Recent advances in primary Sjogren's syndrome

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.

The role of faecal microbiota transplantation in chronic noncommunicable disorders

The gut microbiome plays a key role in influencing several pathways and functions involved in human health, including metabolism, protection against infection, and immune regulation. Perturbation of the gut microbiome is recognised as a pathogenic factor in several gastrointestinal and extraintestinal disorders, and is increasingly considered as a therapeutic target in these conditions. Faecal microbiota transplantation (FMT) is the transfer of the microbiota from healthy screened stool donors into the gut of affected patients, and is a well-established and highly effective treatment for recurrent Clostridioides difficile infection. Despite the mechanisms of efficacy of FMT not being fully understood, it has been investigated in several chronic noncommunicable disorders, with variable results. This review aims to give an overview of mechanisms of efficacy of FMT in chronic noncommunicable disorders, and to paint the current landscape of its investigation in these medical conditions, including inflammatory bowel disease (IBD), chronic liver disorders, and also extraintestinal autoimmune conditions.

Gut Dysbiosis and Fecal Microbiota Transplantation in Autoimmune Diseases

Gut microbiota dysbiosis has recently been reported in a number of clinical states, including neurological, psychiatric, cardiovascular, metabolic and autoimmune disorders. Yet, it is not completely understood how colonizing microorganisms are implicated in their pathophysiology and molecular pathways. There are a number of suggested mechanisms of how gut microbiota dysbiosis triggers or sustains extraintestinal diseases; however, none of these have been widely accepted as part of the disease pathogenesis. Recent studies have proposed that gut microbiota and its metabolites could play a pivotal role in the modulation of immune system responses and the development of autoimmunity in diseases such as rheumatoid arthritis, multiple sclerosis or type 1 diabetes. Fecal microbiota transplantation (FMT) is a valuable tool for uncovering the role of gut microbiota in the pathological processes. This review aims to summarize the current knowledge about gut microbiota dysbiosis and the potential of FMT in studying the pathogeneses and therapies of autoimmune diseases. Herein, we discuss the extraintestinal autoimmune pathologies with at least one published or ongoing FMT study in human or animal models.

The role of Th9 CD4+ T cells and IL-9 during primary Sjogren's syndrome

OBJECTIVE

The objective of this study is to investigate the expression levels of Th₉ CD4⁺ T cells and IL-9 secretion in peripheral blood mononuclear cells of patients with primary Sjogren's syndrome. Further, this study aimed to investigate the role of Th₉ cells in the occurrence and development of pSS.

METHODS

A total of 20 pSS patients and 20 healthy people, matched with age and gender, were selected as the experimental and control group, respectively. Flow cytometry and ELISA were used to detect the expression of Th₉ cytokines in peripheral blood mononuclear cells and IL-9 in serum, respectively. These factors were then correlated to other clinical indicators.

RESULTS

The levels of Th₉ CD4⁺ T cells and IL-9 of pSS patients were significantly higher than those of the control group. Th₉ CD4⁺ T cells and IL-9 levels in peripheral blood of pSS patients were negatively correlated with salivary flow rate, while IL-9 level was positively correlated with globulin. The transcription levels of IL-9 and immune-related genes including IL-4, IL-7, IL-17, SMAD3, STAT5 and JAK3 were dramatically increased in serum of pSS patients.

CONCLUSION

The expression levels of Th₉ in peripheral blood and serum IL-9 of patients with pSS were significantly increased, which were correlated with clinical immunological indexes. Together, these data suggest that Th₉ cells and IL-9 may be involved in the pathogenesis of pSS.

Comparative analysis of the efficacy and safety of herbal decoction CheReCunJin alone and combined with hydroxychloroquine for treating primary Sjögren's syndrome: A randomized controlled trial

INTRODUCTION

There is currently no established effective treatment for primary Sjögren's syndrome (pSS). Traditional Chinese Medicine (TCM) is widely used in China and is reported to improve patient symptoms. This study compare the clinical efficacy and safety of herbal decoction CheReCunJin alone and combined with hydroxychloroquine for the treatment of pSS.

METHODS

Seventy pSS patients without visceral involvement were randomly assigned in equal numbers to oral administration of CheReCunJin decoction only (group 1) or CheReCunJin decoction combined with hydroxychloroquine (group 2), Efficacy was evaluated after 3 months of treatment by the TCM syndrome and total effectiveness scores, European League Against Rheumatism (EULAR) Sjögren's Syndrome Patient Reported Index (ESSPRI), and Sjögren's Syndrome Disease Activity Index (ESSDAI), Schirmer's test, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and immunoglobulin G (IgG) levels. Safety was assessed.

