximab or placebo and evaluated for skin dryness using a visual analogue scale (VAS) out of 100).

RESULTS

Skin manifestations included in the EULAR Sjögren syndrome disease activity index (ESSDAI) were rare in the ASSESS cohort (n=16/395, 4.1%, mainly purpuras; only 3 had high activity), but they were associated with activity in the other ESSDAI domains (peripheral neurological (P<0.001), muscular (P<0.01), haematological (P<0.05), biological (P<0.05), history of arthritis (P<0.01), splenomegaly (P<0.05) and higher gamma globulin levels (P<0.01)). In the diapSS cohort, compared to pSS patients not receiving a dermatological consultation, the pSS patients who had a dermatological consultation had significantly more dermatological involvement outside the ESSDAI score [38.2% (29/76) versus 15.9% (10/63); P<0.01]. The TEARS study showed a high prevalence of cutaneous dryness (VAS>50; 48.2%) and found that patients with dry skin had higher VAS pain (P<0.01) and drought (P<0.01) scores.

CONCLUSION

ESSDAI skin activity is rare and associated with hypergammaglobulinemia and ESSDAI activity. Systematic dermatological examination is informative for non-specific lesions. The most common skin disorder is skin dryness, which is associated with a higher pain and overall subjective dryness.

Drug-induced Bullous Pemphigoid and Lupus Erythematosus Occurring under Anti-TNF-α and IL-6 Therapy in a Patient with Rheumatoid Arthritis

A 65-year-old Japanese woman, who was diagnosed with rheumatoid arthritis and Sjögren's syndrome with various autoantibodies including anti-DNA antibody, developed bullous pemphigoid (BP) and hematological abnormalities like lupus erythematosus after adalimumab therapy. The discontinuation of adalimumab resolved those disorders but polyarthritis thereafter relapsed. The introduction of abatacept was not effective, but tocilizumab was found to be effective for polyarthritis, however, thereafter both bullous disease and severe pancytopenia developed. Discontinuation of tocilizumab was effective, but polyarthritis again developed, and baricitinib resolved it. There is an increasing number of reports of drug-induced BP and lupus erythematosus, and biologics might trigger an alteration in the pathophysiological/clinical course of rheumatic disorder.

Psoriasis and Connective Tissue Diseases

Psoriasis is a chronic systemic inflammatory disease with various co-morbidities, having been recently considered as a comprehensive disease named psoriatic disease or psoriatic syndrome. Autoimmune diseases are one form of its co-morbidities. In addition to the genetic background, shared pathogenesis including innate immunity, neutrophil extracellular trap (NETs), and type I interferon, as well as acquitted immunity such as T helper-17 (Th17) related cytokines are speculated to play a significant role in both psoriasis and connective tissue diseases. On the other hand, there are definite differences between psoriasis and connective tissue diseases, such as their pathomechanisms and response to drugs. Therefore, we cannot expect that one stone kills two birds, and thus caution is necessary when considering whether the administered drug for one disease is effective or not for another disease. In this review, several connective tissue diseases and related diseases are discussed from the viewpoint of their coexistence with psoriasis.

Non-specific orbital inflammation: Current understanding and unmet needs

Non-specific orbital inflammation (NSOI) is a noninfectious inflammatory condition of the orbit. Although it is generally considered the most common diagnosis derived from an orbital biopsy, it is a diagnosis of exclusion, meaning that the diagnosis requires exclusion of a systemic process or another identifiable etiology of orbital inflammation. The clinical diagnosis of NSOI is ill-defined, but it is typically characterized by acute orbital signs and symptoms, including pain, proptosis, periorbital edema, chemosis, diplopia, and less commonly visual disturbance. NSOI poses a diagnostic and therapeutic challenge: The clinical presentations and histological findings are heterogeneous, and there are no specific diagnostic criteria or treatment guidelines. The etiology and pathogenesis of NSOI are poorly understood. Here we recapitulate our current clinical understanding of NSOI, with an emphasis on the most recent findings on clinical characteristics, imaging findings, and treatment outcomes. Furthermore, gene expression profiling of NSOI and its implications are presented and discussed.

Current State of Knowledge on Primary Sjögren's Syndrome, an Autoimmune Exocrinopathy

Primary Sjögren's syndrome (pSS) is a chronic systemic autoimmune rheumatic disease characterized by lymphoplasmacytic infiltration of the salivary and lacrimal glands, whereby sicca syndrome and/or systemic manifestations are the clinical hallmarks, associated with a particular autoantibody profile. pSS is the most frequent connective tissue disease after rheumatoid arthritis, affecting 0.3-3% of the population. Women are more prone to develop pSS than men, with a sex ratio of 9:1. Considered in the past as innocent collateral passive victims of autoimmunity, the epithelial cells of the salivary glands are now known to play an active role in the pathogenesis of the disease. The aetiology of the "autoimmune epithelitis" still remains unknown, but certainly involves genetic, environmental and hormonal factors. Later during the disease evolution, the subsequent chronic activation of B cells can lead to the development of systemic manifestations or non-Hodgkin's lymphoma. The aim of the present comprehensive review is to provide the current state of knowledge on pSS. The review addresses the clinical manifestations and complications of the disease, the diagnostic workup, the pathogenic mechanisms and the therapeutic approaches.