RESULTS

There were no differences in the baseline characteristics of the two groups. Compared with baseline values, the TCM syndrome, ESSPRI and ESSDAI scores, ESR, CRP, and Schirmer's test results improved significantly in both groups after treatment (p < 0.05). There was no significant difference in the TCM syndrome total effectiveness rate between the two groups (p = 0.31). Between-group differences in the changes in ESSPRI, ESSDAI, ESR, CRP, Schirmer's test, and IgG after treatment were not significant (all p> 0.05). Adverse reactions were reported in 5.88% of group 1 and 3.33% of group 2 participants (p = 0.83).

CONCLUSION

CheReCunJin decoction alone was effective and safe for the treatment of pSS.

TRIAL REGISTRATION

Chinese Clinical Trial Registry: ChiCTR1800016471.

A phase 2 randomized, double-blind, placebo-controlled, proof-of-concept study of oral seletalisib in primary Sjögren's syndrome

OBJECTIVES

This phase 2 proof-of-concept study (NCT02610543) assessed efficacy, safety and effects on salivary gland inflammation of seletalisib, a potent and selective PI3Kδ inhibitor, in patients with moderate-to-severe primary Sjögren's syndrome (PSS).

METHODS

Adults with PSS were randomized 1:1 to seletalisib 45 mg/day or placebo, in addition to current PSS therapy. Primary end points were safety and tolerability and change from baseline in EULAR Sjögren's Syndrome Disease Activity Index (ESSDAI) score at week 12. Secondary end points included change from baseline at week 12 in EULAR Sjögren's Syndrome Patient Reported Index (ESSPRI) score and histological features in salivary gland biopsies.

RESULTS

Twenty-seven patients were randomized (seletalisib n = 13, placebo n = 14); 20 completed the study. Enrolment challenges led to early study termination with loss of statistical power (36% vs 80% planned). Nonetheless, a trend for improvement in ESSDAI and ESSPRI [difference vs placebo: -2.59 (95% CI: -7.30, 2.11; P=0.266) and -1.55 (95% CI: -3.39, 0.28), respectively] was observed at week 12. No significant changes were seen in saliva and tear flow. Serious adverse events (AEs) were reported in 3/13 of patients receiving seletalisib vs 1/14 for placebo and 5/13 vs 1/14 discontinued due to AEs, respectively. Serum IgM and IgG concentrations decreased in the seletalisib group vs placebo. Seletalisib demonstrated efficacy in reducing size and organisation of salivary gland inflammatory foci and in target engagement, thus reducing PI3K-mTOR signalling compared with placebo.

CONCLUSION

Despite enrolment challenges, seletalisib demonstrated a trend towards clinical improvement in patients with PSS. Histological analyses demonstrated encouraging effects of seletalisib on salivary gland inflammation and organisation.

TRIAL REGISTRATION

https://clinicaltrials.gov, NCT02610543.

Salivary glands ultrasonography as a diagnostic aid in Sjögren syndrome: A prospective pilot investigation

OBJECTIVE

The aims of this pilot investigation were to calculate the levels of sensitivity and specificity of salivary glands ultrasonography (SGUS) in diagnosing Sjögren syndrome (SS) and to assess the ultrasonographic findings of parotid and submandibular glands.

STUDY DESIGN

Patients diagnosed with SS or dry mouth and healthy controls were enrolled. Bilateral parotid and submandibular glands were assessed for (1) parenchymal inhomogeneity (PIH), (2) median size of the glands, (3) visibility of glandular posterior borders, and (4) size of sialolith, if present.

RESULTS

This study included 34 female patients, of whom 12 had SS (35.3%), 12 had dry mouth (35.3%), and 10 were healthy controls (29.4%). Patients with SS showed higher PIH scores in all glands with the median differences being statistically higher in the right and left parotids and left submandibular glands (P < .001, P = .012, and P < .001, respectively). SGUS, with a PIH cutoff ≥2, showed a sensitivity of 100% and a specificity of 81.6% for detecting SS. The majority of SS had invisible glandular posterior borders (P < .001). Median size of the glands and size of the sialolith did not show any statistically significant differences between groups.

CONCLUSIONS

SGUS is a noninvasive imaging modality with good sensitivity and specificity that might be valuable as a diagnostic aid for SS.

Burden of illness among subgroups of patients with primary Sjögren's syndrome and systemic involvement

OBJECTIVES

To describe how patients with primary SS (pSS) and systemic organ involvement are classified and clustered in routine practice.

METHODS

This multinational, cross-sectional survey of real-world quantitative data was conducted across Europe and the US. Rheumatologists who treated seven or more adult patients per month with pSS and current/past systemic manifestations undertook a survey before completing a patient record form capturing demographic, clinical and treatment information for their next six eligible patients. Patients with a completed patient record form were invited to complete a patient self-completion questionnaire capturing insights into their disease and treatment. Subgroups were defined by physicians' assessment of disease severity; clusters were derived based on key clinical characteristics using latent class analysis.

RESULTS

Rheumatologists completed 316 physician surveys and 1879 patient record forms; 888 patients completed the patient self-completion questionnaire. pSS severity reflected organ involvement and symptomatology. Latent class analysis produced five clusters distinguished by the organ systems involved and the presence of pain and fatigue symptoms at the time of the survey. A minority of patients [n = 67 (4%)] were categorized with multiple organ involvement and the highest frequency of pain and fatigue. A total of 324 patients (17%) were categorized as 'low burden'. The remaining three clusters exhibited high frequencies of articular involvement but were distinguished by the extent of other organ system involvement.

CONCLUSION

Cluster analysis using a real-world cohort of patients with pSS and systemic organ involvement highlights the heterogeneous presentation of patients with pSS and confirms the importance of pain and fatigue as well as organ involvement when determining disease burden.

Recurrent optic neuritis in a patient with Sjogren syndrome and neuromyelitis optica spectrum disorder: A case report

RATIONALE

Neuromyelitis optica spectrum disorder (NMOSD) patients, especially those with anti-aquaporin-4 antibody positivity, a water channel expressed on astrocytes, is often accompanied by autoimmune diseases (ADs) including Sjogren syndrome (SS). Here, we report a case of a young Chinese woman with recurrent optic neuritis who was diagnosed with asymptomatic SS and NMOSD.

PATIENT CONCERNS

A 22-year-old Chinese woman suffered from optic neuritis for 3 years. The main manifestation was recurrent loss of vision. The anti-aquaporin-4 antibody was positive in the cerebrospinal fluid, and she was diagnosed with NMOSD. Other laboratory tests revealed positive anti-SSA and anti-SSB antibodies, and labial gland biopsy showed lymphocytic infiltration. She also fulfilled the international criteria for SS.

DIAGNOSIS

On the basis of recurrent vision loss and laboratory examination, we defined the patient with SS accompanied by NMOSD.

INTERVENTIONS

When the patient first experienced vision loss, the corticosteroid treatment in the external hospital was effective, and her visual acuity improved significantly. However, in several later attacks, such treatment was no longer obviously effective. Considering the patient's condition, she was treated with corticosteroids, cyclophosphamide, and immunoglobulin therapy on admission.

OUTCOMES

The patient's visual acuity was increased to the right eye 20/800 and left eye finger counting when she was discharged from the hospital.

LESSONS

SS accompanied with NMOSD is common in clinical practice, and always with the positive Anti-AQP4 antibody as a potential biomarker. Patients with SS and NMOSD showed significant neurological symptoms and had a worse prognosis than SS patients with negative anti-AQP4 antibody because of cross-immunity between anti-SSA antibody and anti-AQP4 antibody. Rheumatologists and ophthalmologists should pay attention to this and perform appropriate tests.

Combining surface-enhanced Raman scattering (SERS) of saliva and two-dimensional shear wave elastography (2D-SWE) of the parotid glands in the diagnosis of Sjögren's syndrome

In this study, we combine the molecular structural information gained by SERS of saliva samples with the morphological data given by two-dimensional shear wave elastography (2D-SWE) (SuperSonic Imagine, Aixplorer) of parotid glands in the case of n = 31 patients with Sjögren's syndrome (SjS) and n = 22 controls, with the aim to discriminate between the two groups. The overall classification accuracy yielded by a hybrid principal component analysis-linear discriminant analysis (PCA-LDA) model based on both SERS and elastography (81%) was superior to that yielded by SERS spectra alone (75%) and elastography data alone (71%). This preliminary study is the first report on the use of 2D-SWE of parotid glands for the diagnosis of SjS as well as the first to describe the diagnosis of SjS based on the SERS spectra of dried saliva samples, the results suggesting that the strategy of combining the two methods could improve the diagnosis of SjS.