Sicca Symptoms, Oral Health Conditions, Salivary Flow and Oral Candida in Sjögren's Syndrome Patients

This study aimed to investigate the relationships among sicca symptoms, oral health conditions, salivary profiles and oral Candida in Sjögren's syndrome (SS) patients. Eighty-five SS patients (mean age = 50.5) and 40 healthy non-SS individuals (mean age = 51.4) were recruited. They self-completed the Sicca Symptoms Inventory (SSI). Decayed, missing and filled surface (DMFS) scores, salivary flow rates, pH and oral Candida colonization were determined. Mean SSI summary scores of SS patients and non-SS individuals were 11.1 and 5.4 respectively (p < 0.001). The most prevalent sicca symptoms in SS patients were eye irritation (93%), dry throat or nose (88%) and need of fluid for mouth wetting (88%). SS patients had significantly lower whole salivary flow rates than the non-SS individuals. Candida strains were isolated from over 60% of SS patients but not in non-SS patients. C. albicans was the predominant species. SSI summary score was negatively correlated to salivary flow rates while SSI summary and domain scores were positively correlated to the number of filled surfaces (FS) and DMFS scores and oral Candida counts. In conclusion, SS patients had more severe sicca symptoms than non-SS individuals. SSI scores were negatively correlated to the salivary flow rates but positively correlated to caries experience and oral Candida colonization.

Can artificial intelligence replace manual search for systematic literature? Review on cutaneous manifestations in primary Sjögren’s syndrome

Objectives

Manual systematic literature reviews are becoming increasingly challenging due to the sharp rise in publications. The primary objective of this literature review was to compare manual and computer software using artificial intelligence retrieval of publications on the cutaneous manifestations of primary SS, but we also evaluated the prevalence of cutaneous manifestations in primary SS.

Methods

We compared manual searching and searching with the in-house computer software BIbliography BOT (BIBOT) designed for article retrieval and analysis. Both methods were used for a systematic literature review on a complex topic, i.e. the cutaneous manifestations of primary SS. Reproducibility was estimated by computing Cohen’s κ coefficients and was interpreted as follows: slight, 0–0.20; fair, 0.21–0.40; moderate, 0.41–0.60; substantial, 0.61–0.80; and almost perfect, 0.81–1.

Results

The manual search retrieved 855 articles and BIBOT 1042 articles. In all, 202 articles were then selected by applying exclusion criteria. Among them, 155 were retrieved by both methods, 33 by manual search only, and 14 by BIBOT only. Reliability (κ = 0.84) was almost perfect. Further selection was performed by reading the 202 articles. Cohort sizes and the nature and prevalence of cutaneous manifestations varied across publications. In all, we found 52 cutaneous manifestations reported in primary SS patients. The most described ones were cutaneous vasculitis (561 patients), xerosis (651 patients) and annular erythema (215 patients).

Conclusion

Among the final selection of 202 articles, 155/202 (77%) were found by the two methods but BIBOT was faster and automatically classified the articles in a chart. Combining the two methods retrieved the largest number of publications.

Recent advances of exosomes in immune-mediated eye diseases

Exosomes, nanosized extracellular vesicles of 30-150 nm, are shed by almost all cell types. Bearing proteins, lipids, RNAs, and DNAs, exosomes have emerged as vital biological mediators in cell-to-cell communication, affecting a plethora of physiological and pathological processes. Particularly, mounting evidence indicates that immunologically active exosomes can regulate both innate and adaptive immune responses. Herein, we review recent advances in the research of exosomes in several immune-mediated eye diseases, including Sjögren's syndrome (SS) dry eye, corneal allograft rejection, autoimmune uveitis, and age-related macular degeneration (AMD). Additionally, we discuss the potential of exosomes as novel biomarkers and drug delivery vesicles for the diagnosis and treatment of eye diseases.

Sex and autoimmunity: proposed mechanisms of disease onset and severity

INTRODUCTION

Chronic autoimmune diseases affect 5-10% of the population worldwide and are largely predominant in women. Sex hormone changes have been widely investigated based on changes in the clinical phenotypes observed during pregnancy and menopause. It is known that females with autoimmune diseases manifest a higher rate of circulating leukocytes with a single X chromosome, and there have been several reports on the role of X chromosome gene dosage through inactivation or duplication in autoimmunity. However, it is also important not to overlook men with autoimmune diseases, who might manifest a more frequent loss of the Y chromosome in circulating leukocytes. Areas covered: In the present review, we will discuss the current evidence supporting the mechanisms of female predominance in rheumatic diseases, by discussing the role of reproductive history, sex hormones and abnormalities related to them, clinical differences between male and female patients, and epigenetic changes that have been evaluated through twin studies on genetic and environmental changes in rheumatic patients. Expert opinion: The influence of sex hormones and chromosomes on the function of the innate and adaptive immune systems needs to be clarified, to better understand the risk of autoimmune diseases, early diagnostic tools, and therapeutic response.