Recent Advances in Mouse Models of Sjögren's Syndrome

Sjögren's syndrome (SS) is a complex rheumatoid disease that mainly affects exocrine glands, resulting in xerostomia (dry mouth) and xerophthalmia (dry eye). SS is characterized by autoantibodies, infiltration into exocrine glands, and ectopic expression of MHC II molecules on glandular epithelial cells. In contrast to the well-characterized clinical and immunological features, the etiology and pathogenesis of SS remain largely unknown. Animal models are powerful research tools for elucidating the pathogenesis of human diseases. To date, many mouse models of SS, including induced models, in which disease is induced in mice, and genetic models, in which mice spontaneously develop SS-like disease, have been established. These mouse models have provided new insight into the pathogenesis of SS. In this review, we aim to provide a comprehensive overview of recent advances in the field of experimental SS.

Predicting lymphoma outcomes and risk factors in patients with primary Sjögren's Syndrome using gradient boosting tree ensembles

Primary Sjogren's Syndrome (pSS) is a chronic autoimmune disease followed by exocrine gland dysfunction, where it has been long stated that 5% of pSS patients are prone to lymphoma development. In this work, we use clinical data from 449 pSS patients to develop a first, rule-based, supervised learning model that can be used to predict lymphoma outcomes, as well as, identify prominent features for lymphoma prediction in pSS patients. Towards this direction, the gradient boosting method combined with regression tree ensembles is used to derive a rule-based, decision model for lymphoma prediction. Our results reveal an average accuracy 87.1% and area under the curve score 88%, highlighting the importance of the C4 value, the rheumatoid factor and the lymphadenopathy factor as prominent lymphoma predictors, among others.

Sex-mediated elevation of the specialized pro-resolving lipid mediator levels in a Sjögren's syndrome mouse model

Our previous results showed that the specialized pro-resolving mediator (SPM) Resolvin D1 (RvD1) promotes resolution of inflammation in salivary glands in non-obese diabetic (NOD)/ShiLtJ, a mouse model for Sjögren's syndrome (SS). Additionally, mice lacking the RvD1 receptor ALX/FPR2 show defective innate and adaptive immune responses in salivary glands. Particularly, ALX/FPR2 KO mice exhibit exacerbated inflammation in their salivary glands in response to systemic LPS treatment. Moreover, female ALX/FPR2 KO mice show increased autoantibody production and loss of salivary gland function with age. Together, these studies suggest that an underlying SPM dysregulation could be contributing to SS progression. Therefore, we investigated whether SPM production is altered in NOD/ShiLtJ using metabololipidomics and enzyme-linked immunosorbent assay (ELISA). Our results demonstrate that SPM levels were broadly elevated in plasma collected from NOD/ShiLtJ female mice after disease onset, whereas these drastic changes did not occur in male mice. Moreover, gene expression of enzymes involved in SPM biosynthesis were altered in submandibular glands (SMG) from NOD/ShiLtJ female mice after disease onset, with 5-LOX and 12/15-LOX being downregulated and upregulated, respectively. Despite this dysregulation, the abundances of the SPM products of these enzymes (ie, RvD1 and RvD2) were unaltered in freshly isolated SMG cells suggesting that other cell populations (eg, lymphocytes) may be responsible for the overabundance of SPMs that we observed. The elevation of SPMs noted here appeared to be sex mediated, meaning that it was observed only in one sex (females). Given that SS primarily affects females (roughly 90% of diagnosed cases), these results may provide some insights into the mechanisms underlying the observed sexual dimorphism.

Prevalence of Sjögren's syndrome associated with rheumatoid arthritis in the USA: an observational study from the Corrona registry

The objectives of this analysis were to assess the prevalence of Sjögren’s syndrome (SS) associated with rheumatoid arthritis (RA) and to compare baseline characteristics of patients with RA with and without SS. Adult patients with RA from a large observational US registry (Corrona RA), with ≥ 1 visit for assessment of SS status between 22 April 2010 and 28 February 2018, were considered. Patients with RA with versus without SS were compared. SS status was determined from a yes/no variable and reported at enrollment into the Corrona RA registry and follow-up visits. Outcomes were unadjusted prevalence of SS in patients with RA, prevalence of SS by RA disease duration, and baseline characteristics in patients with RA by SS status. Of 24,528 eligible patients, 7870 (32.1%) had a diagnosis of RA and SS. The unadjusted overall rate for SS prevalence in patients with RA was 0.30 (95% confidence interval 0.29, 0.31). SS prevalence increased with increasing RA duration. Patients with RA with versus without SS were more likely to be older, female, and seropositive; had a longer RA duration; higher disease activity; and a higher incidence of comorbidities (hypertension, cardiovascular disease, malignancies, and serious infections), erosive disease, and subcutaneous nodules at index date. Patients with RA and SS had a higher disease burden than those with RA only. The prevalence of SS increased as duration of RA increased. RA with SS was associated with seropositivity, more severe RA, extra-articular manifestations, and comorbidities.

Key Points • The overall prevalence of SS among patients with RA was 30%. • The prevalence of SS increased with increasing RA disease duration. • Identifying specific clinical characteristics of patients with RA with SS, such as a greater incidence of extra-articular manifestations and comorbidities, may help clinicians to better characterize this patient population.

Unstimulated whole saliva flow for diagnosis of primary Sjögren's syndrome: time to revisit the threshold?

Background

Unstimulated whole saliva (UWS) flow rate is one of the ACR/EULAR 2016 criteria for primary Sjögren’s syndrome (pSS). With a single threshold of ≤ 0.1 mL/min, UWS flow does not take into account the age- and sex-related physiological variations. Furthermore, it has a low sensitivity for the diagnosis of pSS (about 50%), contrary to the screening test for xerophthalmia, Schirmer’s test (sensitivity of about 70%). We aimed to identify UWS thresholds allowing better performances for a screening test for pSS comparable to Schirmer’s test, and considering age- and sex-related variations.

Methods

A prospective cohort of 185 patients with oral and/or ocular dryness was classified into 3 groups: men, women < 50 (< 50 years old), and women ≥ 50 (≥ 50 years old). The diagnostic performances of UWS flow rate in these groups were compared in terms of sensitivity, specificity, positive and negative predictive values, and ROC curves. The identification of thresholds that optimize diagnostic performances was carried out using Youden’s index.

Results

The diagnostic performances of UWS flow rate varied according to age and sex. UWS had poor diagnostic performances whatever the threshold in the women ≥ 50 group. The threshold of 0.2 mL/min had a sensitivity of ≥ 70% and a specificity of ≥ 50% in both men and women < 50 groups. In the whole population and compared to the current cutoff, a threshold of 0.2 mL/min increased sensitivity (+ 19.8%) and positive (+ 2.3%) and negative (+ 7.0%) predictive values, with a better specificity (65.2%) than Schirmer’s test.

Conclusion

For objective assessment of xerostomia, raising the threshold of the UWS flow rate to 0.2 mL/min would optimize its screening performances for pSS.

Developing Modern Pain Therapies

Chronic pain afflicts as much as 50% of the population at any given time but our methods to address pain remain limited, ineffective and addictive. In order to develop new therapies an understanding of the mechanisms of painful sensitization is essential. We discuss here recent progress in the understanding of mechanisms underlying pain, and how these mechanisms are being targeted to produce modern, specific therapies for pain. Finally, we make recommendations for the next generation of targeted, effective, and safe pain therapies.

The effect of pilocarpine on dental caries in patients with primary Sjögren's syndrome: a database prospective cohort study

Background

Primary Sjögren’s syndrome (pSS) is associated with dental caries. Pilocarpine, a salivary stimulant, can improve the amount and flow rate of saliva in patients with pSS. This study aimed to assess whether the risk of dental caries decreases with the use of pilocarpine in patients with pSS.

Methods

For this prospective cohort study, we identified pSS patients from the catastrophic illnesses registry of the National Health Insurance Research Database of Taiwan between 2009 and 2013. We divided participants into pilocarpine and non-user groups based on the pilocarpine prescriptions available during the first 3-month follow-up. The primary endpoint was dental caries. The secondary endpoints were periodontitis and oral candidiasis. We compared the risk of these oral manifestations using the Cox proportional hazard model.

Results

A total of 4973 patients with new-onset pSS were eligible for analysis. After propensity score matching, we included 1014 patients in the pilocarpine group and 2028 patients in the non-user group. During the mean follow-up of 2.6 years, the number of events was 487 in the pilocarpine group (48.0%) and 1047 in the non-user group (51.6%); however, the difference was not significant (hazard ratio [HR] 0.93, 95% confidence interval [CI] 0.82 to 1.06). Furthermore, there was no significant difference between groups regarding risk of periodontitis (HR 0.91, 95% CI 0.81 to 1.03) and oral candidiasis (HR 1.16, 95% CI 0.70 to 1.94).

Conclusion

Pilocarpine may have no protective effect on dental caries, periodontitis, or oral candidiasis in patients with pSS.