GPR55 controls functional differentiation of self-renewing epithelial progenitors for salivation

GPR55, a lipid-sensing receptor, is implicated in cell cycle control, malignant cell mobilization, and tissue invasion in cancer. However, a physiological role for GPR55 is virtually unknown for any tissue type. Here, we localize GPR55 to self-renewing ductal epithelial cells and their terminally differentiated progeny in both human and mouse salivary glands. Moreover, we find GPR55 expression downregulated in salivary gland mucoepidermoid carcinomas and GPR55 reinstatement by antitumor irradiation, suggesting that GPR55 controls renegade proliferation. Indeed, GPR55 antagonism increases cell proliferation and function determination in quasiphysiological systems. In addition, Gpr55-/- mice present ~50% enlarged submandibular glands with many more granulated ducts, as well as disordered endoplasmic reticuli and with glycoprotein content. Next, we hypothesized that GPR55 could also modulate salivation and glycoprotein content by entraining differentiated excretory progeny. Accordingly, GPR55 activation facilitated glycoprotein release by itself, inducing low-amplitude Ca2+ oscillations, as well as enhancing acetylcholine-induced Ca2+ responses. Topical application of GPR55 agonists, which are ineffective in Gpr55-/- mice, into adult rodent submandibular glands increased salivation and saliva glycoprotein content. Overall, we propose that GPR55 signaling in epithelial cells ensures both the life-long renewal of ductal cells and the continuous availability of saliva and glycoproteins for oral health and food intake.

Dry Eye Disease in Routine Rheumatology Practice

Dry eye disease (DED) is one of the most frequent ophthalmological conditions, with a major impact on patients’ quality of life. Tear film instability and tear hyperosmolarity are considered to play a crucial role in the vicious cycle of dry eye disease. They occur as a result of, either a reduced lacrimal secretion or an excessive evaporation from the tear film. There is a well-known association of DED, not only with autoimmune diseases but also with other systemic diseases and medication. Early diagnosis is important and it is based on the presence of classical symptoms and signs of dry eye in combination with specialized methods. The comprehension of the pathophysiology is significant, as different approaches can be taken to treat DED, depending on the cause and primary source of the disease, as well as on disease severity.

Prevalence, severity, and predictors of dry eye and dry mouth in Chinese patients with primary Sjögren syndrome

Dry eye and dry mouth are typical clinical symptoms of primary Sjögren's syndrome (pSS), yet not considered in the assessment of severity and predictors in China. This study aimed to investigate the prevalence, severity, and potential predictors of dry eye/dry mouth among Chinese pSS patients. A cross-sectional study was conducted from the Affiliated Hospital of Nantong University. A series of questionnaires were applied: Ocular Surface Disease Index (OSDI), EULAR Sjogren's Syndrome Patient Reported Index (ESSPRI)-dry mouth items, fatigue severity scale (FSS), the 10 cm visual analog scale (VAS). Laboratory examinations were taken to obtain some biochemical indicators (i.e., C-reactive protein, erythrocyte sedimentation rate, anti-SSA/SSB antibody). Stepwise logistic/linear regression model was used to investigate the potential predictors of dry eye/dry mouth, respectively. Statistical analysis was performed using SPSS version 20.0. Two hundred twenty-four pSS patients were included in this study. Among them, 215 (95.98%) patients reported ESSPRI-dry mouth items score > 0, and the mean score was 4.92 ± 2.43. In addition, according to the score of OSDI, 84 (37.5%) subjects reported non-dry eye, whereas 140 (62.5%) subjects reported dry eye (44 mild, 31 moderate, 65 severe), and the mean of the total OSDI score was 25.01 ± 23.58. Then, using logistic regression and linear regression respectively, we found that age and fatigue were the potential predictors of dry eye, whereas dry mouth was predicted by age, fatigue, total pain, and ESR. The results of this study suggested that rheumatologists should pay attention to pSS patients' dry eye and dry mouth, especially those with older age, higher level of ESR, more severe fatigue, and pain.

PBC and related extrahepatic diseases

Patients with PBC have at least 60% of probability to have an autoimmune extrahepatic condition. The pathogenesis of these conditions includes a common mechanism involving both innate and adaptive immune responses targeting cholangiocytes and different extrahepatic tissues. The recent EASL guidelines recommend the management of these conditions, although detailed practical treatments have not been indicated. Autoimmune extrahepatic conditions may include: rheumatologic, endocrine, pulmonary, gastrointestinal, dermatologic diseases. This review aims to focus the most important extrahepatic autoimmune conditions associated to PBC with practical recommendation regarding diagnostic approach and management.