Case report on a 32-year-old female with elevated serum creatinine levels and primary Sjögren's syndrome-chronic interstitial nephritis

Primary Sjögren's syndrome (PSS) is a chronic autoimmune disease characterized by lymphoplasmacytic infiltration of the exocrine glands, which results in multiple organs damage. Renal injury affects 0.3–27.0% of PSS patients, and tubulointerstitial nephritis is the most frequent form of nephropathy in PSS. The present study reports on the case of a 32-year-old female with a 1-year history of elevated serum creatinine levels, and a 6-month history of mild pain in the waist and leg. Blood biochemistry tests indicated a creatinine level of 221.3 µmol/l and estimated glomerular filtration rate of 24.6 ml/min/1.73 m² [Chronic Kidney Disease Epidemiology (CKD-EPI) formula]. Accordingly, the patient was diagnosed with stage IV chronic kidney disease. To clarify the underlying cause of the disease, a kidney biopsy was performed, which revealed tubular epithelial cells with multiple focal and lamellar atrophy (~60%), as well as extensive renal interstitial fibrosis with scattered inflammatory cell infiltration. Based on these results, the patient was finally diagnosed with severe chronic interstitial nephritis, chronic kidney disease stage IV, PSS and anemia due to chronic kidney disease. The patient was treated with half-dose glucocorticoid (prednisone, 25 mg oral qd maintained up to 12 months). The patient's serum creatinine levels had decreased to 172.4 µmol/l after 1 month and to 178.7 µmol/l after 12 months. The present case concluded that young patients with chronic renal failure should first be assessed for rheumatic immune system diseases. PSS may involve several organs and the clinical manifestations may be varied. Although chronic renal failure is frequently the first manifestation of renal disorder due to PSS, it may be overlooked by clinicians. The present results suggest that further attention should be paid to determine the association between symptoms in the clinical setting.

Clair EW. Recent advances in the search for a targeted immunomodulatory therapy for primary Sjögren's syndrome

Primary Sjögren's syndrome is a chronic autoimmune disease characterized by salivary and lacrimal gland dysfunction, leading to substantial morbidity and reduced quality of life. Many patients with primary Sjögren's syndrome also have extraglandular systemic complications, some of which can be organ- or life-threatening. Over the last decade, numerous targeted immunomodulatory therapies for primary Sjögren's syndrome have failed to show a benefit in clinical trials, and as yet no disease-modifying therapy has been approved for this disease. Herein, we provide an updated review of the clinical trial landscape for primary Sjögren's syndrome and the numerous efforts to move the field forward, including the development of new classification criteria and outcome measures, the results of recent clinical trials in this field, the challenges faced in the search for effective therapies, and the expanding pipeline of novel therapies under development.

The Effectiveness and Safety of Total Glucosides of Paeony in Primary Sjögren's Syndrome: A Systematic Review and Meta-Analysis

Objective: To assess the effectiveness and safety of the total glucosides of paeony (TGP) on the treatment of primary Sjögren's syndrome (pSS) by conducting a meta-analysis. Methods: Eight databases were searched from their inception to December 10, 2018 for randomized controlled trials (RCTs). The Revman 5.3 software was used for this meta-analysis. Results: Nine RCTs which included 770 participants were identified. Pooled results showed that significant difference in Schirmer's test (P < 0.00001) comparing TGP with placebo (PBO). However, the pooled results displayed significant differences in salivary flow rate, Schirmer's test, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), rheumatoid factor (RF), serum γ-globulin, immunoglobulin G (IgG), IgA, IgM, and effective rate (P ≤ 0.01) in the co-administration of TGP with immunosuppressant (IS) compared with IS alone. Subgroup analyses revealed both heterogeneities in ESR and serum γ-globulin were eliminated, showing combined intervention of TGP + IS being more advantageous than single usage of IS (P < 0.00001). However, the advantage varied among three subgroups and showed a gradual weakening over time. Furthermore, our results showed statistical significance in Schirmer's test (P = 0.0006), when hydroxychloroquine (HCQ) was jointly applied, but not in the case of combined TGP with methotrexate (MTX) (P = 0.41). For the safety analysis, the most common adverse events (AEs) were diarrhea or gastrointestinal discomfort, and no severe AEs were reported in TGP group. Meanwhile, six trials showed statistically insignificant differences between TGP + IS and IS in AEs (P = 0.76). Conclusions: Improving the lacrimal gland secretion (Schirmer's test) is the prominent function of TGP compared with PBO. TGP + IS can improve the clinical symptoms, such as lacrimal and salivary gland secretion function (Schirmer's test, salivary flow rate), inflammatory indices (ESR, CRP, and RF) and immunoglobulins (γ-globulin, IgG, IgA, and IgM) on the basis of IS monotherapy. In addition, TGP has an acceptable safety profile and AEs were not increased when TGP combined with IS in pSS. Therefore, TGP can be considered to be a potentially valid and safe drug for the treatment of pSS in the clinic. In view of the limitations of the included trials, the potential beneficial effectiveness and safety of TGP need additional high-quality, multi-center, and large-scale RCTs to assess its use in pSS treatment.

Towards the Establishment of a Biomedical Ontology for the Primary Sjögren's Syndrome

Primary Sjögren's Syndrome (pSS) has been characterized as a hypersensitivity reaction type II systemic autoimmune chronic disease causing exocrine gland dysfunction mainly affecting women near the menopausal age. pSS patients exhibit dryness of the main mucosal surfaces and are highly prone to lymphoma development. This paper presents a first biomedical ontology for pSS based on a reference model which was determined by pSS clinical experts. The ensuing ontology constitutes the fundamental basis for mapping pSS-related ontologies from international cohorts to a common ontology. The ontology mapping (i.e., schematic interlinking) procedure is, in fact, a preliminary step to harmonize heterogeneous medical data obtained from various cohorts.

Inducible nitric oxide synthase-mediated injury in a mouse model of acute salivary gland dysfunction

AIM

Inducible nitric oxide synthase (iNOS) is a key regulator of the innate immune system. The aim of the current study was to explore whether innate immune-mediated iNOS and reactive nitrogen species acutely perturb acinar cell physiology and calcium homeostasis of exocrine salivary tissues.

METHODS

Innate immunity in the submandibular gland of C57BL/6 mice was locally activated via intraductal retrograde infusion of polyinosinic:polycytidylic acid (poly (I:C). Expressions of iNOS and the activity of the reactive nitrogen species peroxynitrite, were evaluated by immunohistochemistry. Mice were pre-treated with the selective iNOS inhibitor aminoguanidine in order to substantiate the injurious effect of the nitrosative signal on the key calcium regulator sarcoplasmic/endoplasmic reticulum calcium ATPase (SERCA2b) and calcium signalling.

RESULTS

Challenging salivary gland innate immunity with poly (I:C) prompted upregulated expression of iNOS and the generation of peroxynitrite. Inhibition of iNOS/peroxynitrite revealed the role played by upregulated nitrosative signalling in: dysregulated expression of SERCA2b, perturbed calcium homeostasis and loss of saliva secretion.

CONCLUSION

iNOS mediates disruption of exocrine calcium signalling causing secretory dysfunction following activation of innate immunity in a novel salivary gland injury model.

Biomarkers for Sjögren's syndrome

Sjögren's syndrome (pSS) is a complex and heterogeneous disorder characterized by different clinical subsets. Recently, great efforts have been made searching for reliable biomarkers able to ameliorate the diagnostic algorithm and the prognostic stratification of pSS patients and ultimately allowing the scientific community to address some of the unmet needs for the disease. In this review, we have summarized the state of the art of 'traditional' widely acknowledged clinical, serological and histologic biomarkers for pSS with the aim of highlighting their relevance and limitations in clinical practice. We have also explored some of the novel potential biomarkers that have been proposed more recently, potentially able to open new ways in the assessment of the disease.

Circulating small non-coding RNAs reflect IFN status and B cell hyperactivity in patients with primary Sjögren's syndrome

BACKGROUND

Considering the important role of miRNAs in the regulation of post-transcriptional expression of target genes, we investigated circulating small non-coding RNAs (snc)RNA levels in patients with primary Sjögren's syndrome (pSS). In addition we assessed if serum sncRNA levels can be used to differentiate patients with specific disease features.

METHODS

Serum RNA was isolated from 37 pSS patients as well as 21 patients with incomplete Sjögren's Syndrome (iSS) and 17 healthy controls (HC) allocated to two independent cohorts: discovery and validation. OpenArray profiling of 758 sncRNAs was performed in the discovery cohort. Selected sncRNAs were measured in the validation cohort using single-assay RT-qPCR. In addition, unsupervised hierarchical clustering was performed within the pSS group.

RESULTS

Ten sncRNAs were differentially expressed between the groups in the array. In the validation cohort, we confirmed the increased expression of U6-snRNA and miR-661 in the iSS group as compared to HC. We were unable to validate differential expression of any miRNAs in the pSS group. However, within this group several miRNAs correlated with laboratory parameters. Unsupervised clustering distinguished three clusters of pSS patients. Patients in one cluster showed significantly higher serum IgG, prevalence of anti-SSB autoantibodies, IFN-score, and decreased leukocyte counts compared to the two other clusters.

CONCLUSION

We were unable to identify any serum sncRNAs with differential expression in pSS patients. However, we show that circulating miRNA levels are associated with disease parameters in pSS patients and can be used to distinguish pSS patients with more severe B cell hyperactivity. As several of these miRNAs are implicated in the regulation of B cells, they may play a role in the perpetuation of the disease.

Tertiary Lymphoid Structures Among the World of Noncanonical Ectopic Lymphoid Organizations

Tertiary lymphoid structures (TLOs), also known as ectopic lymphoid structures, are associated with chronic infections and inflammatory diseases. Despite their association with pathology, these structures are actually a normal, albeit transient, component of the immune system and facilitate local immune responses that are meant to mitigate inflammation and resolve infection. Many of the mechanisms controlling the formation and function of tertiary lymphoid structures have been identified, in part by experimentally triggering their formation using defined stimuli under controlled conditions. Here, we introduce the experimental and pathological conditions in which tertiary lymphoid tissues are formed, describe the mechanisms linked to their formation, and discuss their functions in the context of both infection and inflammation.

A functional variant in the OAS1 gene is associated with Sjögren's syndrome complicated with HBV infection

Hepatitis B virus (HBV) has been suspected to contribute to several autoimmune diseases, including Sjögren's syndrome (SS), although the exact mechanism is unknown. The 2'-5' oligoadenylate synthetase (OAS1) is one of the most important components of the immune system and has significant antiviral functions. We studied a polymorphism rs10774671 of OAS1 gene in Han Chinese descent. The minor allele G was significantly associated with a decreased risk for SS, anti-SSA-positive SS, and anti-SSA-positive SS complicated with HBV infection, which have not been seen in anti-SSA-negative SS and HBcAb-negative SS patients. Gene expression analysis showed that the risk-conferring A allele was correlated with lower expression of p46 and increased expression of p42, p48, and p44. A functional study of enzymatic activities revealed that the p42, p44, and p48 isoforms display a reduced capacity to inhibit HBV replication in HepG2 cells compared to the normal p46 isoform. Our data demonstrated that the functional variant, rs10774671, is associated with HBV infection and anti-SSA antibody-positive SS. The SAS variant switches the primary p46 isoform to three alternatives with decreased capacities to inhibit HBV replication. These data indicated that individuals harboring the risk allele might be susceptible to hepatitis B infection and SS development.

Diagnosis and treatment of primary Sjogren’s syndrome: an update

Primary Sjogren’s syndrome (SS) is a systemic autoimmune disease that primarily affects the exocrine glands, resulting in dryness of the mucosal membranes, particularly of the eyes and mouth. Considerable advance has been made for the classification and treatment of primary SS in the past few years. This article reviews the recent classification criteria for primary SS and briefly discusses the conventional and novel therapies of the disease.

Dry Eye Management: Targeting the Ocular Surface Microenvironment

Dry eye can damage the ocular surface and result in mild corneal epithelial defect to blinding corneal pannus formation and squamous metaplasia. Significant progress in the treatment of dry eye has been made in the last two decades; progressing from lubricating and hydrating the ocular surface with artificial tear to stimulating tear secretion; anti-inflammation and immune regulation. With the increase in knowledge regarding the pathophysiology of dry eye, we propose in this review the concept of ocular surface microenvironment. Various components of the microenvironment contribute to the homeostasis of ocular surface. Compromise in one or more components can result in homeostasis disruption of ocular surface leading to dry eye disease. Complete evaluation of the microenvironment component changes in dry eye patients will not only lead to appropriate diagnosis, but also guide in timely and effective clinical management. Successful treatment of dry eye should be aimed to restore the homeostasis of the ocular surface microenvironment.

Tertiary lymphoid organs in systemic autoimmune diseases: pathogenic or protective?

Tertiary lymphoid organs are found at sites of chronic inflammation in autoimmune diseases such as systemic lupus erythematosus and rheumatoid arthritis. These organized accumulations of T and B cells resemble secondary lymphoid organs and generate autoreactive effector cells. However, whether they contribute to disease pathogenesis or have protective functions is unclear. Here, we discuss how tertiary lymphoid organs can generate potentially pathogenic cells but may also limit the extent of the response and damage in autoimmune disease.